We conducted a histological investigation of the ovaries and testes during the gametogenesis and spawning in the giant jellyfish Nemopilema nomurai, which has bloomed in East Asian marginal seas almost annually since 2002. Oocytes arising from the ovarian epithelium make intimate contact with special epithelial cells, called trophocytes, which have microvilli on the subgenital sinus side, Golgi complexes and vesicles in the cytoplasm. In the early vitellogenic stage, yolk bodies occur in the ooplasm adjacent to the trophocytes, suggesting that the trophocytes transfer nutrients from the subgenital sinus to the oocyte. Later, yolk bodies are formed by the Golgi complexes in the entire ooplasm and accumulate until the oocyte matures. In the late vitellogenic stage, the oocyte separates from the trophocytes and forms microvilli on its surface, indicating nutrient uptake from the surrounding mesoglea. Nutrient support from the trophocytes in the early vitellogenic stage may make the oocytes mature rapidly after medusae are physically damaged. Microvilli-rich epithelial cells also associate with sperm follicles where spermatocytes arise from the follicle cells and accumulate, but their function in nutrient uptake is possibly less than that of trophocytes according to their morphology. During ovulation, which takes 1.5 hours after light exposure, trophocytes separate from each other and make an ovulation pit where the oocyte passes out to the subgenital sinus with the surrounding basal lamina. Spermiation occurs 5–20 minutes after light exposure, and spermatozoa are liberated through the spermiation pit that was formed by which the microvilli-rich cells dissociate. The trophocytes in ovaries and microvilli-rich cells in testes have important roles not only in the gametogenesis but also in the spawning of N. nomurai.

A new species of calanoid copepod, Centropages uedai sp. nov., is described from the neritic waters of the northern Red Sea. This species is characterized by: (1) symmetry of a globular female genital double-somite that is ornamented with an anterior irregular group of spinules as well as transverse and dorsolateral rows of spinules on each side; (2) second exopodal segment of female leg 5 bearing a strong trough medial process serrated along the distal 4/5 of its posterior margin; (3) second exopodal segment of male right leg 5 serrated laterally along distal 1/5 of its medial process; (4) third exopodal segment of male right leg 5 with medial seta bifurcated at its tip and with hyaline ridge on both sides; and (5) second exopodal segment of male right leg 4 asymmetrical with undulating, thicker and longer lateral spine than left leg. The new species does not belong to any known species groups of the genus.

There is clear evidence that marine reserves can be used as effective tools to foster the recovery of disturbed ecosystems. In the Azores, intense exploitation of the patellid limpets Patella candei and P. aspera has led to a rapid decline in their populations and subsequent collapse of the fishery in 1985. In 1993, legislation was passed to protect limpets, including the establishment of limpet protected zones (LPZs) where harvesting was completely prohibited. Outside LPZs, a seasonal fishing closure prohibited the harvesting of limpets from October to May. Here we examine the effect of such measures 16 years after they were put into practice. In each of the 3 years examined, limpet density, biomass and size were generally similar both inside and outside the LPZs. In addition, there were clear signs of exploitation as most individual limpets inside the LPZ were smaller than the legal catch size suggesting that illegal harvesting was taking place. Observations confirmed that illegal harvesting of limpets was common both inside and outside LPZs. Lack of enforcement of regulations is therefore a likely reason for the failure of legislation to protect limpet populations and facilitate stock recovery.

The demersal fish assemblages of the south-western Sea of Marmara and the north-eastern Aegean Sea were examined in relation to their biogeographical and environmental conditions. Sampling was carried out during bottom trawl surveys conducted during five periods between June 2006 and August 2007. A total of 40 hauls were processed, including 16 in the Sea of Marmara (38–74 m deep) and 24 in the north-eastern Aegean Sea (63–401 m deep). A total of 47,940 individuals, from 91 species and 47 families were collected. Cluster analysis of catch data indicated that there were three assemblages, one in the shelf of the Sea of Marmara and two in the Aegean Sea (<100 and >200 m depth). The numerical abundance and biomass of fish, mean fish weight, mean species richness, diversity and evenness were compared between these assemblages. Multivariate analysis was used to test differences in environmental conditions between areas, and relationships between species and environmental variables were explored by using redundancy analysis. In addition to bathymetric differences, differences in both diversity and species composition were observed between shelf assemblages in the two nearby areas. The distinct biogeographical, environmental characteristics (depth, dissolved oxygen and temperature) and fishing pressure are discussed as the main factors which could explain the differences detected.

The jumbo flying squid, Dosidicus gigas, support an important squid fishery off the Exclusive Economic Zone of Chilean waters. However, we only have limited information about their biology. In this study, age, growth and population structure of D. gigas were studied using statoliths from 533 specimens (386 females and 147 males) randomly sampled in the Chinese squid jigging surveys from 2007 to 2008 off the Exclusive Economic Zone of Chile. Mantle lengths (MLs) of the sample ranged from 206 to 702 mm, and their ages were estimated from 150 to 307 days for females and from 127 to 302 days for males. At least two spawning groups were identified, the main spawning peak tended to occur between August and November (austral spring group), and the secondary peak appeared during March to June (austral autumn group). The ML–age relationship was best modelled by a linear function for the austral spring group and a power function for the austral autumn group, and the body weight (BW)–age relationship was best described by an exponential function for both the groups. Instantaneous relative growth rates and absolute growth rates for ML and BW did not differ significantly between the two groups. The growth rate of D. gigas tended to be high at young stages, and then decreased after the sub-adult stage (>180 days old). This study suggests large spatial and temporal variability in key life history parameters of D. gigas, calling for the collection of more data with fine spatial and temporal scales to further improve our understanding of the fishery biology of D. gigas.

Advanced stages of Scyllarus phyllosoma larvae were collected by demersal trawling during fishery research surveys in the western Mediterranean Sea in 2003–2005. Nucleotide sequence analysis of the mitochondrial 16S rDNA gene allowed the final-stage phyllosoma of Scyllarus arctus to be identified among these larvae. Its morphology is described and illustrated. This constitutes the second complete description of a Scyllaridae phyllosoma with its specific identity being validated by molecular techniques (the first was S. pygmaeus). These results also solved a long lasting taxonomic anomaly of several species assigned to the ancient genus Phyllosoma Leach, 1814. Detailed examination indicated that the final-stage phyllosoma of S. arctus shows closer affinities with the American scyllarid Scyllarus depressus or with the Australian Scyllarus sp. b (sensu Phillips et al., 1981) than to its sympatric species S. pygmaeus.

Meiofauna, macro-infauna and epifauna were sampled at two offshore sandbanks in the southern North Sea in 2006. The epifaunal and infaunal communities in the dynamic environment of the sandbank crests were species poor, with lesser weever, solenette, Crangon crangon, amphipods and deposit-feeding polychaetes the predominant benthic taxa. Abundant early life-history stages (24–39 mm) of the lesser weever Echiichthys vipera on the sandbank crests indicated that these habitats may be important nursery grounds for this species. Species diversity of infauna and epifauna was greater in the deeper waters parallel to the sandbanks. Contrasting patterns were evident for meiofaunal nematodes, where communities collected on the sandbank crests were more diverse than those recorded in the deeper off-bank sites. The fauna of sandbank crests is composed of a restricted range of the fauna typically associated with sandy habitats, particularly taxa adapted to live in this dynamic environment.

The effects of deep-sea bottom longlining on fish communities and the benthic ecosystem, as well as the interactions between fishing and seabirds, were studied based on data collected from a joint collaboration between the Spanish Institute of Oceanography and a longliner, carried out on the Hatton Bank area (north-east Atlantic) in 2008. A total of 38 longline sets were distributed mainly along the rugged bottom of the rocky outcrop at depths ranging from 750 to 1500 m. Deep-water sharks and lotids were predominant in the catches contributing respectively 80.4% and 13.1% in terms of weight. Deep-water sharks were predominant in the discards. By-catch of cold-water corals and small glass sponges occurred along the western flank of the Hatton Bank, while large hexactinellids were found along the eastern flank. Longlines fished the adult fraction of vulnerable deep-water sharks and lotids. High catches per unit effort values for these species were obtained in coral areas. A combination of seabird-scaring streamer lines and other measures of preventing seabird by-catch were used. Only one fulmar was captured and it survived. Data on distribution of marine litter and derelict deep-sea gillnets are also presented.

A new species of Admete Møller, 1842 (Cancellariidae), A. clivicola is described from the upper continental slope off south-western Norway, and the species Admete contabulata Friele, 1879 is reinstated as a valid species. Iphinopsis inflata (Friele, 1879) is redescribed and a lectotype for the species is established. The taxonomic status and bathymetric distribution of the species of Admete and Iphinopsis in the Norwegian Sea are discussed.

The variability in motion behaviour properties was investigated for three species of intertidal gastropods at the inter-specific, inter-individual and individual levels in the absence of abiotic and biotic cues. Interspecific differences in movement patterns were reminiscent of the optimal searching behaviours expected for Austrocochlea porcata, Nerita atramentosa and Bembicium melanostomum in their natural environment. Specifically, N. atramentosa, A. porcata and B. melanostomum respectively displayed extensive and intensive foraging strategies consistent with their feeding ecology. The related inter-individual variability within each species highlights the potential ability of species to adapt their movement patterns to new environmental conditions and to persist over long-term changes. Finally, the strong variability observed in the speed and turning angle of individuals of the three species and the resulting behavioural plasticity may be an adaptive strategy to optimize energy expenditure and to react to an environmental fluctuation. Specifically, it is suggested that the lack of significant differences in individual behavioural variability between the three species indicates that despite clear inter-specific differences in motion behaviour, at the individual level A. porcata, N. atramentosa and B. melanostomum have similar abilities to face environmental fluctuations. This work stresses that individual variability in the motion behaviour of intertidal gastropods constitutes a fundamental evolutionary advantage when facing heterogeneous environmental conditions.

Diel fluctuations in nearshore fish communities were studied at a sandy beach in south-eastern Brazil. A total of 192 samples were performed by beach seines, during 3-hour intervals throughout 48-hour periods, between spring 2005 and winter 2006. Mean biomass and number of species were significantly higher at night, while number of individuals did not differ between day and night. Major disruptions in the fish community occurred during the winter when the assemblages underwent restructuring. Harengula clupeola, Sardinella janeiro, Anchoa lyoleps and Umbrina coroides were the predominant species at night, while Atherinella brasiliensis, Pomatomus saltatrix and Trachinotus carolinus peaked during the day, although significant diel changes in community structure were recorded only in the summer. Biological interactions, behavioural variations and local constraints might explain diel differences in the fish distribution. This study confirms that changes in diel activity in juvenile fish species can differ in similar areas, even for a given species, and the causes of these changes needs to be investigated.

A new species of the genus Onchidoris is described from the south-western Atlantic, on the coast of Brazil, in the States of Rio de Janeiro and São Paulo. To date, the genus Onchidoris is known almost exclusively from the northern hemisphere, especially the Atlantic coast of Europe and the Mediterranean Sea. The single previous record from the southern hemisphere is Onchidoris maugeansis, described from Australia. This is the first record of the family Onchidorididae from the coast of Brazil. Onchidoris brasiliensis sp. nov. is very similar to Onchidoris depressa, from England and the northern coast of Spain, but is distinguished by the presence of a triangular protuberance on the edge of the inner lateral radular tooth and a wide closed branchial circle with tubercles inside. Furthermore, the egg mass of O. brasiliensis sp. nov. contains a single row of eggs, whereas that of O. depressa has multiple rows. Onchidoris brasiliensis sp. nov. has lecithotrophic development, the first record of this type of development in the genus. There is a relationship between O. brasiliensis sp. nov. and the bryozoan Parasmittina protecta.