ALBERT

Beschreibung: Illex illecebrosus squid appear to have a species‐typical and internally organized spatial arrangement of their groups. Squid maintained an average angle of 25° with respect to their nearest neighbour, and mostly had angular deviations between 5° and 20°. They maintained distances to nearest, second and third neighbours in a ratio of 1:1.5:2. The distances were strongly affected by group size (4, 20, or 38), with larger groups maintaining closer distances. Interindividual distances were not affected by two variables, day‐night and presence of a current in the large pool in which they were kept. The similarity of this organization to that of fish schools is discussed.

Beschreibung: The behaviour of Chelophyes has been analysed from the point of view of coordination between stem and nectophores, and an electron microscope study of the effectors and conducting elements has been carried out. Coordination between the stem and anterior nectophore involves two pathways, one epithelial and the other nervous. The nervous link consists of a bundle of small neurites and a single giant axon. There is some evidence that this mediates rapid escape behaviour. After the nerves have been cut, coordination is maintained via the epithelial route. Impulses can jump from epithelial cells into nerves but the transmission process is unclear. Neuro‐epithelial transmission involves conventional synapses. As in physonectid siphonophores, the stem has two nervous systems each with its own giant fibre, and a slow system, the endodermal epithelium. In the nectophore, marginal nerve centres generate a swimming rhythm. Conduction in the subumbrellar muscle is myoid. The exumbrellar epithelium and the subumbrellar endoderm are conducting tissues. Histological study reveals synapses in the predicted locations and gives details of myo‐epithelial organization and nervous layout. Novel histological features include elements resembling steroid‐secreting cells, which ensheath nerves and are innervated by them, and innervated giant non‐nervous cells lying between the nerve ring and the hydroecium. The subumbrellar muscle cells are shown to have sarcolemmal invaginations reminiscent of the f‐tubule system of vertebrate muscle.

Beschreibung: We studied the formation of exocellular precipitates of struvite (Mg NH4PO4.6H2O) by 96 kinds of calcite‐pro‐ducing bacterial strains isolated from soil. We also studied the influence of calcium ions on struvite precipitation. The number of strains producing struvite was 20. Only four consistently formed large amounts. These results seem to indicate that the bacterial precipitation of struvite is not a general phenomenon. The strains studied were taxonomically identified, and no relationship was found between the production of struvite and the taxonomic identity of such strains. Calcium, supplied as Ca acetate in the culture medium, appeared to inhibit the biological precipitation of struvite.

Beschreibung: There are many kinds of squid and cuttlefish in the oceans of the world, and the stock sizes of some are presumed to be large. However, few attempts have been made to quantitatively assess standing stocks. In Japan, the commercial yield ranges from 400,000 to 900,000 metric tons annually, accounting for about 50 to 80% of the total cephalopod catch in the world. Jigging surveys have been conducted since 1971 in the Sea of Japan and since 1973 in the Pacific Ocean off Japan. Their purpose has been to assess the abundance of oceanic squid. The stock size index (N) and the density index (F) for Todarodes pacificus, Ommastrephes bartrami, and Onychoteuthis borealijaponica were calculated for the Pacific from 1968 to 1979 and for the Sea of Japan from 1971 to 1979. N and F correspond reasonably well to periodic changes in the annual yield (Y) of T. pacificus in the Pacific and the Sea of Japan. Since Y is presumed to correspond well to abundance, the results of these surveys give rough estimates of T. pacificus abundance. Changes in N and F for O. bartrami and O. borealijaponica do not show good correspondence with Y, probably because the study area covers only a part of the range of the two species.

Beschreibung: Three large data sets on cephalopods are critically examined with respect to several sources of error: day-night avoidance, net size, mode of fishing, and patchiness. Catches are low and variable and results only suggest problems with present sampling techniques. Specific field sampling is suggested to quantify several of these sources of error. Volume filtered and time fished are compared as measures of "effort." Variability of volume filtered and net speed within a single tow are examined.

Beschreibung: This is a study of larval abundance and distributional pattern of the winter population of the Japanese common squid, Todarodes pacificus Steenstrup, based on plankton net collections made by the R/V Soyo-Maru during January to March (1959–1976) in the seas extending from the south of Kyushu to the Pacific coast of central and eastern Honshu. The larval abundance index (LI) was compared with CPUE (catch per boat day), an index of recruitment of adult stock size. The main spawning ground of this population is located to the southwest of Kyushu. The larvae (rhynchoteuthion) grow while they are advected by the Kuroshio Current to the northeast. Hence early larvae are more abundant in the west, while advanced larvae are more abundant in the east. Mortality seems to be highest for stages up to several millimeters DML than for later stages. The stock size of the Pacific winter population has fluctuated greatly. It declined since the peak 1960 year class to very low levels. The decrease of the stock size took place in three phases. 1960–1963: While the stock size (CPUE) of the 1960 year class was large, the larval population (LI) produced by this year class was very low, resulting in a decrease of recruitment (CPUE) in following years. 1964–1969: The larval abundance for the 1964 year class was second highest (next to 1960) but the recruitment was remarkably low, probably because of unfavorable conditions for survival during the period between larval and advanced stages. This failure caused a further decrease of larval abundance for the 1965 and subsequent year classes. 1970–1976: The larval abundance remains at a very low level and CPUE has declined since 1970. Because of the short life-span (one year) of this squid, abrupt decreases of larval abundance and/or recruitment have a serious effect on stock size. The future recovery of the stock will depend on biotic and physical conditions that are favorable for the survival of early stages south of Kyushu. A significant positive correlation between catch per effort of adults and the abundance of larvae (LI) in the following year indicates that larval abundance can be used to assess the size of the spawning stock of the winter population of T. pacificas.

Beschreibung: An examination of the knowledge about sampling Loligo opalescens populations leads to two general conclusions regarding the assessment of their abundance. First, it is suggested that studies concentrate on spawning ground organisms, since they aggregate during spawning, are commercially fished at this time, and their numbers can be assessed using a combination of data from market catch, adult and egg case densities, acoustic sensing, and perhaps larval densities. Second, it is suggested that large-scale acoustic surveys coupled with large midwater trawling activities be used to qualitatively assess adult organisms off the spawning grounds.

Beschreibung: The authors believe that Globorotalia mayeri Cushman and Ellisor and Globorotalia siakensis LeRoy cannot be maintained as separate taxa. This opinion comes after reexamination of the holotype of Globorotalia mayeri and of additional illustrations of the holotype of Globorotalia siakensis together with examination of large numbers of specimens of the plexus from Bodjonegoro-1 well in Java and from Trinidad in the Caribbean. Both taxa were described in 1939 but, due to the rules of priority, Globorotalia mayeri would now be the valid name. We consider that Globorotalia continuosa Blow is a four-chambered variant of Globorotalia mayeri that cannot usefully be separated from it.

Beschreibung: Two morphological abnormalities have been found in planktonic foraminifera. The origin of twinned and flattened tests is enigmatic and further study is required to clarify this problem.

Beschreibung: The major light and dark components of body displays are described and classified for the octopus Eledone cirrhosa (Lamarck) under aquarium conditions. Comparisons are made with Octopus vulgaris and Eledone moschata. Upon the basic similarity of white display components in the three species is superimposed a trend of modification. Dark components are less various in Eledone cirrhosa and although the chromatophores are organised with leucophores into chromatic units these are not clearly limited morphologically by “grooves”. The mottle patterns of Eledone seem to be arranged along the longitudinal and latitudinal (radial) axes of the animal, the grade of mottle does not respond to grade of background contrast.

Beschreibung: Growth is described from size-at-age data. Size-at-age was determined from counts of daily growth rings on the statoliths of 65 individuals. A mean growth rate of 2 mm/day was calculated for a dorsal mantle length range of 15-52 cm. The month in which each individual hatched was back-calculated from the age data. A histogram of the frequency of hatching through the year is presented and shows peaks in May and October.

Beschreibung: Foraging rate was highly variable among shore crabs of the same size category and for individual crabs from day to day. Possible physiological reasons for this variability are discussed. Shore crab foraging rate, both in terms of mussels eaten per day and energy intake per day, was estimated to be higher at 17°C than at 10°C. The shape of diet curves and their mode for male shore crabs at 17°C closely resembled those for 10°C, indicating that the temperature increase had no effect on their previously demonstrated optimal foraging strategy. Female and certain male shore crabs showed a preference for prey smaller than for other equivalent sized males. These suboptimally feeding male and female crabs attained a relatively higher prédation rate (mussels day‐1), although their energy intake (KJ day‐1) remained lower than that of optimally feeding males. Preferred mussel size, number of mussels eaten per day and energy intake were strongly related to master chela height. The diet curves for female and suboptimally feeding male shore crabs could be explained by these crabs’ proportionately smaller master chelae.

Beschreibung: A study of benthonic foraminifera in 837 samples from the U Cenozoic deposits of 9 DSDP holes located in the middle bathyal zone of the S Atlantic, S Pacific and Indian Oceans revealed that the Oligocene and Quaternary assemblages consist of nearly all the same species. These species do not show any important morphological changes. This means that the Quaternary fauna developed not later than the Oligocene. Late Cenozoic benthonic foraminiferal assemblages contain, in total, more than 400 taxa; however, less than 5% of them can be used as stratigraphic guide fossils and even those with some reservations.

Beschreibung: The distribution of benthic foraminifera in Miocene deposits of the continental margin of southeastern South America is compared with that in the Recent. The comparison indicates that Miocene zoogeographic boundaries were located in higher latitudes than at present, suggesting that the climate at that time was warmer than now. In the Pliocene, temperatures were lower than at present. This signifies that a considerable decrease in water temperature took place in the latest Miocene or at the Miocene/Pliocene boundary in the southwestern Atlantic. The main reason for this drop in temperature was the opening of the Drake Passage and the establishment of the Circumpolar Antarctic Current and a branch — the Malvin Current. The opening resulted from strong orogenic movements, in the latest Miocene, which created the main part of the Andes. Prior to the opening of the passage, the anticyclonic (counterclockwise) gyre of surface currents in the South Atlantic was much larger and warm Brazilian waters reached higher latitudes. The Austral Strait, connecting the Pacific and Atlantic Oceans, may have existed from the Cretaceous in the southern part of South America, but its location and character did not permit the establishment of the true Circumpolar Antarctic Current. The Austral Strait was closed simultaneously with the opening of the Drake Passage.

Beschreibung: The annual cycle of sedimentation in Kiel Bight is described from data collected over 3 years with multisample sediment traps. Settling matter was collected from 2 depths (15 and 18 m) in a 20 m water column at 2-4 day intervals. The pattern of sedimentation was alike each year, although considerable differences in the quantity collected were present. Resuspended sediment and primary settling matter originating from the pelagic system (phytoplankton cells, detritus) were the main contributors to the particulate material collected by the traps. High sedimentation rates from November to March were due to resuspended sediment. The composition of this material differed from that of bulk surface sediment due to the selective effect of water movement during resuspension. Peaks in sedimentation of primary material were observed in spring and autumn when the pelagic food web is poorly developed. From May to August sedimentation rates were low although this is the period of high primary production with large standing stocks of plankton. Apparently, organic substance produced here is consumed within the pelagic food web, as herbivore and carnivore populations are well developed and turnover time of particles is short. Sedimentation rates of primary material are estimated to be in the range of 50-65 g C · m-2 · yr-', but in reality year to year differences are probably greater than indicated by this range.

Beschreibung: Benthic foraminifera from surface Sediments of the Ross Sea were studied to determine modern distributions of important assemblages. Factor analysis of the raw data distinguished nine significant factor assemblages which account for 86% of the raw data. These factor assemblages provide a means of understanding modern oceanographic and ecologic conditions because they show the response of this faunal group to different environments. Environmental conditions are in turn controlled by the modern climatic regime of the region. Four benthic assemblages from the relatively shallow (500 to 700 m) eastern Ross Sea Continental shelf are predominantly arenaceous. This may be because the relatively late seasonal breakup of pack ice inhibits productivity in the surface waters and permits a buildup of CO, thus causing the CCD to occur at shallow depths. On the Western part of the Continental shelf, three assemblages are composed primarily of calcareous species even though water depths are often greater there than they are in the east. One of these calcareous assemblages occurs in samples from water depths as great as 755 m in the southwestern part of the region, below the CCD as defined for the Ross Sea by previous workers. We relate this depressed CCD to early seasonal breakup of pack ice in the Western Ross Sea. Within the eastern arenaceous and Western calcareous regions on the Continental shelf, distributions of benthic assemblages are probably related to water depth and other ecologic variables. Two benthic assemblages from the Continental slope north of the Ross Sea also are calcareous. We attribute their distributions to high rates of productivity in the overlying surface waters, where the interface between eastward-flowing Circumpolar Deep Water and Ross Sea water masses is marked by a narrow zone of intense upwelling.

Beschreibung: Afferent activity in the stellar nerves of Octopus vulgaris has been recorded in response to a probe applying a mechanical stimulus of approximately 5 gm/mm2 to the inner surface of the mantle. Mechanical sensitivity is distributed throughout the mantle surface and there is a large degree of overlap between the peripheral fields of nearby stellar nerves but no overlap of either ventral or dorsal midline. The afferent activity probably results from stimulation of sensory receptors located in the mantle and skin, but antidromic discharge in motor fibres is also possible.

Beschreibung: Six lakes of the Wadi Natrun, Egypt, were studied with respect to the chemical composition of their brines and the occurrence of microbial mass developments. All investigated lakes showed pH values of approximately 11 and a total salt content of generally more than 30%. The main components were sulfate, carbonate, chloride, sodium, and minor amounts of potassium. Only traces of magnesium and calcium were present, but unusually high concentrations of organic carbon compounds, nitrogen compounds, and phosphate were found. Mass developments of phototrophic sulfur bacteria, halobacteria, cyanobacteria, and green algae were observed. The functions of complete nitrogen and sulfur cycles in the alkaline brines are discussed. The properties of the lakes and their ecology are compared with data on the Dead Sea and Great Salt Lake, Utah.

Beschreibung: Microbiological transformations of sulfur compounds discriminate to various degrees between the stable sulfur isotopes 32S and 34S. Comparatively little is known on isotopic effects associated with sulfur‐oxidizing organisms, and the interpretation of results is complicated since the sulfur pathways are poorly defined and compounds containing two or more sulfur atoms at different oxidation states may be involved. Dissimilatory reduction of sulfate, and sulfite reduction by certain assimilatory microorganisms, causes particularly marked isotopic effects, the expression of which depends on the extent of reaction and other incompletely defined environmental conditions. Models have been proposed to account for these effects based on current knowledge of the reduction pathways. Many of the trends observed during dissimilatory sulfate reduction in the laboratory can also be found in the modern environment leaving little doubt that microbiological factors play a significant role in determining sulfur isotope distributions in nature. However, unusually large isotopic effects, rarely approached in the laboratory, are often observed in nature. The reasons for this are not entirely clear, but in sediments it is possible that diffusional isotopic effects are imposed on biological effects.

Beschreibung: Intracellular and extracellular recordings from the stem, gastrozooids, palpons, tentacles and nectophores of physonectid siphonophores are presented. The stem organization previously described for Nanomia applies with only minor differences to Forskalia and Agalma. The endodermal epithelium of the stem is shown to be the pathway for slow potentials. Pumping cycles and feeding activities are organized locally in gastrozooids and palpons. Protective retractions are coordinated, probably through a direct nervous link with the stem. This is also true of tentacles. The ectoderm of bracts is a conducting epithelium; excitation in it can induce nervous activity in the stem, but the mechanism is unknown. Impulse traffic between stem and zooids is erratic and breaks down rapidly with repeated stimulation. The motor centres of the nectophores are connected to the stem by a labile nervous link, but an alternative epithelial pathway exists.

Beschreibung: From a series of direct shear and laboratory vane shear tests conducted on natural pelagic and terrigenous marine soils, we have proposed a combined shear test procedure that involves obtaining the total stress failure envelope from tests on only two submarine soil samples. On one of the samples, both the direct shear and vane tests are conducted at zero normal stress. The second soil sample is consolidated under normal stress σn greater than the precompression stress Pc and sheared in a direct shear device under normal stress equal to the above consolidation pressure σn , the laboratory vane shear test on the same sample is conducted under zero normal stress. The combined test program results in four datum points (two from direct shear and two from laboratory vane shear tests. By connecting the two vane test datum points, the cohesion line (the failure envelope corresponding to vane shear tests) is obtained. By connecting the direct shear test datum points (from the soil consolidated under cn 〉 Pc) to the origin of the r vs. σn plane, the part of the failure envelope that lies beyond the precompression load is determined. The part of the failure envelope curve below the precompression stress is obtained by drawing a line parallel to the cohesion line through the direct shear datum point (corresponding to zero normal stress). The data and procedure reported herein indicate that the investigator can realize considerable time savings as well as conservation of sometimes expensive and limited submarine soil samples by using the proposed combined test procedure.

Beschreibung: The strontium, magnesium, and calcium contents of the shells of the planktonic foraminifer Globorotalia truncatulinoides from continental rise sediments were determined by electron microprobe. This species spends the early part of its life cycle in the upper water column where it precipitates the lamellar portion of its shell. It then sinks below the permanent thermocline where it is secondarily calcified with a blocky calcite coating. This change of environments through the organism’s life allows a test of the hypothesis that an individual can change the composition of the carbonate material secreted in response to changes in the temperature of of the water mass in which it lives. All individuals except a juvenile showed decreasing magnesium contents in the outermost portion of their shells, corresponding to decreasing temperature in successively deeper water. The juvenile form showing no secondary calcification was uniform in composition. Because the Mg/Ca ratio in seawater is constant, this differentiation strongly supports the contention that an individual organism, as it precipitates shell material, can regulate its composition in response to environmental changes in temperature. No significant differences in composition were found between left- and right-coiling specimens. The difference between lamellar and blocky calcite was found to be significantly less in a sample from 10 cm below the top of the piston core than those from above or below this level. This difference is produced by a decrease in the magnesium content of the lamellar calcite and may correspond to a surface water temperature 2.5°C lower approximately 1,100 years ago.

Beschreibung: Stomach contents of 68 black petrels, Procellaria parkinsoni, 12 Westland black petrels, P. westlandica, and 3 white‐chinned petrels, P. aequinoctialis, were compared. The main prey were Cephalopoda and fish, and these indicated predominantly nocturnal feeding with selection for bioluminescent forms. There is marked latitudinal variation in the Cephalopoda available to these petrels.

Beschreibung: Plankton records from three ATLANTIS II cruise tracks near the west African coast reveal a deep penetration of northern forms into tropical waters. They are carried there by the clockwise movement of the North Atlantic Gyre and are found mixed with subtropical and tropical forms. In light of these plankton records, and previous ones from other parts of the Gyre, a view of North Atlantic faunal parcelling is given. The traditional three-fold parcelling (northern, subtropical and tropical) is recognizable. However, gyral circulation tends to generate a rotary pattern of distribution with abundant faunal mixing. The subtropical fauna occupies the core of the Gyre and mixed faunal associations occur around the margins. The northern and tropical faunas contribute to these mixed faunal associations along clockwise dispersal routes.

Beschreibung: Fifty-two species of Ostracoda are distinguished in the Palaeogene succession of Soekor borehole Jc-1 on the continental shelf off Natal. Two species and one new genus are described, and the ostracod faunas can be grouped into four well-defined assemblages. Vertical variations in the make-up of the ostracod faunas, together with various parameters measured in the forminifera populations, are used to discriminate changes in the conditions of deposition and rates of sediment accumulation. These can be summarized: lower Palaeocene environments were hyposaline, restricted circulation, with rapid accumulation; upper Palaeocene through Eocene conditions were normal marine, alternating restricted and open water circulation, with rapid accumulation in the Palaeocene, and slower accumulation in the Eocene; Oligocene conditions were normal marine, with open water given way to restricted circulation, shallow water environments in the upper part. Sediment accumulation rates in the Oligocene vary rapidly, major changes in the composition of the ostracod populations are recognized as important local biostratigraphical events.

Beschreibung: Plankton records from three ATLANTIS II cruise tracks near the west African coast reveal a deep penetration of northern forms into tropical waters. They are carried there by the clockwise movement of the North Atlantic Gyre and are found mixed with subtropical and tropical forms. In light of these plankton records, and previous ones from other parts of the Gyre, a view of North Atlantic faunal parcelling is given. The traditional three-fold parcelling (northern, subtropical and tropical) is recognizable. However, gyral circulation tends to generate a rotary pattern of distribution with abundant faunal mixing. The subtropical fauna occupies the core of the Gyre and mixed faunal associations occur around the margins. The northern and tropical faunas contribute to these mixed faunal associations along clockwise dispersal routes.