The ichthyoplankton of Galway Bay was sampled over the spring and summer of 2007 and 2008 to determine what environmental factors influenced the distribution of larval and early juvenile fish. A total of 549 fish representing 27 taxa were caught. Catches decreased throughout each sampling season, and were generally poor in 2007. Catches were numerically dominated by sprat (Sprattus sprattus), dab (Limanda limanda), sand eel (Hyperoplus immaculatus) and whiting (Merlangius merlangus). Environmental factors driving distribution of fish were modelled using a binomial generalized linear model. The strength and direction of wind in the five days preceding sampling was the only significant environmental factor. Sustained onshore winds increased the probability of encountering larval fish in the areas sampled. The rainfall, tidal state, tow depth and wind conditions during sampling were not significant. Among the parameters measured it appears that onshore winds sufficiently strong to overcome the residual circulation are the main physical driver for the distribution of larval fish in Galway Bay.

Thalassomonhystera bathislandica sp. nov. (Nematoda: Monhysteridae) was found in abundance in a few gelatinous phytodetritus aggregates collected from the surface of bottom sediments in the north-eastern Atlantic at depths of about 4000 m. The new species resembles T. islandica (De Coninck, 1943), an inhabitant of saltmarshes. Viscous detrital aggregates, including sediment agglutinations made by the nematodes themselves, are perceived as the preferred habitats of nematode species in fluffy surficial muds. It is suggested that physical constraints prevent nematodes from a fast invasion into freshly sedimented, loose detritus deposits.

The amphipod genus Aoroides is reported for the first time in European marine waters. Specimens of Aoroides semicurvatus and Aoroides curvipes were collected in oyster reefs in Arcachon Bay between 2009 and 2014 and in Hossegor Lake in 2014 (SW France). Specimens of Aoroides longimerus were collected in 2013 and 2014 in subtidal slipper limpet beds and Zostera marina meadows in Arcachon Bay and in 2014 on floating pontoons in the Bay of Brest (W France). These species, native to Asia, may have been accidentally introduced in Arcachon Bay and Hossegor Lake with oyster transfers and in the Bay of Brest through both oyster transfers and shipping.

Habitat modelling requires incorporation of both biotic and abiotic information. For juvenile flatfish the factors that most influence growth are water temperature, food abundance and predatory pressure. This study focuses on the impact the predator, the shore crab, Carcinus maenas, has on the foraging activity of sole, Solea senegalensis. The results show that in the presence of both prey (ragworm, Nereis diversicolor) and predator, ≃10% decrease in foraging activity is observed when compared to the sole in the presence of only food. This suggests that when the shore crab is present, Senegalese soles are not only affected by direct predation but sub-optimal foraging is also found. Behaviours most correlated with foraging were crawling and tapping and these activities were also affected by the presence of the predator. This study also provides further support for visual recognition of predators and olfactory prey recognition in the Senegalese sole. Predator–prey encounters shape species behaviours profoundly and have to be looked at from different levels of ecology, behaviour and modelling.

The age and growth of the snowy grouper, Epinephelus niveatus, from central and south-eastern Brazil were studied by otolith analysis from a sample of 341 specimens, ranging from 325 to 1216 mm in total length (TL) caught with bottom longlines between 1996 and 1998. Otolith length grew proportionally with the increasing TL of the fish. Marginal increment analysis indicated that a single opaque band forms each year during autumn–winter. The maximum estimated age was 54 years, which significantly extends the previously estimated life-span of 21–29 years for this species. The von Bertalanffy growth parameters for both sexes were estimated as L∞ = 1098.4 mm TL, K = 0.062 year −1 and t0 = –2.68. The study revealed differences in mean length-at-age and size at recruitment, as well as in growth parameters between the central and the south-eastern Brazilian coast, which can be attributed mainly to different fishing pressures. The snowy grouper was found at depths of 82–492 m, and showed a positive relationship between age and depth, suggesting differential movements of older fish to deeper waters.

Ectoparasitic crustaceans (Copepoda: Caligidae) occurred at considerable frequency in stomach contents of young specimens of Diplodus sargus and Diplodus puntazzo (Pisces: Sparidae) from two central Mediterranean coastal lagoons. This finding suggests that the ectoparasites might give a non-negligible contribution to the diet of the studied fish species and reveal a certain adaptive advantage of cleaning behaviour in coastal environments.

Shell morphological features of the larvae and early postlarvae of species from two venerid (Mollusca: Lamellibranchia) subfamilies, Chioninae (Mercenaria mercenaria, M. campechiensis, M. campechiensis texana and Chionecancellata) and Pitarinae (Pitar morrhuanus), were examined using scanning electron microscopy. A single elongated fold on the anterior half of the left valve became more robust and a small fold in the centre of the right valve increased in length along the hinge line throughout the larval period. A MANOVA of shell length, shell height and provinculum length detected statistically significant (P) differences between the larval shells of Chioninae and Pitarinae, and within the Mercenaria.

The full developmental embryonic sequence of Gobius cruentatus is described for the first time. Embryonic development lasted 13 days (14·0–15·0°C). The newly hatched larvae (3·3 mm total length) presented pigmented eyes, the yolk is fully absorbed, and the mouth and anus were opened allowing the onset of exogenous feeding almost after hatching.

The respiratory function of the naked body of sea slugs (Opisthobranchia) has long been recognized. The gross anatomy of the gills of dorid nudibranchs was first published by Hancock & Embleton (1852) and was later revised and corrected by Eliot in 1910 in his supplement to the Ray Society monograph by Alder & Hancock (1845–55). Herdman (1890) and Rao (1936) give histological details, but do not seriously add to the understanding of the function of dorid gills or their circulation system. While the gill ciliation of bivalves (Atkins, 1938) and prosobranchs (Yonge, 1947) has been thoroughly examined this is not so in dorid nudibranchs and only the ciliation of the notaspid Pleurobranchus membranaceus has been described in any detail (Thompson & Slinn, 1959; Thompson, 1976) and the dorsal mantle of some dorids (Kress, 1981). Much of the general anatomy of opisthobranchs is reviewed by Hoffman (1939).

Comparative morphology of the cement delivery apparatus of three lepadomorph barnacles indicates that the lepadid Lepas anatifera is unable to relocate voluntarily, whereas the two scalpellids Pollicipes pollicipes and Capitulum mitella can. Mean relocation speeds of up to 50 μm d−1 were measured for both scalpellids, which are probably underestimates of maximal rates given the absence of a directed stimulus. In the laboratory neither gravity nor unidirectional flow proved effective stimuli in directing scalpellid relocation. The two scalpellid species use quite different mechanisms to effect relocation at a leading edge of the base, although both slough basal material at the trailing edge. It is suggested that basal growth effectively accounts for the mobility of P. pollicipes but C. mitella is likely to employ muscular activity.

1. The characters of the species of “Portunus” are redescribed in detail and comparatively.

2. On the basis of the characters studied an attempt is made to determine the relationships of the constituent species, both within the genus and with allied genera, P. corrugatus and P. arcuatus, being regarded as the more primitive forms.

3. P. marmoreus and P. holsatus are separated by a large number of characters.

4. The status of various foreign, fossil and doubtful species is discussed.

5. An account is given of the present state of knowledge regarding the distribution of the species.

6. The synonymy of the generic name is considered at length.

Detailed studies of post-larval shell, hinge and/or internal morphogenesis, from metamorphosis to the completion of development, are available for a very small number of infaunal bivalves (for review of studies see Webb (1984). This paper continues the description, using scanning electron microscopy (SEM), of the post-larval ontogeny of some common infaunal bivalves from north-west European communities and presents the development of Nucula turgida, Venus striatula, Spisula subtruncata and S. elliptica. The association between larval shell morphology and certain features of development in some protobranch bivalves is examined.

Arm loss in two species of starfish Marthasterias glacialis and Asterias rubens (Echinodermata: Asteroidea) was recorded at eight sites in Lough Hyne, south-west Ireland. There was a significant positive correlation between the density of predators (Luidia ciliaris (Echinodermata: Asteroidea) and Cancer pagurus (Crustacea: Brachyura)) and arm loss in both species of starfish. The results suggest that predators may be responsible for a significant proportion of observed arm loss in these two species of starfish in Lough Hyne.

Whole flounder serum has been fractionated by gel filtration on Ultrogel AcA22. Pooled material from the first major peak of the elution profile was further fractionated by FPLC ion-exchange chromatography and this yielded one major and three minor peaks. Under both reducing and non-reducing conditions SDS electrophoresis showed that the major peak and two of the minor ones were immunoglobulin (Ig). All three of these Ig populations were tetrameric, with estimated molecular weights of 710 kD. However, approximately 90% of the major Ig species consisted of tetramers which were covalently linked by disulphide bonds, whereas the remaining 10% was composed of dimeric molecules held together by non-covalent interactions. The heavy chains of all three Ig populations had apparent molecular weights of approximately 72 kD but the light chain composition showed considerable heterogeneity. In the major population, five polypep-tides were detected in the light chain region of the gel with apparent molecular weights covering the range 22–28 kD. However, there was no difference in the light chain composition of covalently and non-covalently linked tetramers. The two minor populations differed both from each other and from the major species in respect of their light chain compositions. No evidence was found for a monomeric serum Ig, and alkaline urea electrophoresis failed to demonstrate a J chain.

Zooplankton was collected by a diver-towed net close to the substratum at four depths (0, 6, 12 and 18 m) over a 17 month period in three locations in Lough Hyne, Co. Cork, Ireland. Zooplankton was identified to phylum or class levels and mean numbers were calculated for each taxon, site and depth. Seasonality was observed in several meroplanktonic groups (Echinodermata, Nemertea, Mollusca and fish postlarvae), and in gelatinous zooplankton. Depth preference was found to be statistically significant in the polychaetes (larvae and pelagic species), molluscan and ascidian larvae. However, the influence of depth on overall zooplankton community composition was found to be negligible. Sampling location, adjacent substrata and flow conditions were found to influence zooplankton in that area.

The distribution of the larvae of four of the five species of Ammodytidae occurring in Scottish waters is examined. The two most abundant species, Ammodytes marinus Raitt and Gymnammodytes semisquamatus (Jourdain) are described in detail and their abundance recorded. A. marinus larvae were found throughout the survey area, but were most abundant in the Moray Firth and around Orkney. G. semisquamatus larvae were most abundant along the north and west coasts, although they were recorded in a few areas off the east coast of Scotland. A. lanceolatus Lesauvage larvae occurred generally in Scottish waters, although few larvae were caught. A. immaculatus Corbin larvae, which have not previously been recorded in the Scottish area, were also rare and were restricted to areas off the north and west coasts. The material was not suitable for demonstrating the distribution of larvae of A. lancea Raitt. The occurrence of larvae is related to the spawning season of each species.

A twelve-month investigation was undertaken on how copepod community structure varied in relation to environmental factors in the Coleroon estuary, south-east India. Sampling was monthly, from Station 1 in the sea to Station 4 in the Vettar backwaters. Canonical correspondence analysis (CCA) was applied to elucidate the environmental factors affecting the copepod community. A total of 104 copepod species in 38 genera and 26 families were recorded, with the Calanoids, Acartia erythraea and Oithona brevicornis being the most dominant. At all four stations, both these species loaded near the intercept of CCA axes 1 and 2, perhaps reflecting that they were autochthonous. Most species occurred in distinct seasonal patterns. Abundances ranged from 13 × 103 to 215 × 103 (ind. m−3). Coleroon waters showed high diversity (bits/ind.), from 5.29 at Station 3 to 4.97 at Station 4. Abundance correlated positively with temperature and salinity and negatively with rainfall, dissolved oxygen concentration (DO) and pH. Species diversity correlated strongly with abundance (P < 0.01). Abundance and diversity were highest during the summer, and both correlated positively with salinity. Temperatures (air and water), salinity, pH and DO varied in the ranges 26–36°C, 25–34.2°C, 9–38, 7.0–8.7 and 3.0–6.8 ml l-1, respectively. Nitrate, nitrite, phosphate and silicate (µM) varied in the ranges: 4.7–64.5, 0.4–14.1, 0.2–12.9 and 9.3–148, respectively.

In a study investigating the composition and spatial and temporal variation of the benthic macrofauna associated to the discharge of domestic sewage off Fortaleza, north-eastern Brazil, a new species of Syllis was found. This new species, S. guidae sp. nov., is characterized by having blades of falcigers with subdistal tooth about same length as distal tooth, but stouter than it, with spines on cutting edge almost reaching the tip of subdistal tooth, blades of falcigers with conspicuous subdistal triangular process and unusually long anal papilla between anal cirri, measuring about one-quarter of their length. Syllis guidae sp. nov., is herein described and compared with the most similar congeners.

The structural parameters of sponge-dominated benthic communities from two Mediterranean caves in two seasons, autumn (November) and spring (June) were compared. The percentage of species in common between communities in each cave was calculated as a rough estimate of the capacity of species dispersion in each cave. The Shannon diversity index and Kulczynski similarity index were calculated for each community. Moreover, we studied the spatial distribution, patchiness and interspecies contacts of the most abundant species. The value of α-diversity was quite constant among communities of the Cabrera cave but decreased from the external to the innermost community in the Medes cave. The Kulczynski similarity index was generally lower among samples of the Cabrera cave. The most abundant sponge species showed a predominantly clumped distribution, especially in the most internal communities of the two caves. The innermost community of the Medes cave had the highest number of patches. Finally, the study of contacts among species that were non-random (meaning species that were in contact with a given species significantly more or less frequently than expected) showed that they were very common in the two seasons and in all communities, indicating the importance of biotic associations among benthic species in cave assemblages.

This work focuses on the species associations of the Baronie Seamount (north-eastern Sardinia, Italy), according to variations in depth and time of day. The aim was to highlight the potential vertical movements of the species and to compare these results to existing data from a submarine canyon. Twenty-two samples were taken at different depths and times along two trawl lines over the seamount. A total of 94 species were caught; among these, 48 bony fish, 9 cartilaginous fish, 13 molluscs and 24 crustaceans were selected for analysis. Cluster analysis showed 3 groups in which both depth and time of day play an important role in grouping. Nine species showed some daily and nocturnal movement, probably linked to trophic requirements. The daily movements according to size and sex of the shrimps Aristaeomorpha foliacea and Aristeus antennatus were also studied. For these two populations, the analysis showed an uneven distribution and the diel cycle appears to involve only the females. These species seem to adapt their life cycle to the geomorphology of the sea bottom. The diurnal movements from the base of the seamount to the edge of the continental shelf increase the range of the species distribution. In fact, the seamount, due to its geomorphological conformation, offers these species the opportunity to very quickly span a considerable range of depths. These movements are known to occur in the continental shelf and slope, but in the seamount they are broadened and can be studied more easily.