Patterns in community structure of meiofauna and macrofauna in relation to Portuguese clam dredging were compared during a 2-y-period off Lagos and Vilamoura, south Portugal. SCUBA divers randomly sampled corer and quadrat samples before and immediately after simulating commercial dredge fishery. Univariate measures (abundance, number of taxa, evenness, diversity and biomass) and multivariate analyses (Cluster, MDS and SIMPER) revealed changes in the meio- and macro-benthic community structure caused by dredge disturbance (short-term effects), with a general decrease in all measures. Macrofauna were found to be more sensitive to dredge disturbance, and aggressive predatory behaviour was observed after disturbance in the continuously dredged area. Nevertheless, higher significant natural changes were found between seasonal periods, indicating that dredging may only cause a small-scale and short-term impact.

The population structure of Mithraculus forceps sampled monthly on Anchieta Island from January 1999 to December 2000 was studied. A total of 68 individuals were collected by SCUBA diving. The population presented normal and unimodal distribution, and the total sex ratio was 1·4:1·0 in favour of males. Ovigerous females were captured during all seasons. The pattern observed for the M. forceps population in Anchieta Island indicated the strategy favoured by environmental characteristics of the island and by coexistence with other decapod crustaceans in the studied area.

The morphology of burrows constructed by the eel goby Taenioides cirratus was studied using resin castings of burrows in situ as well as aquarium observations. Burrows had several openings, one of which was associated with a crateriform mound. The structure of the burrows consisted of the mound, gently sloping interconnected tunnels, and many short cul-de-sac side branches. The presence of the mound suggests that the fish actively process sediment.

A specimen of Arnoux's beaked whale was recorded from the coast of Brazil on 4 August 1993. The specimen was identified from the skeleton in 1994. Arnoux's beaked whales (Berardius arnuxii) are known to have a circumpolar distribution in the Southern Hemisphere, from the Antarctic continent and ice edge (78°S) north to about 35°S in the southern Pacific, southern Atlantic, and Indian Ocean. Few sighting and stranding records are known. Its distribution in deep and cold waters, mainly far from the coast and in higher latitudes, is probably the main reason preventing the collection of more information on the biology of this species. It is still considered as ‘insufficiently known’ by the International Union for the Conservation of Nature and Natural Resources. Sighting records are more common in Antarctic waters, where some individuals sometimes become trapped in ice holes, and in the South Pacific. Strandings are relatively rare. About 30 strandings were reported around New Zealand, and single ones occurred in southern Australia, in South Africa, Argentina and the Falkland Islands. The majority of records occurred south of the latitude 40°S (Ross, 1984).

Minke whale (Balaenoptera acutorostrata) distribution was derived from a 12 year observation programme in the Mingan Islands (Canada) and related to three geological features of the sea-floor: maximum depth, topography and geomorphology. Minke whale distribution was not uniform nor random in relation to maximum depth and topography, however, no evident trend was found. The most prominent factor was the presence of underwater sand dunes, where significantly more minke whales were observed than on any other bottom types. Because sand dunes are the favoured habitat of the minke whale major prey in the study area, an indirect link between minke whale distribution, geomorphology and substrate type is suggested.

A new neritiliid gastropod, Neritilialittoralis, lives in a unique, intertidal, subterranean, brackish environment on Amami-ohshima Island, Japan. It lives exclusively on rubble that is embedded deeply in coarse-grained sand whose interstices are filled with a mixture of subsoil water and seawater. Empty shells of this species were also found in tide pools at the foot of limestone terraces on Okinawa Island, where a large volume of karst-related freshwater gushes out. The species is characterized by a very small, white shell and unpigmented skin. Neritilia has previously been found in freshwater streams, rivers, estuaries, and in anchialine and phreatic waters, and the present find expands its range of known habitats and has implications for the history of the invasion of freshwater by neritiliids. The spiral protoconch suggests that the larva of N.littoralis is long-lived, planktotroph and a very effective disperser, and all the individuals collected appear to be part of a panmictic population.

Sulphur-isotopic composition of soft tissues from Bathymodiolusmarisindicus collected from hydrothermal vents in the Indian Ocean was reported. The δ34S values of the soft tissues (+3∼+5‰ vs Cañyon Diablo troilite) were nearly identical to those from the associated hydrothermal fluid and chimney sulphides (+5 to +8‰), but were significantly different from that of the common seawater sulphate (+21‰), which suggested that the endosymbiotic bacteria used sulphide in the fluid as an energy source. Transmission electron microscopic observation of the endosymbionts also suggested that the symbiont is a thioautotroph. Bathymodiolus species, which depend on either sulphide or methane oxidation, or both, have a worldwide distribution. Bathymodiolus marisindicus from the Indian Ocean has a close relationship with congeners in the Pacific Ocean as evidenced by form of symbiosis. Biogeography and migration of the genus Bathymodiolus based on the relevant data are briefly discussed.

Spinosphaera is a Terebellinae genus with three species described from the Pacific Ocean, S. pacifica from Japan, S. oculata from California, and the doubtful S. cowarrie from Western Australia. The genus is presently unknown in the Grand Caribbean region. Spinosphaera is characterized by the absence of branchiae, by the great number of notopodia, and the presence of a special type of notochaetae, called ‘Spinosphaera-chaeta’. These chaetae have three different regions: distal denticulate blade, neck separating the former from a middle swollen spinous region, and a proximal smooth or bilimbate region; two sizes are present. The genus is redefined, with redescription of all species currently known. Three new species are described here, two from the Mexican Caribbean coast, S. hutchingsae and S. carrerai, and one from California, S. harrisae. A taxonomic key to identify all species is given. Hutchingsiella gen. nov. is proposed for S. cowarrie; it differs from Spinosphaera in having notochaeta from segment 5 and neurochaetae from segment 6, and for lacking Spinosphaera chaeta.

Mouthpart and proventriculus structure of the brachyuran crab Nectocarcinus tuberculosus was described by scanning electron microscopy and histology and characteristics indicative of dietary preferences were identified. A qualitative stomach content analysis was conducted to verify structural interpretations with respect to diet. The mouthparts and proventriculus of N. tuberculosus have features that are typical of macrophagous crabs and are consistent with a carnivorous diet of hard items. However, the mandibular arrangement indicates that N. tuberculosus is also adapted to ingest soft plant material and fleshy items, revealing that this crab is omnivorous which is consistent with its habitat of rocky shores and sea grass beds. Carnivorous features of the feeding apparatus include large crista dentata on the third maxillipeds that grip food items during ingestion and cuspidate setae on the second maxillipeds and first maxillae. Nectocarcinus tuberculosus has a complex arrangement of proventricular ossicles, 5-denticulated accessory teeth, and a spiny cardio-pyloric valve with rough, calcified protuberances. It has a robust, strongly calcified gastric mill with a prominent anterior cusp and 11 roughly surfaced vertical ridges on each lateral tooth specialized for crushing and grinding. In contrast to true carnivorous crabs, the mandibles in this species are symmetrically arranged, with two sharp cutting edges and no teeth, an arrangement adapted to cut softer plant-like materials and flesh. Structural interpretations with respect to diet were confirmed by stomach content analysis where items identified included gastropods, bivalves and the sea grass Posidonia australis. Functionally, the filtering system in the proventriculus of N. tuberculosus is complex. The cardiac stomach has a well developed ventral filtration system or ‘cardiac filter’ which comprises coarse and fine filters. Different modifications of setation between the distal and proximal regions of the inner valve of the pyloric filter are unique to this crab species, with an intersetule width 600 nm in the distal region and 80–100 nm in the proximal region. This suggests that some differentiation in filtration occurs between regions within the pyloric filter.

A roughtail stingray, Dasyatis centroura, and a spiny buterfly ray, Gymnura altavela, were caught near Kolocčep Island (Elafiti Archipelago, southern Adriatic) and the settlement Crkvice (Pelješac Peninsula, southern Adriatic) in October 2002 and November 2000, respectively. The roughtail stingray is the largest specimen recorded. Morphometric data of spiny butterfly ray are the first for this species in the Adriatic Sea.

The parasitic copepod, Alimeda orientalis, is recorded from the gill of the sea hare, Dolabrifera brazieri (Gastropoda: Opisthobranchia: Anaspidea). Ten specimens of D. brazieri from a population on the coast of New South Wales, Australia were examined for the incidence of parasitism. Histological techniques and scanning electron microscopy were utilized to determine the feeding mode of A. orientalis and its effect on the host. Alimeda orientalis is a tissue feeder on the gill tissue, and damage caused by feeding and attachment is minimal.

A new genus of terebellid polychaetes is described, from material collected from living colonies of a stony coral (Mussismilia hispida) in the State of São Paulo, south-eastern Brazil. Articulatia is characterized by possessing notopodia from segment 5, neuropodia from segment 5 or 6 with double rows of uncini from segment 7 until near pygidium. Up to segment ten, notopodia with bilimbate capillaries; from segment 11 onwards two types of notochaetae are present, articulated chaetae, due to a deep cut at the sulcus of the third tooth, as well as capillary chaetae, both types with serrated blades. The presence of deep-cut chaetae is unique among all previously described terebellomorph polychaetes. This new genus is compared with other terebelline genera, and the phylogenetic analysis previously performed for the group is rerun, in order to determine the position of Articulatia within the subfamily. The type species of the new genus, A. aberrans, is also new to science and herein described.

The capture of a specimen of Kentrocapros rosapinto at Vema Seamount in the south-east Atlantic Ocean is reported as the first record of this species in the Atlantic Ocean. This species was previously known only from the western Indian Ocean.

The first documented record of the Indo-west Pacific pufferfish Arothron firmamentum was reported off Mar del Plata, Argentina at a depth of ∼45 m and is the first occurrence of the starry toadfish in American Atlantic waters. Some morphological and biological characteristics are given for the two specimens caught. Different explanations of how the two pufferfish specimens arrived in south Atlantic waters are discussed.