The abundance and latitudinal and vertical (0-100 m) distribution of planktonic Foraminifera was investigated on the basis of 38 samples collected in November 1994 in the southwestern Atlantic Ocean (34-60°S, along 51-56°W). Mean foraminiferal densities were 1.5 ind. l−1 (range: 0.15.9 ind. l−1), with highest concentrations in subsurface waters (20-50 m). Couplings between the distribution of chlorophyll a and foraminiferal abundances were very loose. Distribution patterns of the 15 species recorded allowed 6 distinct areas to be defined along the transect surveyed. From north to south these are: Subtropical (dominated by Globigerinoides ruber and G. trilobus), Cold intrusion (Globigerinita uvula), Transitional-Subtropical and Transitional (Globigerina bulloides, Globigerina quinqueloba), Subantarctic (G. quinqueloba), and Antarctic (Neogloboquadrina pachyderma, left coiling). Close comparisons with the yields of a similar data set collected in November 1993 show very good agreement. Foraminiferal thermic régimes were also similar in 1993 and in 1994, but for some species significant differences with previous data were detected. While the southwards extensions of the ranges of warm water species are fairly well circumscribed by the Brazil current-influenced waters, several foraminifers widely used as indicators and palaeoindicators of cool waters (in particular Globigerina bulloides, Globigerina quinqueloba and Globigerinita uvula) were recorded in very significant numbers at temperatures as high as 20-24°C. The implication of these findings for hydrological, ecological, and palaeoecological interpretations is discussed.

In Carcinus maenas haemolymph, zinc is almost entirely bound to the respiratory pigment, which is the copper-protein haemocyanin (Hc). Zinc ions are loosely bound, as indicated by the low value of the association constant (k = 1.7 × 105 M-1 at pH = 8.0). The number of binding sites N is equal to 4 per minimal functional subunit (75000 Dalton). No co-operativity has been found between the different metal sites. Data reported in this paper support the hypothesis that haemocyanin can act as metal carrier in the haemolymph of C. maenas.

The pattern of paragnaths in Nereis diversicolor differs markedly between 17 populations from eastern and south-west England. There is a substantial heritable component to these differences, and there is no evidence that sediment type during development has any influence on them. Comparisons with previous studies reveal no consistent relationships of paragnath pattern with either sediment type or salinity. Evidence from scanning electron micrographs and correlations between different groups indicates that the anterior and posterior bands of paragnaths have rather different roles in feeding and suggest that the inter-population differences may be adaptations to different diets. The orientation of the jaws confirms that they play an important role only during predation and the handling of large particles, but not during the more usual browsing of the sediment surface.

When beginning research into the cultivation of marine shrimps and prawns, it is usually the most worth while of the local species that is chosen for study. From this it follows that in tropical regions the penaeids tend to be favoured, especially following the pioneering work of Hudinaga (1942) with Penaeus japonicus (Bate), whereas in the temperate regions of Europe and Canada it is the carideans that are receiving most attention, particularly the palaemonids. One notable exception is the advanced study of the Asiatic Giant Prawn Macrobrachium rosenbergii (de Man), which was initiated in Malaysia and subsequently taken up in Hawaii and Great Britain (Ling, 1962).

Doubtless each chosen species has its merits, but overriding importance must be attached to ease of mating, for this imposes an immediate limit on the reliability of the whole process and holds the key to the selective breeding of improved strains. Indeed, it has been pointed out that reliance on wild-spawned animals is a major obstacle to commercial development (Tabb et al., 1969) and such vagaries in the supply of young shrimps has already limited some research (Cook & Murphy, 1969).

Under captive conditions it has proved a great deal easier to mate carideans than penaeids, but the continuing part played by caridean females in incubating the eggs over a contracted period is a disadvantage. Relieving the ovigerous females of this task would allow the eggs to be incubated at greatly increased densities in conditions no longer dictated by the females. Further, it would lead to the more effective use of the female during the period she would otherwise be incubating.

The effects of surface roughness and microsolubility on fouling levels are examined using glass and acrylic samples. It is found that both of these, often overlooked, physical characteristics have a noticeable effect on the rate of fouling. The microsolubility of acrylic results in lower fouling than found on glass despite the higher hydrophobicity of acrylic and the resultant increase in initial attraction for fouling organisms. Fouling levels were found to increase with increasing surface roughness and therefore studies on the fouling susceptibility of different materials should report the roughness values of the samples examined.

The genus Bathyporeia was established by Lindström (1855, p. 59) on specimens collected in the Baltic at Wisby and Landskrona. His description is based, apart from a reference to the epimera as small and beset with hairs, on the form of the appendages. He assigned to the genus one species, pilosa, in which the segments of the body are described as smooth, the form generally rounded, the eyes black, small and somewhat reniform, and the length under three lines. He gives a detailed description and drawing of the appendages. From the description of the antennae and of the eyes it may be assumed that the specimens were females.

1. An air turbine ultracentrifuge suitable for biological work and capable of developing a centrifugal force from 10,000 to 500,000 times gravity has been described. Advantages of the ultracentrifuge are: (1) The temperature does not vary in the centrifuge chamber over 2 or 3 degrees from that of the atmosphere; this is not sufficient to be an important factor in general biological work. (2) The cost of constructing the apparatus is very low in comparison with that of other high speed centrifuges.

2. A modification of the air turbine ultracentrifuge in which the turbine rotor drives a second rotor, in this case the centrifuge rotor which spins in a vacuum, has been described. Here the centrifuge chamber is thermally insulated which is an important item in preventing troublesome convection currents from arising in the centrifuged material where such special problems as the rate of molecular sedimentation are being observed. Forces in excess of one million times gravity can easily be obtained by such an apparatus.

The histology and histochemistry of whiting skin was studied in larval, juvenile and adult fish. The adult specimens were obtained throughout the year but there was no evidence of seasonal variation in the areas of the body sampled. The skin of the whiting is considerably more complex than that of any other teleost fish which has been described in detail. The epidermis of the mature fish comprises five layers, consisting of Malpighian cells and a variety of other structures including large cystic bullae, which ultrastructurally and histochemically are relatively amorphous but comprise a major proportion of the epidermis. A reticulum of epidermal melanocytes occurs above these structures and two types of mucous cell are described. The major histochemical feature of the epidermis was the alkaline phosphatase reaction, similar to that found in higher animals. Succinic dehydrogenase activity was found at all levels. The epithelial mucins were mainly acid mucopolysaccharide with a small sialic acid component and a greater proportion of sulphated muco-substance. The dermis was morphologically similar to that of other scaled fishes. Mast cells were particularly prominent and occasional non-pigmented ‘melanophores’ were seen.

In an earlier study of the biochemical composition of barnacle cement, Walker (1972) found that the cements of two sessile barnacles, Balanus hameri and B. crenatus contained small amounts of lipid (< 1% of total dry wt.) and carbohydrate (♎ 2% of total dry wt.) but were mainly composed of protein ( > 85 % ° of total dry wt.). Lindner & Dooley (1973) similarly found that a large proportion of B. crenatus cement was protein (80%), but Cook (1970) found only 70% protein, lipid (27.4%) being the other major constituent. There is therefore general agreement that barnacle cement is mainly a proteinaceous secretion, but controversy still exists over the amount of lipid present.

The mechanisms of accumulation of zinc and cadmium by the marine polychaetous annelid Neanthes arenaceodentata (Moore) have been studied. Animals have been exposed to EDTA chelate buffered sea water containing 65Zn and 109Cd. The calculated free ion activities of the zinc and cadmium in the sea water were 10-8.13 M and 10-7.65 M, respectively. Uptake occurs from the free ionic pool of metal and EDTA and EDTAmetal complexes are largely excluded from the animal. In unfed animals, the metals accumulate linearly with time at a rate which decreases when the temperature is reduced but increases in the presence of metabolic inhibitors. Experiments using [14C]EDTA as an extracellular marker indicate that the observed increase in accumulation caused by the inhibitors is at least partially due to media entering extracellular anatomical compartments such as the coelom and lumen of the gut which are normally isolated from the seawater by cilia or sphincters.

Surface longline targeting mainly swordfish is considered a major threat for loggerhead turtle populations in the western Mediterranean Sea. For this reason, it is necessary to analyse the relationship between the characteristics of longline sets and loggerhead turtle by-catch. The objective of this study is to look for differential spatial distribution of loggerhead turtle and swordfish captures along the longline to gain insights that might be useful to diminish unintended, incidental catch of turtles without affecting the captures of the target species.

Longlines are divided into transects separated by two consecutives buoys. During the 1999 fishing period of the traditional (without roller) Spanish surface drifting longline fleet (August to November), 59 technically homogeneous fishing operations, composed of 23 sections each, were observed. Chi-square test was used to compare loggerhead turtle and swordfish distributions among transects with those expected at random. Significant differences were obtained only for loggerhead turtles, with 93% of the specimens caught in the second half of the longline transects, which were retrieved from the sea during daytime. Significant differences were not found for the swordfish along the whole longline or for loggerhead turtle captures retrieved during daytime. We conclude that swordfish captures are independent of retrieval time whereas the incidental catch of loggerhead turtles occurs mainly during daytime, probably because loggerhead turtles use vision to locate baits.

Lipids of sulphur-oxidizing bacteria isolated from Thyasim flexuosa had large amounts of 18:l(n-7) together with lesser amounts of both 16:l(n-7) and 16:0 as their major fatty acids. Smaller amounts of the cyclopropyl fatty acids, cyclic δ9,10 C16 and especially cyclic δll,12 C18 were also present. A similar pattern was found for methylotrophic bacteria isolated from Thyasira, Myrtea and Lucinoma, except that 16:l(n-7) and 16:0 were both present in larger amounts than 18:l(n-7) and small amounts of cyclic δ9,10 C16 and lesser amounts of cyclic All,12 C18 were present in all cases. The fatty acids 18:l(n-7), 16:l(n-7), 16:0, cyclic δ9,10 C16, and cyclic δll,12 C18 were all present in varying amounts in several free-living, non-marine, sulphur-oxidizing bacteria analysed, and in one bacterium both cyclic δ9,10 C18 and cyclic δll,12 C20 were abundant. Branched-chain fatty acids and polyunsaturated fatty acids were not detected in any of the sulphur-oxidizing or methylotrophic bacteria analysed. The lipids of the sulphur-oxidizing and methylotrophic bacteria consisted largely of phosphatidylethanolamine, phosphatidylglycerol and cardiolipin. The results are discussed in terms of fatty acids as indicators of nutritional relationships in bacterial-invertebrate symbioses.

Boring sponge diversity in the area of the Conero Promontory, the most important rocky emergence on the west coast of the Adriatic Sea (Italy), was assessed. Four species were recorded; one of them, Cliona adriatica, is new and is described here. The new species differs from all the other excavating sponge species, characterized by yellow papillae and lacking or scarcity of microscleres, in the large size of the boring chambers and the presence of numerous styles. Cliona adriatica is present on about 12% of the surface of rocky bottoms in the Conero Promontory area. The impact of this highly destructive species on the carbonatic micritic rock of the promontory was evaluated calculating a relationship between the volume of the boring chambers and the surface of the epilithic portions. Consequently, it was estimated that 1 cm2 of epilithic tissue corresponds to 8.5 g of excavated rock. The recorded correlation between the excavated volume and the area of the papillar zone (roughly the area of the substratum affected by the erosion) allows an estimation of the substratum removed by a boring sponge, using only visually oriented, non-destructive, sampling methods.

Understanding the spatial distribution of fish species and fish trophic guilds in reef environments may help improve our knowledge about ecological relationships and therefore favour sound strategies for sampling, coastal management and conservation policy. To verify if small-scale changes are important in forming the fish community structure at a tropical rocky coastal island, we assessed the depth, structural complexity and wave exposure gradients. The community structure changed along all gradients analysed. The trophic guilds found on the sheltered, low and intermediate exposure zones, in the deepest areas and in areas of highest structural complexity showed significant differences when compared with the general assemblage. Rocky reefs, even of narrow (transversal) extension, can show great changes in fish community structure at so small a scale that these changes are generally overlooked. The relationships evidenced between community and environment provide strong support for the importance of considering a wide array of such distinct environmental conditions when determining the structure patterns of the community.

Polymorphism may allow individuals to expand habitat use through morph-specific resource demands. However, the underlying mechanisms maintaining different morphotypes in nature are difficult to identify. We sampled populations of the shrimp Hippolyte obliquimanus in the macroalgae Sargassum furcatum and Galaxaura marginata to examine morph-specific distribution patterns, population structure and female reproductive output, as an initial step to understand polymorphism in this species. Two main colour morphotypes were identified: homogeneous shrimps (H), which change their colour, mostly from pink to greenish-brown tones, and striped translucent shrimps (ST), whose colour remain unaltered. Distribution of individuals between habitats was clearly morph-specific. H shrimps occupied colour-matching substrates, mainly Sargassum, where they can attain large densities, and ST individuals were evenly distributed in both algae. Brood production and size-fecundity relationships were similar between morphs and habitats, suggesting these are relatively fixed traits in the population. However, sex proportions, defined as the male to female ratio, were different between morphs and macroalgae. H shrimps were chiefly females (1:2.04) and ST shrimps mostly males (1:0.30). Given the likely polygynic pure-search mating system in H. obliquimanus, the female-biased sex ratio observed in Sargassum is apparently more advantageous than the Mendelian proportion found in Galaxaura habitat. Clustering on vegetated habitat, the female-biased H morph may be relatively cryptic and sedentary, compared with the male-biased ST morph which apparently combines a more neutral camouflage strategy to a generalized habitat use. Altogether, results suggest that selection for sex-specific traits favours the maintenance of polymorphism in H. obliquimanus.

The aim of this study was to assess if sea surface temperature does affect cetacean distribution in the western Ligurian Sea. Relationships with temperature were investigated for: striped dolphin (Stenella coeruleoalba), fin whale (Balaenoptera physalus) and sperm whale (Physeter macrocephalus). Remotely sensed sea surface temperature (SST) data were studied. A series of 20 monthly images (i.e. June to September monthly images from 1996 to 2000) was considered. Concurrently, distribution data collected during shipboard summer surveys, and covering an area of about 20,000 km2 in the western Ligurian Sea, were analysed. The relationship between the three species presence and SST was investigated by using a grid of 3 × 3 nautical mile cell units. For every cell the SST mean, standard deviation, coefficient of variance and the deviation from the monthly average were calculated. Finally, binary logistic regression functions allowed to assess significant (P < 0.05) relationships with temperature in these species. These logistic models, were able to predict 60–78% of the species presence(1)/absence(0) cells, and suggest the need for further investigations spanning longer time periods to assess how the global climate change has been changing and will change in the future cetacean distribution in the western Ligurian Sea.

1. Regeneration from different levels in the polychæt worm Chætopterus variopedatus has been studied.

2. Regeneration can occur posteriorly from any segment, but anteriorly only from segment XIV forwards.

3. Where regeneration occurs at all, given sufficient time, it will be complete, i.e. the original segments occupy in the new worm the relative position they originally occupied in the old worm.

The spectral composition of the light of Chaetopterus variopedatus has been measured by means of spectral niters and multiplier phototube. Spectral emission extends from about 405 to 605 mμ, with a maximum at about 465 mμ. The spectral curve of Chaetopterus light is compared with a human visibility curve (scotopic vision), a visibility curve for Limulus, and an absorption curve for fish visual purple. Luminous efficiencies, based on these curves, are calculated.

Barnacle encrustation negatively influenced every aspect of swimming in the scallop Chlamys hastata measured in this study. Scallops swam significantly longer, travelled further and attained greater elevation once epibiotic barnacles had been removed. Shell morphometry of barnacle-encrusted scallops was similar to shells of unencrusted scallops. Specifically, shell length was positively allometric with shell height and shell mass was negatively allometric. However, adductor muscle mass scaled isometrically to shell height, in contrast to unencrusted scallops. In the laboratory, the drag coefficient (Cd) of barnacle-encrusted scallops decreased after barnacle removal, in contrast to sponge-encrusted scallops in which no decrease in Cd was detected when the sponge was removed from the scallop's valves. Furthermore, scallops swimming with barnacle encrustation required more energy than did unencrusted scallops. Although there was no significant difference in aerobic energy expenditure between swimming barnacle-encrusted and unencrusted scallops, differences in anaerobic energy expenditure were detected. Specifically, barnacle-encrusted scallops required more arginine phosphate than unencrusted scallops to swim to exhaustion although octopine levels were similar. Thus, barnacle encrustation dramatically decreased a scallop's ability to swim, partly by increasing the drag coefficient experienced by the scallop and the energy required for swimming.

The starfish Pharia pyramidatus is a tropical species of high ecological importance, mainly because of its role as generalist predator. Nevertheless, there are no studies about its reproduction. This study analysed the reproductive biology of P. pyramidatus based on monthly time-series samples from April 2008 to March 2009 at Isla Montosa in the Mexican tropical Pacific. The gonad index (GI), and pyloric caecum index (PCI) were determined and the results were corroborated by histological examination of the gonads. Pharia pyramidatus is a gonochoric asteroid and the ratio of males to females was not significantly different throughout the year. Gametogenesis showed high synchrony among males and females and five stages were recognized for both sexes. Spawning occurred from July to September. Maximum oocyte size was ~150 μm and mean fecundity was 7.3 ± 1.2 millions of oocytes per female. GI and PCI showed seasonal variations and an inverse relationship from May to August. Sea-bottom temperature and photoperiod showed a direct relationship with GI, and apparently constitute the proximate causes of the seasonal reproductive pattern observed in P. pyramidatus, while the highly seasonal rainfall and strong upwelling probably act as ultimate causes.