Synisoma albertoi sp. nov. (Isopoda: Valvifera: Idoteidae), is described and illustrated from specimens collected in the Strait of Gibraltar (southern Spain). The new species can be distinguished from all other species of the genus, with the exception of S. bellonae and S. raqueliae, by the fusion of the flagellar articles of the antenna. It is easily distinguishable from both S. bellonae and S. raqueliae by the presence of a tubercle on the cephalon; these three species also differ in the morphology of pleotelson, pereopods and appendix masculina. A key to the known species of Synisoma is provided.

Lindia gravitata, previously considered a synonym of L. tecusa by several authors is redescribed. Body shape and trophi structure show that both species are closely related, and unequivocally differentiated by e.g. toe shape, number of sensory papillae, and shape of subunci and epipharynx. Other related, but insufficiently described congeners are listed. The diagnostic features of the subgenus Halolindia are discussed.

Thirty species of sponges (29 Demospongiae, 1 Hexactinellida) have been recorded in association with a white coral bank situated off Cape S. Maria di Leuca (southern Italy) at depths ranging from 430 to 1160 metres. Notwithstanding the occurrence of clearly eurybathic species, two depth-dependent sponge groups can be identified along the bathymetric gradient. Two species, Geodia nodastrella and Plocamiopsis signata, are reported for the first time from the Mediterranean Sea. The sponge assemblage shows a higher affinity with the fauna from the Boreal region, with very low number of Mediterranean endemic species. Systematic notes concerning the poorly known and intriguing species, studied using scanning electron microscopy analysis, are reported.

The development and growth of a feather star Decametra tigrina from Notojima Island, Japan, is reported. This is the first record describing the complete development, from early embryos to juveniles, in the family Colobometridae. Their larval development was observed to progress independently from the adults, and was similar to other feather star species. Embryos hatched as uniformly ciliated gastrulae, which turned into doliolaria larvae when four narrow circumferential ciliated bands were formed. Skeletal ossicles began to form inside the doliolaria larvae, which subsequently settled to the substrate, proceeding to the cystidean stage. The protrusion of the arms from the oral opening marked the beginning of the pentacrinoid stage. About 45 days after hatching, they autotomized their stalks and became juvenile comatulids with arms about 6 mm long. These early juveniles apparently differ from the adults in morphological characters, such as having no pairs of tubercles or spines on the dorsal of their cirrals, and no proximal pinnules except for the first pinnule (P1). Both features are prominent in adults and are used for the classification of D. tigrina. Morphological differences between juveniles and the adults may also occur in other feather star species. A revision of the classification of comatulids, which considers morphological changes with growth, is required.

During 1998–2003 stomach contents of 47 marine mammals stranded on the coast of Normandy were analysed. The animals were first examined by a veterinary network and stomach contents were analysed at the University of Caen. The sample comprised: 26 common dolphins (Delphinus delphis), four bottlenose dolphins (Tursiops truncatus), seven harbour porpoises (Phocoena phoecoena), five grey seals (Halichoerus grypus), two long-finned pilot whales (Globicephala melas), one white beaked dolphin (Lagenorhynchus albirostris), one minke whale (Balaenoptera acurostrata) and one striped dolphin (Stenella coeruleoalba). The identification of food items was done using hard parts (i.e. fish otoliths and cephalopod beaks). Diet indices were computed including prey frequency and percentage by number. Common dolphins ate mainly gadoid fish (Trisopterus sp.), gobies and mackerel (Scomber scombrus). Cephalopods occurred in small numbers in the diet and commercially important species (cuttlefish and common squid) were scarce.

An optimized method, using polyclonal antibodies in an immunoassay, for prey detection in the diet of paralarvae of South African Loligo reynaudii is described. The study has increased the specificity of the antisera by determining the optimum antiserum dilutions and the detection limits of the antisera. Unfed laboratory-hatched paralarvae (negative control) were exposed to antisera and showed cross-reactions with polychaete antiserum.

Specimens of Mesochaetopterus (Chaetopteridae) from seven geographical sources in the Pacific Ocean are compared on the basis of their hard structures: specialized chaetae, uncinal plates and tubes. There geographical variations are investigated both locally (New South Wales and the Solomon Islands) and over the whole Pacific Ocean from Australia (New South Wales) through the Solomon Islands to Galapagos and Hawaii. The most interesting result is the existence of intra-regional morphological variations with the hard structures differing on specimens sampled in two areas from New South Wales or in two areas from the Solomon Islands out of a total of three areas. These newly described morphologies imply that M. minutus, isolated in a first step from M. sagittarius and confined to the Pacific, is a pseudo-sibling species complex. Each element of this complex is morphologically distinguishable. Consequently the generally accepted role of the long-lived planktonic larvae characteristic of Mesochaetopterus, as a source of geographical homogeneity must be re-examined.

A new species of cirrate octopod, Opisthoteuthis borealis sp. nov. is described from specimens caught at depths of 957–1321 m off the coast of Greenland. Opisthoteuthis borealis sp. nov. is the most northerly of the Atlantic species of the genus and can be distinguished from the other species by the form of the digestive gland and the arrangement of enlarged suckers on the arms of mature males.

The feeding of the most important chaetognath species (Sagitta enflata, Sagitta minima, Sagitta setosa and Sagitta serratodentata) found in a grid of 35 stations in the north Aegean Sea (Strymonikos and Ierissos Gulfs) was investigated through gut content analysis during five sampling periods from June 1997 to May 1998. Sagitta enflata and S. minima were the most abundant species in summer–autumn 1997 and in spring 1998, respectively. Copepods were the main food for all chaetognath species in spring 1998, while cladocerans in summer–autumn 1997 dominated the diet, especially of S. enflata. In September 1997, the juvenile specimens of cladocerans were the most important prey of the immature Stage I specimens of S. enflata, which resulted from the major breeding period in late summer. The estimated impact of chaetognath predation on the copepod and cladoceran communities ranged between 0.02–2.76% and 0.01–1.29% of the copepod and cladoceran standing stock, respectively. Stage I specimens of S. enflata accounted for nearly 90% of the total copepod and cladoceran standing stock consumed per day by the total population of this species in September 1997.

Repopulation by green sea urchins Strongylocentrotus droebachiensis of a steeply sloping rock bottom was monitored at a wave-exposed headland (Chebucto Head) following a disease outbreak that caused mass mortality in September 1999. Density and size of urchins were sampled in four depth strata: at 8–10 m in an urchin grazing aggregation (front) along the lower margin of a kelp bed, at 12 m and 16 m on a bedrock ramp, and at 24 m on a cobble and boulder field where urchins were unaffected by the disease. Shoreward migration of adults along the ramp from the surviving population at 24 m was the primary means of repopulation, which was augmented by recruitment via planktonic larvae. At 16 m, urchin density stabilized (at ∼50 urchins m−2) within six months of the die-off while repopulation at 12 m took more than eight months. A grazing front of large urchins (40–60 mm, test diameter) had formed along the lower edge of a kelp bed by January 2002, which reached densities of up to 284 urchins m−2. Video surveys at Chebucto Head and two adjacent locations of similar bathymetry revealed an extensive urchin population between 25 and 55 m depth, with a mean density on rocky substrata of 73 urchins m−2.

An historical data set, collected in 1958 by Southward and Crisp, was used as a baseline for detecting change in the abundances of species in the rocky intertidal of Ireland. In 2003, the abundances of each of 27 species was assessed using the same methodologies (ACFOR [which stands for the categories: abundant, common, frequent, occasional and rare] abundance scales) at 63 shores examined in the historical study. Comparison of the ACFOR data over a 45-year period, between the historical survey and re-survey, showed statistically significant changes in the abundances of 12 of the 27 species examined. Two species (one classed as northern and one introduced) increased significantly in abundance while ten species (five classed as northern, one classed as southern and four broadly distributed) decreased in abundance. The possible reasons for the changes in species abundances were assessed not only in the context of anthropogenic effects, such as climate change and commercial exploitation, but also of operator error. The error or differences recorded among operators (i.e. research scientists) when assessing species abundance using ACFOR categories was quantified on four shores. Significant change detected in three of the 12 species fell within the margin of operator error. This effect of operator may have also contributed to the results of no change in the other 15 species between the two census periods. It was not possible to determine the effect of operator on our results, which can increase the occurrence of a false positive (Type 1) or of a false negative (Type 2) outcome.

A biometric analysis was performed on crabs (Paguristes eremita) collected in the soft bottom of the Sicilian Channel (southern Mediterranean Sea), on associated suberitid sponges (Suberites domuncula), and on shells inside sponges. Populations of crabs living in sponges overgrown on shells were compared with populations of crabs living in shells associated with the sea anemone Calliactis sp. Results from multivariate ordinations (principal component analysis, non-metric multidimensional scaling) and univariate linear regression analysis were discussed considering two possible models: (1) sponges are preferred to clean shell because they are a growing home; and (2) sponges are not preferred: they are used as an ‘emergency’ refuge by crabs searching for shells suitable for carrying sea anemones. Differences in shell assemblages and in biometric variables between populations living in sponges and populations living in shells associated with anemones, suggest that crabs, especially small ones, may live briefly in sponges and that sponges may be inhabited by a series of crabs over a long period.

The aim of this study was to investigate the factors that affect the patterns of occurrence and habitat utilization of bottlenose dolphins around Aberdeen harbour, on the north-east coast of Scotland (UK), and their responses to boat traffic. Land-based surveys were conducted over a period of nine weeks, between early May and late July, 2002. During this time 83 sightings of bottlenose dolphins were recorded. Dolphins occurred more frequently around midday and early afternoon, while their abundance was greater around high tide and late afternoon. Foraging was the most commonly observed activity.

Dolphins were usually concentrated around the entrance of Aberdeen harbour. Their responses to boats varied considerably according to boat size, activity and speed, but there is evidence of habituation to boat traffic.

Some aspects of the reproductive biology of the polychaete Gorgoniapolynoe caeciliae have been described for the first time. Gorgoniapolynoe caeciliae is a deep-sea commensal species associated with Candidella imbricata, an octocoral that populates the New England Seamount chain. Gorgoniapolynoe caeciliae is a dioecious species with an equal sex ratio and fertile segments throughout most of the adult body. The gonads of both sexes are associated with genital blood vessels emerging from the posterior surface of most intersegmental septa. In the female, oogenesis is intraovarian with oocytes being retained within the ovary until vitellogenesis is completed. The largest female examined contained over 3000 eggs with a maximum diameter of 80–90 μm. In the male, the testes are repeated in numerous segments and consist of small clusters of spermatogonia, spermatocytes, and early spermatids associated with the walls of the genital blood vessels. Early spermatids are shed into the coelom where they complete differentiation into mature ect-aquasperm with a spherical head (4 μm), a small cap-like acrosome, and a short mid-piece with four mitochondria. Indirect evidence suggests that this species is an annual breeder that releases its gametes into seawater and produces a planktotrophic larva following fertilization. The reproductive biology of G. caeciliae is consistent with that of most other polynoids including many shallow water species suggesting that phylogenetic history strongly shapes its biology.

Vesicomyid clam species are abundant in many deep-sea chemosynthetic communities, including cold seeps. They rely primarily on thiotrophic (sulphide-oxidizing) gill symbionts for nutrition and thus require sulphide-rich environments. Submersible surveys of megafaunal distributions at the Blake Ridge Diapir, a deep-sea methane-hydrate seep located ∼200 miles off the coast of Charleston, South Carolina, documented massive mortalities of vesicomyid clams. The cause of these mortalities is unknown, but sulphide deprivation, sulphide toxicity, and disease are possible agents of mortality in this system. Similar redox profiles in sediment cores from live and dead clam beds do not support the hypothesis that there has been a transient shift in the flux of sulphide. To address the potential for disease as a cause of mortality, we undertook a histological survey of microparasites and other indications of disease in clam tissues. Six morphological types of parasites were identified using light microscopy, including two viral-like inclusions, Rickettsia-like gill inclusions, possible bacterial gut inclusions, bacterial gill infections, and a protistan inclusion. Of these parasites, two were pathogenic: viral-like inclusions in mantle tissues caused tissue degradation; bacterial gill infections resulted in localized disruption and degradation of gill filaments. Infection prevalence and densities were low for all parasites observed. The majority of clams examined showed intense haemocytic responses in the absence of any obvious etiologic agent, suggesting the presence of parasites not detectable by our methods. Our findings indicate that the clam population at the Blake Ridge seep was in relatively good health at the time of sampling.

Food and feeding activity of juvenile pompano Trachinotus ovatus (25–97 mm) collected in the summer–autumn in 2003 in coastal shallow-water bays in the south-eastern Adriatic were examined. Juvenile pompano were exclusively daytime feeders and fed in the entire water column, from surface to bottom taking not only plankton, but benthic and terrestrial species as well. Of 18 prey taxa identified, crustaceans—particularly copepods—were the major group, followed by benthic foraminiferans and insects. Feeding on benthic species is reported for the first time in this study.

The benthic system of the Golfo San Jorge was characterized from physico-chemical parameters based on samplings obtained during seasonal research cruises carried out on board the INIDEP vessels from springtime 1999 through wintertime 2000. Spatial and seasonal variations of temperature, salinity, density, oxygen content and chlorophyll-a in bottom water and concentration of total organic matter, total organic carbon, total nitrogen, chlorophyll-a and phaeopigments in sediments were analysed. The origin and nutritional value of the deposited organic matter were also assessed. The behaviour of the physico-chemical characteristics of the benthic habitat, studied applying statistical techniques, defined three sectors with particular characteristics and minimum seasonal variations: sector 1, the largest and deepest one, comprises the central area of the gulf and corresponds to a depositional environment; sector 2 comprises the areas next to the extremes of the gulf and corresponds to a flow or erosive environment; sector 3 includes the coastal area and south-east part of the gulf and belongs to a transitional environment.

Amphipods of the genus Phronima are known to make a barrel-shaped house from the gelatinous matrix of pelagic tunicates or siphonophores. Among the seven barrels examined here, one barrel of Phronima curvipes was supposed to be made from a swimming bell of a siphonophore based on its morphology, while the other six barrels made by P. sedentaria were immunochemically and/or morphologically identified as tunicates (i.e. Thetys vagina, other salps and pyrosomas). Histological observation showed that the phronimids had completely eaten the animal tissues other than the gelatinous matrix (i.e. tunic or mesoglea). Tunic cells were found in the tunicate barrel and some were probably tunic phagocytes that appeared to be alive and functional. In the tunicate barrels, cuticular layers of the tunic were found on both the outer and inner side of the barrel wall. Tunic cuticle would be regenerated on the inner side after the epidermis was grazed by the phronimids. The cuticular layers would protect the tunic matrix from the invasion of microorganisms. In the barrel supposed to originate from Thetys vagina, there are minute protrusions on the tunic cuticle as found in the intact tunic of this species. In the barrel from a siphonophore, neither cells nor cuticle regeneration were found. No bacteria were observed in the barrel, suggesting that the barrel has some antibiotic system.

The phylogenetic position of Xenoturbella spp. has been uncertain since their discovery in 1949. It has been recently suggested that they could be related to Ambulacraria within Deuterostomia. Ambulacraria is a taxon that has been suggested to consist of Hemichordata and Echinodermata. The hypothesis that X. bocki was related to Ambulacraria as well as the hypothesis of a monophyletic Ambulacraria is primarily based on the analysis of DNA sequence data. We tested both phylogenetic hypotheses using antibodies raised against SALMFamide 1 and 2 (S1, S2), neuropeptides isolated from echinoderms, on X. bocki and the enteropneust Harrimania kupfferi. Both species showed distinct positive immunoreactivity against S1 and S2. This finding supports the Ambulacraria-hypothesis and suggests a close phylogenetic relationship of X. bocki to Ambulacraria. In particular, the presence of immunoreactivity against S2 can be interpreted as a synapomorphy of Enteropneusta, Echinodermata, and Xenoturbella spp.