ALBERT

Beschreibung: A collection of cephalopods from the British Antarctic Survey’s Offshore Biological Programme is described and the cephalopod prey of vertebrate predators at South Georgia is reviewed. Comparison of these data indicates that predators catch larger specimens and a greater diversity of species than nets. There are also differences between samples from different types of net. The RMT 25, the largest research net used to date, has caught most of the species thought to occur in the Scotia Sea but specimens are generally smaller than those taken by predators. Cephalopods which are thought to have potential commercial value are Martialia hyadesi, Kondakovia longimana, Moroteuthis ingens, M. knipovitchi, M. robsoni and Gonatus antarcticus. Other possibilities include species of brachioteuthid, psychroteuthid and neoteuthid. It is likely that Antarctic stocks will be sensitive to exploitation and liable to dramatic fluctuations if overfished. The possible consequences of commercial exploitation of cephalopods for the reproductive success of the vertebrate predators, which prey on cephalopods in the Scotia Sea, are examined.

Beschreibung: Post-recruit Illex argentinus were collected from the fishery on the Patagonian Shelf between 1986 and 1988. Age was determined by analysis of daily growth increments in ground sections of the statolith, female fecundity was determined, specimens were dissected, weighed and assigned a maturity stage. The relation between mantle length and age is best approximated by a linear model. Both sexes live approximately one year. Females grow faster and attain a larger size than males, but males mature younger. Hatching occurs during the austral winter, peaking in June-July. There is a consistent trend of increasing growth rate with later date of hatching. Statolith growth is negatively allometric with body growth and there is greater divergence between statolith and body growth in females. In post-recruit Illex growth in mass of somatic tissues, apart from the digestive gland, approximates isometry with growth of the whole body. Growth of the digestive gland and the reproductive organs is positively allometric with growth in whole body mass. There is poor correlation between the female reproductive organs and whole body mass, which is due to differences in size at maturity. Mating rarely occurs on the feeding grounds. Fecundity of fully mature females in the sample falls in the range 113835-246098 eggs per individual. This possibly underestimates average fecundity because mature squid on the feeding grounds may be precocious and smaller than average at full maturity. A model combining absolute and relative growth, predicts average male and female growth and growth of the major somatic and reproductive organs. This poorly predicts average female maturity indices with age because of variability in mass of the female reproductive organs. A model that treats maturity stages separately gives close agreement with measured mass of the reproductive organs and maturity indices of a mature female at age one year. Females invest approximately 20% of total body mass in gonad and accessory reproductive organs at full maturity.

Beschreibung: The biology of the chokker squid Loligo vulgaris reynaudii on inshore grounds in the South-East Cape was studied by examination of trends in jig catches, length frequency analyses, length/weight relationships, analyses of maturity stages and SCUBA diving transects in a spawning area. Commercial catches probably reflected the influx of squid into shallow waters to spawn. Modal length at spawning was between 265 and 305 mm mantle length (ML) in males and between 175 and 195 mm ML in females. There was no modal progression to indicate growth, nearly all squid were mature, a percentage of males were spent, the level of feeding on the grounds was very low, and mantle walls were thinner than those of squid offshore. These factors all indicate that the squid population inshore had reached the end of its life cycle and was in the spawning phase. The sex ratio was biased towards males, an indication either of differential inshore migration or of greater longevity in males than in females. The frequency of occurrence of trawled egg capsules was highest in summer and all eggs were between 18 and 25 m deep. The preferred substratum for spawning appeared to be low-relief reef interspersed with coarse sand, and the stalks of egg capsules were always embedded in the sand to form individual clusters, as in most other loliginids. No evidence was found of post-spawning mortality in the areas examined.

Beschreibung: The stomach contents of 1345 Sepia officinalis and 717 Sepia elegans caught in the Ria de Vigo have been examined. The feeding analysis of both species has been made employing an index of occurrence, as other indices gave similar results. The diet of both species is described and compared. Cuttlefish feed mostly on crustacea and fish. S. officinalis shows 40 different items of prey belonging to 4 groups (polychaeta, cephalopods, crustacea, bony fish) and S. elegans 18 different items of prey belonging to 3 groups (polychaeta, crustacea, bony fish). A significant change occurs in diet with growth in S. officinalis, but not in S. elegans, within the range studied. The variety of prey decreases with increase in size of S. officinalis, but not in S. elegans. Differences in feeding habits of male and female S. officinalis were not observed at any size, but were found in S. elegans. The feeding intensity of females increases with sexual maturity in S. officinalis but not in S. elegans. No seasonal changes in diet were found in absolute values and in order of importance of the prey clusters. S. officinalis fed on a wider variety of prey than S. elegans. The value and significance of some indices employed in feeding ecology is discussed.

Beschreibung: Increasing concentrations of CO2 and other gases seem likely to warm the earth in the next century. This article examines opportunities to prepare for the consequences, and focuses on options that are rational even if one is skeptical about global warming. These include rerouting the Mississippi River to save coastal Louisiana, changing coastal land use conventions to enable ecosystems to migrate inland as sea level rises, and phasing out federal water subsidies in the west. The merits of deferring action on the greenhouse effect until its consequences are proven must also be weighed against the relative ease of reaching a consensus on what is fair today, while the consequences still seem remote.

Beschreibung: Serological methods for prey identification have been applied to detection of residues ofsandeel (Ammodytidae) protein in faeces of common seals (Phoca vitulina) and grey seals(Halichoerus grypus) from the Moray Firth, north-east Scotland. Antisera raised to muscleprotein from Ammodytes marinus were evaluated by testing their reactions with proteinextracts made from a range of North Sea fish species and protein residues in in vitro digestates,seal digestive tracts and seal faeces. It was concluded that, using fused rocketimmuno-electrophoresis, linkage of precipitin peaks from unknown samples with peaksfrom standard sandeel extract was a reliable indicator of the presence of sandeel in theunknown sample. Seasonal variation in the incidence of sandeels in common seal diet in theMoray Firth was examined by identifying otoliths, bones, and proteins, and all threemethods indicated that sandeels occurred in the majority of samples tested in the summer,but were less important during the winter. Proteins were detected in fewer samples thanotoliths, particularly in February and March. Possible reasons for this difference arediscussed. Serological identification of sandeel proteins is potentially applicable to dietarystudies on all marine predators.

Beschreibung: The authors report the discovery of large specimen of Ommastrephes caroli (Ayn.O.bartramii), caught wirth a pelagic drifting net in Southern Thyrrenian Sea.

Beschreibung: A detailed structural study of Naxos (Attic-Cycladic massif, Greece) reveals two major deformation events. The first one is associated with large scale thrusting and high-pressure-low-temperature metamorphism during an early Alpine subduction episode. The second event occurred during continental extension and the associated development of localized thermal domes, where lower crustal rocks were brought into contact with upper crustal units along a major shallow dipping shear zone. We agree with a model of Naxos as a Cordilleran type Metamorphic Core Complex. However, our observations show that the sense of shear was ‘upper plate moving North’ during the second event, calling for a reinterpretation of existing tectonic models of the Cyclades.

Beschreibung: Alteration patterns in the lavas and dykes of the Troodos Ophiolite, Cyprus, record a complex history of axial hydrothermal alteration, crustal aging, and subsequent uplift and emplacement of the ophiolite. Field mapping shows that distribution of five alteration zones, each with distinct mineralogical, geochemical, and hydrologie characteristics, is influenced by igneous stratigraphy, structure, and the nature and thickness of the overlying sediments. Paragenetic sequences of secondary minerals indicate that alteration conditions changed progressively as the crust cooled and moved off-axis. Along spreading axes, low temperatures (≤50°C) were maintained by the rapid flow of seawater in and out of the lavas, and only minimal alteration took place. In contrast, lower water/rock ratios and higher temperatures (〉200°C) in the dykes promoted extensive seawater-rock interaction. Although the sharp rise in temperature between the two regimes generally coincides with the lava-dyke transition, late-stage intrusions or hydrothermal upwelling zones locally cause high-temperature alteration to extend upward into the lavas. As a segment of crust moved off-axis, temperatures remained low in the lavas and progressively decreased, from 〉250° to 〈80°C, in the dykes. High permeability in the uppermost lavas led to the downward migration of an oxidative alteration front whose thickness and spatial distribution was dependent upon the rate and nature of sedimentation and, thus, the original seafloor morphology. Although field relations show that alteration has a consistent vertical pattern in Troodos, the alteration zones are not laterally continuous, and the stratigraphie depth of their boundaries varies considerably.

Beschreibung: Mean intracellular pH (pHi) and PCO2 (PiCO2) have been analysed based on pH and total CO2 measurements in tissue homogenates. Tissues were sampled from undisturbed worms (Sipunculus nudus), squid (Illex illecebrosus), trout (Salmo gairdneri), toads (Bufo marinus), and rats. Homogenate metabolism was inhibited by the addition of potassium fluoride and nitrilotriacetic acid (NTA). Model calculations revealed that the influence of dilution, medium buffers, and contamination by extracellular fluids was negligible. In white muscle tissue the resulting pHi values were virtually the same as found in studies using DMO (dimethyloxazolidinedione). If large fractions of mitochondria were present (e.g. in heart muscle), DMO derived pHi values were considerably higher, probably representing overestimates. Homogenate derived pHi values are concluded to represent the effective mean pHi by taking into account pH gradients, and the volumes and buffering of cellular compartments. High time resolution and small variability make this method especially useful to assess rapid changes in pHi, e.g. in exercising animals.

Beschreibung: The in vitro oxygen-binding characteristics of haemocyanin were investigated in whole blood of two species of pelagic squid, Illex illecebrosus and Loligo pealei. pH-independent Haldane coefficients (ΔHCO3−/ΔHcyO2) (where HcyO2 is haemocyanin-bound oxygen) slightly smaller than —1 were found in both species. Oxygen-linked CO2 binding was not present. Buffer values ranged between 5 and 5.8 m mol l−1pH unit−1. For further analyses a pH/saturation diagram was selected to show the effect of pH on oxygen binding at constant POO2 in a continuous plot. The slopes of the resulting oxygen isobars (ΔHcyO2/ΔpH or ΔS/ΔpH) (where S is oxygen saturation) depend on pH. The diagram allows evaluation of both the Bohr coefficients (ΔlogP50/ΔpH) and the Hill coefficients (n50) at specific pH values. It provides an integrated illustration of the importance of the Bohr effect and cooperativity for oxygen binding. In accordance with Wyman's linkage equation, Bohr and Haldane coefficients are found to be identical. Both are pH-independent between pH7 and 8. The changing slopes of the oxygen isobars are likely to reflect changes in cooperativity with pH. Maximum values of n50 coincide with maximum steepness of the oxygen isobars in the physiological range of pH and POO2. Assuming that the haemocyanin acts as a buffer for venous POO2, this maximum in pH sensitivity and its decrease in the higher and lower pH ranges are discussed in the light of the maintenance of pigment function in vivo.

Beschreibung: In the western equatorial Pacific, the El Niño/Southern Oscillation (ENSO) phenomenon is characterized by precipitation variability associated with the migration of the Indonesian low pressure cell to the region of the date line and the equator. During ENSO events, Tarawa Atoll (1°N, 172°E) experiences heavy rainfall which has an estimated δ18O of about −8 to −10‰ δ18OSMOW. At Tarawa, sufficient precipitation of this composition falls during ENSO events to alter the δ18O and the salinity of the surface waters. Oxygen isotope records from two corals collected off the reef crest of Tarawa reflect rainfall variations associated with both weak and strong ENSO conditions, with approximately monthly resolution. Coral skeletal δ18O variations due to small sea surface temperature (SST) changes are secondary. These records demonstrate the remarkable ability of this technique to reconstruct variations in the position of the Indonesian Low from coral δ18O records in the western equatorial Pacific, a region which has few paleoclimatic records. The coral isotopic data correctly resolve the relative magnitudes of recent variations in the Southern Oscillation Index. Combining the Tarawa record with an oxygen isotopic history from a Galápagos Islands coral demonstrates the ability to distinguish the meteorologic (precipitation) and oceanographic (SST) anomalies that characterize ENSO events across the Pacific Basin over the period of common record (1960–1979). Comparison of the intensity of climatic anomalies at these two sites yields insight into the spatial variability of ENSO events. Isotope records from older corals can provide high-resolution, Pacific-wide reconstructions of ENSO behavior during periods of different climate boundary conditions.

Beschreibung: As shown by the work of Dansgaard and his colleagues, climate oscillations of one or so millennia duration punctuate much of glacial section of the Greenland ice cores. These oscillations are characterized by 5°C air temperature changes, severalfold dust content changes and 50 ppm CO2 changes. Both the temperature and CO2 change are best explained by changes in the mode of operation of the ocean. In this paper we provide evidence which suggests that oscillations in surface water conditions of similar duration are present in the record from a deep sea core at 50°N. Based on this finding, we suggest that the Greenland climate changes are driven by oscillations in the salinity of the Atlantic Ocean which modulate the strength of the Atlantic's conveyor circulation.

Beschreibung: The growth of “Growing Sealife”™ plastic squid was tested against the principles of the von Bertalanffy growth theory. The von Bertalanffy growth curve fits the data well on visual inspection, although the Schnute curve actually provides a statistically superior fit. If the von Bertalanffy growth curve provides a reasonable fit to data, this is frequently interpreted as evidence for anabolic and catabolic changes. The results of this paper for plastic squid are intended to provide a warning that such an interpretation does not necessarily follow.

Beschreibung: Thirty-four adult individuals of Loligo forbesi (males and females with dorsal mantle lengths from 27–77 cm) were observed in captivity in a 3 m diameter closed sea-water system on Faial Island, Azores. Squids were caught by jigging and were fed with horse mackerel (Trachurus picturatus) and chub mackerel (Scomber japonicus), either alive or dead. The maximum survival was 73 days. Feeding behaviour was dependent upon both the size of prey and its state of preservation;e.g. the squid would eat the head of small fish (〈 about 15 cm), reject the head of medium-sized fish (about 15–35 cm) and would eat only the dorsal part of a big fish (〉 about 35 cm) or a fish poorly preserved. Seventeen chromatic, 9 postural and 6 movement components of body patterns were observed and described. Conspecific interactions considered to be aggression and dominance were observed among males; no such interactions occurred when one male and two females were kept together. Body patterns in relation to relaxation, stress, shock, feeding, locomotion and aggression are also described.

Beschreibung: Antarctic petrels (Thalassoica antarctica) brooding young chicks at Scullin Monolith (67°7′S, 66°42′E), Antarctica, fed fish and crustaceans (87% and 13%, respectively, on a mass basis) to their young. Amounts of solids fed were equivalent to 6.6% of the body mass of adult birds with an empty stomach. The prey comprised species known to occur in the surface layers of the Antarctic ocean in the east wind drift, such as Pleuragramma antarcticum, Notolepis coatsi and Euphausia superba, consistent with the surface feeding habits of Antarctic petrels.

Beschreibung: Methodology for assessing squid fisheries is presented focusing on the estimation of exploitation rate, stock size and the fishing power of the vessels. The assessment is designed to provide input into management decisions for effort limited fisheries. The fishery for Illex argentinus around the Falkland Islands is used as an example for the methods. The development of a management policy for this fishery is described more fully in a related paper. The methods are based on modifications to standard Leslie-Delury analysis. Various regression methods are utilized depending on the number of fleets for which detailed data are available. The statistical procedures also yield estimates of the standard errors of the estimates for evaluating the assessment advice.

Beschreibung: Iridoteuthis iris (Berry, 1909) was originally described from a unique specimen collected in the main Hawaiian Islands, but the holotype is no longer extant. New material was collected from the southern Emperor-northern Hawaiian Ridge seamounts, extending the known range of I. iris by about 3200 km. The new samples are described, including the first description of adults.

Beschreibung: Two general circulation models forced by mean annual insolation and having an energy balance ocean have been run on an Earth with polar continents and a tropical continent. Polar continents produce strong meridional temperature gradients and a maximum hydrological cycle. A tropical continent produces the warmest planet and a minimal hydrological cycle. Both models produce more arid continents than exist today.

Beschreibung: Original Phanerozoic sediment flux rates can be approximated by fitting an exponential decay curve to the observed massjage distribution of sediments, then multiplying the ratio of the observed mass to the exponential decay curve mass by the zero-age flux rate predicted by the exponential decay curve. Applied to the massjage distribution of existing Phanerozoic sediments, the reconstruction method indicates that original global sediment flux rates varied cyclically by a factor of up to three. This implies significant changes in the rates of uplift and mountain building and global plate tectonic activity.

Beschreibung: The list of the Cephalopods from the Adriatic Sea, which includes 41 species, iS reported. References are given to the findings that occurred in the last 15 years; the presence of Heteroteuthis dispar and Neorossia caroli, cephalopods new to the Adriatic, is also recorded. The overall distribution of the Adriatic teuthofauna and its affinities with the eastern Mediterranean fauna are discussed.

Beschreibung: The biology of exploited cephalopod stocks is reviewed. Individual growth rates are high, slowing drastically or becoming erratic at sexual maturity. Growth estimates depend on aquarium studies and population modal analysis. In some cases, ring markings in the statolith appear to be age-related, but at present there is no generally applicable method of age determination. Sexes are separate and fertilization is normally by direct mating. Rapid maturation is followed by a single spawning season and, with few exceptions, an early death. Methods for estimation of fecundity are poorly developed. Annual recruitment to the population is essential and depends critically on each year's breeding success and the survival of eggs and hatchlings. Many cephalopod species have a planktonic stage of variable duration but no specialized larval stages. Cephalopods are carnivorous animals with very high gross growth efficiency. They are also consumed in large quantities by higher trophic levels leading to suggestions that cephalopods are potentially capable of supporting significantly increased levels of exploitation. The difficulties of modelling these populations are recognized

Beschreibung: Three new species of Octopus are described and illustrated from south-eastern Australian waters: Octopus warringa, Octopus kaurna and Octopus bunurong. Octopus warringa also occurs in New Zealand.

Beschreibung: In accretionary wedges, often morphologically similar sedimentary intrusions, when observed by remote geophysical means, may have one of two quite different driving mechanisms and a highly variable significance for the regional hydrogeologic picture. For example, mud diapirs are driven by buoyancy forces that arise from bulk density contrasts. In them, mud and pore fluid upwell en masse and fluid migration is a related (sometimes important) but generally subsidiary process. In contrast, diatremes contain sediments fluidized during rapid fluid advection and are forcibly and directly driven by the hydrogeologic system. The nature of fluid input from local and exotic source regions can, therefore, strongly affect sedimentary intrusive processes and vice versa. This complicates the process of defining the main features of the hydrogeological systems operating in accretionary wedges. Focused vertical advection through steep sided (piercement) mud diapirs requires conduit systems, otherwise flow will be diffuse and directed more horizontally out of the low-permeability mud mass. However, where the permeability of the overburden is less than that of the diapir, the whole diapir may act as a conduit. Apart from this special case, conduits will be associated with highly anisotropic scaly fabrics that can sometimes develop in the marginal shear zone of diapirs. Scaly fabrics form during deformation and compaction of a mud matrix under conditions of constant or increasing effective stress. However, the effective stress path can be complex as it is both controlled by the relative rates of upward intrusion and burial (by sedimentation and/or structural thickening) and the hydrogeologic system. Due to this, it appears likely that even in a geographically related group of diapirs, effective stress histories will vary widely between intrusions so that some can form advective pathways for fluids and some cannot. Mixed systems of behavior may also be present with local diatremes developing within diapirs above the terminations of conduit systems and rapidly expanding methane gas pockets. The potentially heterogeneous near-surface behavior may be why the surface manifestations of sedimentary intrusions are so variable when observed in the field. Diatremes can also form separately as large primary features above any structural or stratigraphic conduit that rapidly expels water or gas into the base of an unlithified sediment column. When active, large diatremes require enormous quantities of fluid (water or gas) to drive them, particularly if they are long lived features and hence are a direct indication of at least an episodically vigorous hydrogeologic system.

Beschreibung: The organization of the chitin-proteoglycan in Loligo vulgaris pen was examined ultrastructurally and related to the molecular order indicated by X-ray diffraction. There is a centrosymmetric striated repeat of 22 nm in the system which is based upon dark and light bands of unequal width. The banding is orientated perpendicular to the direction of the major molecular axis of the chitin fibres. The chitin molecules are laid down in sheets with a mutual, though irregular, twist to produce a laminated ‘plywood’ material.

Beschreibung: A deep Seismic reflection profile collected by DEKORP and BELCORP in the western Rhenish Massif was supplemented by wide-angle measurements. Signals from a vibrator source were successfully recorded to a distance of 60 km. A passive recording array was operated that recorded all shots along the profile. The wide-angle and near-vertical data were used to construct a velocity model for the profile. Most of the wide-angle reflections coincide with strong near-vertical reflections or bands of high reflectivity. The North Variscan Deformation Front, seen as a prominent shallow reflection on many profiles in this region, separates an upper crust with rather nigh velocities from a layer with lower velocities underneath. At a depth of 20–22 km a thin (2–3 km thick) layer of high velocities is found. The Moho is not reflective either in the near-vertical or in the wide-angle data, suggesting the presence of a thick crust-mantle transition zone.

Beschreibung: The investigation on the geology of the Sierra Leone Rise contains seismic, petrographic and sedimentological data from the Soviet expedition of R/V »Professor Shtokman«. New results on bottom relief and structure of the Sierra Leone Rise (SLR) are documented in Figs. 1–7. Detailled descriptions of dredge samples of trachyandesites, trachytes, trachyte tuffs, trachybasalts and their tuffs and their chemical composition (Tab. 2) together with the seismic structure of the SLR allow some assumptions on the age and origin of the Rise. The SLR is part of the equatorial Atlantic oceanic crust, that formed in the initial phase of break-up of Gondwana (110–80×106y). During the period 80–90×106 years, when volcanic eruptions were highly intensified in the area, major parts of the SLR have been formed. Some of the volcanic seamounts appeared as islands above sea-level in the Late Cretaceous/Paleocene: the magmatic rocks are more similar to ocean island basalt than to normal oceanic crust. Cenozoic sediments of the SLR reveal continuous sedimentation, which was controlled by surface water productivity, carbonate dissolution and terrigenous matter supply. The Eocene chert sedimentation phase was followed by a period of cyclic carbonate sedimentation. In the Neogene tectonic activity lead to vertical displacements. On several peaked seamounts coral reefs grew. The reef phase was followed by a sinking of the area. At the end of the Neogene the SLR became aseismic. The Late Quaternary sediment cover is studied by means of grab samples and sediment cores from various water depths. The main finding is varying CaCO3 content with depth and with time, controlled mainly by dissolution.

Beschreibung: The Quaternary Herchenberg composite tephra cone (East Eifel, FR Germany) with an original bulk volume of 1.17·107 m3 (DRE of 8.2·106 m3) and dimensions of ca. 900·600·90 m (length·width·height) erupted in three main stages: (a) Initial eruptions along a NW-trending, 500-m-long fissure were dominantly Vulcanian in the northwest and Strombolian in the southeast. Removal of the unstable, underlying 20-m-thick Tertiary clays resulted in major collapse and repeated lateral caving of the crater. The northwestern Lower Cone 1 (LC1) was constructed by alternating Vulcanian and Strombolian eruptions. (b) Cone-building, mainly Strombolian eruptions resulted in two major scoria cones beginning initially in the northwest (Cone 1) and terminating in the southeast (Cones 2 and 3) following a period of simultaneous activity of cones 1 and 2. Lapilli deposits are subdivided by thin phreatomagmatic marker beds rich in Tertiary clays in the early stages and Devonian clasts in the later stages. Three dikes intruded radially into the flanks of cone 1. (c) The eruption and deposition of fine-grained uppermost layers (phreatomagmatic tuffs, accretionary lapilli, and Strombolian fallout lapilli) presumably from the northwestern center (cone 1) terminated the activity of Herchenberg volcano. The Herchenberg volcano is distinguished from most Strombolian scoria cones in the Eifel by (1) small volume of agglutinates in central craters, (2) scarcity of scoria bomb breccias, (3) well-bedded tephra deposits even in the proximal facies, (4) moderate fragmentation of tephra (small proportions of both ash and coarse lapilli/bomb-size fraction), (5) abundance of dense ellipsoidal juvenile lapilli, and (6) characteristic depositional cycles in the early eruptive stages beginning with laterally emplaced, fine-grained, xenolith-rich tephra and ending with fallout scoria lapilli. Herchenberg tephra is distinguished from maar deposits by (1) paucity of xenoliths, (2) higher depositional temperatures, (3) coarser grain size and thicker bedding, (4) absence of glassy quenched clasts except in the initial stages and late phreatomagmatic marker beds, and (5) predominance of Strombolian, cone-building activity. The characteristics of Herchenberg deposits are interpreted as due to a high proportion of magmatic volatiles (dominantly CO2) relative to low-viscosity magma during most of the eruptive activity.

Beschreibung: This paper describes the large-scale distribution of laminated sediments and the deposition of nutrients in the Baltic offshore accumulation region. The area of laminated surficial sediments in the Baltic proper, excluding the Gulf of Finland and the Gulf of Riga, has been estimated to cover approximately one third of the total area. Accumulation of autochthonous and allochthonous material accounts for only a minor part of the total amount of nutrients sequestered in these deep offshore accumulation bottoms; most of the nutrients may originate from shallow sediments that are eroded as a result of the isostatic land uplift.

Beschreibung: Three multivariate statistical methods for the analysis of aquaculture experiment data are introduced and their application is demonstrated on different datasets. The methods are based on multiple regression and path analysis (causal analysis). The two multiple regression methods are termed the 'extended Gulland-and-Holt method' and the 'extended Bayley method', where the latter is derived and presented here for the first time. With these methods, the variables controlling fish growth rate in aquaculture experiments can be identified and their effects quantified in form of empirical, multiple regression models. Both methods permit the derivation of parameters of the von Bertalanffy growth function. These can be used for growth prediction and decision making in fish farm management and production under a wide range of environmental and treatment conditions. By computing the index of growth performance,ϕ' (phi-prime), the obtained growth parameters can be compared. The application of the presented methods is demonstrated on different types of datasets: 1) integrated livestock-fish farming experiments with mixed-sex populations of Nile tilapia (Oreochromis niloticus) conducted in the Philippines, 2) chicken manure-fed Nile tilapia culture experiments at Dor Station in Israel, 3) all-male hybrid tilapia, grown in polyculture at commercial farms in Israel, 4) pig and duck manure-fed Nile tilapia culture trials in Lima, Peru, and 5) experiments with mixed-sex populations of Oreochromis andersonii in Zambia, Africa. Depending on the amount of variables available in the datasets, and the precision of their measurement, models of different accuracy could be derived. The effect of the different variables was investigated with sensitivity analysis. Differences between the methods were studied. From the understanding gained by analyzing different types of datasets, recommendations are given for future applications of the methods, and for the design of new experiments that are to be analyzed with these methods.

Beschreibung: Brain pathways controlling the chromatophores of the squidLolliguncula brevis are described using cobalt iontophoresis. The results show several input and output pathways of the anterior and posterior chromatophore and lateral basal lobes. These connections allow coordination and modification of the chromatophore motor program throughout the motor pathway. Unlike other cephalopod species, there seems to be no direct input from the optic lobes to the lateral basal lobes inL. brevis. This species displays only a few simple patterns; therefore the underlying neural pathways for chromatophore control may be different from those of other cephalopods with more extensive patterning repertoires.

Beschreibung: The challenges of collecting, transporting, and maintaining healthy wild squids have been nearly as formidable as those of determining the structure and function of ion channels in squid giant axons. The differences are a matter of scale, not complexity. Careful perusal of the literature indicates clearly that failures have been the rule, especially with squids of the genus Loligo. It is an unfortunate fact that the vast majority of biomedical research on Loligo has been done on animals that were moribund when they were prepared for experiments. This was due in most cases to skin damage incurred during capture and transport from the field to the laboratory, and to the secondary infections that invariably followed immediately. Furthermore, the availability of live squids for research is limited seasonally because of the migratory behavior of these fast-swimming invertebrates. Thus any improvements in maintenance, rearing or culture will lead not only to greater availability to meet the demand from researchers, but hopefully to the provision of healthy squids for a wide range of experimentation.

Beschreibung: A mechanism exists whereby global greenhouse warning could, by intensifying the alongshore wind stress on the ocean surface, lead to acceleration of coastal upwelling. Evidence from several different regions suggests that the major coastal upwelling systems of the world have been growing in upwelling intensity as greenhouse gases have accumulated in the earth's atmosphere. Thus the cool foggy summer conditions that typify the coastlands of northern California and other similar upwelling regions might, under global warming, become even more pronounced. Effects of enhanced upwelling on the marine ecosystem are uncertain but potentially dramatic.

Beschreibung: Der Konsum von Tintenfischen (Cephalopoden) steigt in der Bundesrepublik Deutschland von Jahr zu Jahr. Während in den sechziger Jahren Tintenfische noch als Exoten auf den Speisekarten geführt wurden, sind sie nunmehr "Standard". Der vorliegende Beitrag soll vermitteln, welchen Stellenwert die Tintenfisch-Anlandungen der Bundesrepublik Deutschland im Vergleich mit den Fängen anderer Nationen im Atlantik haben.

Beschreibung: DISTRIBUTION AND SEXUAL MATURATION OF THE ARGENTINIANS QUID, Illex argentinus OFF SOUTHERN BRAZIL. - Catches of the argentinian squid Illex argentinus were sampled in four seasonal demersal fish assessment surveys on the outer shelf and slope of Rio Grande do Sul from Santa Marta Grande Cape (28º40' S) to Chui lighthouse (34º30' S) and at depths ranging from 124 to 587 m in July and September 1986 and March and May 1987. A total of 1249 squids from 4 to 34 cm mantle length was caught in 50 of the 66 effective trawls with a 28 m headrope net with steel bobbins on the groundrope. Squid catches were poor with a maximum of 7.36 kg/h and 5% of total catches in spring and less than 1.26 kg/h and 1.2% on the rest of the cruises. Young squids under 10 cm ML were found on all cruises in depths less than 350 m and at 13ºC to 17ºC bottom temperatures. Subadults and mature squids were fished at depths greater than 350 m and bottom temperature of 4ºC to 12ºC. Mature specimens found in winter and spring were bigger than those in summer and autumn. In southern Brazil, spawning seems to take place at different times of the year with a peak in winter and early spring.

Beschreibung: Im Bereich des Nordatlantiks stehen für die numerische Analyse und Prognose nur äußerst lückenhafte Informationen über die Feuchteverteilung zur Verfügung. Durch die Nutzung von Satellitenbildinformationen wird eine Erhöhung der Datendichte angestrebt. Voraussetzung hierfür ist eine direkte Beziehung zwischen den Wolken und dem vertikalen Feuchteprofil. Die Herleitung eines solchen Zusammenhanges ist Ziel dieser Arbeit. Für die Untersuchungen werden die Wolkenbeobachtungen und die Empirischen Orthogonalfunktionen (EOFs) der spezifischen und der relativen Feuchte verwendet. Die letzteren werden aus den Radiosondenaufstiegen der Wetterschiffe C,L und R vom April bis Oktober 1979 berechnet. Die Meldungen der Wetterschiffe werden zusammen betrachtet. Die Wolken werden entsprechend ihrer Entstehung in Konvektions- und Stratuswolken unterteilt. Bei den Untersuchungen kann lediglich eine signifikante Beziehung zwischen dem ersten zeitabhängigen Koeffizienten der spezifischen Feuchte und den beiden Wolkengruppen festgestellt werden. Durch Konvektion entstandene Wolken sind im Mittel mit einem negativen ersten zeitabhängigen Koeffizienten kombiniert, während Stratusformen mit einem positiven verbunden sind. Die Zusammenhänge sind jedoch durch eine starke Streuung um die jeweiligen Mittelwerte gekennzeichnet. Werden die Wetterschiffe getrennt betrachtet, läßt sich bei den Schiffen C und L zusätzlich eine signifikante Beziehung zwischen den Konvektionswolken und dem dritten Koeffizienten herleiten. Der dritte zeitabhängige Koeffizient ist im Mittel negativ. Auch er ist mit einer starken Streuung behaftet. Insgesamt kann festgehalten werden, daß das Profil der spezifischen Feuchte für Konvektionswolken einen signifikant trockeneren Verlauf als für Stratustypen aufweist. Die Untersuchungen mit dem EOF-analysierten Profil der relativen Feuchte zeigen ebenfalls eine signifikante Beziehung zwischen dem ersten zeitabhängigen Koeffizienten und den beiden Wolkengruppen. Dabei handelt es sich um die gleiche Kombination wie bei der spezifischen Feuchte. Die statistische Aussagekraft aller Ergebnisse ist bedingt durch den zu geringen Umfang des Datenensemble eingeschränkt. Anhand einer Häufigkeitsverteilung der relativen Feuchte für Konvektions- und Stratuswolken wird gezeigt, daß Standardprofile, wie sie vom DWD operationell angewendet werden, zu Problemen sowohl mit der Eindeutigkeit der Feuchtewerte als auch mit der Repräsentanz für reale Verhältnisse führen.

Beschreibung: Japanese common squid, Todarodes pacificus, (DML=13-20cm) were maintained in a 12 tons tank for 29 days after capture. To mark the statolith, they were fed walleye pollock fry soaked tetracycline-HCl or strontium chrolide solution twice at an interval of 14 days. The mark with tetracycline was observed like a zone, not two bands, in the peripheral region of the ground statolith under UV light. Numbers of the growth increments from the beginning of the mark to the edge of statolith in 4 individuals were 18, 21, 21, and 23, respectively. The elapsed time from the first feeding of the fry added tetracycline to the sacrifice was 20 days. These results suggest that the growth increments are formed daily in the statolith of Japanese common squid. The mark with strontium in the ground statolith was not detected by the electron probe microanalyzer

Beschreibung: Aptenodytes patagonicus and Pygoscelis papua both fed on fish predominantly, albeit in different proportions and frequently on different species and sizes. King penguins preyed extensively in offshore waters on myctophid fishes; the gentoo diet included a substantial amount of inshore fish species supplemented with crustaceans.

Beschreibung: Gray whales (Eschrichtius robustus) feeding in the northern Bering Sea produce prey-rich mud plumes that provide ephemeral foraging opportunities for seabirds. Approximately 67% of all gray whales were attended by birds. In four whale-associating bird species (Northern Fulmar, Fulmarus glacialis; Red Phalarope, Phalaropus fulicaria; Black-legged Kitti-wake, Rissa tridactyla; and Thick-billed Murre, Uria lomvia), from 17 to 87% of all individuals that we observed on the water or foraging were in the whales' mud plumes. The combined density of these same four species was strongly correlated with whale density over a broad range of spatial scales. The whale-associating seabirds exhibited species-specific patterns of foraging behavior at plumes, including differences in mean group size, mean residence time, and patterns of movement between plumes. Birds tended to form larger groups and to form more mixed-species flocks in association with whales. The association of marine birds with gray whales in the Bering Sea provides a model system for examining seabird interactions at fine-scale oceanographic patches and demonstrates the importance of these patches in shaping patterns of seabird distribution and behavior.

Beschreibung: Cephalopods of poor or no commercial interest within the sicilian channel. First description of cephalopods of poor or no commercial interest in the Sicilia Channel is reported. The information utilized are those of two years of trawl-surveys in the Sicilian Channel ("Pelagian Sea"), combined with contributions offered by the southern sicilian landing places.

Beschreibung: THE LARGE animals in the sea are almost all vertebrates: fish, turtles and whales. Only one group of invertebrates has produced creatures of comparable size and activity. These are the molluscs, on the face of it an unlikely group to have given rise to some of the ocean’s most outstanding athletes. Yet it did. The cephalopods, a class of animals that includes the squids, cuttlefish and octopuses, are indisputably molluscs. They share a common body plan with clams and snails, but are greatly modified to allow them lifestyles comparable with those of the vertebrates. Between them, the cephalopod molluscs, the fish and the toothed whales constitute a formidable assemblage of predators, eating each other and anyone else available as a source of protein in the sea. The molluscs established themselves as predators of the midwater zone before the fish. The cephalopods apparently arose from small limpet-like animals that crawled on the seabed. These primitive forerunners of today’s sophisticated predators disputed possession of the late Cambrian sea floor with a range of other animals, most of them armoured, and many, we may safely assume, predatory. What distinguished the early protocephalopod from the rest of the mob was a capacity to secrete gas into the apex of its shell.

Beschreibung: The functional morphology of the suckers of several benthic octopus species was studied using histology and cinematography. The suckers consist of a tightly packed three-dimensional array of musculature. Three major muscle orientations are found in the wall of the sucker: (1) radial muscles that traverse the wall; (2) circular muscles that are oriented circumferentially around the sucker, including a major and minor sphincter muscle; and (3) meridional muscles that are oriented perpendicular to the circular and radial muscles. The connective tissue of the sucker includes inner and outer fibrous connective tissue layers and an array of crossed connective tissue fibers embedded in the musculature of the sucker. Attachment is achieved by reducing the pressure inside the sucker cavity. We propose the following mechanism to explain this pressure reduction. Contraction of the radial muscles thins the wall and thus increases the enclosed volume of the sucker. If the sucker is sealed to the substratum, however, the cohesiveness of water resists this expansion. Thus, contractile activity of the radial muscles reduces the pressure of the enclosed water. The radial muscles are antagonized by the circular and meridional muscles so that the three-dimensional array of muscle functions as a muscular-hydrostat. The crossed connective tissue fibers of the sucker may store elastic energy, providing a mechanism for maintaining attachment over extended periods.

Beschreibung: Because of the implications of shallow gas accumulations to drilling and the integrity of platform foundations, it is important to determine whether gas accumulations can be considered as effectively static, unchanging for the duration of offshore operations, or dynamic. Shallow gas is frequently seen in association with seabed features, such as mud lumps, gas domes and pockmarks. These are considered to have been caused by the escape of gas through the seabed, consequently it can be implied that gas has migrated to, and through, the seabed. This indicates that shallow gas is not static, but it does not suggest a time-scale over which migration occurs. Is shallow gas mobile on a geological or a human time-scale?

Beschreibung: Recent developments in side-scan sonar technology have increased the potential for fundamental changes in our understanding of ocean basins. Developed in the late 1960s, “side looking” sonars have been widely used for the last two decades to obtain qualitative estimates of the acoustic properties of the materials of the seafloor. Modern developments in the ability to obtain spatially correct digital data from side-scan sonar systems have resulted in images that can be subsequently processed, enhanced, and quantified. With appropriate processing, these acoustic images can be made to resemble easily recognizable optical photographs. Any geological interpretation of these images requires an understanding of the inherent limitations of the data acquisition system. When imagery is collected, these limitations are largely centered on the concept of resolution. In side-scan sonar images, there are several different types of resolution, including along- and across-track resolution, display resolution, and absolute instrumental resolution. All of these parameters play a critical role in our ability to calibrate and ultimately to interpret the new pictures of the ocean floor. Acoustic image processing is a new application of an old and well-established technique. Digital optical images have benefited from several decades of development in processing techniques. These relatively sophisticated techniques have been applied to photographic images from satellites and spacecraft, images which are “noisy” and difficult to obtain but extremely valuable. Side-scan sonar systems, on the other hand, have only recently been able to produce spatially correct, digital images of the seafloor. The application of digital signal-processing techniques to side-scan sonar data will now allow us to quantify what had been previously very subjective and qualitative interpretations of images of the seafloor. The goal of all this processing of acoustic images remains clear: the development of an interpretable map of the geology of the seafloor.

Beschreibung: In dieser Arbeit werden die Strukturen der ITCZ und die Verhältnisse im Bereich der ITCZ am Boden über dem Atlantik für einen Zeitraum von fünf Jahren untersucht. Das Datenmaterial besteht zum einen aus Auswertungen von METEOSAT-Fotos, anhand derer die Position der ITCZ festgelegt wird, zum anderen aus routinemäßig abgesetzten Wettermeldungen von Handelsschiffen, die die bodennahen Verhältnisse über dem Atlantik beschreiben. Für die Berechnung und Mittelung der Bodenfelder werden die Wettermeldungen in ein zur ITCZ relatives System übertragen. Die ITCZ-Position schwankt im laufe eines Jahres zwischen 2°N und 10°N. Bei der Nordwärtswanderung liegt die ITCZ parallel zum Äquator. Während der Südwärtswanderung verlagert sich die ITCZ mit einer Nordwest-Südost-Orientierung. Die ITCZ liegt innerhalb der tropischen Tiefdruckrinne. Hier erreichen die Temperaturen von Luft- und Ozeanoberfläche ihre höchsten Werte. Die maximale negative Differenz zwischen Luft- und Ozeanoberflächentemperatur bildet um die ITCZ-Position ein etwa 4° breites Band aus. Das heißt, daß die Ozeanoberfläche in diesem Bereich wärmer als die darüberliegende Luft ist, was eine Labilisierung der bodennahen Luftschicht zur Folge hat. Das Konvergenzmaximum am Boden dehnt sich bis +/- 5° um die Lage der ITCZ aus. Die maximale Bedeckung befindet sich direkt oberhalb der ITCZ-Position. Die Lage der Null-Linie der meridionalen Windkomponente stimmt nicht mit der ITCZ-Position überein. Im Jahresmittel liegt sie zwischen 60°W und 25°W nördlich der ITCZ. Westlich von 25°W tritt sie südlich der ITCZ-Position auf. Im Jahresgang ist das Konfluenzgebiet in den Nordwintermonaten südlich, in den Nordsommermonaten nördlich der ITCZ-Position zu finden.

Beschreibung: The isotopic composition of dissolved O2 in seawater, expressed as the δ18O of O2, is unique among the bioactive tracers of the aphotic zone in that it is not linearly related to oxygen utilization via the stoichiometry of organic matter decomposition. In fact, δ18O of O2 depends on the history of water mixing and O2 consumption in the sample studied (Craig and Kroopnick, 1970; Kroopnick and Craig, 1976). For this reason, the variation of δ18O of O2 with O2 concentration depends on regional circulation patterns and oxygen utilization rates. The δ18O of O2 can be used to chartacterize these processes by decoupling their effects. As an example of this assertion, we interpret the covariation between the concentration of O2 and its isotopic composition in the Pacific Ocean as reported by Kroopnick (1987), using four simple representations of seawater mixing and respiration. Kroopnick's data are in general accord with an elementary model of isopycnal mixing represented by diffusive exchange and oxygen utilization in the ocean's interior, coupled with atmospheric equilibrium at the point where the isopycnals outcrop at the sea surface. This specific result illustrates the general point that δ18O of O2 in seawater can serve as an important constraint on more extensive and sophisticated physical models used to estimate rates of oxygen utilization in the deep sea.

Beschreibung: The ventilatory system of cephalopods has evolved so that the animals minimise the energetic cost of either oxygen extraction or jet propulsion. Optimal design for jet propulsion requires a large stroke volume moving water through the system with minimal acceleration, so the oxygen-carrying capacity of the ventilatory stream is always greatly in excess of requirements. Oxygen uptake in a jet-propelled animal must be independent of the volume of the jet to avoid locking locomotion to oxygen uptake. Any such link is incompatible with the repayment of an oxygen debt after exercise, with added oxygen demand during digestion, and with regulation of uptake under hypoxic conditions. Cephalopods evolved for efficient jet propulsion must be able to alter the rate of oxygen extraction from the ventilatory stream. Squids and Nautilus do this; oxygen extraction is normally low, in the range 5–10% during jet-propelled cruising at subcritical speeds, but can rise to as much as 25% in acute hypoxia or at rest after exhausting exercise. Other cephalopods, such as Octopus, minimise the cost of oxygen extraction by propelling a minimal volume of water through the gills, extracting 35–50% (exceptionally 75%) of the available oxygen. This leaves little scope for a further increase in extraction, and any added demand is met by increasing the ventilation stroke volume. A consequence is that jet propulsion becomes extravagant; octopuses show much greater jet pressures than squid when they choose to swim. The two alternative specialisations are linked to life-style and cut across systematic boundaries.

Beschreibung: One hundred and nine specimens of young squids were identified. They were caught from off Peru in the period from December 1987 to March 1988 during exploratory fishing of the jumbo squ1d, Dosidicus gigas. Six species were identified, but the majority of them (97 out of 109) was Sthenoteuthis oualaniensis. Six juvenile specimens (15.5-18.8mm ML) seemed to be D. gigas. Such a poverty of juvenile of D. gigas will suggest that the fishing ground does not coincide with dispersal area of juveniles. In contrast to this, the present finding show an extensive dispersion of juveniles of S. oualaniensis in the surveyed area.

Beschreibung: Abraliopsis (Abraliopsis) pacificus n. sp. is described. This species is characterized by having diffused photophore arrangement on head, developcd carpal flap and aboral keel on tentacular club, unequal offset crests on hectocotylus and rectangular arm sucker ring teeth. It is distributed commonly in the midwater of Northwest Pacific Basin.

Beschreibung: Rates of protein synthesis in the whole body and tissues ofOctopus vulgaris collected in September 1985 and 1986 from the Bay of Naples were measured following a flooding dose injection of3H phenylalanine. There were stable phenylalanine free pool-specific radioactivities and linear incorporation of radiolabel into arm-tip protein from 10 to 30 min after the injection. In starved individuals there were no significant differences between the fractional rates of protein synthesis of the following tissues: ventricle, brain, branchial heart, arm tip, gill, stomach, arm, renal appendage and mantle. The mean value (± SE) for all the tissues was 3.02 ± 0.17% d−1. In individuals fed varying amounts of crab, resulting in differing growth rates, there was a linear increase in fractional rates of whole-body protein synthesis with growth rate. A standard 148 g octopus growing at 3.0% d−1 synthesised 0.54 g of protein, with 0.43 g of this protein retained as growth. The proportion of the total protein synthesis which was retained as growth increased with increasing growth rate; at a maximum growth rate of 6% d−1, over 90% of the protein synthesised was retained as growth. The ventricle, arm tip, gill, arm and mantle also showed similar patterns of a linear increase in fractional rates of protein synthesis with increased growth rates. The RNA concentrations in the whole body and tissues increased with increasing growth rates, but the major change was an increase in the efficiency of translation. It is concluded that rapid growth rates inO. vulgaris are brought about by high rates of protein synthesis and high efficiencies of retention of synthesised protein and, therefore, little protein degradation.

Beschreibung: A major extension of the geographic range of Loligo pealei, in quantitative as well as spatial aspects, is described. The species' range is extended northward and eastward to approximately 47°30′N: 53°06′W, based on its occurrence in Newfoundland inshore trap samples in the autumn of 1986. Biological data from these samples, as well as from collections from Nova Scotian inshore traps from 1974 to 1986, indicate that L. pealei becomes sexually mature and spawns in Nova Scotian waters but not at Newfoundland. Loligo pealei appears to be prevalent in Canadian waters at times when its sympatric competitor, the short-finned squid Illex illecehrosus, is not abundant. The reported catch of L. pealei in Atlantic Canada for 1986 was 67 t, which suggests that this species could possibly support a small Canadian fishery in some years.

Beschreibung: Changes in the ovaries and testes during sexual maturation of Loligo vulgaris reynaudii were examined histologically. Fonnation and development of the spermatozoa and oocytes could be divided into four distinct stages for males and five for females, and frequencies of these stages in the morphologically determined categories of development of the whole reproductive System were calculated. These frequencies were then compared between morphological categories. Results showed that microscopic changes are reflected in macroscale changes for Categories I-IV, but differences between Categories IV and V are mostly morphological for both sexes. It is suggested that Loligo v. reynaudii is an intermittent spawner.

Beschreibung: A theoretical basis is suggested for examining habitat limitations of artificial surfaces for population enhancement of crevice-dwelling, or territorial organisms such as reef fish or lobsters, that takes into account known growth and mortality rates. This approach is compared with the crevice frequency at size in a ‘natural’ substrate, which, it is assumed, corresponds to fractal expectation. With naturally dissected surfaces, fractal expectation predicts that crevice availability declines with size, so that a ‘bottleneck’, limits the population of larger-sized individuals, but that natural mortality, or rate of loss of individuals displaced from crevices, will also decline with age. The paper considers a surface perforated with circular niches of a limited number of discrete radii, distributed at random over a surface, without overlap, and considers what is the size frequency of hole radii needed to complete the life history of an infaunal organism with a given mortality and growth schedule, and a constant occupancy rate. Determining a priori crevice frequency at size before constructing an artificial surface, and for a given packing density, distributing the crevices over it in two dimensions, is referred to as ‘mapping’ the growth and mortality rates onto the surface. Sample calculations are described either for continuous recruitment or where recruitment occurs as a ‘pulse’ during a specific season, and subsequent cohort growth obeys a common scheduling. It is shown that fractal surfaces limit the production of larger individuals unless migration intervenes, but are more suitable for recruitment enhancement. Using units with a limited size range of perforations is biologically inefficient, and depends on natural recruitment elsewhere for stock replenishment by migration. These calculations are relevant to the design of artificial surfaces, throw light on mechanisms limiting productivity of dissected surfaces, and point to effects of individual niche size on abundance at size of niche-limited organisms. The existence of nursery areas which can support large numbers of small individuals but few adults, and migratory stages in the life history of crevice-dwelling organisms, could be functions of the fractal nature of natural surfaces. An experimental field approach (a ‘niche sampler’) measuring occupancy at size of existing habitats is proposed that could be used prior to designing and installing artificial reefs in a given area to determine the optimal hole frequency at size.

Beschreibung: The Rhynchoteuthion larvae of Illex argentinus resulting from summer spawning in North Patagonic shelf waters, its distribution and abundance, are described in this paper. The material was collected in the Argentine Sea (35–55°S) by means of plankton nets. The research cruises were made by the R/V Shinkai Maru and the R/V Walther Herwig during the period April 1978 to April 1979. The most important spawning ground of the summer spawning subpopulation is found in continental-shelf waters (between 43 and 46°S) during the period December-February. This area was established on the basis of both ripe (December) and spent females (February). The larvae which were caught during the same period, especially in March, confirmed the spawning area of this demographic unit. The larvae showed the length of the mantle (ML) to be from 1.2 to 6.5 mm. Tentacles were splitting in specimens from 5.0 to 6.5 mm ML (transition stage). When 7.0 mm ML or more, all specimens were juveniles and had their tentacles completely separated. Larvae were characterized as type C, following the proposal of Sato (1973) and Sato and Sawada (1974) in the Bulletin of the Shizuoka Prefectural Fisheries Experimental Station.

Beschreibung: Se presenta una escala para la identificaciön de estadios de desarrollo sexual, de ambos sexos, del calamar ( lllex argentinus). Ella permite la discriminaciön de siete estadios en los machos y ocho en las hembras. La escala propuesta para las hembras tiene en cuenta los cinco estadios ovaricos enunciados por Schuldt (1979) mediante el analisis histolögico, asl como Indices gonadosomaticos y nidamentales. La escala considera las caractensticas propias (estructura, color, forma) y rrtodificaciones de las gonadas, ductos y glandulas accesorias, durante los diferentes estadios de ambos sexos.

Beschreibung: Our contribution attempts to give a review of the most important papers dealing with the ontogenesis of Sepia officinalis which appeared since the comparative cephalopod embryology of KOLLIKER (1844). First considered are the normal tables, the reuslts of experimental embryology and some cinematografic activites. Then, the description of the different embryonic periods (progenesis, cleavage formation of the germ layers and above all the organogenesis) stays in the centre of interest; special attention is paid to the influence of the rich yolk content on the development. In contrast to the Loliginids, Sepia has not been investigated thoroughly during the last fifteen years, These recent studies are dealing with ultrastructural research of progenesis, the midgut gland, topological aspects of the development of the intestine and the gonad, postembryonic digestion, the ontogenesis of the shell complex, the statocytst and the ectodermal metabrachial vesicles and finally with TEM- and REM-analyses of the vacuolized round cells, the differentiation of the eyes and the integument. The highly differentiated hatching stage as an externally adultlike young cuttlefish bases on an accentuated embyronic growth between the stages XVIII and XX according to NAEF; it is typical for the benthonic type of development. The postembryonic period, which was received much attention during the last years, has been very well reviewed and is therfore not considered in detail. We also try to compare the development of Sepia, Loligo and Octopus and to demonstrate the lack in our momentan knowledge. Different aspects are only analysed in older papers and new research with modern methods would be highly desirable.

Beschreibung: The stomach contents of 1522 adult seals (Arctocephalus pusillus pusillus) and 673 pups, which were collected around the West and South Coasts of Southern Africa, were examined and cephalopod prey identified. About 20 cephalopod species (some identifications were uncertain) were found in the stomachs, of which only six were significant: Loligo vulgaris reynaudii. Sepia spp., Octopus sp., Todaropsis eblanae, Todarodes angolensis and Ocythoe tuberculata. This list suggests that A. pusillus feeds exclusively on the continental shelf, frequently on or near the bottom. Among adults, cephalopod prey varied in importance around the coast. It was most important on the South Coast of South Africa where it comprised 35.0% of the weight of all prey, of which L. v. veynaudii constituted about 88%. On the West Coast cephalopods comprised about 26.6% by weight of all prey, and Octopus sp. predominated, whereas in Namibian waters cephalopods were least important, constituting only 3.4% by weight of all prey, with Todarodes angolensis and Octopus sp. being most significant. Among pups (aged 8–10 months) in the Lüderitz (Namibia) area, cephalopods were about 16.9% of prey by weight, of which Ocythoe tuberculata, small Sepia spp. and Octopoda were most important.

Beschreibung: The global mass/age distribution of Phanerozoic sediment shows maxima in the Middle Paleozoic, at the Paleozoic-Mesozoic boundary, and in the Late Mesozoic. All of these total sediment mass maxima are also maxima of masses of volcanogenic sediment and non-marine sediment, and represent times of maximum sediment flux on the surface of the earth. The Middle Paleozoic and Late Mesozoic maxima correspond to the great marine inundations of the continents, and the Late Paleozoic-Early Mesozoic maximum to the time of transfer of a large number of terranes across the Tethys from Gondwanaland to Eurasia. All three maxima of sedimentary mass correspond to times of rapid sea-floor spreading and orogeny. Organic carbon in dispersed form is enriched in sediments forming hydrocarbons during the sediment flux maxima of the Middle Paleozoic and Late Mesozoic (Jurassic-Cretaceous), but is preserved as coal during sediment flux minima of the Carboniferous and Early Cenozoic. Sedimentary iron deposits and phosphorite deposition are most widespread when the global sedimentary flux is minimal. Potassium salts were deposited at times of sediment flux

Beschreibung: All incirrate embryos, except Argonauta, undergo two inversions; one by ciliary action during early organogenesis, the other by muscular action late in embryonic development. The iterature devoted to these peculiar processes is critically surveyed; functional aspects are discussed.

Beschreibung: General biology of cephalopods is described. First, all commercially important cephalopods are classified and the general morphology and distribution of all major families is described in detail. Mating and spawning characteristics of all major families are discussed in detail. This is followed by a discussion on early life history, growth and principal ecoological changes that occur during the growth period. Schooling and migration characteristics are also taken up in considerable detail. The paper closes with a brief discussion on the trophic relation. The author points out that cephalopods are extremely important to mankind due to their unique position in the food chain extending from the oceans to man.

Beschreibung: Four general circulation models, forced by mean annual insolation and having an energy balance ocean, have been run for pole-to-pole continents: (1) low relief, 750 m average elevation; (2) high plateau, 1500 m average elevation; (3) mostly low, 750 m, but with 3 km mountains on the west, and (4) mostly low, 750 m, but with 3 km mountains on the east. The high plateau continent emphasizes the contrast between high and low pressure systems. Marginal mountains on either coast enhance moisture transport from the west to the continental interior, but mountains on the east eliminate the tropical wet belt and produce the most arid scenario. In none of the experiments do zonal climate boundaries trend steeply equatorward from east to west. All of the models produce more arid continental conditions than exist today.

Beschreibung: Feeding trials in which salmon was fed to captive seals are described and sources of evidence for the presence of salmon in the diet of seals are evaluated. In faecal samples, the recovery rate of salmon otoliths is too low and bony remains are too fragmented to be useful. Protein extracts from the faeces of salmon-fed captive seals will react with anti-salmon antisera, but the reaction is not strong enough for the methods to be presently applied to field samples. In the digestive tract samples from seals, the use of bony remains for the identification of salmon significantly increases the probability of recognising this species. Protein extracts from digestive tract contents will react positively with anti-salmon antisera and this shows that serological methods can provide evidence for the presence of Salmonidae in the diet of seals, in the absence of solid remains.

Beschreibung: Octopuses are known to be highly efficient at the extraction of flesh from their crustacean prey. Experiments on capture and handling of crabs (Carcinus maenas) by the octopus Eledone cirrhosa show that paralysis of the crab invariably precedes hole boring of the carapace. The time course of feeding is described and it is shown that the ingestion of crab meat does not occur before about 40 min after capture for this specific predator-prey interaction although crabs are paralysed after 1-5 min. Comparative observations on hole-boring behaviour are given for Octopus vulgaris and O. dofleini. The results are discussed in relation to recent data on the biochemical composition of the secretions of the posterior salivary gland.

Beschreibung: Karyological studies were made on the embryos of seven cephalopods using chopping method. Two sepiids (Sepia esculenta and Sepia lycidas) and three loliginids (Sepioteuthis lessoniana, Heterololigo bleekeri and Photololigo edulits) were all 2n = 92). Their karyotypes and total length of chromosomes were slightly different from each other. Two octopuses (Octopus ocellatus and O. vulgaris) were both 2n=60. Their karyotypes and total length of chromosomes were, however, remarkably different from each other.

Beschreibung: Statistical heterogeneity of abyssal hill properties is often evident in seafloor topography, even under periods of relatively constant spreading direction and rate. In this paper we relate the statistics of topographic slopes computed on finite spatial scales to the autocovariance function and investigate the practicality of using these functions in describing such heterogeneous abyssal hill terrains. For a two-dimensional homogeneous surface, a direct relation exists between the sample autocovariance and the slope distributions at different spatial scales. However, for a heterogeneous field characterized by large transient signals, the computed autocovariance estimate no longer has a clear statistical interpretation and becomes dominated by the transients. In contrast, the family of slope distributions can still be used to derive stable descriptors of the field. Slope statistics are thus useful in deriving a more robust estimate of the autocovariance than the usual sample autocovariance. Moreover, slope statistics may also be used to derive stable estimates of quantities not measurable with the autocovariance function or power spectra, such as the statistical asymmetry of features. Examples of the use of slope statistics and a comparison with autocovariance methods are presented. We document and quantify evidence of statistical asymmetry in a region of abyssal hills in the northeast Pacific and, in a second example, the presence of multiple lineations in a region where a fracture zone cuts through abyssal hill terrain.

Beschreibung: A seismic refraction profile across Langeland (Denmark) obtained from land stations recording airgun shots allowed to resolve upper crustal velocities to a depth of 8 km. The profile traverses the proposed Caledonian Deformation Front and the Ringkoebing-Fyn High. The Ringkoebing-Fyn High is about 10 km wide and the top basement lies less than 2 km below the surface. Basement velocities as high as 6.4 km/s, at depths between 6 and 8 km, can be best explained by compositional changes between adjoining basement units to the north and south. South of the Ringkoebing-Fyn High another high velocity basement unit is encountered and most probably represents a basement affected by the Caledonian orogeny. Along this profile on Langeland the positions of the Caledonian Deformation Front and the northern limit of the Zechstein deposits coincide.

Beschreibung: Some basic characteristics of ridge axis topography are related to spreading rate and distance from neighboring transform faults. For example, the presence of an axial depression coincides in most cases with slow spreading rates, and the overall depth of the ridge axis increases toward ridge-transform intersections (RTIs). On the other hand, it is also well known that the relief and width of the axial valley on, say, the Mid-Atlantic Ridge (MAR) vary along strike in an unpredictable manner. The purpose of the present study is to quantify how much of the observed variation in the first-order topography at the axis is related to changes in other parameters, such as spreading rate and distance from RTIs. To carry out this test, the zero-age depth and the relief and width of the axial valley have been estimated on 46 profiles that cross the axis of the MAR between the equator and 50°N (full spreading rates 22–36 km/Ma). Zero-age depth is here defined to be the depth at age zero of the best fit thermal subsidence trend. Axial valley relief and width have been measured with respect to the ridge flanks by the least squares fit of a Gaussian bell. The measured axial valley relief varies between 600 and 2100 m (average ∼1300 m), while the valley width varies between 16 and 62 km (average ∼35 km). The correlation between zero-age depth, axial valley relief and width, latitude of axial crossing, spreading rate, distance from nearest RTT, and offset on the nearby transforms has been investigated using linear regression techniques. The main results of the present study are that (1) zero-age depth significantly correlates with latitude of crossing, distance from nearest RTI, and offset on the nearby transforms; and (2) the variation in axial valley relief and width is essentially uncorrelated with spreading rate, zero-age depth, distance from nearest RTT, and offset on nearby transforms. The preferred explanation for the observed spatial variation in axial valley geometry is that it reflects a temporal variation. In fact, if the rough abyssal hill topography typical of the MAR flanks is created within the axial valley, the shape of the axial valley cannot be steady state (although the existence of an axial valley may be a steady state phenomenon). This hypothesis is supported by the observation that the variability in axial valley relief is similar to the overall amplitude of abyssal hill topography, measured as the residual on the thermal subsidence trend.