The egg mass of the diamond-shaped squid, Thysanoteuthis rhombus (Oegopsidae: Thysanoteuthidae) was sighted in surface waters off south-east Sulawesi. It was a sinuous hollow tube-like structure about 2 m long and 0·15 m diameter. It was estimated to contain in the order of 180,000 purple eggs of 1 mm diameter with little or no yolk. Development of the embryos from early differentiation to hatching took between 47 and 57 h at about 28°C.

Stomach contents analysis and stable isotope results indicate M. hubbsi is a generalist predator that feeds mainly on demersal fishes, followed by crustaceans and cephalopods. Ontogenetic changes in diet were identified, with fish importance increasing in the diet with hake size. Smaller hake (<250 mm) fed mostly on the sepiolid Semirossia tenera (89.45%IRI) and engraulid fish (89.96%IRI). Mid-sized hake (250–300 mm) fed mainly on benthic fish such as Bellator brachychir (95.63%IRI) and euphausiids (56.46%IRI), while larger hake (>300 mm) fed heavily on Dactylopterus volitans (94.80%IRI) and occasionally on a variety of teleosts. Significant correlations between δ13C (P < 0.05), THg (P < 0.001) and hake size occurred, whereas no relationship was observed between δ15N and hake size or δ15N and total mercury. Signatures were lowest in smaller hake with a tendency of increasing with size. Smaller and larger hake were significantly different in δ13C. Differences regarding isotopic niche width were quantified for each size group; trophic diversity and trophic redundancy among them were negligible, but hake >300 mm possibly have a larger feeding plasticity due to the combination of prey from a wide trophic level range.

Twenty species, one of them represented by two ecologically different isolates, were grown at salinities from 0 to 60‰ at intervals of 5‰ or less. Growth was measured spectrophotometrically on a pigment extract, and formation of sexual organs was recorded. For each species the results are presented in a diagram, and compared with the salinity preference suggested by information in the literature and by the author's observations in nature.

Recent studies on the osmotic responses of marine invertebrates to dilution of the external medium have tended to emphasize the osmotic and ionic regulation at the intracellular level rather than at blood/body fluid level. Even in those invertebrates, principally euryhaline crustaceans, possessing osmoregulatory mechanisms which enable them to maintain concentrations of the blood above those of dilute media, the regulation is not perfect, and there is some lowering of the blood concentration below the level exhibited in full-strength sea water (Lockwood, 1962). This requires the establishment of a new osmotic equilibrium between the intracellular solutes and those of the blood. The nature of the intracellular osmotic constituents is, however, strikingly different from those of the blood, even in those invertebrates which are stenohaline and purely marine in their distribution (Robertson, 1961). The osmotic pressure of the blood is due almost entirely to the same inorganic electrolytes as are present in sea water, although the percentage contribution of the various ions may differ. On the other hand these inorganic ions account for only about one third to one half of the intracellular osmotic pressure. The remainder is accounted for by organic solutes, most particularly free amino acids.

Three species of lithistid sponges, Neoaulaxinia zingiberadix, Isabella mirabilis and Neoschrammeniella fulvodesmus were collected from deep seamounts off New Caledonia to address questions about their population structure, gene flow and the relative contribution of sexual and asexual reproductive strategies to their populations. The sponges were tested by sequencing the ITS (internal transcribed spacer) and CO1 regions of their genomes. These rare and presumably ancient sponges have a distribution restricted to seamounts in the south-western Pacific. Deep seamounts represent geographically separated islands. Although the sponges could be expected to have sexual reproduction restricted to near neighbours due to low sexual dispersal opportunities via larvae, this study found surprisingly high levels of gene flow between the seamounts. Amongst the specimens of N. zingiberadix taken from two seamounts there was no population structure; CO1 resulted in identical genotypes. For the population structure within N. fulvodesmus, as revealed by ITS, most of the variation was within each individual from the six seamounts on which it occurred and CO1 revealed no difference between individuals or seamounts. The third species I. mirabilis showed four genotypes based on CO1, which were distributed across all the seamounts. Indirect measures of different species showed a range of reproductive strategies from asexual to sexual, but with much higher connection between seamounts than previously thought. Individual seamounts did not show a separate population structure as one might expect from ‘islands’. The conclusion must be that these sponges have mechanisms to attain greater dispersal than previously thought.

Although several authors have suggested a plausible involvement of steroids in the reproductive biology of echinoderms, their definitive role is still poorly understood. In this paper we focused on oestradiol (E2), whose presence and variations were previously revealed in different echinoderm tissues. The aim of this investigation was to provide further information on the scarcely known role of this hormone in the reproductive biology of sea urchins. We injected two different concentrations (5 ng ml−1 and 50 ng ml−1) of 17ß-oestradiol into specimens of the common Paracentrotus lividus for 10 weeks. The E2 treatment did not influence the maturation stage of the gonads and the development of the gametes; it caused a slight decrease in the gonad index and an increase in lipid content. Our present results suggest that E2 could have a function different from that reported for vertebrates and suggested for other echinoderms such as asteroids.

Polychaetes of 31 species from 17 families (Amphinomidae, Chrysopetalidae, Eunicidae, Glyceridae, Hesionidae, Iphionidae, Lumbrineridae, Maldanidae, Nereididae, Oenonidae, Phyllodocidae, Polynoidae, Sabellidae, Serpulidae, Syllidae, Terebellidae, Trichobranchidae) were studied from five locations around Abu Musa Island, the Persian Gulf. Perinereis iranica sp. nov. is described as a new species for the Persian Gulf. Perinereis iranica sp. nov. is most similar to members of the Perinereis cultrifera species complex, which are also found in the Persian Gulf, but can be most easily distinguished from them by the number, shape and arrangement of paragnaths in Areas V and VI. Perinereis camiguana is compared to members of the genus Pseudonereis, and found to resemble them closely, but until type specimens can be re-examined, we recommend treating this species as Nereidinae incertae sedis. Fifteen species, belonging to 13 genera: Eunice ‘sp_Abu Musa’, Marphysa ‘sp_Abu Musa’, Glycera cf. tesselata, Hesione splendida, Lumbrineris ‘sp_Abu Musa’, Notoproctus ‘sp_Abu Musa’, Nereis sp. cf. N. pelagica, Eteone ‘sp_Abu Musa’, Harmothoe liaoi, Potamilla ‘sp_Abu Musa’, Branchiosyllis cf. exilis, Trypanosyllis ‘sp. 1_Abu Musa’, Trypanosyllis ‘sp. 2_Abu Musa’, Terebella ‘sp_Abu Musa’, Terebellides cf. stroemi are reported for the first time from the Persian Gulf; nine species remain to be named formally. Three genera: Notoproctus, Eteone, Terebella are recorded for the first time from the Persian Gulf.

Fundamental information on the reproductive biology of the grey triggerfish Balistes capriscus from the Gulf of Gabès (south-eastern Mediterranean Sea) is based on 751 specimens, collected between June 2005 and May 2010, from commercial catches at different fishing ports at Chebba (34°14′N 11°06′E), Kerkennah (34°45′N 11°17′E) and Zarzis (33°41′N 11°48′E). The species were caught in this area using pelagic trawl nets. The calculation of the gonadosomatic index suggested that the spawning season of grey triggerfish occurred mainly between July and mid-September with a peak in July, coinciding with summer time. The first maturation occurred at 20.26 cm fork length for females and 21.3 cm fork length for males. The monthly values of hepatosomatic index and condition factor (K) indicated that the liver was the most severely stressed organ in the reproduction process of energy transfer. The absolute fecundity (F) ranged from 290,120 to 984,990 eggs per female. The fecundity of the species was determined by the size and weight of the individuals.

Periodic fish ingressions into intertidal areas during high tide are known to occur on tropical mudflats. This study aimed to elucidate the feeding ground function of coastal mudflats for three common stingray species in the Klang Strait, Malaysia. Stingrays (disc width range from 5.65–54.50 cm) sampled over 17 months using a large barrier net (~2 ha enclosure) at two sampling sites were examined for their diet composition, prey frequency and prey volume according to predator species and maturity. The index of relative importance and Schoener's index of diet overlap were calculated. The three stingray species fed on relatively similar prey items which varied in size and contribution. Brevitrygon heterura fed on the widest range of prey taxa (28) whereas Hemitrygon bennetti (22) and Telatrygon biasa (17) showed higher prey specialization. The Penaeidae (dominantly Metapenaeus brevicornis and M. affinis) were the most important food item in the stingray diet which also included Actinopterygii, Amphipoda, Brachyura and Calanoida. The stingray diet showed an ontogenetic shift, with young stingrays tending to be generalists whereas the more mature stingrays (except H. bennetti) become more specialized in their feeding habits. This shift in feeding strategy reflects the diversity of prey taxa abundantly available to young stingrays on the mudflats, while the larger stingrays adapt to feed on larger prey once they enter deeper waters.

In the following Notes on the Fishing Industry of Plymouth the information obtained is divided into three sections, which are again subdivided as follows:

I.—Methods of fishing, localities fished, and fish caught. There are eleven different methods of fishing carried on in Plymouth:

1. Beam trawling. 2. Drift-net fishing. 3. Moored-net fishing. 4. Seine fishing. 5. Bultering, or long-line fishing. 6. Hand-line fishing. 7. Eel spearing. 8. Mullet trapping. 9. Crab and lobster fishing. 10. Shrimp and prawn fishing. 11. Oyster, mussel, and cockle fishing.

Structure and diversity of sessile zoobenthic assemblages seem to be driven not only by chemical-physical constraints and biological interactions but also by substrate lithology and its surface features. Nevertheless, broadly distributed crustose epilithic corallines could mask the role of substrate on animal settling. To evaluate the direct influence of different rocky substrates, occurrence and coverage of several sessile species, growing on the dark (i.e. coralline-free) face of sublittoral limestone and granite boulders were compared in the Tavolara MPA (Mediterranean Sea). The analysis of photographic samples demonstrated significant differences in terms of species composition and coverage, according to lithology. Moreover, limestone boulders were widely bare, while the cover per cent was almost total on granite. The leading cause of observed patterns could be the different level of dissolution of the two types of rocks, due to their different mineral composition and textural characteristics. Limestone has previously been shown to have higher dissolution compared with granite, and consequently, a more unstable surface. Our results suggest that, in dark habitats, the absence of the crustose coralline layer allows more rock dissolution and consequent lower stability of the limestone compared with granite, which, in turn, reduces the zoobenthos colonization.

Balanophyllia europaea is an endemic Mediterranean sublittoral zooxanthellate solitary coral. Given the broad distribution of the species throughout many areas of the Mediterranean surprisingly little is known of preferred habitat niches or susceptibility of the species to environmental change. In this study we investigated in the laboratory the net prey capture rates of the coral achievable under a range of flow velocities (2.5, 5, 7.5 and 15 cm s−1) and under exposure to different suspended particulate concentrations (0, 7.3 and 170 mg l−1). In recirculation flumes we simulated both commonly occurring and the occasionally high flow velocities and various suspended particulate concentrations reported from the Gulf of Lions (north-west Mediterranean). We then delivered ca 500 A. salina nauplii l−1 as food (Artemia salina nauplii) to the flumes and monitored net prey capture over time. We found net prey capture rates by the species to be highest under flow velocities of 5 cm s−1, with 230 µg C coral individual−1 h−1 achieved. The presence or absence of even environmentally high particulate concentrations (up to 170 mg l−1 resuspended seabed material) did not significantly affect the net prey capture rates achieved by the coral polyps. We found that net prey capture in Balanophyllia europaea is not inhibited during periods of heavy particle exposure, as has been observed in other temperate scleractinian corals. Also, flow velocities of ca ~5 s−1 appear to be optimal for maximum net prey capture by the species.

The common dolphinfish (Coryphaena hippurus) is widely distributed and represents an important part of the currently exploited fishery resources. This species’ feeding behaviour, however, is poorly understood. This study aimed to investigate the feeding behaviour of dolphinfish and the effect of body size (and the consequently aggregated learning experience) on the strategies used for capturing their prey. Observations were made from an oil platform in north-eastern Brazil. Dolphinfish length was visually estimated and classified into three size classes. The following foraging strategies were observed in our study: ‘active chasing’, ‘leaping out’, ‘swimming in circles’, ‘surf’, ‘using floating objects’ and ‘cleaning turtle carapaces’. The most frequently used foraging strategy was ‘active chasing’, suggesting a strong preference of dolphinfish in using visual cues during predation. Smaller size-classes of dolphinfish did not perform the ‘swimming in circles’ and ‘surf’ strategy, probably due to a lack of learning experience, since further social interactions could be needed in order to show this strategy. Smaller dolphinfish regularly showed the ‘using floating objects’ as a foraging strategy, probably reflecting an opportunistic behaviour. The smallest individuals were using more simple strategies, to chase smaller prey that could have different and less complex escape strategies. It indicates learning experience could play an important role into the dolphinfish ontogeny, moving towards more complex foraging strategies throughout their lives. Independently of the age class, the dolphinfish displayed a varied repertory of foraging strategies, maximizing hunting success in the open ocean, a hostile pelagic environment with a low prey availability.

Six specimens of an unknown Argulus species were found on a cod caught off the coast of Finnmark in northern Norway. All six were found to be sixth stage male larvae, ∼2·6 mm long and 1·6 mm wide. Argulus has not previously been recorded from cod and this is also the first record of a marine Argulus from Norwegian waters. The Argulus sp. from cod can be easily distinguished from other marine species found in northern European waters, and also from Norwegian freshwater species of Argulus. It is believed that it represents a new species, but a complete species description must await the finding of adult stages.

Patella ferruginea is an endangered marine gastropod, distributed on the western Mediterranean coasts, whose range has progressively contracted, due to intense human exploitation. A genetic analysis was performed on two unidentified young individuals belonging to the genus Patella found attached to the shell of an adult of P. ferruginea, with a twofold aim: (i) to achieve their correct taxonomic attribution by means of the DNA barcoding; and (ii) to shed some light on the hypothesized larval philopatry and/or juveniles phoresis in P. ferruginea. The survey was carried out comparing the sequences of the cytochrome c oxidase subunit I (COI) Folmer region obtained for the two juveniles with those obtained for adults of P. ferruginea, P. caerulea, P. rustica, and P. ulyssiponensis, from different sites of the western Mediterranean, by means of maximum likelihood cluster analysis and a Bayesian-based assignment test. Results obtained evidenced that: (i) COI may be used with confidence as DNA barcoding in the genus Patella; and (ii) the two juveniles studied are not conspecific: one belonged to P. ferruginea, the other to P. rustica. The latter finding raises doubts about the juvenile phoresis and about the occurrence of larval philopatry in P. ferruginea, suggesting that an extensive use of a molecular approach for a better evaluation of the recruitment features of this endangered species should be adopted.

Polyplacophoran molluscs (chitons) are phylogenetically ancient and morphologically constrained, yet multiple living species are often found co-occurring within widely overlapping ecological niches. This study used two sets of experiments to compare interspecific variation among co-occurring species in the North Atlantic (Ireland) and separately in the North Pacific (British Columbia, Canada) chiton faunas. A complementary review of historical literature on polyplacophoran physiology provides an overview of the high level of metabolic variability in this group of ‘living fossils’. Species examined in de novo experiments showed significant variation in oxygen consumption both under air-saturated water conditions (normoxia), and in response to decreasing oxygen availability (hypoxia). Some species demonstrate an ability to maintain constant oxygen uptake rates despite hypoxia (oxyregulators), while others oxyconform, with uptake rate dependent on ambient oxygen tension. These organisms are often amalgamated in studies of benthic communities, yet show obvious physiological difference that may impact their response or tolerance to environmental change.

Shellfish culture, based on ecological and market assessment, is considered a driving force for socio-economic change in ecologically complex coastal systems such as lagoons throughout the Mediterranean area. To diversify fish production, the Pacific oyster Crassostrea gigas was cultured at commercial farms in the Varano Lagoon (SE Italy). The aims of this study were to evaluate through four condition indices (CI, CICG, CIE and AFNOR index), the Polydora index (PI), lipid content, quality and market aspects of oysters reared at two different sites (FO and LA) of the Varano Lagoon, which are characterized by different hydrodynamic conditions. The results of this study highlighted the potential economic benefits associated with sustainable aquaculture development in the Varano Lagoon, proving that the area surrounding the LA site was more suitable for oyster culture, reaching commercial size (60 mm) in a shorter time (6–8 months). Higher growth performance of oysters was observed in the spring, when the nutrient availability positively affected the feeding response of suspension feeders. The opposite was found in winter and in summer, when the decrease in growth could be due to the reduction of nutrient and to the increase of salinity, TSM and ISM. The presence of the mud blister worm (Polydora sp.) during rearing could be a real problem, as it damages oyster market value and threatens serious financial loss to the local farmers.

The metamorphic responses of mussel (Mytilus coruscus) larvae to pharmacological agents affecting G proteins and the adenylate cyclase/cyclic AMP (AC/cAMP) pathway were examined in the laboratory. The G protein activators guanosine 5′-[β,γ-imido]triphosphate trisodium salt hydrate and guanosine 5′-[γ-thio]triphosphate tetralithium salt only induced larval metamorphosis in continuous exposure assays, and the G protein inhibitor guanosine 5′-[β-thio]diphosphate trilithium salt did not exhibit inducing activity. The non-specific phosphodiesterase inhibitor theophylline and the cAMP-specific phosphodiesterase IV inhibitor 4-(3-Butoxy-4-methoxybenzyl)imidazolidin-2-one exhibited inducing activity, while the non-specific phosphodiesterase inhibitor 3-Isobutyl-1-methylxanthine only showed inducing activity at 10−4 M in continuous exposure assays. The cyclic nucleotide analogue N6,2′-O-Dibutyryladenosine 3′,5′-cyclic monophosphate sodium salt did not exhibit significant inducing activity. Both the adenylate cyclase activator forskolin and the adenylate cyclase inhibitor nitroimidazole exhibited inducing activity at 10−4 to 10−3 M concentrations in continuous exposure assays. Among these tested agents, the adenylate cyclase inhibitor (±)-miconazole nitrate salt showed the most promising inducing effect. The present results indicate that G protein-coupled receptors and signal transduction by AC/cAMP pathway could mediate metamorphosis of larvae in this species.

The sabellariid worms are important ecosystem engineers in coastal zones, due to their ability to construct sand reefs, modify environments and structure biological communities. This article describes the reproductive biology of Sabellaria wilsoni on a beach of the Amazon coast. Each month between May 2008 and April 2009, specimens were collected for morphometric and histological analyses for sexing and determination of gonadal maturity. In females, the number and diameter of the oocytes at different stages of vitellogenesis were also recorded. The results showed that the species is dioecious, with sexual reproduction, females larger than males, and a female-biased sex ratio (overall, 1.6♀: 1♂). Four distinct stages of gonadal maturation were identified in the males and females – (i) initial development, (ii) maturing, (iii) mature and (iv) spawning. Sexual maturity is attained rapidly, and reproduction is continuous, with two breeding peaks, one in the dry season, related to the increased intensity of hydrodynamic conditions and reef erosion; and the other in the rainy season, when the availability of space and nutrients increases. The reproductive strategy of the species reinforces the classification of the sabellariids as r-strategists, adapted to colonize habitats with unstable environmental conditions.

The beryciform fish Hoplostethus mediterraneus is a species discarded from the southern Portuguese coastal fisheries. It is taken as by-catch by deep water trawls, at depths of between 234 m and 618 m. This species is a benthopelagic feeder, preying mainly on crustaceans. The dominant prey species encountered were the euphausid Meganyctiphanes norvegica and the amphipod Anilocra physodes. It seems that H. mediterraneus is an opportunistic rather than a selective feeder.