Knowledge on early ontogeny of Trisopterus luscus is scarce and incomplete. This paper describes the first successful attempt ever at achieving the natural spawning in captivity for this species. The reproductive specimens used for this study were obtained in the Ría de Vigo in September 2008 and subsequently transported to the facilities of the Institute of Marine Research (CSIC). The spawning frequency was variable among females, 1.8–4.6 days, but no size-dependent trend was determined. The average batch size, i.e. the number of eggs released per batch, has proven significantly dependent on female length and weight. In the present study the complete embryonic development in controlled conditions (sand–filtered seawater at ~13°C, with natural photoperiod), from egg to hatched larva, has been described for the first time ever. The development of pouting eggs was divided into six stages, based on the artificially-reared material. Pouting eggs are pelagic with a smooth, clear and spherical chorion, and a homogeneous yolk. The perivitelline space is narrow and oil globules are absent. Live eggs fertilized were 0.95–1.10 mm in diameter. The embryo hatches as a yolk-sac larva with closed mouth and gut. The pouting eggs hatched during the latter half of the fifth day.

On Tarifa Island (Strait of Gibraltar) several amphipod species were studied from intertidal algae: Ampithoe ferox, Apherusa mediterranea, Hyale spinidactyla, Hyale cf. youngi and Jassa cadetta. The allometric growth of gnathopod 2 in male is demonstrated for A. ferox. Jassa cadetta had been recorded previously only from the northern Adriatic Sea, while Hyale spinidactyla and Hyale cf. youngi had been only known from the Atlantic Ocean. Along the intertidal area, A. mediterranea and J. cadetta were dominant in the low levels located near the infralittoral area, while A. ferox, Hyale spinidactyla and Hyale cf. youngi were distributed in intermediate and upper levels, closer to the supralittoral zone. All the species showed the maximum peaks of abundance from April to October, coinciding with the maximum seawater temperatures.

The influence of the lunar phases and tidal range on the fish capture was analysed in a tidal flat in Barra do Paraguaçu (Baía de Todos os Santos). The sampling was realized in the flood tide and ebb tide of the spring (full moon) and neap (waning moon) tides, between June 2007 and May 2008. At all sampling occasions, two parallel drags were accomplished to the tidal flat, in the same direction of the current, in a 100 m long area marked on the beach beforehand, using a seine net of 15 m × 2.0 m with a mesh of 12 mm between adjacent knots. A total of 2312 fish specimens were captured (26.5 kg), belonging to 75 species from 45 families. The mean number of captured fish was significantly larger in full moon at ebb tides, while the mean weight in the captures was larger in ebb tides. There was significant difference in number of species, number of fish, richness and diversity between full and waning moons. The number of fish and biomass were significantly different between tides. Significant differences were found in community structure regarding trophic groups in relation to tide and moon, although the classic diversity indices did not capture this effect between tides. Furthermore, it was possible to identify preferences of occurrence related to the change of tide in dominant species.

Metacercariae of various digenean trematodes are assumed to impair the burrowing capacity of cockles Cerastoderma edule. To reveal if metacercarial infections of the gymnophallid Meiogymnophallus minutus have effects on burrowing and shell closure, a laboratory experiment using cockles with slight and extremely heavy infections was performed at water temperatures of 15, 20, and 25°C. Gaping of the cockle shell valves or other behavioural abnormalities, which have previously been ascribed to M. minutus infections, were not observed. Neither response time nor burrowing time differed significantly between slightly and heavily infected cockles at any of the temperatures tested, suggesting that the effects of the digenean trematode on its second intermediate host are not necessarily as pronounced as proposed by earlier publications, not even when additional environmental stress in the form of high water temperatures is present. Our findings question the hypothesis that M. minutus manipulates the behaviour of C. edule, in order to increase the probability of successful transmission to the avian final host.

In the present study, chthamalid barnacles of the Persian Gulf and Gulf of Oman were collected from the coastal zone of Iran. Extensive collecting of different habitat types resulted in finding two species: Chthamalus barnesi and Microeuraphia permitini. In addition to the Persian Gulf and Gulf of Oman, the former species was also collected from the Red Sea and Gulf of Aden. Both species are described and compared for their key characters with some representative members of the genera from other parts of the world.

The new species Batea aldebaranae from the coast of Belize is described and distinguished from the similar species Batea cuspidata (Shoemaker, 1926) and Batea carinata (Shoemaker, 1926). Characteristic for the new species are: additional set of dorsolateral teeth on pleonites 1–2; pereopod 1 second article small, scale-like; propodus of pereopod 7 elongate, dactylus shortened and telson shallowly cleft.

The bluespotted cornetfish (Fistularia commersonii) is an Indo-Pacific species that in the last ten years colonized a large part of the Mediterranean basin. The aim of this study was to sequence some portions of the mitochondrial DNA (D-loop II, 16S, 12S and Cyt b) of this fish from different localities of the Mediterranean Sea, in order to evaluate the level of its genetic variability in this area. The genetic analysis performed on specimens from seven localities of Sardinia, Tunisia and Libya revealed the presence of at least five mitochondrial lineages. The results obtained, compared with previous studies, indicate that the use of a sufficient number of mitochondrial regions may allow a more accurate estimate of genetic variability in lessepsian invasions.

Digenean trematodes infecting the mud snail Hydrobia ulvae were studied at two key sites of the Mondego Estuary (Portugal), from January 1993 to September 1995: a mud flat covered by the seagrass Zostera noltii, and a bare sand flat where seasonal macroalgal blooms occurred as a result of eutrophication. Digeneans belonging to Microphallidae, Notocotylidae, Haploporidae and Heterophyidae were recorded in snails from both sites whereas representatives from Echinostomatidae were only found in snails from the seagrass bed. The density of infected snails was higher at the seagrass bed than at the eutrophic area partly reflecting the difference in population structure of H. ulvae between sites. The Zostera noltii bed supports an abundant and well-structured mud snail population, with all size-classes represented, in contrast to a less abundant and juvenile dominated population in the eutrophic area. In the Z. noltii bed no clear seasonal and interannual patterns emerged in the infection densities. In the eutrophic area, the density of infected individuals increased in the presence of algae, and decreased during the occurrence of occasional flood events. Small scale spatial and temporal patterns in the prevalence of digenean trematodes in mud snails were therefore demonstrated within the Mondego Estuary that has experienced a mixture of anthropogenic impact and climate instability.

Although mucus plays many different roles among marine invertebrates, relatively little is known about the link between biochemical structure and function. In the present study we focused on some physical and chemical properties of the polychaete Sabella spallanzanii's mucus such as viscosity, osmolarity, electrical conductivity, elemental composition, the protein and carbohydrate content, the total lipids and fatty acid composition, and polychlorinated biphenyls (PCBs) contamination. Moreover, an antimicrobial activity of the mucus was investigated. The water content of S. spallanzanii mucus was 96.2±0.3%. By dry weight 26±1.2% was protein, 8±0.21% was carbohydrate and only 0.1% lipid, much of the remainder of the dry weight was inorganic (about 65.2%). The estimated PCBs content was <0.005 μg g−1. The mucus of S. spallanzanii exerted a natural lysozyme-like activity and produced in vitro the growth inhibition of Vibrio anguillarum, Vibrio harveyi, Pseudomonas aeruginosa and Candida albicans. The findings from this study contribute to improve the limited knowledge available on the mucus composition in invertebrates and have implications for future investigations related to employment of S. spallanzanii mucus as a source of compounds of pharmaceutical and marine technological interest.

The edible cockle Cerastoderma edule is one of the most common soft sediment bivalves in Europe and of commercial relevance in some areas of its range. Information on the parasite fauna of cockles is available from several North Sea and Atlantic shore locations. However, little is known from the British Isles in this context. This study provides an inventory of the macroparasites of C. edule sampled from fourteen localities along the south coast of Ireland. Altogether, we identified ten taxa of macroparasites belonging to three major groups. The majority of them were digenean trematodes using cockles as second intermediate host. Infection rates and levels were comparatively low, with the exception of the gymnophallid Meiogymnophallus minutus, which was found to be prevalent at all sampling sites and often very abundant. Whilst parasite species composition in Irish cockles was similar to the one found in conspecifics from northern Europe, it showed distinct differences from the macroparasite fauna reported from C. edule collected in southern Europe and northern Africa.

To evaluate the effect of antioxidant defence in coelomic fluid of sea cucumber, Apostichopus japonicus in aestivation was studied in the field from July to November 2006 in Qingdao. During the sampling period, activities of superoxide dismutase and catalase increased significantly in August and November. Activities of glutathione reductase and glutathione decreased significantly in August and increased significantly in November and activities of Se-glutathione peroxidase increased significantly in August. There were no significant differences in total glutathione peroxidase. In relation to the water temperature in the field, it is known that the oxygen consumption rate dropped and antioxidant defence was enhanced in August. The structure and function of respiratory trees of A. japonicus were completely vivified as normal in November, and it is suggested that antioxidant defence was enhanced because of the sharp change of oxygen consumption. Data indicate that both enzymatic and metabolite antioxidant defences in sea cucumber are adaptable systems that are modulated during pre-aestivating stage and arousing stage.

A biogenic structure ecosystem of extensive worm tubes of Chaetopterus sp. harbouring different fish species was investigated at Anacapa Island, southern California to determine the numerical abundance, species composition, body size, and seasonality of the ichthyofauna associated, and their relation with the worm patch size. Bimonthly, a 30-m swimming transect and a quadrat-based survey estimated the length of each fish, the type of habitat it occupied, and the worm tube patch size-class. Larger worm mats harboured higher densities of fish, mainly the dominants Rhinogobiops nicholsii and Chaenopsis alepidota, which live inside the worm tube patches. Fish population density varied between the ‘inside’ and ‘edge’ of Chaetopterus beds as smaller and younger individuals were hindered from reaching the middle of the patch by larger, older and territorial individuals. The prevalence of positive and significant correlations between the abundance of smaller individuals of R. nicholsii and specific habitat features (e.g. edge) suggests that the abundance and distribution of juveniles might be habitat-dependent besides intraspecific competition between older and younger individuals. There was a decreasing density of R. nicholsii at greater than 20 cm away from worm tubes and there were no individuals beyond 6 m away from structure. Chaenopsis alepidota was not recorded when the patch size was less than 50% tube coverage. Our results revealed that complex habitat structure had a positive influence on the abundance of juvenile and adult of C. alepidota and R. nicholsii, and suggest that these structured areas are preferentially utilized, which contributes to its patchy distribution pattern. The presence of biological structures in low-relief sedimentary habitats can have critical functional significance even for reef fish. These important habitat features may need to be identified and protected.

Epimeriidae is an amphipod family with a worldwide distribution. A new species was found from the Tasman Sea at a depth of 12 m depth and described in detail. Epimeria norfanzi sp. nov. can be distinguished from other Epimeria by a combination of the following characters: coxal plates 1–3 ventrally rounded; protrusion of coxa 5 reaching the distal end of epimeral plate 2; and urosomite 1 with dorsal keel, telson not cleft. This new species increases the number of Pacific Epimeria species to ten. A brief synopsis of the Pacific Epimeria species is given and a key provided.