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.

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.

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.

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.

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.

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.

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.

This note reports the main morphometric and meristic parameters of a male Bermuda sea chub (Khyphosus sectator) caught off the Algarve coast (southern Portugal). This is the first occurrence of this tropical fish species in Portuguese continental waters, and the second and northernmost capture ever reported for the north-eastern Atlantic.

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.

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.