This study details the feeding ecology of arrow squid, Nototodarus gouldi, collected opportunistically from trawlers in waters south-east off Australia in 2007 and 2008. Combined stomach content and fatty acid (FA) signature analyses provided clear evidence of seasonal dietary shifts in prey composition. Teleost fish remains (mainly otoliths) were found in 67% of stomachs with the two mesopelagic planktivorous fish, Lampanyctodes hectoris and Maurolicus muelleri dominating. Cephalopods and crustaceans were supplementary dietary components, with an increased representation in the diet over winter. Digestive gland lipid content was moderate (16.4 ± 8.4% wet weight) and was rich in triacylglycerol and monounsaturated fatty acids. Multivariate analysis of FA profiles grouped arrow squid with profiles of mesopelagic fish and cephalopods, thus supporting the findings of stomach content analysis. Seasonal differences in total lipid content were likely related to summer upwelling events and local changes in productivity, while intraspecific differences in lipid class and FA composition were related to seasonal differences of prey consumption. FA analyses also demonstrated dietary differences associated with gender, size and female maturation. Such relationships demonstrate that the diet of N. gouldi is closely linked to prey size, abundance and availability and possibly also, to key life-history stages.

Three microhabitat types (dead coral fragments, coral gravel and coral sand) were distinguished and sampled at two locations (Matemwe and Makunduchi) in a tropical lagoon (Zanzibar Island, Tanzania), and the community structure, habitat preferences and biodiversity of the associated harpacticoid copepod fauna was investigated. The harpacticoid fauna is affected by sediment granulometry and by the structural differences between coral and both gravel and sediment. The coral fragments contained a specific assemblage composed of typical ‘phytal’ taxa (Tisbe, Paradactylopodia and Dactylopusia) along with other eurytopic and sediment-dwelling forms (Ameira, Ectinosoma and Amphiascus), which may be attracted by the sediment retained between the coral branches. The assemblages of coral gravel and upper sediment layer did not differ significantly from each other and had mostly the same dominant genera. The sediment from Matemwe was dominated by the interstitial Paramesochridae and the sediment from Makunduchi by Tetragonicipitidae. The coral fragments from Makunduchi sustained a more diverse assemblage than gravel and the different sediment layers. It was assumed that coral form and complexity, with implications for habitable space, nutritional resources and level of predation, are important in structuring diversity of the associated assemblage.

The shell closure mechanism of Mytilus edulis protects the frontal ciliary mechanism against irreversible damage by low environmental salinity levels. Previous experiments had shown that the mantle fluid of mussels exposed to fluctuating salinity regimes was held at a concentration corresponding to about 60% s.w. (20·1‰S) during the period of shell valve closure (Shumway, 1977), while the oxygen tension of the mantle cavity fell rapidly after shell valve closure to 15 mmHg and thereafter remained relatively constant until the valves reopened (Bettison & Davenport, in preparation). These conditions of salinity and oxygen tension were applied to experimental preparations and their ciliary activity assessed. The salinity conditions alone depressed activity by 39·5%. The conditions of oxygen tension alone also produced a depression of 39·5% but there were signs of recovery during the period of simulated shell valve closure. When both salinity and oxygen tension conditions were applied simultaneously a more profound depression of 64·4% was produced by the interacting factors. Exposure of preparations to salinity levels corresponding to the external environment (‘no closure’ simulation) irretrievably damaged the frontal ciliary mechanism on the first exposure to low salinity.

Following the ‘Volgoneft-248’ oil spill, phytoplankton distribution within the affected area was investigated for two years. Simultaneously measured physical variables such as salinity, temperature, Secchi disc, current speed and direction, and total petroleum hydrocarbons (TPH) were evaluated together with phytoplankton data. At the time of the accident, the TPH concentration in surface water was measured as 2.17 mg l−1 and decreased to 88.5 µg l−1 after five days. In the first sampling period, no diatoms were detected in surface water, while dinoflagellates were dominant in the phytoplankton community. The species composition of phytoplankton changed rapidly in two months and the diatoms increased in terms of abundance and diversity. This indicated that the diatoms might be more sensitive to oil pollution than the dinoflagellates. In comparison with the historical datasets, the low phytoplankton abundance following the oil spill should be considered as the small effect of oil on the phytoplankton rather than natural variability of the ecosystem. High oil concentration in the water column caused stress on the phytoplankton and influenced the species composition negatively depending on the sensitivity of groups and the natural variability of the ecosystem.

The caridean prawn Palaemon longirostris (Milne-Edwards) (Palaemonidae) occurs predominantly in the upper regions of large river estuaries in Europe, and reaches its northern limit of geographical distribution along southern parts of Britain (Smaldon, 1979). All post-larval stages are thought to live under dilute and fluctuating salinity conditions, although there are conflicting reports as to whether ovigerous females need to migrate to the sea at times of egg hatching (Gurney, 1923; Fincham & Furlong, 1984). The species has been known to be extremely euryhaline for some considerable time (Gurney, 1923), yet the salinity tolerance limits of larval (Antonopoulou & Emson, 1989) and post-larval stages (Campbell & Jones, 1989) have been established only recently. Apart from studies on salinity tolerances, and some preliminary measurements of blood and urine osmolality (Parry, 1957), the osmoregulatory adaptations of P.longirostris to its dynamic habitat have not been investigated previously. The present paper describes the osmoregulatory responses of P.longirostris acclimated to a wide range of salinities, and also reports on the ability of individuals to compensate for sudden acute salinity change.

The benthic diversity of the soft bottoms in the Taranto Seas (Mar Grande and Mar Piccolo) (eastern-central Mediterranean Sea) was studied during July 2002. Quantitative samples were taken using a Van Veen grab and granulometric analysis of the sediment was carried out. A total of 131 species were identified. Molluscs and annelids made up 77% of the species and 87% of the individual number. Data from these two groups were used for hierarchical clustering and multidimensional scaling. The diversity was calculated using the rarefaction method. Two main benthic species assemblages were identified. The first corresponded to the stations characterized by pelitic sediment and located in the Mar Piccolo, the second was made up by the stations with pelite with increasing percentages of sand and distributed in the Mar Grande. The first assemblage consisted of species that usually live on muddy bottoms rich in organic matter; the second consisted of a greater number of species, usually occurring on different types of bottoms. Diversity was found to be higher in the Mar Grande than in the Mar Piccolo, indicating that physico-chemical alterations of the environment probably play a leading role in controlling community structure.

The aim of this study was to evaluate the dietary composition of the Patagonian seahorse Hippocampus patagonicus in San Antonio Bay, Patagonia, Argentina. To this end, analyses of stomach and gut contents were carried out and the diet composition was compared to the potential preys available in the natural environment. Samples were collected from different places in San Antonio Bay, a Marine Protected Area in San Matías Gulf. Type and number of prey present in the digestive tracts were registered and frequency of occurrence (%FO) and number of prey (%N) were calculated for each study area. Amphipods (Gammaridae, Caprellidae and Hiperidae) and decapods are the main dietary items of H. patagonicus in San Antonio Bay. There were differences in %FO and %N at different sites, which could indicate differences in abundance and availability of prey in the environment. No dietary differences were detected between sex and size of seahorse (ANOVA, P > 0.05). Results from the present study show that, in nature and probably due to limiting environmental factors, H. patagonicus behaves as an opportunistic predator, which preys on the most abundant and vulnerable species present in the environment.

Based on data from 151 underwater surveys (scuba) between 2002 and 2007, the present study assessed the reef fish fauna from a scarcely known region on the north-eastern Brazilian coast (Ceará State). A checklist of 179 taxa is provided and the zoogeographic patterns are analysed and discussed, including six other localities. Based only on assemblage composition, the reef fish fauna from Ceará showed a strong resemblance (73%) with the reefs of Risca do Zumbi (RN) and Paraiba (PB). The data from the visual censuses including abundance values corroborate the evaluation based only on composition and suggest ecological factors as the main drivers of the fish assemblages in the region.

The study presents Cladorhizidae collected during Ifremer cruises in the Atlantic Ocean from 1981 to 2004. Fifteen species are described from the genera Abyssocladia, Asbestopluma, Chondrocladia and Cladorhiza, with complete descriptions of five new species. While a couple of species were collected at 670–1010 m depth at the Rockall Bank, most species were collected at middle to lower bathyal and abyssal depths (~2000–5000 m), ranging from the northern Atlantic to the Mid-Atlantic Ridge and the coast of Africa at Gabon–Congo. A biogeographic analysis of currently known Arctic, Atlantic and some Antarctic species shows that the majority of included cladorhizids are described from the north-east Atlantic and Arctic Oceans while a lower number of species are known from other parts of the Atlantic Ocean. Large regions are poorly investigated, and previously undescribed species can be expected when sampling in these areas. A regional mostly endemic cladorhizid fauna is predicted for shelf and upper slope areas. Species in the lower bathyal and abyssal seem on the other hand to have a wider geographical distribution.

The pigments of pure cultures of algae, of known number per volume, have been extracted with aqueous acetone after separation by filtration. The extracts were compared in a Kober colorimeter with standard solutions of a preparation of bought chlorophyll. The number required to give 1 mg. of chlorophyll was thus determined.

The algae studied included: Chlorophyceae, two species of Chlamydomonas and one Chlorella not yet described; Chrysophyceae, Dicrateria inornata Parke; Bacillariophyceae, Coscinodiscus centralis Ehr., Thalassiosira gravida Cleve and Nitzschia closterium (Ehr.) W.Sm. forma minutissima; Cryptophyceae, Hemiselmis rufescens Parke; Dinophyceae, Gymnodinium sp. The numbers per milligram of chlorophyll varied from 74 × 103 for Coscinodiscus to over 3200 × 106 for Hemiselmis rufescens. Of the nine cultures, six were between 50 and 750 × 106. The volume of the cell is the decisive factor in the milligram count.

Ontogenetic diet changes (prey species richness and size) in juveniles of white sea catfish (Genidens barbus) were tested in three southern Brazilian estuaries: Mampituba (29°12′S), Tramandaí (30°02′S), Chuí (33°44′S). Cluster analysis revealed that white sea catfish juvenile populations in the three estuaries are composed of two feeding groups. These two feeding groups are coincident with a bimodal size–age distribution of the juveniles of white sea catfish. In small catfish (5 to 10 cm TL) copepods were the most numerous prey (Chuí = 86.66%N, Tramandaí = 85.52%N and Mampituba = 52.34%N). In large catfish (10 to 20 cm TL) the most abundant and frequent prey was fish (Chuí: 73.19%N and 74.56%FO; Tramandaí: 85.92%N and 73.33%FO; Mampituba: 52.34%N and 61.54%FO). The Morisita overlap index among small and large fish was low in all estuaries; high values of Morisita's similarity index were observed among same size catfish groups. In all cases, no differences were observed among prey bio-volume curves of same size predator groups (small, F = 0.41, P = 0.65; large, F = 2.19, P = 0.11). In all estuaries, prey size increased significantly with increasing predator size. The 90th regression quantile estimated with most precision the predator–prey size relationship.

Young Homarus vulgaris were reared in the laboratory up to stage V. All settled during stage IV by burrowing under stones placed on a sand or mud substrate. Half of the 100 animals studied burrowed within 6 days of reaching stage IV and did not subsequently vacate the burrow. The burrows were made with two openings on opposite sides of the stone which, in the case of the sand burrows, served as a roof. The burrows were made by the same methods as previously described for young and adult H. americanus

Very little is known about the life history of Robsonella fontaniana. In particular, there are no descriptions of the early life stages that enable correct identification of samples taken from the wild. In this work, eggs and hatchlings are described from egg clutches obtained in the field with brooding females and incubated until hatching. Individual eggs exhibited marked differences in stages of embryonic development within egg clutches or even within a single egg string. For one clutch collected at early stages of embryonic development, embryogenesis took 91 days at 11.5 °C and for a second clutch at intermediate developmental stages it took 68 days at 11 °C and 39 days at 14 °C. For the later clutch the hatching period lasts 25 days at 14 °C. The eggs and paralarvae were small, with an egg length of 3.9–5.2 mm, a dorsal mantle length of 2–3 mm and a total paralarvae length of 3.4–6.0 mm. Chromatophore shape and distribution presented a very distinctive pattern. Characteristics of the eggs, egg strings and paralarvae make it possible to distinguish the early stages of R. fontaniana from those of other octopodid species found off the Atlantic coast of Patagonia.

The feeding habits of Euthynnus alletteratus and its variations compared to predator size in the central Mediterranean Sea were investigated. The stomach contents of 187 specimens were analysed, ranging from 26.8 to 50.3 cm total length, caught by authorized experimental drift-nets. The difference in food items found in the stomachs was evaluated by occurrence of prey frequency, prey weight, and prey abundance; these criteria were used to calculate an index of relative importance. Fish were the dominant food detected according to all numerical indicators examined and were mainly represented by Maurolicus muelleri and larval stages of teleosts. Hyperiid amphipods, dominated by Anchylomera blossevillei and Phrosina semilunata, were well represented in terms of frequency of occurrence. Variations in the diet composition compared to fish size were observed. Comparative analysis performed on prey abundance highlighted a trend of increasing predator size-classes among prey items. The specimens of the smallest sizes ate mainly adult clupeiforms and larvae or other juvenile teleosts. As fish grew, there were increased amounts of adult teleosts, crustaceans (hyperiids and isopods) and cephalopods. Maurolicus muelleri was the most important prey for the largest specimens analysed. Significant differences among size-classes, both in prey abundance and in prey weight, were confirmed by non-parametric multivariate analysis of variance (NP-MANOVA).

A new interstitial hydroid, Sympagohydra tuuli, has been collected from the three-dimensional brine channel system of the coastal fast ice off Barrow, Alaska (71°N 156ºW) in 2003 to 2006. This is the first cnidarian species described from the sea ice interstitial habitat. A morphological and systematic account of the new species is provided here. The hydroid stage is represented by solitary naked polyps, which become almost spherical under contraction. Body length can vary from 200 µm to >1 mm according to the degree of relaxation. The aboral side is extensible into a tubular foot-like projection made by epidermal tissue only, a typical feature of representatives of Protohydridae, order Capitata. However, in contrast to the other two known Protohydridae species, S. tuuli is characterized by three to four solid filiform tentacles, armed with microbasic mastigophore and desmoneme cnidocysts, and located at the base of a short hypostome bearing stenoteles. A small number of mastigophores are also scattered along the body column. Due to its unique combination of features, this taxon is designated here as a new species, and the new genus Sympagohydra is established as a new member of the class Hydroidomedusa, subclass Anthomedusae, order Capitata, family Protohydridae, to accommodate S. tuuli.

This paper describes a study of the ranging and diving behaviour of two ‘offshore’ bottlenose dolphins, Tursiops sp., in the waters off south-east Queensland, determined using satellite-linked time-depth recorders attached to two animals. Animal 1's tag transmitted for 30 days, Animal 2's for 143 days. Immediately after tagging, Animal 1 swam south, reaching a point 146 km south of the point of tagging, then swam generally northwards until the tag ceased working. Animal 2's observed range covered 778 km2, with a core area of 86 km2. The greatest north–south distance between all locations for Animal 2 was 43 km. The manner in which maximum dive depth was related to dive duration was analysed using constrained principal curves. These analyses indicated that for both animals, short dives were to less than 5 m, and there was no clear relationship between dives of greater duration and depth. These dolphins appear to behave differently from ‘offshore’ bottlenose dolphins studied elsewhere.

The Sr, Mg, and Ca chemistry and mineralogy of the shell, beaks, and inorganic compounds of the renal appendages of Nautilus pompilius Linné 1758 reveal a complex physiochemical system of biomineralization. The chemistry of the shell and septal aragonite is similar, and establish that N. pompilius discriminates against the concentration of Sr and Mg in sea water by 78% and more than 99% respectively. Beaks consist of high-Mg calcite (4.4% MgCO3). Renal appendages contain either aggregates of crystals (uroliths) of Mg-oxalate dihydrate with nuclei of hydroxyapatite or disassociated particles of hydroxyapatite or both. There is no evidence that uroliths or hydroxyapatite particles serve as temporary reservoirs of Ca during calcification of septa.

The gametogenic and spat settlement patterns of two Mytihis edulis beds were studied in Dundrum Inner Bay, Northern Ireland. There was evidence of gonad development throughout the year with the main development period between November and March. Spawning was protracted, lasting from May to November. Slight inter-annual and inter-population differences in the riming of the phases were observed but the cycles at both beds were broadly similar to each other and to those of other British and Irish sites. Settlement occurred throughout the year and there was evidence of both primary and secondary spat settlement at both sites. Although the reproductive cycles were similar, distinct seasonal and inter-site differences in spatfall were apparent. At the Downshire Bridge bed, settlement peaked during summer and was dominated by spat in the 0·;5-1·0 mm size range. At Ballykinler, settlement levels were highest in the winter months and larger (>1 mm) spat dominated the samples. The orientation of spat collection pads also significantly affected numbers of the larger (>1 mm) spat. Collectors facing the flood tide attracted significantly more secondary settlers than ebb-facing collectors. This effect varied seasonally and was greater at the Ballykinler bed. It is suggested that hydrodynamic regimes may be an important factor in the differences in settlement patterns of M. edulis.

The feeding habits of Trigla lucerna L. (1758) and Aspitrigla obscura L. (1764) (Pisces: Triglidae), off the coast of the Gulf of Valencia (Spain), were investigated between October 1989 and January 1991. The two species examined in this study appear to have distinct feeding types, based on the species composition of prey and the frequency of occurrence of major food items. Tub gurnard had a more diverse diet and fed mainly on crustaceans (mysids and decapods), teleosts and molluscs, whilst long fin gurnard were less piscivorous and fed mainly on mysids and natantids. No significant differences were found in the annual variation of vacuity coefficient for either species. Diet composition in these species did not show great changes with either season and size of fish. There was little dietary overlap between these two species.