Previous observations in the St Lawrence Estuary (eastern Canada) suggested that larvae of intertidal barnacles (Semibalanus balanoides) would settle almost exclusively inside crevices on shores that are scoured by sea ice every winter. It was suggested that the strong ice scour in winter on that coast (which removes organisms outside of crevices) would select for such a larval behaviour. We tested the generality of this pattern by sampling other ice-scoured shores within the Gulf of St Lawrence system. In particular, we surveyed a shore in Nova Scotia where exposed habitats (subjected to strong ice scour in winter) are interspersed with sheltered habitats (which suffer milder ice scour). Such a topographical complexity might allow for the coastal larval pool to contain a proportion of larvae that have no particular settlement preference for crevices, as selective pressures for such a behaviour would be minimal in ice-sheltered habitats. Consistently with this notion, barnacle recruits (which appear after the winter ice melts) occurred abundantly both inside and outside of crevices across the shore in the spring seasons of 2005 and 2006. Average recruit density on rocky surfaces ranged between 337 and 588 recruits dm−2, depending on the habitat. It is therefore possible that barnacle recruitment patterns on ice-scoured shores may be affected indirectly by the structural complexity of the coast.

A new species of Abyssoninoe (Polychaeta: Lumbrineridae) has been found on sublittoral soft bottoms in the Gulf of Milazzo (central Mediterranean Sea). The description is based on eleven specimens recorded in six grab samples carried out by Van Veen grab from 20 to 50 m depth. Abyssoninoe bidentata sp. nov. differs from the six hitherto known species of Abyssoninoe by having the maxillae III with two subequal teeth instead of one, the shape of the parapodial lobes and chaetal distribution.

Analyses of phosphorus, nitrogen, iron and manganese are recorded for Balanus nauplii (a cirripede crustacean), post-larval Callionymus (a teleostean fish), mature Sagitta elegans (a chaetognath), Pleurobrachia (a ctenophore) and for crab zoeas and megalopas (Table I). A sample of Sagitta setosa in 1934 contained much more iron than that in S. elegans here reported. The ctenophore, Pleurobrachta, is relatively poor in phosphorus, nitrogen and iron and its ash-free protoplasm must evidently be rich in either fats or carbohydrates. Neither Pleurobrachia nor Balanus nauplii effect any appreciable concentration of manganese from sea water.

This cercaria was found to be very common in specimens of Littorina rudis (Maton) and L. obtusata (Linné) collected at Aberystwyth during February and March, 1935, occurring in twenty out of fifty specimens of L. rudis and in four out of forty specimens of L. obtusata. It was, on the other hand, very rare in L. littorea, only two infested individuals being found out of a total of two thousand molluscs examined. In all three species of mollusc the parts of the digestive gland most heavily infested appeared white or creamy-white in colour.

The form described here appears to be almost identical with Cercaria ubiquitoides recorded by Stunkard (1932) from L. littorea and L. rudis occurring on the coast of Brittany. Certain differences are found between my specimens and those of Stunkard. It is difficult to determine whether these differences are individual or specific because there are so few larval characters in cercariæ of the Ubiquita group which can be used for separating species. The problem is rendered more difficult by the close resemblance of the adult trematodes (species of the genus Spelotrema).

A recent inventory of the benthic Gammaridea: Amphipoda species on the French continental coastline catalogued 495 species. An analysis of the biodiversity and the biogeographic relationships that exist between the French Amphipoda: Gammaridea, living on the coastline that extends along 10° latitude range in the temperate region between 41° and 51° North and the other gammaridean faunas living in the north-eastern Atlantic has drawn the pattern of diversity in this marine invertebrate group on a large biogeographical scale. Gammaridean amphipods exhibit a latitudinal gradient over the total number of species, including the continental shelf species and the bathyal species. There are four main fauna groups, which correspond to the biogeographical zones of the north-eastern Atlantic: (1) a cold arctic and cool-temperate Svalbard and Norwegian coastal fauna; (2) a cool-temperate boreal and Boreal–Lusitanian United Kingdom, Irish and English Channel shallow fauna; (3) a warm-temperate Lusitanian Bay of Biscay and subtropical central Atlantic fauna; and (4) a subtropical Mediterranean fauna. The French fauna appears particularly rich, presenting 44% of the 1119 species recorded in the north-eastern Atlantic along the 50° latitude range (30°N–80°N).  

This is obviously due to France's intermediate latitudinal location within the Lusitanian temperate biogeographical zone, which produces a biogeographical cross between the boreal fauna in the north and the warm temperate and sub-tropical fauna in the south.

Spatio–temporal changes in density, breeding cycle, growth and population structure of Hydrobia ulvae (Gastropoda: Prosobranchia) were studied by monthly sampling of a wide bare mudflat in Marennes-Oléron Bay. Four stations, located along a cross-shore transect and characterized by different geomorphological structures, were investigated from March 2000 to February 2001. Hydrobia ulvae was mainly distributed in the upper half part of the mudflat and no individuals were found in the lower part. The breeding cycle extended from March to December and showed two annual peaks, in spring and in autumn. Three cohorts were recruited during the year and showed high growth rates during summer; the parameters of the von Bertalanffy model describing the growth curves were equal to kmax=0·47±0·5 mm month−1 and L∞=5·4±0·2 mm. The snail population had similar size–frequency structure along the transect at the beginning of the survey but summer recruitment initiated spatial differentiation. Reproduction occurred in the middle part of the mudflat but recruits mainly settled down at the upper level of the mudflat; new cohorts appeared with increasing individual densities. The middle part of the mudflat was rather dominated by adult individuals which showed large density fluctuations.

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.

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.

Four species of the genus Haplosyllis from Indonesia are herein described and illustrated. In Haplosyllis aciculata sp. nov. and Haplosyllis ingensicola sp. nov. the longest midbody cirri exceed body width and posterior parapodia have a single broad, strongly curved acicula, while in Haplosyllis tenhovei sp. nov. and Haplosyllis nicoleae sp. nov. cirri are shorter than body width, and the two or more aciculae are straight or curved. The available information on the ecology and host species is provided.

The present study confirms the findings that in the two ocypodid crabs Ocypode saratan and O. ryderi haemocyanin oxygen affinity is increased in ‘replaced’ or dialysed blood compared to whole haemolymph and that this difference can be attributed to a plasma factor. After the replacement of the plasma, the haemocyanin of both species showed up to a 39% increase in oxygen affinity. The change in oxygen affinity was proportional to the logarithm of the amount of native plasma present. Further investigations have shown that this difference is not due to changes in plasma urate or bicarbonate concentrations. Using plasma exchange experiments it could be shown that the factor acts specifically on the haemocyanin of Ocypode spp. and not on Carcinus maenas haemocyanin. Fast protein liquid chromatography (FPLC) techniques indicate that the molecular weight of the factor is <5000 daltons and a specific peak could be isolated. This isolated peak is linearly correlated with changes in haemocyanin oxygen affinity. The results are discussed in the light of the overall modulation of haemocyanin oxygen affinity and the need for negative effectors.

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.

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.

Within a cohort of young copepods, the individual size or growth rate becomes increasingly diversified during the development. The longer the development, the greater the resulting anatomical or functional diversity, since the differences between fast growing and slow growing individuals increase with time. Different factors may contribute to this variability, such as genetic diversity and metabolic differences in the ability to utilize food resources.

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.

The burrowing brittle-star Acrocnida brachiata has so far been regarded as a single, easily identifiable species. Recent studies showed habitat-related differences in maximum size, life span, breeding time and recruitment between intertidal and subtidal populations, which at first were attributed to environmental effects on individuals within the same species. Molecular data, however, strongly suggested the existence of two distinct lineages and ultimately two cryptic species with clear bathymetric segregation. Morphological evidence had so far not been presented, because any differences were interpreted as intraspecific variation. We collected A. brachiata from intertidal and subtidal habitats at the coast of Brittany, France, and examined 15 specimens of each group externally by SEM. A key character of A. brachiata is that the scales at the edge of the disc and on the ventral side are conically enlarged. Intertidal individuals showed a sparser disc scalation, more spine-like than conical ventral disc scales and spatulate, distally widened arm spines. In addition, we dissected several specimens of different size and examined the internal skeleton by SEM. The oral plates showed a rib-like structure on their abradial face that differs between individuals from either habitat. Subtidal specimens have fewer ribs than intertidal ones. These consistent differences support the existence of two species within A. brachiata. To describe the second species, we needed to establish the identity of A. brachiata. We describe a neotype, because no type material has been preserved since it was first described; it corresponds mainly to subtidal samples. The new species is described as Acrocnida spatulispina sp. nov. The taxonomic status of Acrocnida has been debated over the years with reference to its close affinities with Amphiura chiajei. We compared the species of Acrocnida with A. chiajei and Amphiura filiformis and found that Acrocnida is indeed morphologically similar to A. chiajei, among other characters by a similar oral plate structure, whereas A. filiformis differs greatly from Acrocnida as well as A. chiajei. Most strikingly, it has a different type of oral plate. These findings indicate that fundamental taxonomic changes may need to be made in the family Amphiuridae in the future.

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.

The laboratory at Plymouth was notified of the capture of five dolphins in a commercial trawl on 9 December 1982, three of the specimens were living and therefore immediately released. The remaining two were brought to the laboratory, identified as Delphinus delphis Linnaeus, 1758, their size and sex were recorded and the stomachs removed for examination of their contents. The exact location of capture was not recorded, but is known to be within 40 miles of Plymouth.

Reports of strandings of D. delphis collected by the British Museum (Natural History), (Harmer, 1914–27; Fraser, 1934, 1946, 1953, 1974) and more recent recorded sightings (Evans, 1980) show that the common dolphin is clearly not rare in British waters. Although the species has been recorded off all British coasts, sightings and strandings are concentrated off the south and south-west coasts of Britain and Ireland. The variation in their numbers and distribution both during this century and on a seasonal basis each year has been accounted for mainly by the fluctuation and movement of their food supply (Evans, 1980; Sheldrick, 1976).

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.

Growth rates of newly-metamorphosed urchins from a single spawning event (three males and three females) were highly variable, despite being held en masse under identical environmental and nutritional conditions. As individuals reached ~5 mm diameter (0.07–0.10 g wet weight), they were placed in growth trials (23 dietary treatments containing various nutrient profiles). Elapsed time from the first individual entering the growth trials to the last individual entering was 121 days (N = 170 individuals). During the five-week growth trials, urchins were held individually and proffered a limiting ration to evaluate growth rate and production efficiency. Growth rates among individuals within each dietary treatment remained highly variable. Across all dietary treatments, individuals with an initially high growth rate (entering the study first) continued to grow at a faster rate than those with an initially low growth rate (entering the study at a later date), regardless of feed intake. Wet weight gain (ranging from 0.13–3.19 g, P <0.0001, R2 = 0.5801) and dry matter production efficiency (ranging from 25.2–180.5%, P = 0.0003, R2 = 0.6162) were negatively correlated with stocking date, regardless of dietary treatment. Although canalization of growth rate during en masse early post-metamorphic growth is possible, we hypothesize that intrinsic differences in growth rates are, in part, the result of differences (possibly genetic) in production efficiencies of individual Lytechinus variegatus. That is, some sea urchins are more efficient in converting feed to biomass. We further hypothesize that this variation may have evolved as an adaptive response to selective pressure related to food availability.