ALBERT

Notes: Summary The abdominal glands of six ponerine ants belonging to the tribe Ponerini were analysed:Leptogenys ocellifera (Roger),Leptogenys chinensis (Mayr),Diacamma sp.,Ponera coarctata (Latreille),Odontomachus haematodes (L.) andHarpegnathus saltator (Jerdon). A great variety of glands was found. An intersegmental complex gland is located between the sixth and seventh abdominal tergite in each species investigated. But size, arrangement of gland cells and shape of reservoir differ. In addition, representatives of the genusLeptogenys andH. saltator both have sternal intersegmental complex glands. InL. ocellifera andL. chinensis these glands are located between the fifth and sixth and also between the sixth and seventh abdominal sternite. InH. saltator one sternal gland is situated between the sixth and seventh abdominal sternite. In some species we found characteristical sculptures on the cuticle at the orifice of the well developed reservoirs of the glands. These sculptures could be interpreted as an enlarging of the surface of the cuticle or as a reservoir. Another type of gland cells are epithelial glandular cells. They form distinct layers on the seventh sternite inL. chinensis and on the sixth sternite inL. ocellifera. Tergo-sternal bunches of secretory cells were observed inDiacamma sp.,P. coarctata, H. saltator and inO. haematodes. A similar variety of glands was found associated with the sting apparatus in the gonostyli, at the membrane between the two oblong plates and at the membranous connections between the sting apparatus and the last abdominal segment. InDiacamma sp. two distinct glandular cells are located in the gonostylar sclerites, i.e. secretory cells, each drained by a cuticular ductule and epithelial glandular cells. In the two representatives of the genusLeptogenys, inO. haematodes and inP. coarctata only the first type of gland cell was found. In these species as well as inH. saltator the epidermal cells of the gonostylar sclerites form different states of transition from degenerated epithelial cells to glandular epithelial cells. InH. saltator there are no secretory cells with a cuticular ductule in the gonostyli. Likewise, large paired complexes of gland cells were found at the base of two genostylar sclerites inH. saltator and inO. haernatodes. Though less developed, gland cells of the latter type are inDiacamma sp., P. coarctata and inL. chinensis also located at the base of the gonostyli. InDiacamma sp. the epidermal cells of the membrane connecting the two gonostyli do have secretory function. In the other species investigated they are less developed, and a secretory function cannot be considered certain. In each species investigated ductules of gland cells also open dorsolaterally into the sting chamber. Furthermore inDiacamma sp.P. coarctata, O. haematodes and inH. saltator, ductules of gland cells also open laterally and, except inO. haematodes, latero-ventrally into the membranous connection between the sting apparatus and the last abdominal segment.

Notes: Summary Cobalt sulfide (CoS) staining, via axonal filling, was used to reveal the central projections of fibers of the tympanal nerves in the cricket prothoracic ganglion, as well as those of serially homonymous nerves in the mesothoracic and metathoracic ganglia. The main results are: 1. The branch of the anterior leg nerve termed the tympanal nerve (TB in Fig. 2) comprises a few motor fibers and many sensory axons, as do serially homonymous nerves in the two other thoracic segments. The sensory axons are those of sense cells in the tympanal organ (or the serially homonymous parts of the meso and metathoracic segments), the subgenual organ, the campaniform sensilla, and the tibial sensory hairs (Eibl, 1978). 2. On the basis of their branching and projections in the three thoracic ganglia, the sensory fibers of nerve TB can be classified into five types (Figs. 3–7). With respect to function, those of Type 5 can be regarded as auditory fibers (Fig. 10). They project only to the crescent-shaped region (Fig. 8), which represents the auditory neuropile in the strict sense, and are tuned to the carrier frequency of the calling song (Fig. 10B). It is characteristic of Types 1 to 4 that the fibers branch immediately after entering the ganglion (Figs. 3–6); typically, these branches run dorsally and may overlap with the lateral projections from the motor neuropile. In addition, the fibers of Types 2 to 4 project into the rostral and caudal margins of the auditory crescent (Figs. 4–6). 3. The similarity among the three thoracic ganglia with respect to sensory fiber types and projections (Fig. 11) suggests that serially homonymous sensory structures found in each of the leg-bearing segments resemble one another in their sensory projection areas and thus in their connectivity with other neural subsystems within the three thoracic ganglia. That ‘typical auditory nerve fibers’ occur in the meso and metathoracic segments, projecting exclusively to the crescent (Figs. 7 and 11), is anatomical evidence that auditory function need not be restricted to the first thoracic segment. 4. The stained leg motoneurons (Fig. 12), with axons that innervate the femur muscles, are distinguished by a dendritic field that must be assigned to the ventral part of the so-called sensorimotor integration zone (Altman, 1976). These fields are of lesser extent than, for example, those of the flight and singing motoneurons of meso and metathorax. 5. All the sensory and motor elements marked with CoS are bilateral and arranged with approximately mirror-image symmetry. Their central projections are restricted entirely to the ipsilateral half of the ganglion (Fig. 13).

Notes: Summary The structure of the male reproductive systems of two species ofHaplognathia cf.lyra andH. cf.rosacea was described. The structure of the testes and the anterior portions of the sperm ducts in both species was found to be similar. However, considerable species differences were found between the structures of the glands and muscles associated with the reproductive systems. These were more elaborate inH. cf.lyra than inH. cf.rosacea. The former species possessed an H-shaped sperm duct gland, three distinct groups of penis muscles and a penis with two cell types and with a lumen. The latter species had paired sperm duct glands, no specialized penis muscles and a penis with only one cell type and without a detectable lumen. No open gonopore was observed in either species. The sperm presumably exit through a ventral tissue connection observed connecting the penis and the ventral epidermis. These findings were discussed in the light of Mainitz's (1977) theory concerning the primitive penis type within the Gnathostomulida.

Notes: Summary Spermatozoa ofProkoenenia wheeleri have a spheroid part which contains a large vacuole and a smaller appendage in which chromatin filaments and a specialized acrosome are located. The flagellum is missing. In early spermatids rich in rough ER the vacuole is secreted from several Golgi apparatus. Later spermatids show an elongation of the part in which the nucleus and acrosoma are situated. This appendage is coiled around the vacuolated part of the cell. Finally, the cell membranes between the neighboring coils disappear. Spermatozoa and Spermiogenesis of Palpigradi must be considered apomorphic.

Notes: Summary Effects of the workpiece surface vibration on planing noise were investigated theoretically and experimentally. A method of calculating the sound pressure level generated by the workpiece surface vibration due to the impact of planing knives was developed. Sound pressure levels and sound spectra calculated using this method show good agreement with measured values.

Notes: Summary In order to study the wear of tungsten carbide tipped circular saws, three kinds of carbide tips (fine, medium and coarse grained ones) were employed, when sawing particleboards. The saw with coarse grained carbide tips showed the longest working life, while the fine-grained carbide tipped saw retained its usefulness for only a short period of sawing. In an experiment using a saw with all three kinds of carbide tips, it was also confirmed that the fine grained tips wore most and the coarse least. From the observations of the worn tips, it was found that the wear boundary on the clearance face was quite distinct for these tips, although for the fine grained one it was remarkably indented. There were many striations on the wear surface of the fine grained tip, but they scarcely appeared on those of the other two tips. The wear mechanism and the wearing process of the carbide tips are discussed.

Notes: Summary Density and shrinkage were measured in samples of old wood preserved in a glacier, burial grounds, house settlements, harbour installations and ships sunk in the sea. Time of exposure ranged from about 300 to 100,000 years. Density was found reduced in most cases and shrinkage increased. In oak, density was reduced up to 0.13 gr/cm3 (at 12% m.c.) and a tangential shrinkage value of 62.16% was measured. Irrespective of time of exposure and loss of material, old wood retains its gross structural characteristics as long as it remains waterlogged.

Notes: Summary During a survey on the anatomy of New Zealand native woods, trabeculae were observed in the xylem cells of 6 hardwood species endemic to New Zealand. They were not found in a further 216 species. In some species they were observed only in the vessel members while in others they occurred in the vessel members, fibres and axial parenchyma cells. Their diameter is proportional to the thickness of the host cell wall. The similarites and differences between these trabeculae and those described as occurring in softwoods and other hardwoods are discussed. No explanation is proposed for their origin.

Notes: Summary Sapwood of beech and birch was impregnated with aqueous salt solutions and suspensions of carbon particles and india ink under a low initial pressure; the pathways marked by the impregnating substances were examined by the electron microscope. The micrographs revealed dark deposits in cell lumina, pit membranes, and other parts of the cell wall. The size of voids occupied by dark deposits ranged from infinitely small to 700 Å in vessels and rays, and from infinitely small to 1,300 Å in fibers. It was concluded that the penetration path of impregnating substances from one cell to the next was through the minute intermicrofibrillar openings in the communicating pit membranes and in the rest of the cell walls. Carbon particles, suspended in plastic monomer, were not observed either in pit membranes or in the rest of the cell wall; they probably represent a nonpolar substance.

Notes: Summary Air-dried and kiln-dried southern pine sticks, representing a number of different trees, were individually inoculated with one of the nine basidiomycetes most often associated with southern pine utility pole decay. Where available, four different strains of each fungus were used to prepare decayed wood for testing. The partially decayed sticks were then tested with 53 chemicals, or combinations of chemicals (indicators), to determine their efficacy in detection of decay through color changes wrought in the affected wood. Nine indicators, or combination of indicators, showed promise in detection of some of the included decay. Of these, three were subjected to further testing on decayed lodgepole and ponderosa pine woods. The three—butter yellow+methylene blue followed by bromcresol green+methyl orange; chrome azural-S; and methyl orange+indigo carmine—were considered suitable for use in detection of internal decay in pine poles.

Notes: Summary Owing principally to kinetic energy losses, flow in which the flow rate is not linearly proportional to the applied pressure difference occurs to a considerable extent when the Reynolds number exeeds the length-to radius ratio of the capillary. When capillaries are used for flow or viscosity measurements corrections must be made for kinetic energy losses, end-effects and gas expansion. The results obtained for air flow through straight circular capillaries imply that non-linear flow may occur in wood and other heterogeneous porous media at Reynolds numbers in the region of 0.1 to 10.

Notes: Summary A previous article presented the theoretical development of analytical indices to rate the severity of kiln schedules used to dry wood. These indices take into account the dry and wet bulb temperatures used during a kiln schedule together with the points of application and duration of application of each combination of temperature and humidity used. Experimental data for several such indices are presented for collapse development during the kiln drying of incense cedar pencil slats. While promising, the results were inconclusive as to the use of a severity integral for prediction of the effect of different schedules or schedule changes on drying degrade. A lack of homogeneity in the test material confounded the results.

Notes: Summary Peristomial tube feet, ampullae and plates are described in 16 species of regular echinoids. Two basic arrangements are recognised. In cidaroids and echinothurioids there are many tube feet and ampullae per column and the radial water vessel extends on to the peristomial membrane. Tube feet terminate in a small sensory pad. Ampullae are small and flattened. In other echinoids there are only ten peristomial tube feet and the radial water vessel does not extend on to the peristomial membrane. Tube feet terminate in a broad disc and ampullae are cylindrical tubes. Plate structure and pore morphology also vary and are correlated with tube foot structure. Echinothurioids are considered to be derived from a cidaroid ancestor.

Notes: Summary All species of Sironidae possess as a secondary male sex character an epidermal gland organ in the last tarsal joint of the fourth leg. The glandular secretion emanates from a conical apophysis, the adenostyl, which is located dorsally on the joint. InSiro duricorius (Joseph, 1868) the complex organ consists of numerous functional units, the secretion of which flows into the common channel opening on the adenostyl. Every gland unit contains 5 cells: 3 gland cells (DZ), 1 enveloping cell (HZ), 1 duct cell (KZ). The enveloping cell connects the gland cells with the duct cell like a sleeve. A marginal fold of the gland cell apex provides tight connection of gland cells and enveloping cell. Gland cells and enveloping cell are equipped with microvilli, and both cell types secrete in a common reservoir. The duct of the duct cell is divided into two parts: 1) a distal fibrillaceous-spongy one and 2) a proximal massive one. Both are accompanied only by a single duct cell. Besides this complex gland organ a similar one is located in the ventral part of the tarsus. Its collecting channel opens into the channel of the main gland. Isolated functional gland units are scattered over the epidermis of the tarsus; their secretion flows immediately on the tarsal surface. The gland cells proper produce a protein, the fact is indicated by the electronmicrographs. The secretion of the enveloping cell is a different one, but at this time cannot be attached to a chemical group.

Notes: Summary The paired maxillary nephridia ofScutigera coleoptrata were studied by electron microscopy. a) The nephridia lie within the region of the second maxilla. They are subdivided into the sacculus and the four-folded nephridial tubule, which has different morphological regions. b) The multilayered “sacculus” is very compact and without a continuous cavity. Only the peripheral cells are typical podocytes with numerous pedicells. c) A nephrostom mediates between the “sacculus” and the nephridial canal. The cells possess cilia. d) The labyrinthal cells possess basal plasmalemm invaginations and an often well defined brush border. Elongated mitochondria are closely associated with the basal invagination. Large cytoplasmic extrusions are projected into the tubule lumen. e) An intermediate epithelium connects the labyrinth with the utricle. The cells have a small cuticular layer. Muscle cells lie between the epithelial cells. f) The columnar cells of the utricle possess a non-sclerotized cuticular layer. The ultrastructure of the cells of the labyrinth and the utricle is nearly identical. g) The efferent duct of the utricle terminates between the second maxilla and the maxilliped. Its cells are closely packed with microtubules. h) The dorso-ventral part of the labyrinth sends an efferent duct to the “maxillary organ”. The cells are layered by a small cuticle, with muscle cells lying between the epithelial cells. The “maxillary organ” runs to the preoral cavity. i) The compact “sacculus” of the maxillary nephridia ofScutigera coleoptrata is compared with the coelom sacs of other arthropods nephridial organs. The function of the different parts of the nephridial canal is discussed.

Notes: Summary The ultrastructure of the alimentary tract lining, excluding the hepatopancreas, of lobsters,Homarus americanus andH. gammarus, and Dungeness crab,Cancer magister, was investigated with transmission electron microscopy. The foregut lining consists of a cuboidal epithelium with extensive interdigitations of the lateral cell membranes and adhering junctions. The ultrastructural organization of the midgut and midgut caeca resembles that of other transporting epithelia. The cells possess a microvillous border, and the basal cytoplasm contains numerous mitochondria and an anastomosing system of smooth endoplasmic reticulum. Hemocytes, presumed neurosecretory axons, and putative endocrine cells occur within the epithelium of the midgut and midgut caeca. Hindgut epithelial cells have numerous mitochondria in the apical cytoplasm, and their basal cell membranes are elaborately infolded. These observations suggest that one of the principal functions of the midgut, midgut caeca, and hindgut epithelia is the transport of ions and water.

Notes: Summary The male copulatory organs of five species of Gnathostomulida Scleroperalia have been studied by TEM techniques. These observations provide a more solid basis for classification in the light microscope: inLabidognathia longicollis (fam. Mesognathariidae) the stylet is composed of eight, and inSemaeognathia sterreri, Gnathostomula jenneri, Gnathostomula mediterranea andGnathostomula microstyla (Gnathostomulidae) of ten stylet rods. Each rod consists of a microtubule-filled inner rod, and of an outer rod, filled with ‘crystallized inclusions’. The inner rods are continuous with eight — or ten — rod formation cells which are located in the proximal stylet sack. Bipartition of rods occurs by a longitudinal invagination of the basement lamina, underlying the rod cells and the gland cells and continuous with that of the body wall epithelium. InLabidognathia, the outer rods are interlocked, in Gnathostomulidae, the stylet rods are surrounded by an extracellular (‘cuticular’) tube-like stylet sheath of variable fine structure, which is believed to provide extra rigidity. In the species investigated, one single stylet gland, consisting of a monolayered epithelium showing different gland cell types, surrounds the stylet. In the apical gland cell portions, medially and distally membrane-bound secretory granules lie adjacent to the stylet sheath. In Gnathostomulidae, two anterior gland cells are seen in connection with the formation of the stylet sheath. In the muscular sheath the cross-striated fibers, basically derived from the longitudinal body wall musculature, show a tendency towards helical and circumferential arrangement. Musculature is especially prominent in the proximal stylet sack, which is rather a propulsive element than a sperm-storing vesicle, and lacks glands. InGnathostomula species, atrial cells underlie the distal tip of the stylet. The entrance into the male opening is lined with ciliary receptor cells and specialized gland cells. Stylet evolution in Scleroperalia is characterized by progressive differentiation of the muscular sheath, in particular of the proximal stylet sack, and of the stylet — the occurrence of a stylet sheath is seen in connection with increasing diversity of stylet shape.

Notes: Summary The stomachs ofThylogale stigmatica andT. thetis were dissected in situ in adult animals and pouch young of different ages. A detailed description of the topographic anatomy of the stomach and its histology is given. In both species the stomach is differentiated into three regions: the saccular and the tubular forestomach regions and the hindstomach. The saccular forestomach is covered with squamous epithelium, which continues into the tubular forestomach, where it changes into cardiac mucosa. The border between squamous and cardiac lining is situated in different parts of the tubular forestomach in the two investigated species ofThylogale. The hindstomach is lined with fundic and pyloric glands. The changes in relative volumes of the gastric regions, the change in the position of the opening of the oesophagus into the stomach, and the differentiation of the epithelial lining during growth and maturation of pouch young are described. The functional inplications of gastric differentiation are discussed in relation to the biotopes of the animals.

Notes: Summary A Dopa (L-3,4-dihydroxyphenylalanine) oxidizing enzyme was demonstrated in the shell gland ofMicrodalyellia fairchildi (Graff) by cytochemical methods. A positive reaction was shown by one of the two cell types of the gland. These cells are flasklike and arranged in two bundles entering the ovovitelloduct at its proximal part. On testing they are conspicuously blackened due to the formation of dopa melanin. The enzyme does not oxidize catechol, the main substrate of phenoloxidase in the vitelline cells. The enzyme of these cells is unable to process dopa. In contrast to many phenoloxidase systems, including that of the vitelline cells, the oxidizing enzyme of the shell gland could not be inhibited by heavy metal chelating agents (diethyldithiocarbaminate, potassium cyanide). Furthermore, enzyme activity is retained only after fixation with alcohol, whereas formalin fixatives obviously inactivate the enzyme. An intense darkening of the cells depends on the presence of an appropriate quantity of the enzyme. The enzyme content varies due to its periodic release, which is in narrow conjunction with egg formation. The blackening of the cells is most conspicuous about two hours before depletion. Thereafter, melanin was demonstrated as a dark cloud surrounding the ovum and the vitelline cells in the uterus. If the reproductive rate of the animals is high, there is only a weak reaction. After slowing down egg production by deprivation of food, melanin formation is enhanced, indicating the increased accumulation of the enzyme. No further precursors of sclerotin (phenolic substances, NH2-rich proteins) present in the vitelline cells were found in the cells of the shell gland. These results clearly show that one cell type of the shell gland ofMicrodalyellia is involved in the sclerotization process of eggshell formation. As the oxidase of these cells and the phenoloxidase of the vitelline cells apparently differ in the substrate spectra, it is assumed that the oxidation of a phenolic compound which initiates sclerotization is a two-step process.

Notes: Summary The burrowing behaviour of the carabid beetleScarites buparius is described. Like most other Scaritini, although this species digs deep holes in sandy areas. The burrowing behaviour ofScarites is basically different from that of other carabid beetles so far observed. When burrowing, unlike many other burrowing animals, no alternative motions are carried out by the deeply flattened foretibias. Instead, the tibias are held beside the long mandibles and the broadly flattened underparts of the head which is bent downwards. In that manner a very large shovel-like area is built. By moving backwards the beetle carries all the sand out of his hole, which is behind the ‘shovel’. Comparative measurements of foretibias, gula and mandibles of theScarites buparius andCarabus coriaceus, a carabid of similar size, showed that in theScarites these organs are 4–5 times as large as in theCarabus. Thus, the burrowing equipment ofScarites is very efficient. Because of these measurements and the method of burrowing, there is great weight and heavy friction on the forelegs of scaritini during burrowing. The morphological conditions are described for overcoming these obstacles through the shape of the body and elytra and in the structure of the skeleton and musculature of the prothorax. Friction is reduced by the parallel and somewhat cylindrical body shape, by the highly polished surface, and by the shortening of the procoxae which fit closely in the prothorax. The complicated ventral articulation of the procoxae and the enormously strengthened remotor muscles of the procoxa, which are modified by their position, stabilize the forelegs in the course of heavy straining during burrowing and prevent their turning forward. As the origin of the coxal remotors is situated far in front of their insertion at the coxa, these muscles are exceptionally efficient. The possibility of different evolutionary pathways is discussed, since there are enormously different sizes within Scaritini resulting in different mechanical relations between beetle and substrate.

Notes: Summary The development of the ophiocephalous pedicellariae ofSphaerechinus granularis was investigated by means of a continuous series of regenerating pedicellariae with the aid of a scanning electron and light microscope. The anlagen of the three valves appears in the form of isolated triradiate skeleton rudiments; the central axis arises from their center. At the deepest level, the basal plate develops from this horizontal structure, which at last forms the handle segment of the valve. Two more horizontal plates are built above this basal plate, which are supported by spool-shaped elements; around these skeletal elements the connecting collagenous fibers are arranged. Starting from the central axis, five parallel skeletal rods arise under regular ramification and arrangement; they are connected to one another by a meshwork forming the central stem (axis tube). In a similar way, the muscle baskets on both sides of the axis tube are built up, arising from the level of the first horizontal plate. As a median support of the axis tube against the horizontal plate, a vertical, perforated plate develops with the differentiation of the central articulations at its free margin. This middle segment of the valve, as well as the handle segment, proceeds in its development, while the distal, biting segment is more retarded in its increase. Both facts can be proved by function. The final differentiation of the margins of the distal valve segment with regard to the precise meeting of the gripping teeth takes place under the influence of the beginning movements of the valves. Therefore, full differentiated articulations and adequate muscle systems are necessary. Coincidently, reorganization takes place as long as the central articulations and the distal, biting valve segment are joined to a functional unit, with the muscle baskets for the Mm. adductores at both sides. In the same way, the handle segment, the superstructure of the insertions of the Mm. abductores at the outside of the valve, and the supporting structures of the distal segment of the valve all evolve into a functional unit. The primary, rather descriptive formation of a valve into a distal, middle, and handle-bearing segment gets partly lost from this point of view. This reconstruction also becomes clear by the decrease of the perforated plate structure for the benefit of a framework construction by apposition of compact material at stronger loaded zones; highly stressed structures as articulations receive a layer of polycrystalline calcite. A similar allometry, also based on functional conditions, can be seen in the three segments of the entire pedicellariae — head, neck, and stalk — because the neck, which is the essential part for the later high mobility of the head, does not start growing before the final organization of both other segments.

Notes: Summary The heat transfer of two-dimensional impinging air jets was examined. Jet widths from 0.0625 to 0.3750 inches (1.59 to 9.53 mm) operating at exit velocities from 2,000 to 10,000 ft/min (10.2 to 50.8 in/sec) were used. Average and local heat transfer coefficients were measured for jet arrays having a variety of different vertical and horizontal spacings. Predictive equations describing average heat transfer data were obtained which explain approximately 95 percent of the measured variation. Jet exit velocity and the lateral distance between the centerline of adjacent jets had the greatest influence on heat transfer.

Notes: Summary Intra-increment variation in specific gravity of wood is studied in relation to the types of annual increments in Pinus wallichiana. In the normal annual increments specific gravity increases almost linearly across the ring, displaying minimum value in the first-formed earlywood and maximum value in the last-formed latewood. The occurrence of false rings and that of compression wood in an annual ring causes a localized increase in specific gravity. The change in specific gravity at the false growth ring boundary is slight and gradual, whereas at the true annual rings boundary the change is steep and abrupt. The specific gravity in the first-formed earlywood portion gives the most consistent value as compared to whole earlywood, whole latewood and whole ring when studied around the circumference.

Notes: Summary Several important parameters pertaining to the recovery, separation, quantitative identification, and yield correction of permanganate oxidation products from lignins were critically evaluated. The “routine recovery” procedure was amended by a series of “exceptional recovery” operations which permitted retrieval of a maximum of 157 mg of degradation products from 100 mg lignin. The “exceptional fractions” contained more low molecular weight compounds than the routinely isolated fraction, calling for the employment of molecular weight distribution data of degradation product mixtures in combination with data by gas chromatography for interpretation in terms of structural features. Approximately 1/5 to 1/3 of the degradation products had molecular weights in excess of dimeric fragments. Separation and quantitative identification by gas chromatography was reproducible within 1.5 and 3.5%, respectively. Adjustment of experimental yields for yield losses encountered during degradation and separation was best accomplished by the use of a correction factor for the degradation of aromatic ring substituents as advocated by Larsson and Miksche, along with molecular weight distribution data. This method, however, slightly overestimates degradation products with more than one carboxy group per aromatic ring in favor of those with fewer than one.

Notes: Summary This paper discusses aspects of the established methods for determination of the herbicide paraquat. Methyl chloride is shown to be a product of the non-oxidative pyrolysis of paraquat (dichloride) and attention is drawn to the possibility of using this observation as the basis of a sensitive vapour-phase chromatographic method for the detection of paraquat in wood.

Notes: Summary Tensioning is the saw prestressing procedure most commonly used in the forest products industry to increase the stability of thin circular saws. This procedure stiffens the saw blade by introducing favorable in-plane residual stresses either by local plastic deformation or by local heating. In industry today, rolling is the standard procedure for introducing such stresses. The first part of this paper is concerned with a method of tension evaluation. The method examined consists of measuring saw blade modal stiffness, and it correlates the elastic stiffness of the saw, which approximates the vibration modes, and the natural frequencies associated with these modes. The predictions of the saw frequency shift due to stiffness variations were found to agree closely with experimentally determined frequencies. The method thus offers a practical procedure for tension evaluation and could replace the currently used technique of measuring the light gap under a straightedge placed along the saw diameter. The second part of this paper theoretically analyzes the relationship between the rolling load and the resulting tensioning stresses. The procedure followed in the theoretical model determines the identation load by equating the external power of loading with the power of storing in the elastic zones and of internal dissipation in the plastic zone. The residual stresses obtained by superpositioning the stresses due to unloading were generally in good agreement with the experimentally determined tensioning stresses outside the rolled region. The theory developed can be very useful in predicting tensioning stresses for a given rolling load and roller geometry.

Notes: Summary Previous linear and curvilinear regression models for predicting the creep deflection of timber and timber products have failed to provide an adequately good fit. However, this paper shows that the 4-element (and to a lesser degree the 3-element) rheological model provides an extremely good fit to chipboard creep data. A set of experiments has been carried out on the creep behaviour of five commercially-available types of chipboard under 3-point sustained loading at constant temperature and humidity. This range of board types encompassed three types of glue — UF, MF/UF and Pf- and was loaded at two stress levels-30% and 60% of the short term ultimate stress. The lifetime of these specimens ranged from 25 days to over 31/2 years until either failure occurred or the load was removed. Creep curves based on 3- and 4-element rheological models have been fitted to the data from each specimen using an iterative least squares computer program which we developed. The validity of the two models is discussed, together with studies on the comparative behaviour of different board types and the use of the models as predictive tools.

Notes: Summary The retrocerebral complex ofChironomus riparius Meigen consists of both nervous and endocrine structures. The hypocerebral ganglion of the adult is composed of about 20 cells and its anterior part is intimately associated with the aorta. In the larva the ganglion consists of about 6 cells. The nervi corporis cardiaci (NCC) of which there are two pairs in the adult and one pair in the larva run through or around the ganglion before entering the region of the corpora cardiaca. Some of the cardiacal cells contain PAF-positive material in adults but not larvae. The corpora allata are spherical or ovoid and of the pseudolymphoid type. Peritracheal tissue is associated with the nervi corporis allati in both larvae and neoimaginal adults. Postcerebral glands, structures apparently unique to chironomids, are annucleate in adults but granular material accumulates within them during adult life. It is suggested that the retrocerebral complex ofC. riparius is unusually simple, that the difference between larvae and adults can be attributed to the absence of feeding in the adults, and that the postcerebral glands may be homologous with the pericardial cells associated with the retrocerebral complex in mosquitoes. Furthermore, the nature of the chironomid system suggests that the X-cells of the gland complex in mosquitoes may represent the intrinsic glandular cells of the corpora cardiaca of other insects.

Notes: Summary With the use of a whole mount silver impregnation technique, sensory nerve endings were located in the connective tissue at the base of the modified pectoral fin ray in the gurnard,Aspitrigla cuculus, and within the perichondrium of the barbel in the goatfish,Mullus surmuletus. The location of these endings and their planar receptory fields in such highly mobile structures, suggests that the sensory endings are proprioceptive in nature and that they are associated in monitoring the positional state of the modified pectoral fin ray and barbel, respectively, during voluntary movement. This investigation addresses itself to the general problem of proprioception in teleost fishes and provides histological evidence for the presence of proprioceptive nerve endings.

Notes: Summary 1) Comparable to the bee, but in contrast to the majority of ants, the desert antCataglyphis bicolor has been shown to exhibit a highly developed repertoire of visually guided behavioural responses. This paper deals with the anatomy and fine structure of the peripheral visual pathway of this ant. In the first visual neuropile, the lamina, first and second order neurons are classified by applying Golgi methods adapted for electron microscopy. Synaptic connections within the lamina are described and discussed. The results are summarised in developing a three-dimensional model of the ant's lamina (Fig. 17). 2) Eachretinula within the central eye region is composed of four large (nos. 2, 4, 6 and 8) and four small retinular cells (nos. 1, 3, 5 and 7) and a basal ninth cell. Visual cells nos. 2, 3, 4, 6, 7, and 8 form short unbranched axons (Rs), which terminate within the lamina. The visual cells nos. 1 and 5 (Rl), as well as the basal cell no. 9, show arborisations in the lamina, but terminate in the second visual neuropile, the medulla. Within the lamina all nine retinular cell axons, originating from one retinula, form a cartridge within which they interact with the second order neurons, the monopolar cells. Collaterals of second order neurons and side branches of retinular cell axons form local neuronal circuits. 3) Five types ofmonopolar cells have been classified by means of their dendritic fields within the lamina and the medulla (L1a, b, c, L2 and L4). They relay the retinular cells with higher order neurons within the medulla. In the distal layer of the lamina (stratum A) the spreads of the monopolar cells are restricted to a single cartridge, whereas in the proximal stratum C their collateral processes extend laterally through more than one cartridge. The collaterals of the L4-type of monopolar cells are exclusively confined to stratum C. There they are arranged bilaterally along the dorsoventral axis of the eye. Within stratum A, where all neurons are organised in well defined columns (cartridges), the axons of the short visual cells seem to be distributed over any cross section of a cartridge at random. In this layer, tangential fibres are the only candidates for inter-cartridge cross talk. In stratum C, the columnar organisation of the neuropile becomes less obvious because of the wide spread ramifications of the second order neurons. For instance, the collaterals of the L1a-type of monopolar cell extend over up to 18 neighbouring cartridges. 4) Three types ofcentrifugal fibres running from the medulla to the lamina are observed (T-fibres). Some of them form wide field arborisations either in stratum A (type T2) or in stratum C (type T3). In linear scale, their collaterals may extend over more than 40% of the large (dorsoventral) axis of the lamina. 5) Receptor terminals, especially Rs-fibres, are densely packed with elongated synaptic vesicles, whereas in second order neurons round vesicles are arranged around the presynaptic elements. Especially in Rs-fibres analyses of serial sections reveal T-shaped synaptic ribbons, which are the presynaptic sites as regards four postsynaptic elements. In case of rod-like presynaptic elements diadic and triadic arrangements of postsynaptic fibres can also be observed. Four main types of synaptic configurations are discriminated: (1) Receptor terminals synapse on second order neurons. (2) Second order neurons synapse on receptor cell axons as well as on other second order profiles. These synapses are sometimes observed in feedback configurations. (3) Synapses occuring between receptor axon terminals. (4) A small, probably efferent neurosecretory nerve fibre synapses on second order neurons. Neurosecretory fibres of larger diameters (to 1.5 Μm are frequently found in stratum C.

Notes: Summary Dark- and light-adapted ocelli of three seastars (Patina miniata, Leptasterias pusilla, Henricia leviuscula) were studied by transmission and scanning electron microscopy. In the dark-adapted state the process of each receptor cell is relatively devoid of clear vesicles. Numerous long microvilli arise from the tips and sides of the processes. Cilia from the sensory processes project into the lumen of an ocellus; they are unconnected to the microvilli. In light-adapted ocelli each process is filled with clear pinocytotic vesicles of varying size. The microvilli are now irregular. Many lie free in the lumen of an ocellus or within phagocytic vacuoles in the supportive and corneal cells. These findings are evidence of a microvillar (rhabdomeric) type of photoreceptor in seastars and of cyclic turnover of receptoral membrane.

Notes: Summary The excretory ducts of the silk glands which produce the viscid spiral of the webs ofAraneus diadematus show a complex structure. The duct of aggregate glands consists of three superposed types of cells. Several connective layers cover large and irregular nodule-forming cells which are rich in glycogen and mitochondria surrounded by invaginations of the plasma membranes. The internal cells, whose apical poles are lined by a cuticular intima, would be quite ordinary if not for the fact that they often carry large vacuoles which seem to empty themselves by exocytosis. Activity in the nodule cells is perceived from variations in the glycogen level and from the appearance of the mitochondria. Internal cells of the duct, when within the posterior spinneret, gradually acquire the characteristics of absorbing cells. The duct of flagelliform glands consists of two types of cells. The external cells, bounded by a simple basal lamina, are rich in mitochondria, glycogen, and invaginations of the plasma membranes; their activity is shown by variations in glycogen level and the extent of the extracellular spaces. The internal cells show numerous mitochondria either at the apical or basal poles, variable glycogen levels, long microvilli, and signs of apical absorption by pinocytosis; the sub-cuticular layer of the intima is particularly thick. We propose a functional interpretation of the aspects described above, and discuss it in terms of recent data on the chemical composition of silks. The excretory ducts are held to modify, by their activity, the secretory products of both types of glands. Solutes, especially phosphate ions, cross both cells and intima and would enter the glue of the aggregate glands which then undergoes partial dehydration in the posterior spinnerets. The product of the flagelliform glands seems to all appearance dehydrated during its passage in the duct and up to about the half-way through the posterior spinnerets. The liquid would flow through an extracellular path below the apical septate junctions of the internal cells. This study therefore favours attributing important role to the excretory ducts of silk glands in the final phase of the formation of silk fibres by spiders.

Notes: Summary The eyes in 55 species of 8 subfamilies of long-horned beetles (Cerambycidae) have been examined ultrastructurally. An eye consists of acone ommatidia of which each is assembled by a bi-convex corneal lens, 4 Semper-cells, 8 retinula cells, 2 primary pigment cells, and of a larger and variable number of secondary pigment cells. The differently arranged rhabdomeres of the — as a rule — open rhabdoms can be summed up to two basic patterns: In the case of the basic pattern 1 the central rhabdomeres R 7/8 are completely isolated from the peripheral rhabdomeres R 1–6. As to the basic pattern 2 the central rhabdomeres R 7/8 are structurally attached to the peripheral rhabdomere arrangement through R 1 and R 4. Due to different directions of the microvilli in R 7 and R 8 there occur several rhabdomeral shapes. Furthermore, within some taxa partially fused rhabdoms are present; in one species the fusion is even complete. Nevertheless, a derivation from an open rhabdom with reference to one of the basic patterns is always possible due to a clear homologous comparison of the anticipating retinula cells. The successfully answered question upon a taxon-specifity of the basic patterns and the rhabdomeral shape allows statements as to the value of these ultrastructural patterns for a phylogenetic argumentation. In Cerambycidae the distinct and not uniform arrangement of these patterns and shapes within lower, closer related taxa represents the occurrence of convergencies (as compared to the extraordinarily similar rhabdoms in Chrysomelidae, Wachmann, 1977, which receive in this paper a further support as to their subfamiliar specification). However, these convergencies are demonstrable through the phylogenetic system only. Thus, patterns of open rhabdoms can only be used as more or less additional indices on a monophyly of groups which already has been proved by means of other characteristics. In spite of an extreme conformity within different taxa rhabdomeral characteristics solely are not appropriate enough in order to separate monophyletic groups. The ultrastructural investigations give a good basis as to the interpretation of the function of the different rhabdoms. However, the question remains not answered whether there exist equal or unequal strategies of circuits within the lamina and medulla.

Notes: Abstract After acclimation, the copepod Acartia clausi was allowed to graze for 5 days in a mixed suspension of two discrete size classes (species) of the chaining diatoms Thalassiosira spp. derived from continuous culture. Total particle numbers and particle size distributions of Thalassiosira spp. were stable throughout the 5 days, indicating that the effects of algal removal and modification due to grazing were balanced by algal growth. Grazer ingestion is the predominant process affecting all size classes of the smaller diatom population (T. nordenskioldii); however, both ingestion and chain modification are observed with the larger diatom (T. gravida). Although the greatest percentage removal of algal volume occurs in the largest algal size classes for each algal species, the greatest volume removal occurs at the modal peak (T. nordenskioldii) or just to the right of the modal peak (T. gravida). Flask-to-flask replicability of experiments was tested with the single-celled T. fluviatilis, and these tests were compared to the long-term experiments with T. nordenskioldii and T. gravida. Net particle removal occurs on both the large and small algal species in mixed suspension, not just on the larger-cell-side of the T. gravida distribution. Although 80% of the particles ingested are from the T. nordenskioldii distribution, 80% of the volume ingested is from the T. gravida distribution. The apparent multi-peak selection observed in our data is discussed in reference to two separate hypotheses and in light of other recent work pertaining to selective grazing by copepods.

Notes: Abstract Existing viewpoints and theories of selective grazing by copepods are briefly reviewed in order to formulate explicit hypotheses to be tested experimentally. Based on these hypotheses, a series of grazing experiments was run to determine (1) the extent of the selective ingestion capabilities of Acartia clausi and (2) how these capabilities were affected by previous feeding histories. Groups of copepods were separately preconditioned on a small diatom (Thalassiosira pseudonana), a large diatom (T. fluviatilis), or a plastic sphere. The ingestive behavior was then examined on various combinations of spheres and food particles. Spheres offered alone were not ingested. In mixtures of diatoms and spheres, the copepods avoided ingesting spheres intermediate in size between the sizes of the diatoms. The copepods either ingested particles on either side of the spheres, or ignored all particles less than the size of the largest spheres. The pattern observed depended upon the size of the preconditioning food. However, if the spheres were larger than the largest food particles, the copepods still selectively ingested the food particles. The above results demonstrate that A. clausi has a complex grazing behavior consisting of (1) more efficient grazing on larger particles within its particle-size ingestion range; (2) the ability to alter “effective” setal spacing to optimize feeding behavior (i.e., the ability to increase efficiency of capture of food particles, and to avoid non-food particles); and (3) the ability for post-capture rejection of non-food particles when they interfere with the ingestion of food particles on which the copepod has been preconditioned. The behavioral patterns observed depend heavily on the food preconditioning and the presence or absence of non-food particles. These results clearly indicate that a simple “mechanistic” explanation of selective grazing is insufficient.

Notes: Abstract When fed shrimp every 2 days, the isopod Glyptonotus antarcticus Eights assimilated over 90% of the ingested food. Errors in this estimate due to loss of food material during maceration by G. antarcticus were investigated and allowed for. These results are discussed in relation to data for other isopods and marine invertebrates.

Notes: Abstract To elucidate the population dynamics of abundant meiofauna, a 15-month field study of 3 species of harpacticoid copepods was conducted in a South Carolina (USA) estuary. Per capita birth and death rates and average brood size (number of eggs per adult female) were lowest for Enhydrosoma propinguum (Brady), Microarthridion littorale (Poppe), and Stenhelia (Delavalia) bifidia (Coull) from November–February, indicating that food or density-independent factors such as temperature regulated winter densities. Reproduction for all species began in February, with the first appearance of copepodites approximately 1 month later. From March–October, M. littorale displayed high per capita birth and death rates (〉0.6 individual-1 day-1), and high average brood size (8 to 9 eggs per adult female). As this species is epibenthic, and thus susceptible to grazing by detritivores, these data suggest that M. littorale was limited by predation. S. (Delavalia) bifidia displayed a sharp increase in density, birth rate and average brood size in July, but birth and death rates (≈0.3 individual-1 day-1) were always lower than those of M. littorale and average brood size gradually decreased from July–December. As this species burrows and is less susceptible to grazing predation, these data are consistent with the hypothesis that S. (Delavalia) bifidia became food-limited as population growth approached its carrying capacity. Although E. propinguum was the most abundant species, quantification of birth potential was not accomplished due to an underestimate of the number of ovigerous females. Therefore, little can be concluded about the mechanism of the summer density regulation of E. propinguum.

Notes: Abstract Development of the planktotrophic veliger of the dorid nudibranch Doridella steinbergae (Lance) was studied by histological examination of 4, arbitrarily defined larval stages. Following an embryonic period of 7 1/2 to 8 days (12° to 15°C), the newly hatched veligers possess a functional digestive tract, a pair of nephrocysts, a secondary kidney, a pair of cerebral ganglia, a larval shell consisting of a two-thirds whorl, and the metapodial component of the foot. Development during Stage I mainly involves growth of the larval shell and the visceral organs. Stage II is marked by the retraction of the mantle fold from the shell aperture and the appearance of the eyespots, gonadal rudiment, larval heart, and the optic, pedal, and pleural ganglia. At Stage III the radular sac rudiment evaginates from the esophageal wall, the buccal ganglia differentiate, and the propodial rudiment begins to develop on the ventral surface of the metapodium. Stage IV veligers, which are competent to metamorphose, possess 6 pairs of radular teeth, lipid deposits in the left digestive gland, rudiments of the adult kidney and the oral lip glands, an hypertrophied mantle fold, a propodium, and densely packed cilia over the entire ventral surface of the foot. The length of the obligatory larval period, from hatching of the veliger until the attainment of metamorphic competence, is 25 to 26 days under laboratory culture conditions and the larval shell grows from 142 to 168 μm in length. The sequence of morphogenetic events and the structure of the competent veliger of D. steinbergae is compared to that of other opisthobranch veligers. It is suggested that the relatively small maximal shell size attained by D. steinbergae results from precocious retraction of the mantle fold. It is further suggested that interspecific differences in the kinds of structures that develop during the veliger phase of opisthobranchs may relate to variations in the requirements of the juvenile phase. The functional adaptations of the gut of planktotrophic veligers are discussed and compared to those of lecithotrophic veligers.

Notes: Abstract Some simple devices for collection of lipid films and adhering microorganisms have been tested at various places along the Swedish west coast and in model systems. Information is given about enrichment of microorganisms and the magnitude of accumulation in these films. The present work indicates that the use of a Teflon sheet is a suitable method for lipid film sampling, both for microbiological and chemical purposes.

Notes: Abstract The effect of 3x10-6 M DCMU [3-(3,4-dichlorophenyl)-1, 1-dimethylurea] on in vivo chlorophyll a fluorescence was observed in nearshore waters of the Southern California Bight. We compared fluorescence readings in the presence and absence of this inhibitor using parallel flow-through fluorometers. The increase in fluorescence induced by DCMU is expressed as the FRI (fluorescence response index). Theory and laboratory studies on batch cultures of phytoplankton suggest that the FRI is correlated with photosynthetic efficiency and/or physiological state, but other studies have produced results in apparent conflict with this interpretation. Although sufficient information does not exist to justify the use of fluorescence response as a precise physiological indicator in the field, we suggest that very low FRI values are a manifestation of photosynthetic debility in a sample. Vertical profiles showed a wide range of the fluorescence response index. At a station close to shore, low FRI values were observed well below the 1% light level, but the fluorescence response of the phytoplankton throughout the euphotic zone was similar to that of growing cultures. Farther offshore, the FRI was depressed near the surface, but increased in the enhanced nutrient conditions of the lower euphotic zone. The patterns observed were strong, and consistent with hypotheses which relate low values of the FRI to diminished photosynthetic capacity.

Notes: Abstract The intertidal anemone Actinia tenebrosa is viviparous. An electrophoretic study of 3 polymorphic enzymes in Western Australian populations has confirmed genetic identity of adults and their brood young, indicating asexual reproduction. The population effects of this clonal reproduction are seen as linkage disequilibrium and departures from Hardy-Weinberg equilibrium within populations, and large differences between populations. The data also suggest occasional sexual reproduction, and the likelihood of a mixture of reproductive modes in this species.

Notes: Abstract The bloodworm Glycera dibranchiata Ehlers, 1968 accumulates cadmium through the general body surface and the intestine. Absorption through the gut accounts for cadmium which rapidly binds to coelomic proteins. Intracoelomic injection of 109Cd demonstrates that cadmium binds readily to hemoglobin and other proteins. The degree of cadmium binding is pH-dependent. The apparent pK of binding sites in body wall and musculature homogenates is 5.39. Cadmium ions injected into the coelom at 7 μg g-1 tissue increase proline incorporation rates into the positively charged hemoglobin (cathode fraction) by 15-fold in 3 days. A 3-fold increase of proline incorporation was observed in the anode hemoglobin fraction over the same time period. Radioactivity in various protein fractions decreases at different rates after injection of 109Cd. Comparisons between the function of mammalian metallothionein and the coelomic fluid proteins of G. dibranchiata as a detoxification mechanism are discussed.

Notes: Abstract Onchidoris muricata (Müller) and Adalaria proxima (Alder and Hancock) are sympatric, potentially competing species of dorid nudibranchs, which preferentially graze the cheilostome polyzoan Electra pilosa (L.). O. muricata is small and lays small eggs which hatch as poorly-developed planktotrophic veliger larvae. A. proxima is larger and reproduces by means of larger eggs which hatch, as well-developed lecithotrophic larvae, that can metamorphose within approximately 24 h of release. A. proxima larvae can feed in the plankton, but do not require extrinsic nutrition to undergo complete development. Both species spawn in February–april, and have a strictly annual life-cycle. Comparisons of the calorific content of spawn have shown that A. proxima apportions a greater number of calories to reproduction, but that O. muricata makes a greater relative effort. A. proxima shown considerable individual variability in reproductive effort, which fails to correlate with, body size or rate of spawning. A more deterministic situation applies to O. muricata, because body size and fecundity follow an allometric relationship. It appears that there is a threshold of absolute energy required to support the lecithotrophic larval strategy in nudibranchs, and that this is not attained by the smaller species, O. muricata. A. proxima thus appears to have both reproductive strategies open to it, and to have adopted lecithotrophy in order to offset the unpredictability of energy available for reproduction.

Notes: Abstract Several tissues (e.g. kidney, blood, digestive gland) in oceanic cephalopods which do not exhibit in vivo bioluminescence, luminesce when homogenized in the presence of air or when simply exposed to air in a vial (blood). The source of the luminescence appears to be a luciferin: treatment of kidney homogenates and blood with a photophore extract presumably containing luciferase resulted in a 20-fold increase in light production. Luminescence was also found in the renal fluid, which may be the source of luminescent clouds produced by squids. The variability in luminescence found in some tissues of cephalopods appeared to be related to feeding. Luminescence was also detected in the digestive glands of midwater octopods.

Notes: Abstract Mytilus edulis L. were exposed to abrupt (30‰→15‰ and 15‰→30‰) and fluctuating (sinusoidal 12 h cycles of 30‰→15‰→30‰) changes in salinity, and the changes in the total osmoconcentration of the haemolymph were recorded. The response of nitrogen metabolism to the altered extracellular osmotic concentrations was investigated in terms of the concentrations of the total NPS (ninhydrin-positive substances) pool and the individual amino acids of the tissues, the concentration of the amino acids of the haemolymph, and the rates of excretion of ammonia and amino acids by whole individuals. The haemolymph became isosmotic with the seawater with abrupt changes in salinity, but with fluctuating salinity was slightly hyperosmotic as the salinity decreased and then slightly hypo-osmotic as the salinity increased. This resulted in a reduction in the extent of the extracellular osmotic change compared to the change in fluctuating salinity to which it was exposed. Total NPS of the tissues decreased with an abrupt decrease in salinity and increased with an abrupt increase in salinity, but a seasonal dependence of the response was indicated. The short-term response of tissue NPS to fluctuating salinity was equivocal, but with long-term exposure the concentration declined. Ammonia and amino acid excretion increased with both an abrupt decrease in salinity and fluctuating salinity and decreased with an abrupt increase in salinity. Haemolymph amino acids increased with an abrupt decrease in salinity. The increased rates of nitrogen excretion accounted for the reductions in the NPS concentrations of the tissues except in the early stages of fluctuating salinity. Taurine, aspartate, threonine, serine, glycine and arginine declined with an abrupt decrease in salinity while alanine and glutamate increased slightly. With an abrupt increase in salinity, alanine and ammonia accumulated in the tissues and then declined while the other amino acids increased slowly over a longer time-course. Similar individual amino acid responses were seen with long-term exposure to fluctuating salinity, except for taurine which did not decrease in concentration. On the basis of the changes in tissue amino acids and ammonia, it is suggested that the “alanine dehydrogenase reaction” is the primary nitrogen-fixing reaction in marine bivalves such as M. edulis.

Notes: Abstract The amounts of Cr, Cu, Cd and Pb in the copepod Anomalocera patersoni were determined for 47 individuals by flameless atomic absorption spectrophotometry. The following mean body burdens of these elements were obtained: Cr 0.6, Cu 13, Cd 0.5, Pb 1.5 ng individual-1, or Cr 2.1, Cu 42, Cd 1.5 and Pb 4.8 ng mg-1 (dry weight). Cr, Cu and Cd contents did not differ significantly between males and females, however Pb did, with males having more. The data indicate that while the Cr, Cu and Pb body Hurden in these copepods follows the logarithmic normal distribution, Cd follows a normal distribution. Thus, the arithmetic means and the modes of Cd body burden are almost the same, while for the other elements the arithmetic means differ from the geometric means. This indicates that measurements of a few individuals suffice for estimating the mean body burden of Cd. On the other hand, many measurements are necessary for the body burden estimation of other elements, especially Cu.

Notes: Abstract The distribution of epibenthic penaeid prawn postlarvae has previously been shown to relate to the degree of marine influences in the flora, sediment and water conditions in littoral and infralittoral habitats in Moreton Bay. The postlarvae are part of a complex faunal assemblage of approximately 400 mobile epibenthic species. Samples of the assemblage from stations situated throughout Moreton Bay were analysed by multivariable methods, to detect whether the environmental influences volated to the distribution of penaeid prawns, were related to the fauna as a whole. This was found to be so. The fauna occurred in two groups in areas of either less marine or more marine influences. Animals in the first group were less diverse, with distributions unrelated to depth or presence of seagrasses, but related to the level of marine influences between geographical areas sampled. Animals in the second group were closely related to depth and presence of seagrasses, but no overall differences were attributable to marine influeces apart from those attributable to depth. Temporal changes in species composition were smaller than spatial changes, and changes in relative abundance were, in both groups, related to differences between (i) summer and winter, and (ii) spring and the rest of the year.

Notes: Abstract Egg extracts from 32 species of marine hydromedusae, siphonophores and sessile hydroids were tested for sperm attracting activity using the sperm of all species in both homo- and heterospecific combinations. Species-specific sperm chemotaxis could be demonstrated in nearly every species tested. Of the 1,024 possible combinations, 272 could not be attempted for lack of material. Of the 752 which were carried out, only 13 heterospecific cross-reactions were found. The bulk of these involved reactions which were either weaker in the heterospecific direction or unidirectional. The sperm behavior in response to both homospecific and heterospecific egg extracts is described. In the latter case, no changes in sperm motility or direction of movement were observed. In the former case, the sperm show turning behavior which brings them closer to the source of the extract. Since most of the Hydrozoa tested share the same habitat and are reproductively active at the same time of year, it appears that species-specific sperm chemotaxis may be a significant mechanism for both ensuring fertilization in an environment which subjects the gametes to massive dilution and preventing hybridization.

Notes: Abstract Gel filtration on highly cross-linked molecular sieves of the sperm attractants of some hydromedusae revealed that the active agents differ in their molecular weights. These differences fall roughly along taxonomic lines, at least at the order level. Anthomedusae have attractants with molecular weights greater than 5,000, while the Leptomedusae attractants have weights less than 1,000. The Limnomedusae and Trachymedusae attractants have weights above 5,000. All the attractants are heat-stable, but only those of the Leptomedusae can pass across a dialysis membrane with a molecular weight cut-off of 14,000.

Notes: Abstract It is widely documented that in Bonellia viridis Rolando (Echiura), the larvae settle on the proboscis of the adult female and differentiate into males. This study shows that although settlement on the proboscis is preferred, the larvae can also settle on the body trunk of the adult and differentiate into males. Aqueous extracts of homogenized trunk tissues are as effective as those of proboscis tissues in masculinizing the larvae. The natural secretion of the female body trunk, which is produced when the worm is disturbed, has potent masculinizing properties. The preferential settlement on the probiscis may not result from a different chemical nature of the substratum.

Notes: Abstract Stomachs from over 323 specimens of Hymenocephalus italicus, 168 Nezumia aequalis, 160 Coelorhynchus coelorhynchus and 1670 Trachyrhynchus trachyrhynchus were collected from September 1976 to September 1978 from the West Mediterranean continental slope at depths between 200 and 800 m. Copepods, amphipods and other pelagic crustanceans form the main fraction of the diet of H. italicus. The diets of N. aequalis and C. coelorhynchus consist largely of polychaetes, isopods, amphipods, mysids and decapod crustaceans. T. trachyrhynchus feed heavily on decapods. Decreasing fractions of small crustaceans are found in diets of all species as fish size increases. The mean size of prey increases with the body size of the fish. A positive size-depth correlation has been observed in macrourids. Juveniles and intermediates of N. aequalis, C. coelorhynchus and T. trachyrhynchus were found in shallow-water zones (〈400 m), while adults were more common in deeper areas. Niche breadth and niche overlap were calculated between size groups. Niches are relatively broader with respect to habitat and narrower for prey size and prey type. The food overlaps between N. aequalis C. coelorhynchus and between C. coelorhynchus and T. trachyrhynchus are notably the greatest. Overlap in relation to habitat is high, while the correlation between niche parameters is very poor, indicating a certain degree of independence between these factors. Alpha matrices were estimated using both multiplicative (α product) and additive (α summation) multidimensional estimates for niche overlaps. Rates of competitive exclusion are low.

Notes: Abstract Nauplii of Calanus pacificus were raised on a mixture of algae. Details of the mouth-parts, such as denticles, labial palps and lobes, setations and structure of the masticatory teeth were examined by scanning electron microscopy (SEM). Under the experimental conditions (15°C and 300 μgC l-1), exponential growth coefficients for the period Nauplii II–VI were 0.179 for carbon and 0.228 for nitrogen. C:N ratios dropping from 5.1 to 4.7. Growth was isochronous, each stage lasting 1.5 days. Respiratory losses were 15 to 19.6% of body carbon daily. Nauplii raised on a given alga showed higher rates of ingestion in the presence of this food, compared to nauplii switched to other algae. Minimal threshold concentrations for feeding were found, depending on the size of the food offered and ranging from 5.8 μgC I-1 for Lauderia borealis (28.7 μm spherical diameter) to 47.1 μgC 1-1 for Chlamydomonas sp. (11.0 μm). Unlike the Copepodite I stage, Nauplii II–VI larvae were not able to ingest small cells such as Isochrysis galbana (4.3 μm), or very large ones such as Ditylum brightwellii (47.5 μm) at more than maintenance rations. Below the critical concentration for maximal feeding, ingestion was clearly dependent on size of the cells offered, but the size-dependent relationship was different for diatoms and non-diatoms. Filtering rates increased from a threshold concentration to a maximal rate at about 50 μgC 1-1, and decreased at higher concentrations. Critical concentrations ranged from 125 μgC 1-1 for L. borealis to 1000 μgC 1-1 for Chlamydomonas sp. Maximal daily rations ranged between 100 and 150% of body carbon.

Notes: Abstract The luminescence of the solitary radiolarianThalassicolla sp. has a spectral emission maximum at 446±4 nm and the luminescence of crude homogenates can be activated by calcium ions. Electrical stimulation of single individuals frequently causes them to produce repetitive post-stimulus flashing akin to that reported in a number of other marine animals. The possible relationships between the luminescent system ofThalassicolla sp. and of certain coelenterates are discussed.

Notes: Abstract The ultrastructure and pigment content of algal chloroplasts (derived from Bacillariophyceae or Chrysophyceae) are described from 3 benthic species of brackish-water foraminiferans.Elphidium williamsoni Haynes contains 4×106 chloroplasts mg-1, whereas the contents ofNonion germanicum (Ehrenberg) andE. excavatum (Terquem) are about 10% of this value. The two former contain chlorophyllsa andc and fucoxanthin, but these pigments were not detectable in the latter.E. williamsoni andN. germanicum had a net uptake of14C−HCO 3 - , proportional to their content of chlorophyll and number of chloroplasts, increasing linearly up to approximately 10 Klux. At light saturation the former assimilates 2.3x10-3 mg C mg-1 h-1 and the latter only about 20% of this value. Dark uptake was insignificant in all cases. Uptake could not be demonstrated inE. excavatum. The photosynthesis effected by these species is trivial in terms of the total benthic carbon fixation effected by the microflora. The chloroplasts survived longer in forminiferans kept in the dark than in light/dark adapted individuals. To keep a steady state population of chloroplasts under light/dark conditions,E. williamsoni must eat at least 65 chloroplasts individual-1 h-1, whereas the minimum consuption rate inN. germanicum is 20.

Notes: Abstract The biomass of bacteria suspended in water flowing over coral reefs at Lizard Island and Yonge Reef (Northern Great Barrier Reef) was estimated by measurement of muramic acid. Values ranged from 20 mg C m-3 in the open water up to about 60 mg C m-3 over the reef flat. Direct counts of total numbers of free bacteria were made for comparison. Values of around 2.0x109 cells μg-1 muramic acid showed that there was a good agreement between direct counts and muramic acid content of free bacteria in the open water. In samples containing suspended particulate matter, ratios of direct counts to muramic acid concentration were lower, because bacteria on particles could not be counted. Thus, these ratios were used to indicate the proportions of bacteria attached to particles. Changes in the biomass and numbers of bacteria were determined in water masses identified either by a drogue or fluorescein, as they moved across the reefs. In the zone on the outside of the reef, the number of free bacteria decreased compared to open sea water, but total biomass increased, showing that particulate matter containing bacteria was thrown up into suspension. About 50% of bacteria were attached to particles. Water flowing over the reef flats contained much particulate material with bacteria attached. Bacteria constituted between about 5 and 20% of particulate organic carbon.

Notes: Abstract Length/weight relationships have been computed for shell, flesh and byssus ofAulacomya ater (Molina) and energy values used to convert the weights to energy equivalents. Shell accounts for some 26% of total body energy, while the contribution of the byssus declines from 15 to 8% during growth. Observations of juvenile growth rates have been used to generate a Gompertz growth equation which predicts attainment of maximum length (90 mm) after 11 years. Reproductive condition has been assessed by monitoring seasonal fluctuations in the flesh weight of standard-sized individuals, calculated from monthly length/weight regressions. There appear to be three spawnings, of variable date and intensity, each year. From the above data, annual energy expenditure on growth and gonad output has been calculated for individuals of various sizes. The ratio of total production to biomass $$(P:\bar B)$$ is a declining clining function of shell length, dropping from 29.5 at 5 mm to 0.8 at 85 mm. The proportion of total production expended on gamete output increases steadily from 25% at attainment of maturity (15 mm) to 81% at 85 mm length. The considerable effects of changing size composition on the amount and type of production in natural populations are discussed.

Notes: Abstract Detailed information is presented on the changes in lipid-class profiles (polar lipids, total neutral lipids, free sterols, steryl esters, triacylglycerols, neutral ether lipids and free fatty acids), which are manifest during the annual reproductive cycle of the seastarAsterias rubens for both the storage organs (pyloric caeca) and utilizing organs (ovaries). The ovaries appear to accumulate all individual lipid components proportional to progression of vitellogenesis. Pyloric caeca, in contrast, show variable lipid-class levels, probably due to more complex processes in these organs, operating simultaneously: digestion of food, accumulation of storage lipids, mobilization of stored lipids and their release. The results are discussed in terms of current knowledge on the role of lipids in echinoderm reproduction.

Notes: Abstract In mid-summer 1975 throughout the Western Slope Water of the North Atlantic Ocean, massive numbers ofSalpa aspera performed a diel vertical migration of at least 800 m. This resulted in a movement of 85 to 90% of the total zooplankton biomass out of the upper 500 m during the day. Fecal pellet production and losses from this salp population were estimated to contribute approximately 12 mg C m-2 day-1 to the deep planktonic and benthic populations. If all this organic matter reached the deep-sea floor, it would represent over 100% of the daily deep-sea benthic infauna energy requirements.

Notes: Abstract Lymphomyeloid (haemopoietic) tissues produce or store blood cells — among these leucocytes rich in lysosomal enzymes. The thymus, unlike the other lymphomyeloid tissues found in fish, produces exclusively lymphocytes. The carbohydrate-hydrolysing enzymes lysozyme (EC 3.2.1.17), chitinase (EC 3.2.1.14) and exo-N-acetyl-β-D-glucosaminidase (NAGase; EC 3.2.1.30) were assayed in various lymphomyeloid tissues of the cartilaginous fish Chimaera monstrosa, Squalus acanthias, Etmopterus spinax and Raja radiata, and in the thymus of the marine teleost Lophius piscatorius. Lysozyme activity was high in the cranial lymphomyeloid tissue of C. monstrosa; in Leydig's organ (oesophageal lymphomyeloid tissue) and the spleen from E. spinax; and in Leydig's organ, the epigonal organ and the spleen from R. radiata. Little or no lysozyme activity was found in Leydig's organ and the epigonal organ of S. acanthias, or in the thymus of C. monstrosa, R. radiata and L. piscatorius. The pH optima for lysozyme activities lay between 4.8 and 5.4 when assayed photometrically. Chitinase was most active at pH 1 in Leydig's organ from R. radiata, and at pH 2.7 in the epigonal organ from S. acanthias. The chitinolytic activity in Leydig's organ of E. spinax may be due to lysozyme. The optimum for NAGase activity in Leydig's organ from R. radiata lay at pH 4.0, that from S. acanthias and E. spinax at pH 4.5. The role of the enzymes in the defense against microorganisms and parasites is discussed.

Notes: Abstract Experiments were made with natural populations of both zooplankton and phytoplankton from Southampton Water (England), using an electronic particle counter to measure grazing effects. What appear to have been large differences within and between experiments in size of particles selected are shown to have been mainly a result of variations in total amout of grazing. When this was taken into account it was found that there was no difference in size of particles selected most strongly whether the zooplankton was dominated by copepods or smaller cirripede nauplii. This can be accounted for by similarities in the setous feeding appendages of these two forms. It is suggested that similarity in particle selection would lead to competition between the two grazers if they were not separated seasonally.

Notes: Abstract Chitinase, exo-N-acetyl-β-D-glycosaminidase (NAGase) and lysozyme activities were assayed in the digestive tract of 6 species of marine fishes: Myxine glutinosa (cyclostome), Chimaera monstrosa (holocephalan), Squalus acanthias, Etmopterus spinax, Raja radiata (elasmobranchs) and Coryphaenoides rupestris (teleost). Strong chitinase activity was found in the gastric mucosa of the elasmobranchs (S. acanthias, E. spinax and R. radiata) and the teleost (Coryphaenoides rupestris). A remarkably high chitinase activity occurred in the pancreas of the stomachless holocephalan fish Chimaera monstrosa. NAGase activity was strong in the digestive tract of all species. It could be concluded that marine fishes with diets consisting largely of chitinous invertebrates may display high chitinase and NAGase activities in their digestive system; however, only low chitinase activity was found in the intestine of the cyclostome Myxine glutinosa. Coryphaenoides rupestris gastric mucosa chitinase had one optimum activity at pH 1.25, whereas S. acanthias chitinase had two optima, at pH 1.6 and 3.6. The NAGase pH-activity curves from S. acanthias and R. radiata gastric mucosa displayed similar optima, at pH 4.5 and 4.25 respectively. Chimaera monstrosa pancreatic chitinase had a very strong optimum around pH 8 to 10, and one less strong at pH 3. These enzyme activities could not be separated by gel filtration or isoelectric focusing. The pI (isoelectric point) was approximately 4.9 for both enzymes. The molecular weight of the C. monstrosa pancreatic chitinase was estimated to be approximately 43 000. Lysozyme activity was absent or extremely weak in the material studied.

Notes: Abstract A nitrogen-deficient batch culture of the marine diatom Skeletonema costatum, when resupplied with a mixture of nitrate and ammonium, showed an initial enhanced nitrate uptake rate leading to a large internal concentration (pool) of nitrate. Following this initial nitrate uptake event, nitrate uptake ceased, and nitrate assimilation was inhibited until the ammonium present was used. At this point, nitrate uptake resumed and nitrate assimilation began. No internal ammonium pool was observed during nitrate utilization, but a large nitrate pool remained throughout the utilization of external nitrate. The internal nitrate pool decreased rapidly after exhaustion of nitrate from the culture medium, but growth of cellular particulate nitrogen continued for about 24 h. A mathematical simulation model was developed from these data. The model cell consisted of a nitrate pool, ammonium pool, dissolved organic nitrogen pool, and particulate nitrogen. It was found that simple Michaelis-Menten functions for uptake and assimilation gave inadequate fit to the data. Michaelis-Menten functions were modified by inclusion of inhibitory and stimulatory feedback from the internal pools to more accurately represent the observed nutrient utilization.

Notes: Abstract Population distributions, densities and percentage deaths and individual size variations of the barnacles Chthamalus stellatus and Tetraclita squamosa, and the distribution of the vermetid snail Spirogluphus annulatus are measured to clarify determinants the Florida Keys (USA). The species composition of the pilings community and barnacle population densities correspond to physical gradients dependent on piling distance from shore. Interspecific competition for space is insignificant in determining C. stellatus presence or absence on pilings. Intraspecific crowding in highdensity zones of adult T. squamosa is evidenced by a significant decrease in basal diameter as density increases. The peak percentage of dead C. stellatus coincides with peak densities. The percentage of dead T. squamosa is at a low point at peak densities due to the ability of T. squamosa cyprids to settle and survive on adult shells in high-density regions. Feasible perturbation experiments for testing the importance of interspecific competition in determining the densities and vertical distributions of the species are discussed. The results of such experiments can be used to test the assumptions and predictions of the widely applied competition coefficient measure proposed by Levins (1968). Several theoretical deficiencies of Levins' measure are discussed.

Notes: Abstract A rapid method for measuring the redox potential (Eh) values of marine sediments is described. This method has been used to relate changes in the areas of highly reduced sediment in a sea loch system to the continuously fluctuating inputs of organic waste from a pulp and paper mill. Subsequent faunal changes in these areas can be related to changes in the measured sedimentary redox level. The method is suggested as a rapid means of assessing the potential impact of an additional organic input to a marine sediment.

Notes: Abstract The lethal levels of mercuric, lead and zinc chlorides were determined for the marine ciliated protozoan Uronema marinum Dujardin; the 24 h LC50 values were 0.006, 60 and 400 mg l-1, respectively. A factorial experiment was used to study the inhibition of cell division in U. marinum cultures by mixtures of mercury, lead and zinc. The three metals were found to interact in their effects. A regression model was fitted to the experimental results and the response surface was plotted. The addition of mercury, lead or zinc at concentrations which inhibited cell division did not appear to affect the duration of the lag phase or the yield of cells. A culture of U. marinum was maintained for 18 weeks in a medium containing mercury, lead and zinc in an attempt to acclimatise the ciliates to heavy metals. A subsequent factorial experiment which examined the cell division rate indicated that a prolonged exposure did not induce in the ciliates a measurable tolerance to the metals.

Notes: Abstract Ammonia excretion of individual Crangon franciscorum Stimpson was monitored in response to ingestion of single meals. The three experimental diets were tubificids, mysids and fish. Ammonia excretion was also monitored for individual shrimp which had been starved. The rate of ammonia excretion was higher for fed than for starved individuals in all cases. Ammonia excretion rates were higher for shrimp which were fed tubificids than those fed the other diets. The rate of excretion was influenced by both weight of the individual and the amount ingested of each diet. Ammonia excretion was influenced by dietary factors other than nitrogen content of the diet or the quantity ingested. The data suggest that field estimates of ammonia excretion based on the excretion rates of starved animals may be underestimates. The recent feeding history of an organism influences the rate of ammonia excretion as well as the relationship between the rate of excretion and weight.

Notes: Abstract Ammonium ion uptake and excretion rates were measured in water samples taken from Kaneohe Bay, Oahu, Hawaii, by monitoring the 15N/(15N+14N) isotope ratio in dissolved ammonium ion in incubated samples which had been spiked with 15N-labeleled crops of microzooplankton (organisms passing a 0.333 mm mesh gauze), but the actual excretion was due primarily to smaller organisms (less than 0.035 mm in nominal diameter). Preliminary results indicate that excretion rates were substantially higher during the night than during the day, and that on the average daily uptake and excretion of ammonium ion were roughly in balance.

Notes: Abstract The gammaridean amphipods Cymadusa compta (Smith), Gammarus mucronatus Say, Melita nitida Smith and Grandidierella bonnieroides Stephensen from a seagrass community in the Indian River estuary of Florida (USA) fed variously upon large drift algae, small algae epiphytic on seagrasses and seagrass leaf debris and detritus. Consumption was measured in the laboratory using an index (CI) equivalent to mg ingested mg-1 amphipod day-1. Observations revealed that the amphipods fed by macrophagy, an attack upon large algae and seagrass debris, and by microphagy, small particle detritus feeding and scraping of plant surfaces for diatoms and other epiphytic algae. C. compta was a macrophagous feeder with a generalized diet of algae and seagrass debris, preferring epiphytic algae and drift algae at mean rates of 1.10 and 0.87 CI, respectively. Gammarus mucronatus fed upon epiphytes and seagrass debris equally at mean rates of 0.90 and 0.97 CI, respectively. The diet of M. nitida condisted primarily of epiphytes, consumed at an average rate of 1.05 CI. Grandidierella bonnieroides fed in a specialized microphagous manner, “grooming” plant surfaces for small particle detritus and diatoms at an approximate CI rate of 1.45. Assimilation of plants ingested, as reflected by carbon-14 uptake, varied similarly among the 4 amphipods. Epiphytic algae appeared to be most useful as food, providing means of 41 to 75% carbon-14 uptake as ingesta. Drift algae and seagrass debris were of less value, with means varying between 11 and 24 % of carbon-14 uptake by the amphipods. The data show a pattern of feeding which resembles resource partitioning of food both by size and kind. Other evidence, however, including population limitation by predators and an apparent overabundance of food, indicate that resource partitioning as seen may be an artifact, and one which has no co-evolutionary basis among the present species.

Notes: Abstract Basic to nearly any prediction concerning the behavior and structure of entire communities or of their components is knowledge of trophic connections among species. A major impediment to such understanding of soft-bottom benthos is methodological. Because none of the routinely available methods of food web analysis (e.g. visual gut content analysis, direct observation of feeding, tracer techniques) is generally suitable for examining all trophic interactions of benthic infauna, we rought to evaluate the potential of immunological methods for identifying predatorprey relationships in one typical, estuarine, intertidal sand flat. Whole-organism extracts of individual macro- and meiofaunal taxa were injected into rabbits to produce antisera of varying specificity. Double immunodiffusion precipitin tests of antiserum specificity revealed both phyletic and trophic relationships among 20 taxa. Using relatively unspecific antisera, preliminary analysis of the stomach contents of a few surface deposit-feeders and particle browsers was successful, giving positive identification of several trophic links which would otherwise have gone undetected. The production of taxon-specific antisera is expected to provide the methodological tool necessary to document the breadth of trophic connections in a marine benthic food web.

Notes: Abstract Three species of sea anemones, clearly exhibiting zonation on the shore, are grouped into intertidal [Phymactis clematis (Drayton, 1846), Anthothoe chilensis (Lesson, 1830)] and infralittoral [Antholoba achates (Drayton, 1846)] forms. A series of observations revealed that intertidal forms have the ability to retain water in the coelenteron during exposure to air,/while the infralittoral form cannot do so. This different behaviour is attributed to morphological characteristics, such as the specific body shape and the structure of the sphincter and retractor muscles. These features, in combination with specific abiotic factors of the various habitats under consideration, determine the upper limits of distribution of each species, while zonation below these limits seems to be affected in addition by biological interactions.

Notes: Abstract Habitat selection of two bivalve species, Cardium edule (L.) and C. glaucum (Bruguière) is described for sympatric and allopatric populations of both sibling species. It is demonstrated that C. edule grows faster than C. glaucum and is absent from localities with periodic low food-availability. The ability to burrow of C. glaucum is low compared with that of C. edule; the former species does not occur in very loose, well-sorted sand near the coast. Earlier studies which suggest that tidal range determine the species distribution could not be confirmed.

Notes: Abstract A method for determining filtration rates in undisturbed suspension-feeding bivalves is described. Concentrations of particulate matter in the water collected in the inhalant (C i) and exhalant (C e) currents were estimated with an electronic particle counter. The clearance was calculated as $$Y = Fl(1 - \frac{{C_e }}{{C_i }})$$ , where Fl=flow rate through the tube collecting exhalant water. Only above critical levels of water flow (Fl) were clearances representative of filtration rates. At 10° to 13°C, the filtration rates (F, 1 h-1) within one or two orders of magnitude of dry weight (w, g), in Cardium echinatum L., C. edule L., Mytilus edulis L., Modiolus modiolus (L.) and Arctica islandica (L.) followed the allometric equations: 4.22w 0.62, 11.60w 0.70, 7.45w 0.66, 6.00w 0.75 and 5.55w 0.62, respectively. Five species of bivalves [Spisula subtruncata (da Costa), Hiatella striata (Fleuriau), Cultellus pellucidus (Pennant), Mya arenaria L. and Venerupis pullastra (Montagu)] filtered with the same rates as individuals of Cardium echinatum and A. islandica of equivalent soft weight. In Pecten furtivus and P. opercularis filtration rates were about twice the rates measured in individuals of Mytilus edulis of comparable body weight. The gill area in M. edulis increases with size at the same rate as the filtration rate.

Notes: Abstract The levels of genetic variation and estimates of genetic similarity and distance were determined for populations of Crassostrea gigas (Thunberg) and Saccostrea commercialis (Iredale and Roughley). The proportion of polymorphic loci in Japanese populations of C. gigas ranged from 0.58 to 0.63, while the individual heterozygosities ranged from 0.20 to 0.22. The proportion of polymorphic loci in Australian populations of S. commercialis ranged from 0.43 to 0.46, the individual heterozygosities from 0.17 to 0.19. The genetic similarity between different geographical populations of both species was approximately 99%. The genetic distance and similarity data derived from this investigation has resulted in some provisional reclassifications. The Portuguese oyster C. angulata (Lamarck) appears to be more appropriately regarded as a recent colonized isolate of C. gigas. The New Zealand oyster S. glomerata (Gould) is considered a subspecies of the eastern Australian rock oyster S. commercialis. The Japanese Kumamoto population of C. gigas warrants reclassification as the non-sibling species C. sikamea.

Notes: Abstract The estimated levels of genetic variation are reported for 6 Crassostrea and 3 Saccostrea species. The estimates are based on examination of 25 to 34 genetic loci. The average heterozygosities ranged from 6 to 22% for the Crassostrea species and from 17 to 19% for the Saccostrea species. A new sibling species (S. manilai) from the Philippines has been identified by means of protein electrophoresis. The genetic similarity and distance between species has been computed for each genus. Also, a pairwise comparison of loci and a dendrogram of the phylogenetic relationship of species has been constructed from the two genera. Some of the taxonomic levels during oyster speciation have been computed from the data of the electrophoretic study of the two lineages. The possibilities of oyster superspecies (e. g. C. gigas, C. virginica and S. cucullata) are discussed based on our population genetic study.

Notes: Abstract Anthopleura elegantissima containing zooxanthellae, as well as isolated zooxanthellae, incubated with acetate-1-14C under both light and dark conditions readily incorporate radioactivity into their total lipid pools. In both cases, the specific activity was greatly increased in the light. Dark-incubated anemones and isolated zooxanthellae incorporate activity predominantly into polar lipid; the remainder being present principally in the triglyceride moiety. Light-incubated organisms, however, show a dramatic redistribution of isotope towards greatly increased triglyceride and was ester incorporation, with a concomitant drop in polar lipid. onder light conditions, 70 to 75% of the radioactivity found in the fatty acids of the total zooxanthellae lipid was present in hexadecanoic (16:0) and octadecenoic (18:1) fatty acids. These are also the two major fatty acids by mass. Octadecanoic acid (18:0) is less than 5% by mass. Isotope incorporation patterns suggest that octadecenoic acids arise by elongation of hexadecenoic acids and that this conversion is blocked in the dark. Isotope incorporation patterns for anemones suggest that fatty acids, primarily in the form of saturated or monoenoic fatty acids, are translocated from algal to animal cells. No activity was found in either octadecadienoic (18:2) or octadecatrienoic (18:3) acids. The significance of these data is discussed.

Notes: Abstract Copper-tolerant strains of the marine fouling alga Ectocarpus siliculosus (Dillw) Lyngb. have been recorded. The mechanisms of tolerance which may operate in a copper-tolerant strain were investigated by comparing the growth characteristics, copper content and extracellular organic production of tolerant and non-tolerant strains. Growth was measured by a wet-weight method. The copper content of dryashed cells was measured spectrophotometrically using tetraethylthiuram disulphide. The extracellular material is ultra-violet absorbing, and the production was measured by recording absorption at 265 nm. Evidence suggests that an exclusion mechanism is operating in the tolerant strain under investigation. The extracellular material, the cell wall or an associated organism make little or no contribution no this exclusion. Membrane and intracellular changes are believed to account for the tolerance in this strain of E. siliculosus.

Notes: Abstract Samples of Halobates robustus Barber (Heteroptera: Gerridae) from the Galápagos Islands were analysed by optical emission spectrometry. The levels (in μg g-1 dry weight) of Zn (134), Cu (155), Pb (〈 1), Cd (7), and Cr (3) were not significantly different among insects of different sexes or developmental stages. The low natural levels of Cd in H. robustus from the relatively unpolluted environment of the Galápagos Islands are compared to the high concentrations of Cd in Halobates spp. from relatively polluted regions. Since the measured levels of Cd in their natural zooplankton food rarely exceed 10 μg g-1, and very little of the Cd is found in the soft tissues, the high Cd concentrations (100 to 200 μg g−1) in some seaskater species have evidently been derived by drinking from the surface microlayer of the seawater.

Notes: Abstract The identity of a Tropidoneis sp. previously reported from the intertidal sand flats at Barnstable Harbor, Massachusetts (USA) has been resolved as T. lepidoptera (Greg.) Cl., and its vertical migratory behaviour compared with that of the more common Hantzschia virgata var. intermedia (Grun.) Round.

Notes: Abstract The assemblages of species living on and in intertidal sand flats at Barnstable Harbor, Massachusetts (USA) are briefly described. An endopsammic assemblage of diatoms, mainly Amphora species, living below the surface is described for the first time in such a marine situation. Some aspects of its ecology and relationship to the other diatom assemblages living on the sediments are discussed.

Notes: Abstract Gene-enzyme variation was studied electrophoretically within and between barnacle populations of the genus Chthamalus from 8 intertidal stations from central California to the Pacific coast of Panamá. Horizontal starch-gel electrophoresis separated and resolved 18 enzymes from 512 individual barnacles. A maximum of 25 gene-enzyme systems was interpretable from the resulting zymograms. Electrophoretic phenotypes and patterns of phenotypic variation generally conformed with those observed in other organisms. The amount of genetic variation within barnacle populations varied; average heterozygosity, for example, ranged from a low of 3.4% in a Mexican population of the C. fissus group to a high of 10.4% in C. anisopoma from the Gulf of California. Observed and expected average heterozygosities agreed in all population samples, indicating that these species are outbreeding. In contrast to the prediction stemming from a hypothesis that trophic stability regulates the amount of genetic variation in marine species, average heterozygosity tends to be positively correlated with latitude. Data from these and other barnacle species may support a hybrid “environmental heterogeneity-trophic diversity” model recently proposed to explain genetic variation in decapod crustaceans. Juxtaposition of individuals from different localities revealed numerous genetic differences among populations of the C. fissus group. At least three partially sympatric sibling species are separated by genetic distances as large as those observed between the C. fissus group and the distinct species C. dalli and C. anisopoma. A cladistic analysis places C. anisopoma close to the Mexican and Panamanian sibling species, with C. fissus from San Diego and C. dalli successively farther removed.

Notes: Abstract The spatial relationship of interstitial metazoans to sources of oxygen has been studied on a tidal flat in the Wadden Sea near Sylt (eastern part of the North Sea). Consistently, meiofauna remains in close proximity to oxygenated layers or pocket areas within the sediment. This is exemplified by the pattern of meiofaunal abundance and species composition alongside oxic burrows of the lugworm Arenicola marina L. A specific meiofauna confined to oxygen-deficient horizons of the sediment does not exist.

Notes: Abstract The population dynamics of Euterpina acutifrons (Dana), a pelagic, harpacticoid copepod, are summarized in a life table based on field data. Highest mortality occurred in the last naupliar stage (NVI) and the first copepodite stage (CI). Overall survival in the field was 0.06% from the first naupliar stage (NI) to adult (CVI). The net reproductive rate (R o=55.590) and intrinsic rate of increase (I m=0.28) were sufficiently high to maintain a population with such a low survival rate in nature. E. acutifrons was present and breeding in the field from April through December. Low temperatures limited breeding, which began when the temperature reached 16.5°C and ceased when it fell to 11°C. Optimum temperature for North Inlet E. acutifrons was 25°C, with a maximum laboratory survival of 15.3% and a generation time of 10.3 days. Generation time in the field (20°C) was 14 days. Temperature also affected the abundance of dimorphic males. Small males were always most abundant, but peaked during the coldest month; large males became equal in abundance only during the varmest months.

Notes: Abstract Seasonal patterns of growth, reproduction, and productivity of Codium fragile spp. tomentosoides (van Goor) Silva were monitored at 3 locations in Rhode Island. Maximal growth occurred during the summer and was more significantly correlated with temperature than any other factor measured in this study. Multiple correlation models suggested an interaction between temperature, irradiance, and available nitrogen. Maximal reproduction occurred in late summer and early fall. The maximal productivity, based on harvested quadrats, was 2. 10 g dry weight m-2 day-1. A large amount (up to 87.3%) of the annual production entered the detrital food chain during the winter by fragmentation of the thallus. Culture studies examined the effects of temperature (6° to 30°C), irradiance (7 to 140 μE m-2 sec-1), daylength (8 h light: 16 h dark to 24 h light: O h dark) and salinity (6 to 48‰) on growth. Differentiated thalli grew over a broad range of experimental conditions, with maximal growth at 24°C, 24 to 30‰ S, a minimal irradiance of 28 μE m-2 sec-1, and 16 h daylength. The effect of increasing daylength was due to increased total daily irradiance rather than to a true photoperiodic effect. Undifferentiated sporelings survived and grew in a narrower range of environmental conditions than thalli. c. fragile spp. tomentosoides grew equally well with nitrate, nitrite, ammonium, and urea as a nitrogen source. The addition of NaHCO3 stimulated growth at levels of 2.4 to 4.8 mM, suggesting an inorganic carbon limitation in static cultures. This study supports the hypothesis that the in situ seasonal growth pattern of c. fragile spp. tomentosoides is primarily due to the interaction of temperature and irradiance.

Notes: Abstract The critical nitrogen concentration of Codium fragile ssp. tomentosoides (van Goor) Silva was 1.90% on a dry weight basis. Internal nitrogen levels of thalli collected from three Rhode Island populations ranged from 0.75±0.08 to 3.72±0.08%. Internal nitrogen content was minimal in summer and maximal in winter, indicating nitrogen limitation during the summer and nitrogen storage during the winter. Part of this nitrogen storage appeared to support new growth of C. fragile in the spring. Carbon:nitrogen (C:N) ratios were inversely related to the internal nitrogen concentration. Low internal nitrogen content indicated nitrogen limitation better than C:N ratios because the C:N ratio could be influenced by both carbon and nitrogen metabolism.

Notes: Abstract 45Ca washout data of living thalli of Amphiroa foliacea Lamouroux in the light and dark show that there are three kinetically distinct Ca2+-exchanging compartments with approximate half-times (t 1/2) of 300, 20 and 3 min. The two slower compartments appear to be exchange from organic Ca2+-binding components of the cell wall, while the fast compartment probably represents exchange on the CaCO3 crystal surface. Killed and decalcified thalli have a fourth compartment, with a t 1/2 of 20 to 35 min (other compartment half-times are ≈ 300, 40, 3 min), which has been identified as the greatly increased intercellular space produced during drying and decalcification. The 45Ca and 14C uptake data show that a large proportion of the label initially taken up is into compartments other than the CaCO3. As a result of this uptake, binding, and exchange of radioisotope, significant errors occur during the measurement of calcification rates, unless a kinetic analysis is carried out. Using such a technique, CaCO3 calcification rates of A. folicea were measured with 45Ca or 14C as tracers. Light stimulates calcification by up to 2.6 times, depending upon the age of the plant. Young segments have a markedly higher rate of calcification and photosythesis than do the older segments.

Notes: Abstract The solubility and dissolution rate of silica were investigated using cell walls prepared from two species of diatoms, Thalassiosira decipiens and Rhizosolenia hebetata forma semispina. The solubility (C e) as a function of temperature (T, °C) can be described by the following equation: C e (SiO2 mg l-1)=67.8+1.48 T. The first-order reaction equation without the surface-area term was considered to be reasonable in estimating the dissolution rate of biogenic silica in the ocean system. The rate of dissolution differed not only from one species to another but also from one portion to another portion of the same wall. The rate constants of dissolution in the ocean system were estimated to range in the order of from 10-1 to 10-9 per hour.

Notes: Abstract The ophiuroid Ophiothrix oerstedi Lütken spawned in the laboratory at Barbados, West Indies, from August, 1975 until early December. The embryo passes through a wrinkled blastula stage, and the larva is a reduced lecithotrophic ophiopluteus with a shortened pelagic existence. A larva of this type is unusual for brittle stars in general and unique for ophiothricids for which development has been described. Metamorphosis is completed 4.3 days (24° to 27°C) after fertilization with a single pair of ciliated larval arms, the postero-lateral arms, being retained as a swimming device for the late larva. Settlement, with subsequent separation of the postero-lateral arms from the young brittle-star, begins as early as 4.5 days, but can be delayed for at least one week, at the end of which time midwater separation can occur resulting in the pelagic dispersal of post-larvae. A comparison of gametic and larval characteristics of O. oerstedi with the literature suggests that the larva of this species is most closely allied to the abbreviated developers. The adaptive significance of this larval form is discussed.

Notes: Abstract Variations in amylase and trypsin activities were studied in Artemia salina L. exposed to concentrations of copper or zinc which impair their growth. Disturbances in the levels of these enzymes were compared with decreases in growth rate. Amylase activity was disturbed within 24 h by 2 ppm copper and within 72 h by 5 ppm zinc. Inversely, trypsin activity was disturbed within 24 h by 5 ppm zinc and within 72 h by 2 ppm copper. Disturbances at the enzymatic level occurred more rapidly than decreases in growth rate, except for trypsin in A. salina polluted by copper. In the latter case, both were affected simultaneously. The possibility of growth disturbance by modified development of digestive enzymes is discussed. The possible use of enzymatic variation for rapid detection of sublethal effects of pollutants on aquatic organisms in situ is suggested. However, suitable controls would be necessary. Either polluted and unpolluted areas could be compared if their natural ecology were already well known, or reference areas could be monitored before pollutants are introduced.

Notes: Abstract The relative importance of accumulation of cadmium by Artemia salina (L.) directly from solution and from ingested food has been studied at 3 cadmium concentrations (0.1, 1 and 10 ppm) under controlled experimental conditions. At each cadmium concentration, A. salina were exposed to cadmium in 4 ways; in solution; in solution in the presence of latex “food” particles; in solution with cadmium-rich Dunaliella tertiolecta as a food source; and to cadmium-rich D. tertiolecta alone. Net accumulation of cadmium by A. salina continued throughout 5 days exposure under all 4 conditions. When the brine shrimp were removed to cadmium-free conditions, their accumulated cadmium concentrations declined and levelled off to a stabilised plateau after 10 days. From consideration of these stabilised levels it was shown that at least 30% of cadmium accumulation directly from solution occurs via uptake through the alimentary tract. The ratio of cadmium accumulated from solution to cadmium accumulated from food was found to be 1:4.9, 1:6.7 and 1:1.1 at 0.1, 1 and 10 ppm Cd exposure, respectively. At lower cadmium exposures uptake from food is the major route for cadmium accumulation, but at higher exposures the cadmium-saturated food source displaced cadmium-rich water from the gut and therefore actually inhibited cadmium accumulation. This study, therefore, concludes that the food chain will be the major source of cadmium as long as the previous trophic level has the ability to accumulate the metal to such an extent as to make it more available to the consumer than by direct uptake from seawater.

Notes: Abstract Epifluorescence microscopy was applied as a new technique to observe the response of Crassostrea virginica veliger larvae to the algal foods Monochrysis lutheri or Chlorella autotrophica. Uptake, lysis, and digestion or rejection of these algae by oyster larvae were observed microscopically through the autofluorescence of chlorophyll a and its derivatives. Both species of algae were taken up by large numbers of larvae within 5 min after being added to larval cultures. The good growth of larvae obtained with M. lutheri as a food source was related to rapid uptake, lysis, and digestion of this alga. Larvae fed with C. autotrophica did not grow. Althogh C. autotrophica was also taken up rapidly by the larvae, there was no lysis or digestion of these algae and cells were eventually voided.

Notes: Abstract A baited trap set on the bottom (4855 m) in the eastern North Atlantic Ocean caught over 600 specimens belonging to 7 species of lysianassid amphipods. Photographic evidence showed a slow build up of numbers and demonstrated fluctuations apparently related to current and pressure changes and to the presence of fish. Length-frequency distributions for the more abundant species reveal size classes related to growth stages. Paralicella caperesca produces a single brood of about 90 eggs. Maturity in this species may be attained in 7 to 11 moults, the precise number possibly being determined by food availability. Orchomene gerulicorbis requires about 11 moults to reach maturity, and females are double-brooded. Mortality within the trap is discussed. A comparison of species of Paralicella and Orchomene based on morphological, developmental, reproductive and ecological characters indicates that the former genus are specialized necrophages whereas the latter are opportunist generalists. The abundance and mobility of necrophagous amphipods indicate that they play a very significant role in the trophic web.

Notes: Abstract The mass mortality by disease of a localized population of sea urchins, Strongylocencrotus franciscanus, on the seaward side of a kelp forest was followed by the rapid seaward expansion of 4 species of brown algae, Macrocystis pyrifera, Laminaria dentigera, Pterygophora california, and to a lesser extent, Nereocystis leutkeana. One other brown alga, Cystoseira osmundacea, failed to become established in the newly available area. Competition among M. pyrifera, L. dentigera, P. californica, and N. Leutkeana apparently was severe, and within 1 year after the demise of the sea urchins, M. pyrifera formed a dense, nearly monospecific stand. Experimental removal of M. pyrifera demonstrated that the canopy of these plants limited light penetration to levels below that necessary for the growth and survival of other brown and red algae.

Notes: Abstract The occurrence of light-induced chromatophore displacements and concomitant transmittance changes in marine algae was investigated by microscope and photometrically with an automated recording microphotometer system; 16 brown, 6 green and 20 red algae were studied. In most of the brown algae, both phaeoplast displacements and transmittance changes were found. In some red algae which are frequently exposed to direct sun light during emergence at low tide, light-induced transmittance changes were measured, but they could not unequivocally be correlated with changes in the position of rhodoplasts. Among green algae, only Ulva lactuca shows chloroplast displacements which, however, follow circadian rhythms and are consequently not light-induced in the strict sense. The dose-response curves of light-induced chromatophore displacements were measured in the following Fucus and Laminaria species: F. spiralis, F. vesiculosus, F. serratus, L. digitata, L. saccharina and L. hyperborea. While in Fucus species correlations between light-induced transmittance changes and zonation of the intertidal area seem to exist, no significant differences have been found in the Laminaria species. The physiological role and ecological importance of light-induced chromatophore displacements for seaweeds living in the intertidal belt are discussed.

Notes: Abstract It has been suggested that industrial waste discharges are associated with the occurrence of fin damage and skin lesions. A mixed population of diseased and healthy blatfish consisting ofLimanda limanda, Pleuronectes platessa, Platichthys flesus andSolea solea were collected from an industrialised area (Calais, France) and were compared with diseased and healthyl. limanda caught in a non-industrialised area (Brixham, England). Analysis of skin samples from necrosed and healthy fish by X-ray microanalysis and atomic absorption spectroscopy has shown that no elemental accumulation occurs either in necrosed fish, or fish from an industrialised area. The fish from Calais were heavily infested with the ectoparasitic copepodLepeophtheirus pectoralis (O.F. Müller) and, although few were found on fish from Brixham, it is unlikely that this infestation was related to the discharge of industrial effluents.

Notes: Abstract The combined effect of salinity, temperature and chronic exposure to water-soluble fractions (WSF) of a No. 2 fuel oil on the survival and development rate of embryos ofFundulus heteroclitus Walbaum are described. The embryos were exposed at 3 salinities (10, 20, 30‰ S) and 3 temperatures (20°, 25°, 30°C) to 3 different oil concentrations (15, 20, 25% WSF, equivalent to approx 0.28, 0.38 and 0.47 ppm total naphthalenes) and to one control without oil. The results were analyzed by responsesurface methodology. The lowest oil concentration was only mildly toxic to embryos under optimal salinity/temperature conditions, while the highest was extremely toxic in all factor combinations. Under optimal conditions, only the highest oil concentration resulted in more than 50% mortality. Under suboptimal conditions, especially high and low temperatures, all 3 oil concentrations caused greater than 50% mortality. The interactive effect of salinity and temperature on survival was greatest at the lowest oil concentration. Temperature had a marked effect and salinity only a slight effect on the developmental rate of the embryos. Exposure to the low oil concentration tended to increase the temperature sensitivity of developmental duration slightly. Generally, exposure to oil decreased the time interval between fertilization and hatching.