Fatty-acid and energy content of Maja brachydactyla eggs at different developmental stages (recently spawned, half-developed and ready to hatch) were analysed in order to understand what is being consumed and produced during the embryonic development. Egg volume increased during development (34%, 0.187 to 0.285 mm3, N = 270) and was negatively correlated with egg energy and fatty-acid content (r = −0.80 and r = −0.46, respectively), which decreased through embryogenesis. The most consumed fatty acids were the PUFA (21.2 μg · mg dw−1), followed by the SFA (18.8 μg · mg dw−1) and MUFA (14.9 μg · mg dw−1). Palmitic (16:0), oleic (18:1n-9) and eicosapentaenoic (EPA, 20:5n-3) acids were preferentially consumed (13.14, 9.21 and 8.67 μg · mg dw−1, respectively). The fatty acid composition found in M. brachydactyla eggs reflected the habitat and omnivorous and detritivorous scanvenger diet of the adults, although the consumption of algae was more important than previously thought, at least in the area where these adults were captured. Pre-hatching eggs have a high PUFA content (64.5 μg · mg dw−1 or 46.3% of the egg fatty-acid content). We conclude that larvae of this species might need a diet rich in PUFA, particularly EPA and DHA, for successful development. From the culture perspective, live preys commonly used in aquaculture will likely require to be enriched with DHA.

Nannochloris oculata Droop, an obligate phototroph, has no absolute nutritional requirement for any organic compounds. However, no growth takes place in neutral media lacking base, due to the lengthening of the initial lag phase. Weak acids shorten the lag even though pH has not been altered. The lag is interpreted as the time taken for the cells to excrete sufficient weak anions to lift the carbon dioxide in solution to the minimum required for growth. Glycollate excretion is discussedin the light of this interpretation.

The present study aims to apply a growth model to a species with a conditional reproductive strategy, the grass goby Zosterisessor ophiocephalus (Pisces: Gobiidae), in order to evaluate the adoption of alternative tactics by this species under the constraints of different dates of birth. The model describes the growth pattern (based on age, weight and gonadosomatic index data) of an individual, assumed to be representative of a given cohort, while also taking into account the energetic loss due to parental care. The most important parameters have been calibrated by comparing the results with a set of data collected in the lagoon of Venice. The comparison between the growth pattern of a parental male and that of a late-born male suggests that the birthday could be one of the major constraints affecting the adoption of an alternative tactic during the first breeding season.

The phylogenetic relationships were analysed based on nucleotide sequences of a mitochondrial gene for cytochrome c oxidase subunit I (COI) for the vestimentiferan tube worm Lamellibrachia juni, which inhabits three extremely acidic hydrothermal vent fields in the South Pacific: the TOTO Caldera in the South Mariana Volcanic Arc, the DESMOS site in the Manus Basin, and the Brothers Caldera in the Kermadec Arc. Six haplotypes were obtained from 34 lamellibrachiids from the three sites. Each haplotype was obtained only from a single site, which suggests that the three populations have been isolated from each other. Haplotypes from the DESMOS site formed a monophyletic cluster. All ten individuals from the TOTO Caldera were classified into the same haplotype, which was shown to form a monophyletic cluster with one of three haplotypes from the Brothers Caldera. The population in the Brothers Caldera was shown to consist of two genetically distinct groups.

The first records of thorny skate eggs in stomachs of sperm whales are described. Predation on elasmobranch eggs, especially by marine mammals, is reviewed.

A major contribution to our understanding of the distribution and taxonomy of echinoids in British waters was made by Mortensen (1927, 1928–1951). Many earlier qualitative investigations (e.g. Süssbach & Breckner, 1911; Brattström, 1941) which dealt only with limited areas, were combined in Mortensen (1928–1951) to produce an overall assessment of the North Sea echinoid fauna.

In his discussion paper Ursin (1960) synthesized findings from his 20 year grab sample survey with the work of others to produce a valuable quantitative analysis of the echinoids of the central North Sea (54–5 8° N).

In recent years (1977–1983) participation on demersal fish surveys in the North Sea has enabled the distribution and population structure of the macroepibenthic component of the water column to be recorded (Dyer et al. 1982, 1983; Cranmer, Fry & Dyer, 1984).

Although this present study has added no new echinoid species to the fauna it has given a detailed picture of echinoid distribution in the area.

Advantages and disadvantages of methods used to estimate area of individual secondary lamellae are discussed. Particular attention is given to explain the method which regards filaments as triangles and lamellae as rectangles. Dangers of some injection methods assuming that the whole lamellar microcirculation is equally involved in gas exchange are also emphasized. It is concluded that there is a need for comparisons of results when different methods are applied to the same material.

This study evaluated the population structure, growth and longevity of Xiphopenaeus kroyeri in the State of Sergipe. The obtained data were compared with other populations on a latitudinal scale in order to evaluate whether the latitudinal paradigm applies to this species. Shrimp sampling took place monthly from September 2013 to August 2014, in nine stations distributed at 5, 15 and 30 m depths, using a shrimp fishery boat equipped with a ‘double rig’ net. Sexual maturity was estimated by the logistic function y = a/(1 + b*exp(-cx)), and the sex ratio was analysed with the Chi-square test. The individual growth rate was estimated using the von Bertalanffy model, and the longevity was estimated by the inverse form of this formula. A total of 6418 (3457 females and 2961 males) was analysed. The size at onset of sexual maturity was 12 mm of carapace length (CL) for males and 12.5 mm CL for females. The total sex ratio did not differ from the expected (1:1). Males exhibited higher growth coefficients (k) and smaller asymptotic growth (CC∞ = 28.74 mm, k = 0.0081 day−1) than females (CC∞ = 30.79 mm, k = 0.0058 day−1). The estimated longevity (years) was 1.55 for males and 2.15 for females. No evident latitudinal pattern was observed regarding the size at onset of sexual maturity or the growth parameters for X. kroyeri. The information found, besides contributing to the knowledge about the biology of this shrimp, can also clarify hypotheses presented in relation to the latitudinal paradigm along the Brazilian coast.

The natural abundance of stable carbon and nitrogen isotope ratios for Nereis diversicolor (Annelida: Polychaeta) from 16 sites around the UK are analysed. Differences in the isotopic compositions reflect variations either in the dietary origin or in the estuary characteristics. In contrast to Stiffkey Nereis, the ones from the other estuaries are characterized by broad δ13C (−13.9 to −22.6‰) and δ15N (+11.3 to +17.9‰) ranges. An hypothesis based on sediment denitrification is discussed to explain the anomalously heavy δ15N compositions of Nereis from the Humber Estuary (+16.9 to +18.1‰) and Breydon Water (+17.7±0.5‰).

Bioactive compounds of gonad, respiration tree, cuvierian organ, and body wall of the sea cucumber Holothuria leucospilota collected from the north coast of the Persian Gulf were extracted using ethyl acetate, methanol and water–methanol solvents. Extracts were evaluated for their antibacterial and antifungal activities against Aspergillus niger, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The activity was determined using the disc diffusion test. Cytotoxic activities of the extracts were determined by brine shrimp lethality assay. Results demonstrated that the A. niger was shown to be the most sensitive microorganism followed by C. albicans. The inhibition zone against A. niger and C. albicans had minimum inhibitory concentrations ranging from 3 to 7 μg/ml. The highest antifungal activity was found in G (water–methanol) with an inhibition zone of 50 mm against A. niger at 18 μg/ml extract concentration continuing with CT (methanol) with 46 mm inhibition zone against A. niger at 18 μg/ml extract concentration. The highest cytotoxic effect of methanol extract was found with LC50 values of about 40.31 μg/ml in the gonad organ from H. leucospilota continuing with the respiration tree organ with LC50 values of about 72.49 μg/ml.

Laboratory based experiments, carried out on Littorina neglecta collected from the barnacle zone at Ravenscar, north-east England, showed that this marine prosobranch displays size assortative mating. Males prefer to mate with larger, more fecund females, but they do not necessarily choose the largest available. It is suggested that such size assortative mating may act as a barrier to reproduction between L. neglecta and L. saxatilis. No relationship was found between either male or female shell size and the length of copulation.

Size of ripe eggs and potential fecundity are described in the squid of the subfamilies Todaropsinae and Todarodinae (Oegopsida: Ommastrephidae)—Todaropsis eblanae from West Africa, Todarodes angolensis from Namibia, Todarodes sagittatus from north-west Africa and the Mediterranean Sea, Todarodes sp. from the south-east Pacific, Nototodarus hawaiiensis from the south-east Pacific and West Indian Ocean and Martialia hyadesi from the south-west Atlantic. Females of both subfamilies are characterized by a wide range of ripe egg size (0.7–2.4 mm) and low and medium values of potential fecundity (20,000–2,500,000).

A variety of Sabella pavonina Sav. described by Hornell as bicoronata has been found at Plymouth. It is characterized by the unequal development of the two sides of the branchial crown. The characters by which Sabella pavonina, its variety bicoronata and Spirographis spallanzanii may be distinguished are described. It is concluded that the genus Spirographis is not valid and that its species should be referred to the genus Sabella which is redefined.

The intertidal zonation of the dominant algal species in Beer Bay, south-east Devon, was examined in relation to substratum by means of plane-table maps and transects. The dominance of Ulva lactuca on colonies of the reef-building worms Sabellaria alveolata was noted, but the distributions of Fucus vesiculosus, F. serratus, Gigartina stellata and Enteromorpha spp. showed no correlation with substratum.

To assess the recovery of the lagoon in the Valle di Gorino, Italy, the macrobenthic assemblages were studied throughout a two year period, i.e. before and after the opening of a floodgate. Three stations were located along a gradient of confinement, and sampled for macrofauna, water and sedimentary parameters. Analyses were performed through univariate and multivariate techniques. The macrobenthic assemblages were characterized by a small total number of species, strong dominance in number by a few of these species, and low diversity, but changes in community structure and composition were clearly recognizable. Significant negative correlations were found between macroalgae and macrobenthic community attributes. The altered hydrological regime due to the opening of the floodgate disrupted macroalgal cycles and altered the related macrofaunal successional dynamics: species linked to the macroalgal degradation phase became dominant throughout the Valle. After the intervention, all areas exhibited similar species composition and abundances, and appeared to be in a permanently disturbed condition. A rescaling of environmental conditions repositioned species roles in the community: those species which were typical of a certain phase of the former successional progression, were successively dominating the whole lagoon, irrespective of time and the estuarine gradient. After the intervention, the spatial and temporal distribution of macrobenthic taxa was under the control of factors linked to organic enrichment of the sediments.

The influence of size and density of the blue mussel, Mytilus edulis and the common barnacle, Semibalanus balanoides on the foraging behaviour of the sea urchin Psammechinus miliaris was examined in laboratory studies. Urchins of two size-classes offered six size-categories of barnacles exhibited a constant preference for the smallest category ([les ]7.5 mm plate length). Ingestion rates were independent of the size–frequency distribution of mussels presented to large urchins of 38–46 mm test diameter, which showed a preference for small–medium sizes (>13.4–17.8 mm shell length). Large urchins ingested a maximum of six mussels a day and increased their consumption in a density dependent manner until reaching a plateau once more than ten mussels were offered. In most cases, the rate of successful attacks decreased with mussel size.

Pairwise comparison experiments to determine the ingestion rate of fronds of the algae Laminaria saccharina showed that P. miliaris had no preference for old fronds with or without epifauna, but young fronds of the algae were frequently rejected. These results highlight the omnivorous nature and semi-selective behaviour of this urchin and demonstrate the potential for it to have an important role in structuring algal and epifaunal communities.

The near-bottom mesozooplankton was caught by a four net suprabenthic sledge on six sites in the English Channel during both spring and autumn. Taxa richness showed no significant difference between seasons, nevertheless diversity (H′), evenness (J) and normalized rarefaction number of taxa E(S91) were higher in autumn than in spring at each site except at Site 2 offshore Plymouth, where Calanus helgolandicus dominated at both seasons. Copepods dominated in abundance at each site in spring while crustacean larvae were dominant in autumn except at Site 2 offshore Plymouth, where copepods remained dominant and, at Site 6 in the Dover Strait, where no significant difference occurred between copepod and crustacean larvae abundances. Four assemblages were distinguished depending on the season. Abundance was higher during the day than at night as a result of a mesozooplankton concentration in the near-bottom layer during the daytime. Moreover, three vertical patterns of suprabenthic mesozooplankton were identified according to their distribution above the near-bottom layer: taxa distributed homogeneously in the four nets; taxa concentrated in nets 2 and 4, and taxa concentrated in the three upper nets.

The mysid fauna of the Rockall Trough consists of more than 35 species partitioned between the pelagic water column and the bentho-pelagic environment. The pelagic mysids are dominated by Eucopia grimaldii, E. unguiculata and Boreomysis microps. The benthopelagic mysids, in a transect from 400 to 2900 m depth, are divided into four faunal associations. Pseudomma affine dominates the 400–800 m depth range; the impinging bathypelagic Gnathophausia zoea and the benthopelagic Boreomysis widens dominate the 800–1300 m range;Michthyops parva and Paramblyops rostrata are co-dominants in the 1400–2300 m range; while Amblyopsoides ohlinii dominates the 2170–2965 m range. The benthopelagic mysid fauna is most diverse at depths below 1400 m. It is dominated by species whose geographical distribution is restricted to the North Atlantic, in contrast to the pelagic mysid fauna, which is dominated by cosmopolitan species. Notes on the breeding season, biology and population structure of several species are given.

Anemones of the genus Actinia exhibit a well documented, stereotyped aggressive sequence (Bonnin, 1964; Brace & Pavey, 1978; Brace et ah, 1979) involving specialized, nematocyst-bearing structures called acrorhagi, which can be directed against an opponent. Experiments on the Australian species, A. tenebrosa Farquhar, and on the clonal anemone, Anthopleura elegantissima (Brandt) (which similarly bears acrorhagi), indicate that aggression occurs principally between genetically dissimilar (allogeneic) opponents (Ayre, 1982; Francis, 1973a, b; Bigger, 1980). Once acrorhagial contact has been made with an allogeneic individual, massive discharges of nematocysts ensue, which can cause severe necrotic lesions.

The Hydroids collected on the northern edge of the Bay of Biscay during a five days” cruise in August, 1906, by Dr. E. J. Allen, were entrusted to me for examination. I thank my friend Dr. Allen for giving me the opportunity of working through the collection, which contained thirty-seven species, including two new species (Bimeria arborea and Bimeria biscayana) and several rare deep-sea forms.

Our knowledge of the area occupied by the British Hydroids has been increased by this cruise. All the species taken at six out of the eight stations have been previously recorded for the British area. It was only at the two stations over 400 fathoms that foreign species occurred. Bathymetrical distribution has also made an advance, as several species were taken at a depth considerably greater than that hitherto recorded for them.