Benthic habitat and epibenthic megafauna are described from seabed photographs taken in or near three potential deep-water Marine Protected Areas on the Hebridean Slope, surveyed in 1988, 1995–96 and 1998. Broad bathymetric zones are defined by visible substratum characteristics, and by cluster analysis using presence/absence of identified fauna. The shelf edge and upper slope (to 350 m depth) showed current-swept coarse substrata with a very sparse fauna. A transition to finer sandy sediments was apparent at 350–470 m, with a greater abundance of mobile epifauna. The brittlestar Ophiocten gracilis occurred at high density below 600 m depth in all three areas. Southern stations indicated an abrupt lower boundary for this zone at ca 1000 m. In the north, rippled sands with xenophyophores occurred below the O. gracilis zone at 1000–1100 m. Xenophyophores were also seen in smaller numbers at this depth in the south. From ~1300–1600 m a seabed of burrowed fine mud was recorded in both northern and southern areas. Bioturbated sediments on the Rockall Trough floor at ~2060 m supported more visible epifauna, principally the brittlestar Ophiomusium lymani and the octocoral Acanella arbuscula. The bathymetric pattern differs from a scheme proposed in 2010 for the deep north-east Atlantic in the lack of any obvious zonal boundary at 750 m. No cold-water corals or sponge aggregations were observed. Trawl marks were observed in all three areas, particularly in the 1998 northern survey, with highest frequency at 1300–1400 m.

Through application of carbon (C) and nitrogen (N) stable isotope analyses, we investigated the benthic trophic structure of the upper-slope off southern Chile (~45°S) including a recent methane seep area discovered as part of this study. The observed fauna comprised 53 invertebrates and seven fish taxa, including remains of chemosymbiotic fauna (e.g. chemosymbiotic bivalves and siboglinid polychaetes), which are typical of methane seep environments. While in close-proximity to a seep, the heterotrophic fauna had a nutrition derived predominantly from photosynthetic sources (δ13C > –21‰). The absence of chemosynthesis-based nutrition in the consumers was likely a result of using an Agassiz trawl to sample the benthos, a method that is likely to collect a mix of fauna including individuals from adjacent non-seep bathyal environments. While four trophic levels were estimated for invertebrates, the fish assemblage was positioned within the third trophic level of the food web. Differences in corrected standard ellipse area (SEAC), which is a proxy of the isotopic niche width, yielded differences for the demersal fish Notophycis marginata (SEAC = 5.1‰) and Coelorinchus fasciatus (SEAC = 1.1‰), suggesting distinct trophic behaviours. No ontogenic changes were detected in C. fasciatus regarding food sources and trophic position. The present study contributes the first basic trophic data for the bathyal area off southern Chile, including the identification of a new methane seep area, among the furthest south ever discovered. Such information provides the basis for the proper sustainable management of the benthic environments present along the vast Chilean continental margin.

We examined the benthic macroinfauna at three strata during two seasons (winter and summer) on two sandy beaches (dissipative and reflective) in south-eastern Brazil. The hypothesis raised is that effects of morphodynamics and zonation determine the structure of macroinfauna, with dissipative beaches having comparatively higher species richness and density than the reflective beaches. Flamengo beach (dissipative) had higher species richness but lower density compared to Grumari beach (reflective). A high dissimilarity in assemblage structure (91.75%) was detected between the two beaches. Zonation in the occurrence of macroinfauna was detected for the two beaches in the two examined seasons. At Grumari beach, Emerita brasiliensis occurred mainly in stratum 1 (intertidal swept zone) while Saccocirus sp. occurred in stratum 2 (infralittoral at 0.5 m depth), whereas at Flamengo beach E. brasiliensis and Enoploides sp. had the highest density in stratum 1 (intertidal swept zone) whereas Scolelepis goodbodyi and Donax uncinata dominated in stratum 3 (infralittoral at 1.0 m depth). Scolelepis goodbodyi, Dispio uncinata, Enoploides sp., Nematoda and Trileptium sp. were associated with higher a Dean parameter and content of organic matter at Flamengo beach. In contrast, Hastula sp., Donax sp., Pisionidens indica, Hemipodus californiensis, Saccocirus sp. and Phyllodocidae were associated with the higher wave period and grain size of Grumari beach. The hypothesis that macroinfauna structure differs between the beaches and strata was confirmed, with the dissipative beaches having comparatively higher richness but lower density than the reflective beaches.

Renibacterium sp. QD1, a bacteria strain capable of hydrolysing chitosan, was isolated from the homogenate of small crabs. An extracellular chitosanase, Csn-A, was purified from the QD1 fermentation broth. The enzyme was purified to homogeneity, with a yield of eight-fold, 67% recovery and a specific activity of 1575 U/mg proteins. The molecular weight of Csn-A was estimated to be 26.1 kDa by SDS-PAGE. Unlike other chitosanases, the purified Csn-A displayed maximal activity at a pH range of 5.3–6.5, and it was stable in a broad pH range of 5.0–10.0. The optimum temperature for chitosanlytic activity was 55°C. The enzyme activity was strongly stimulated by Mn2+ but inhibited by Fe3+, Cu2+, Al3+, Zn2+ and SDS. TLC analysis demonstrated that Csn-A hydrolysed N-deacetylated polymeric glucosamines into chito-biose and -triose in an endo-type manner. The amino acid seuquence of Csn-A showed close identity with an uncharacterized chitosanase of strain ATCC33209.

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.

It has increasingly been recognized that organisms can interfere with parasitic free-living stages, preventing them from infecting their specified host and thus reducing infection levels. This common phenomenon in freshwater and terrestrial systems has been termed the ‘dilution effect’ and, so far, is poorly studied in marine systems. Ten common intertidal organisms found in the Dutch Wadden Sea (North Sea) were tested to establish their effects on the free-living cercarial stages of the trematode parasite Himasthla elongata. Most species tested resulted in a significant reduction in cercariae over a 3 hr time period. The amphipod Gammarus marinus removed 100% of the cercariae, while other effective diluters were Crangon crangon (93%), Sargassum muticum (87%), Semibalanus balanoides (71%), Crassostrea gigas (67%), Hemigrapsus takanoi (>54%), Crassostrea gigas shells (44%) and Idotea balthica (24%). In contrast, mixed shells (Cerastoderma edule, Mytilus edulis, Ensis americanus and Littorina littorea) and Fucus versiculosus had no significant effect. These results suggest that dilution effects are widespread in the trematode of H. elongata, with potentially strong effects on its population dynamics.

Five new species of Oncholaimellus are described. They were found in macrofauna samples from the continental shelf in the Potiguar Basin, north-east Brazil. Cuticular pores with a sclerotized outline associated with a gland were observed in some species. Oncholaimellus multiporus sp. nov. is differentiated from other species by the presence of cuticular pores of different sizes; the smaller pores are abundant and give an appearance of ornamentation. Oncholaimellus intersexus sp. nov. and O. distortus sp. nov. are similar, but differ in the size of the external labial and cephalic setae compared to the corresponding diameter, the presence of the cuticular pores and the tail shape. Oncholaimellus paulus sp. nov. and O. sineporus sp. nov. are similar, although features such as the external labial and cephalic setae size compared to the corresponding diameter and the cuticular pores differentiate between them.

Two new species of South African Syllidae of the genus Syllis Lamarck, 1818 are described. Syllis unzima sp. nov. is characterized by having unidentate compound chaetae with long spines on margin, a characteristic colour pattern and its reproduction by vivipary. Vivipary is not common among the polychaetes, but most representatives occur in the family Syllidae Grube, 1850 (in five other Syllis species, two species of Dentatisyllis Perkins, 1981 and two species of Parexogone Mesnil & Caullery, 1818). Syllis unzima sp. nov. differs from the other viviparous species in having large broods (>44 juveniles) which develop synchronously. Development of the juveniles is similar to that of free-spawning Syllis species, but the appearance of the first pair of eyespots and the differentiation of the pharynx and proventricle occur later in S. unzima. Syllis amicarmillaris sp. nov., is characterized by having an elongated body with relatively short, fusiform dorsal cirri and the presence of one or two pseudosimple chaeta on midbody parapodia by loss of blade and enlargement of shaft. Syllis unzima sp. nov. was found in high densities on cultured Holothuria scabra Jaeger, 1833 with single specimens found on a cultured Crassostrea gigas Thunberg, 1793 and on coralline algae, respectively, while S. amicarmillaris was found mainly in sediment outside an abalone farm and less frequently on cultured Haliotis midae Linnaeus, 1758. We discuss the possible benefits of the association with H. scabra to S. unzima sp. nov.

A new species of Abyssoninoe (Polychaeta: Lumbrineridae) has been found on sublittoral soft bottoms in the Gulf of Milazzo (central Mediterranean Sea). The description is based on eleven specimens recorded in six grab samples carried out by Van Veen grab from 20 to 50 m depth. Abyssoninoe bidentata sp. nov. differs from the six hitherto known species of Abyssoninoe by having the maxillae III with two subequal teeth instead of one, the shape of the parapodial lobes and chaetal distribution.

Recent sampling surveys (2011–2012) of the shallow (0–50 m) hard-bottom communities and re-examination of some soft-bottom communities (5–143 m) along the Algerian coast have allowed the collection of 33 species (five Caprelloidea, 27 Gammaridea and one Hyperiidea), which were not recorded before in the inventory of the marine amphipod fauna of Algeria (Bakalem & Dauvin, 1995; Grimes et al., 2009). This paper reports the number of specimens sampled for each of these 33 species and provides data on their geographical distribution and habitats. Fourteen of the species (43%) are considered to be endemic to the Mediterranean Sea; 15 others are north-eastern Atlantic and Mediterranean species, and the four last are cosmopolitan species. Twenty-nine of the new records are known for Italian waters and 19 in Greek waters where there is intensive amphipod inventory. The total number of marine amphipod fauna in Algeria is now 332.

The Norway lobster, Nephrops norvegicus is a target fishery species in European waters. The stock assessment of N. norvegicus is complicated because it is caught in commercial gear only when it emerges from its burrow. Landings are lower in winter, and feeding limitations have been hypothesized as the cause. Wild large-sized male lobsters were sampled each season (winter, spring, summer and autumn), and two groups of animals were kept in captivity for 90 d (fed and food-deprived). The hepatopancreas and muscle were dissected, weighted, frozen for biochemical analyses (proximal analyses and DNA/RNA) and fixed in Bouin solution for microscopic observations. The oxygen consumption rates in the wild individuals caught in the spring and in the captive animals after the treatments were measured. Significant differences among the experimental groups were observed in the lipid concentration of the hepatopancreas and muscle, the water content in the hepatopancreas, and the numbers of vacuoles and pyknotic nuclei in the cells of the tubules of the hepatopancreas. The results showed that the wild Norway lobsters generally presented intermediate values between those observed in the food-deprived and the fed lobsters kept in captivity, but the values were closer to those obtained for the fed animals. This finding indicates that the wild animals exhibit a good nutritional condition throughout the year. Therefore, the wild males of N. norvegicus do not face food deprivation during winter as is suggested by the pattern of commercial catches, the flow of organic matter, and the moulting period/reproductive behaviour of the species.

Detailed molecular data of Artemia (Crustacea, Anostraca) from South Africa are scarce. Here, we provide for the first time genetic data on the species status and phylogeography of Artemia from this region after an extensive sampling expedition. Our 16S rRNA RFLP analysis of 27 Artemia populations, including seven from South African sites, provides evidence for the presence of a mixed bisexual and parthenogenetic component in this area. Phylogenetic and network analyses reveal that three (out of seven) Artemia populations from South Africa belong to the invasive A. franciscana, two of them belong to A. salina while the last two contain both parthenogenetic and bisexual (A. salina) individuals. From a total of 18 haplotypes identified, seven were recorded from South Africa. To our knowledge, this is the first confirmed report of A. franciscana in this region. Its invasiveness is reaffirmed by evidence for the complete replacement of the native A. salina population from Velddrif Saltworks. However, in other cases, parthenogens seem to modify the capacity of A. franciscana to replace natives. Results on the genetic identification of South African Artemia provide insights into the dynamics of invasion and co-occurrence and highlight effects on species interactions and on biodiversity in inland aquatic invertebrates.

Pinna nobilis is an endemic Mediterranean species of high economic and cultural importance. Nowadays, it is under strict protection as a dramatic decline in its populations has been recognized, assigned to the combined effect of fisheries and habitat degradation. This study attempts to evaluate, by non-destructive sampling, the current status of P. nobilis populations in the south Aegean Sea (Dodecanese island complex), where they have been affected for centuries by practically uncontrolled harvesting. Population density and total length of individuals was estimated by diving along strip transects at six islands. Two stations were randomly selected per island, and two depth zones were surveyed per station. Additionally, temporal sampling was carried out at Astypalaia Island from March 2004 to June 2006, to assess relevant trends in density of individuals and size structure of the population. In total 1372 P. nobilis individuals were measured in situ to estimate maximum shell length. The studied populations showed increased density in the shallower depth zone and sheltered sites; small-scale environmental regimes are proposed as shaping factors of P. nobilis distribution. Increased density was also detected during the cold period of the year, probably related to recruitment success. In the lower depth zone the P. nobilis population consisted of larger individuals. A significant decrease in size was detected temporally as mean length was smaller in December 2004; in the same month the presence of small-sized juveniles was depicted in a left-shift in size–frequency distribution. These observations are probably related to the reproductive biology of the species.

Genetic variation of mussels Mytilus galloprovincialis in central–eastern Mediterranean Sea is investigated in this study. A total of 550 individuals sampled from two cultured and 11 wild populations from Italy, Croatia, Greece and Turkey were genotyped at 10 microsatellite loci. Significant deviations from Hardy–Weinberg expectations were observed in more than 75% of the tests performed. All populations showed extensive heterozygote deficits, which remained at significant levels even after correction for null alleles, providing evidence that null alleles were only partly responsible for deviations from Hardy–Weinberg equilibrium in these molluscs. Moreover, null alleles seem to have limited influence on the population genetic differentiation. Similar levels of multi-locus heterozygosity and allelic richness were observed in all populations, cultured and wild, implying the sustainability of the exploited populations. Lack of isolation by distance and markedly low genetic differentiation between the nine Greek sampling sites (shoreline >1000 km) was revealed by Mantel tests, FST values, exact tests and analyses of molecular variance, indicating that mussels from these regions are either at or close to panmixia. Similarly, patterns of genetic homogeneity were also found between the two Italian samples, whereas the observed genetic differentiation of the populations from Turkey and Croatia probably reflects the specific topographic and oceanographic conditions of these regions.

The Ostreidae are well known for their high intra-specific variation, which makes identification problematic. The present paper aims to provide a morpho-anatomical and taxonomic review of the Brazilian species of Crassostrea, as well as some congeneric species from other relevant areas. The Brazilian species are Crassostrea mangle sp.nov. and Crassostrea brasiliana. The exotic species Crassostrea gigas, cultivated in the southern region of the country, is also included in this study. Additional species are: Crassostrea virginica, from the Atlantic coast of the USA, the type species, and Crassostrea rhizophorae, a south-eastern Caribbean species that is supposed to occur in Brazil, but is here understood as a different entity endemic to that region. Taking into account their economic importance, the differentiation between these species is critical, and is essential for a better planning of production and preservation strategies. We point out the differences in almost all structures amongst these species, which are formally redescribed herein. The occurrence of the African species Crassostrea gasar in Brazil is established as false. The voucher specimens of previous studies responsible for this assumption were examined, evidencing a misidentification for Crassostrea brasiliana from an estuarine environment. The geographical distribution of the studied species is recognized as follows: Crassostrea rhizophorae in the south-east Caribbean Sea; Crassostrea mangle sp. nov. from Pará to the Santa Catarina, only in mangroves; Crassostrea brasiliana from Paraíba to Santa Catarina, both in rocky shores and mangroves; Crassostrea virginica ranges from the Atlantic coast of Canada to the Caribbean; and Crassostrea gigas originates from the Indo-Pacific, but has been introduced in southern Brazil. This paper also deals with conchological aspects of the endemic species Crassostrea praia, from south Lagoa dos Patos, Rio Grande do Sul; after a more detailed definition, and considering the deleterious effects of the nearby port and construction sites, it can be classified as an endangered species.

The seasonal variation and spatial distribution of chaetognaths were studied based on samples collected from July to August 2006 (summer), December 2006 to January 2007 (winter), and in April 2007 (spring) on the north-west continental shelf of the South China Sea. A total of 19 species of chaetognaths were identified. The average chaetognath abundances (mean ±SD) were 54.0 ± 44.5, 36.8 ±16.7 and 48.9 ± 95.5 ind. m−3 in summer, winter and spring, respectively. Flaccisagitta enflata and Serratosagitta pacifica were the dominant species during the whole sampling period, and F. enflata determined the spatial distribution of total chaetognath abundance. According to the topography and hydrological conditions, the survey area was divided into three sub-regions: inshore waters of the western Guangdong (Region I), inshore waters to the east of Hainan Island (Region II) and offshore waters from the western Guangdong to Hainan Island (Region III). The community structure and abundance distribution of chaetognaths varied significantly between the three sub-regions. The species richness was significantly different among the three sub-regions, with the lowest in Region I and the highest in Region III. The species richness was correlated positively with temperature and salinity. The abundance of chaetognaths was significantly higher in Region I than in both Regions II and III in summer and spring. The increasing food availability caused by the cold eddy, coastal upwelling and the western Guangdong coastal current was able support a greater abundance of chaetognaths during warm seasons on the north-west continental shelf of the South China Sea.

Long-term studies in the abyssal north-east Atlantic (1989–2005) have revealed large-scale changes in the benthic ecosystem and especially in some megafaunal invertebrate taxa over the period 1996–2002, termed the ‘Amperima Event’. Holothurians dominated the megafaunal samples. Temporal patterns in the abundance of holothurians showed a wide spectrum of responses, possibly related to the feeding and reproductive characteristics of the various species. One of the holothurians, the synallactid Paroriza prouhoi, is a simultaneous hermaphrodite, providing a distinct comparison with dioecious reproductive patterns more typical of deep-sea holothurian species. The reproductive biology and abundance/biomass patterns of P. prouhoi were investigated over the period 1989–2005. Paroriza prouhoi produces oocytes with a maximum diameter of ~370 µm. It has asynchronous patterns of gametogenesis both at the individual and population levels. Mean oocyte diameter and the ratio between previtellogenic and vitellogenic oocytes showed no significant differences between the periods prior to and after the Amperima Event. There were no significant differences in abundance or biomass over the time series. We conclude that the energy investment into gamete production by this hermaphrodite did not change over the 16 years examined. It is hypothesized that the feeding characteristics of P. prouhoi lead to a slow, steady and consistent production of gametes despite large-scale changes in organic matter supply to the seabed evident at the time series locality.