The feeding intensity and the diet of Merluccius merluccius were studied along a 1000 km latitudinal scale on the coasts of the Iberian Peninsula (western Mediterranean) in spring 2000. Merluccius merluccius was distributed along two bathymetric bands corresponding to the deep continental shelf (between 36 to 148 m), and the upper slope (between 215 to 310 m). At the shelf small crustaceans (mainly euphausiids and mysids) were dominant in the diet while fish (mainly Myctophidae) were the preferred prey on the slope. Feeding intensity of hake was significantly higher in areas with higher hake density suggesting feeding aggregations. Also, feeding intensity was significantly correlated with phytoplankton pigment concentrations (ppc), though only with ppc recorded one month before on the hake sampling stations. This delay between ppc and feeding intensity of hake may be a response to higher prey availability, because most hake prey were pelagic in origin (euphausiids, Clupeiformes) and they may reach high densities after exploiting local phytoplankton blooms. This delayed response seems to have more a local or spotted pattern. During three 8-h sampling cycles food consumed by hake ranged between 1·01 to 5·51% body wet weight (BWW), on average within the range of food consumption rates of other benthopelagic, active swimmer, fish.

Small vagile epiphytic crustaceans formed the greatest proportion of the diet of worm pipefish. There were significant differences in the number (Mann–Whitney U=22006·5, P<0·001) and diversity (Mann–Whitney U=11546·0, P<0·05) of prey consumed by male and female pipefish. Harpacticoid copepods are the most numerically dominant form of prey consumed. Further gender analysis of mature pipefish revealed that reproductively mature females and egg-bearing male worm pipefish show significantly greater predatory effort (Kruskal–Wallis H=24·15, df=2, P<0·001). Increased feeding activity, within these groups, is suggested to alleviate the substantial reproductive costs for both female and egg-bearing male pipefish.

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.

This paper details the first recorded instance of the prawn Palaemon macrodactylus in Europe, at the Orwell estuary, Suffolk. The species is native to north-east Asia, including Japan and Korea, and has previously been introduced to other areas outside its natural range. Records of the abundance of caridean species, obtained from routine benthic trawl samples in the Stour and Orwell estuaries, provide a summary of P. macrodactylus' habitat preference in reduced-salinity waters. Consistent catches and records of ovigerous females provide evidence for the stability of the Orwell population. A revised key to British Palaemonidae is also provided.

To evaluate the consequences of the coexistence of the Senegal sea bream Diplodus bellottii with one other species of Diplodus, Diplodus vulgaris, in the Tagus estuary (Portugal), the distribution and feeding habits of juveniles and adults of both species were studied. Sampling took place between May 2001 and March 2002, in five zones, including the estuary and adjacent coastal area, using an otter trawl. Both species were abundant in the estuary and their distribution overlapped. The stomach contents analysis showed that the diet of both species was mainly composed of algae, bivalves and crustaceans. Diphodus bellottii and D. vulgaris showed a generalist feeding behaviour and were clearly omnivorous, being detected in a high trophic niche overlap between the two species. Competition for space and food may occur when densities are high and food became a limiting factor.

The ctenostome bryozoan Alcyonidium diaphanum is widespread and abundant in the coastal waters of the British Isles. During the Centre for Environment, Fisheries and Aquaculture Science groundfish surveys some atypical colonies were found and subsequent histological and genetic analyses have shown that these represent two previously undescribed species of erect subtidal Alcyonidium. They are described here fully and named Alcyonidium condylocinereum and Alcyonidium hydrocoalitum. Comparisons with further museum specimens of erect Alcyonidium species have shown that A. proliferans, A. topsenti and A. gelatinosum form lacourti can be synonymized with A. diaphanum. The northern and southern limits of A. diaphanum are here more clearly defined; however, the identities of Arctic erect Alcyonidium species have yet to be fully investigated using histological and genetic methodologies. It is clear from this study that gross colony morphology is not a good indicator of species identity, but that tentacle number and reproductive mode can be useful taxonomic characteristics in these species.

Little is known about cetacean communities in the tropical and sub-tropical Atlantic. This paper describes the cetacean community found east of Great Abaco in the northern Bahamas (26·5°N) during summer months between 1998 and 2001. Nine species of cetaceans were recorded, which could be divided into two distinct groupings: firstly, ‘permanent’ species, which had relative sightings rates between 0·026–0·084 sightings per hour and which were recorded on many occasions in all years and most months; secondly, ‘sporadic’ species, which had relative sightings rates an order of magnitude lower (0·004–0·008 sightings per hour) and which were recorded on very few occasions. The ‘permanent’ species were the Stenella frontalis (Atlantic spotted dolphin), Kogia simus (the dwarf sperm whale), Mesoplodon densirostris (Blainville's beaked whale) and Ziphius cavirostris (Cuvier's beaked whale). These four species differed significantly in the depth of grid squares utilized (χ=20·25, df=9, P<0·01) suggesting that these species occupied four separate niches. Stenella frontalis dominated the surface feeding niche, while the remaining three deep-diving species segregated into different depth ranges. Kogia simus was the dominant species in water depths of less than 200 m, M. densirostris in water depths of 200 to 1000 m and Z. cavirostris in water depths of greater than 1000 m. The overall relative density (2·533 individuals per hour of effort) and diversity of species in the study area was relatively low and may relate to low levels of local productivity. It is hypothesized that the four ‘permanent’ species may competitively exclude ecologically similar species, resulting in a reduced number of species and that ‘sporadic’ species may only enter the study area during times of higher than usual productivity when the ‘permanent’ species are no longer able to dominate their individual niches.

The John Dory, Zeus faber, has a pair of intrinsic sonic muscles on the swimbladder wall and produces sounds by rapid contractions of the muscles. The physical properties of the sounds and the detailed innervation pattern to the sonic muscle were investigated. The dory emitted two types of the sounds: ‘bark’ and ‘growl’. The bark consisted of continuous multiple pulses and lasted about 85 ms on the average. The growl consisted of a group of intermittent single-pulses and lasted for 50 ms to 1·2 s. The main frequencies of both sounds were almost similar and ranged between 200 to 600 Hz. The sonic muscles were innervated by the sonic branches of the first to fourth spinal nerves. The innervation from the first spinal nerve was newly revealed in the present study. A total of 1700 myelinated axons innervated the sonic muscles on both sides. There were no sex differences in the sonic muscle size as judged by the sonic muscle–somatic index (male: 0·675%, female: 0·670%).

The genetic diversity of the soft-shell clam Mya arenaria from seven locations in Europe (two stations in the southern Baltic Sea (the Gulf of Gdansk) and two in the North Sea (Veerse Meer and Oosterschelde), and three additional stations in the Denmark Straits and Bay of Biscay) was determined using starch gel electrophoresis of allozymes. The results showed a low level of genetic variability and a lack of genetic differentation among the populations studied. Basic polymorphism characteristics calculated for populations from the North Sea estuaries and the Gulf of Gdansk were: He 0·094–0·145, Ho 0·092–0·130, percentage of polymorphic loci 33 (0·95 criterion), mean number of alleles per locus 2·0–2·7. The mean value of FST was 0·0133 and not significant. It is concluded that in spite of a low level of genetic polymorphism the soft-shell clam is a successful colonizer. The genetic homogeneity among the populations reflects rapid population extension, alleles neutrality and a high gene flow.

Seven species of the ctenostome bryozoan genus Alcyonidium from Magellanic, Patagonian and Antarctic shelf coastal waters are described using molecular genetic and morphological characteristics. One species is limited to cold temperate South America. A second species is reported from five stations in the Magellan Strait and a single station in the Palmer Archipelago, Antarctic Peninsula. The remaining five species appear to be endemic to Antarctica; Alcyonidium epispiculum, A. scolecoideum and A. simulatum are species new to science, A. australe, A. eightsi and A. flabelliforme are substantially revised and A. pelagosphaerum is upgraded to species level. Genetic diversity is least in the circumpolar Antarctic species Alcyonidium flabelliforme and greatest in the epibiotic A. eightsi, recorded only from the Palmer Archipelago. The latter is shown to brood lecithotrophic larvae with predicted minimum dispersal capability, five of the remaining species are inferred to shed planktonic larvae with potentially wide dispersal abilities. Reproductive mode of one species is unknown. A phylogenetic analysis of five haplotypes recognized shows the ancestral haplotype to belong to the broadcast spawner A. epispiculum. The two most recently diverged haplotypes were found in the brooding species A. eightsi.

Data on tag recoveries of 31 adult female and two juvenile loggerhead turtles (Caretta caretta) along the eastern Adriatic coast were analysed. All adult females originated from Mediterranean nesting areas: 29 from Greece, one from Cyprus and one from Turkey. This is the largest aggregation of long-distance tag recoveries in the Mediterranean for the loggerhead population nesting in Greece. The short period elapsed between the last observation of some turtles on the nesting beach and their recovery suggests the existence of a migratory pathway from the Ionian Sea into the Adriatic. Recoveries of some turtles within a period of a year indicate that loggerheads reside in the Adriatic for some time, suggesting that some individuals may demonstrate a level of site fidelity for these marine habitats. The high concentration of tag returns in the shallow northern Adriatic highlights this region as an important feeding habitat, for the population nesting in Greece in particular. The Ionian–Adriatic loggerheads form an important management sub-unit for this nesting population.

The ctenostome bryozoan Alcyonidium disciforme is the only known free-living Arctic bryozoan. Alcyonidium disciforme has a strictly Arctic circumpolar distribution. The material studied was collected during 1995–2002 in West Spitsbergen, Svalbard. Densities of the bryozoan in Van Veen grab and SCUBA diving samples are presented together with environmental data. Alcyonidium disciforme is restricted to the inner part of Kongsfjorden—main area of study. The activity of the tidal glacier situated in the inner part of the fjord results in strong environmental gradients, meltwater outflows causing salinity and temperature fluctuations together with high concentrations and rates of mineral material sedimentation. The wide bathymetric range of the species (8 to 240 m) suggests that depth is not its limiting factor within the fjord. High densities of A. disciforme recorded in shallow glacial bay waters indicate that it is highly tolerant of fluctuations in salinity. It also tolerates high mineral sedimentation rates; this is unusual for a suspension-feeding animal. The species has a very regular disc-like shape. Colonies develop a central hole when they reach approximately 3 mm in diameter. There are significant positive correlations between wet mass vs colony diameter, wet mass vs central hole diameter, and diameter of the whole colony vs central hole diameter. Alcyonidium disciforme is adapted, through its colony shape and zooids filled with sand particles acting as a ballast to survive in a dynamic sedimentary environment.

This paper reports the observations recorded on the arcid clam, Anadara demiri, from its first reporting in the Adriatic Sea three years ago, when its presence only was noted, to the present day when its invasive potential is confirmed. Repeated recruitment events were observed and confirmed by the co-existence of two or more cohorts within the population. Anadara demiri appears to be a year-round spawner with two spawning peaks (late winter and summer). Together with the congeneric invader, Anadara inaequivalvis, it has colonized the external belt of the fine well-sorted sand biocoenosis where they may numerically dominate the benthic community. Anadara demiri appears to have gained full status as a component of the Adriatic Sea coastal benthic community despite its very recent first entry. Numerous features make it a strong competitor among which is the ability, retained into adult life, of attaching, by means of byssus threads to all kinds of hard substrata, particularly to other live molluscs such as the gastropod Aporrhais pespelecani and the bivalves Anadara inaequivalvis and Chamelea gallina. The presence of species actively interfering with A. demiri in various ways (the polychaetes, Polydora sp. and Sabellaria spinulosa, that bore into and foul the shell, respectively, and the predatory asteroid Astropecten irregularis) is discussed.

The muzzled blenny Omobanchus punctatus is recorded for the first time in the Mediterranean Sea, collected among fouling organisms covering the frame of aquaculture cages at the entrance to the port of Ashdod, Israel. Its presence there is most likely due to accidental introduction attributed to ship-mediated transfer.

The occurrence of an area of methane seepage off Chile is reported for the first time. Shell fragments of two species of bivalves of the genus Calyptogena and one species of Acharax were retrieved in dredge hauls from 651 to 934 m depth off Concepción (≈36°S). A large quantity of carbonate blocks was also collected, indicating anaerobic oxidation of methane in the sediment. The accompanying, non-chemosynthetic fauna from one of the hauls was diverse, containing some species new to science. Our preliminary data suggests an assemblage similar in structure to those reported elsewhere, albeit with an important endemic component.

Specimens of flounder Platichthys flesus were randomly sampled from three regions of the southern Baltic Sea: the Gulf of Gdańsk, the Pomeranian Bay, the open sea off Łeba and from the northern Øresund, Kattegat. The collected parasites were morphologically identified and their genotypes at seven loci coding for enzymes were checked. Wide ranges in both the numbers of rows of rostellar hooks and the numbers of rostellar hooks per row were detected, indicating the presence of two species in the material: Pomphorhynchus kostylewi and Pomphorhynchus laevis. However, electrophoretic data does not support occurrence of two independent gene pools.

A preliminary ontogenetic series of common pandora (Pagellus erythrinus) larvae is presented showing that larvae of this species possess an occipital crest from 4 to 16 mm total length. Such a trait has been described as a diagnostic character of the larvae of another sparid fish, namely Pagrus pagrus, and has been erroneously considered as being absent in all other Sparidae species. This caused confusion and erratic identifications of the two species of larvae in Mediterranean ichthyoplankton investigations.

An adult specimen of Mycteroperca sp. previously unrecorded was collected from the Azores Islands. Based on comparison of morphological characters and the cytochrome b mitochondrial gene, the specimen was identified as the western Atlantic species M. phenax, a species previously unrecorded from the central or eastern Atlantic Ocean.

The first occurrence of the alien gastropod Melibe fimbriata in the Taranto marine coastal area is reported. This mollusc was observed on muddy bottoms covered with dense algal beds mainly composed of Chaetomorpha linum, Gracilaria spp. and the invasive chlorophyta Caulerpa racemosa. Occasionally, M. fimbriata specimens were found in proximity to mussel farms. Most specimens of M. fimbriata were observed during diurnal foraging activity and associated with anaspideans species, like native Aplysia depilans and the lessepsian immigrant Bursatella leachii. Melibe fimbriata can be considered a definitively resident species in the opistobranch fauna of the Taranto seas.

Adult female loggerhead sea turtles (Caretta caretta) nesting in Japan use different feeding habitats as a function of body size. The Argos location data of two females inhabiting either oceanic or neritic habitats were analysed to infer their foraging and diving behaviour. There were no significant differences in the number of transmissions received per satellite pass, the number of locations per day, and the frequency of location-accuracy classes between oceanic and neritic females, implying that there was little difference in the time these two turtles stayed at the sea surface. Two possible forage-diving behaviours are suggested for these turtles: (1) both dive duration and depth were not different between the two feeding habitats; or (2) although dive duration was not different between feeding habitats, dive depth was different.