Samples containing the marine ostracod Callistocythere badia were collected from upper shore rockpools on Filey Brigg, north-east England in order to examine the life cycle and genetic structure of the species. Reproduction occurred during spring/summer after which the adults died; juveniles over-wintered as A-1 instars. No males were ever found during the study. Analysis at three polymorphic loci (Gpi, Pgm and Mpi), showed significant deviations from Hardy–Weinberg equilibrium, and significant linkage equilibrium at and between all loci. The genetic data and absence of males confirm that Callistocythere is an asexual species. There was a significant positive relationship between the number of clones found within a pool and rockpool size, but not with algal habitat heterogeneity.

A number of biological parameters relevant to the population dynamics of Paranemonia vouliagmeniensis are discussed. The abiotic factors of the lagoon's waters are stable throughout the year. Paranemonia vouliagmeniensis populations follow different patterns of distribution (aggregated or random) in relation to human influence, and can thus become a reliable bioindicator for the lagoon.

Two new species of the recently established genus Echinovadoma (Bryozoa: Cheilostomatida: Echinovadomidae) are described and illustrated from the Banda Sea, off Java, E.alacermatrix sp. nov. and E.magnitorquata sp. nov. Their affinities to the only other known species of the genus, E.anceps, for which both the genus and family were named, are discussed.

Traditional techniques used to sample azooxanthellate coral banks by dredge and trawl cause extensive impact to both the corals and surrounding seabed. Modern sampling techniques using submersibles and remotely operated vehicles cause very little or no damage, but are expensive and require specialized vessels. Here we describe a combination of video camera and benthic grab for sampling azooxanthellate corals and test this method on a Lophelia pertusa bank in Osterfjorden, western Norway. The video-assisted grab was successfully used both for locating and sampling L. pertusa. This method can largely replace the use of traditional, more destructive dredging and trawling techniques for sampling azooxanthellate corals.

In Ireland the purple sea urchin Paracentrotus lividus (Echinoidea) typically inhabits intertidal bored holes. At Lough Hyne, Co. Cork, a population occurs associated with rock scree in the shallow subtidal zone. This study provides unequivocal quantitative evidence to demonstrate diurnal migration in a population of P. lividus at Lough Hyne, Ireland. Most size groups/age-classes did not to migrate, the youngest always and oldest never occurring under rocks. Those that did migrate between the lower and upper surface of rocks (2+, 3+ and 4+ age categories) did so in exactly the reverse circadian pattern to those described from the Mediterranean Sea.

Two species of large extension feeding barnacles are abundant on exposed tropical rocky shores of northern Australia. The cirri of many specimens carry varying numbers of a commensal diatom in some cases with as many as 2000 individuals on a single cirrus. The araphid diatom resembles the genus, Lichmophora within the family Fragilariaceae although no description has yet been published. Species of Lichmophora are common benthic diatoms in these waters as an epiphyte on macroalgae and common primary fouling diatoms on test panels. The diatom reported here has not been found on any substratum other than the barnacles Tetraclita squamosa and Australobalanus imperator, very rarely on Balanus amphitrite. Analysis of the diatom distribution on the cirri shows significantly higher numbers on the posterior captorial cirri. The effect of commensal diatoms on the feeding efficiency of the barnacles is discussed.

It is possible to mark octopus (Octopus vulgaris) paralarvae on a massive scale (up to 3500 paralarvae l−1) with 100% marking reliability using alizarin complexone (ALC). The whole statolith is marked and the best results obtained were with concentrations of 60-300 mg l−1 and bath duration of 3-24 h. Taking into account the quality of marking, mortality and ALC costs suggest using from 60 to 200 mg l−1 for 3-6 h. The only treatments causing significant mortalities were 300 mg l−1 over 6 and 24 h.

Specimens of three zoanthid species, Epizoanthus couchii, Parazoanthus anguicomus and P. axinellae were sectioned. All were gonochoric, with gametes developing during summer. Oocytes in P. anguicomus originate in a single-layered ribbon down the perfect septa, but the ribbon becomes moniliform as, at regular intervals, it folds laterally into lens-shaped nodes, packed with oocytes, doubling polyp fecundity.

Population structure of the short-finned squid Illex illecebrosus (Ommastrephidae) was studied on the Nova Scotian shelf between July–September 1984. It was characterized by a prevalence of winter-hatched squid in summer–early autumn, their short (three months of the summer) occurrence on the shelf, and a predominance of females in sex ratios during the feeding period. Ages of squid were estimated by statolith increment counts and ranged from 128 to 201 d. Growth in length was described by linear model with daily growth rates of 0.99 mm/d−1. Adding the length-at-age data from juveniles caught in 1979 to the 1984 data set enabled to construct an ontogenetic growth curve for the winter-hatched squid which was best approximated by the Gompertz growth function.

Larvae of vent shrimp from the Mid-Atlantic Ridge are known to disperse widely from the adult habitat. Experimental analysis of the temperature/pressure tolerance of the first zoeal stage of Mirocaris fortunata from the Lucky Strike vent field suggest that the upper limit of vertical distribution is determined by temperature. Conversely, the lower limit is controlled by the maximum pressure tolerance of the larvae.

Driftwood was collected from Stuart Creek, North Queensland, to examine the relationship between the wood-boring isopod, Sphaeroma terebrans (Isopoda: Sphaeromatidae), and the wood-boring mollusc, Bankiaaustralis (Bivalvia: Teredinidae). Broadly non-overlapping distributions in individual pieces of driftwood were found for S. terebrans and molluscan wood-borers at the study site.

Luminescence in Amphipholis squamata has only been observed from chemically stimulated individuals, and the present laboratory study assessed the natural expression of luminescence following interaction with co-occurring organisms. The luminescence occurred only in response to (mechanical) stimulus and ranged from weak to intense reaction depending on the contact organism. Only crustaceans triggered an intense luminescence. Brachial autotomy also occurred after prolonged interaction and the luminescence continued only from the autotomized arm, which could lure the crustacean. The study showed that A. squamata luminescence could be naturally stimulated by co-occurring organisms, and the light produced sufficiently intense to be detected.

The relative frequency and destination of limpets relocating from different home-scar positions in respect to aggregations was determined for a population of limpets in Dorset, UK. Limpets on the outside of groups were the most likely to relocate, next were solitary limpets and limpets on the inside of groups were the least likely to move.

The diet of common wolffish Anarhichas lupus from the North Sea is described, from a total of 143 wolffish stomachs, of which 112 contained food. The main prey were crustaceans and molluscs, together representing almost 70% of diet by relative frequency of occurrence in stomachs. Wolffish >55 cm preferred polychaetes and gastropods while wolffish <55 cm preferred sea urchins and brittle stars. The occurrence of empty stomachs was significantly less in spring than in summer or in autumn/winter. Meal size was lowest in winter and highest in spring. These data reflect a period of low food intake in winter during spawning and tooth replacement, followed by a recovery feeding episode in spring.

Specimens of Opisthoteuthis grimaldii were video recorded in a shipboard aquarium and their behavioural traits, such as bottom resting, flat-spreading, web-inversion and ballooning response, were described. Ballooning, as defence response, has been recorded only for cirrate octopod families with an intermediate web (Cirroteuthidae: Stauroteuthidae), and this structure has been supposed to be essential for developing this behaviour. Members of the Opisthoteuthidae family lack an intermediate web, indicating that this is a common defence response in cirrates, expressed in a basic form in the Opisthoteuthidae, offering an illustration of how this behaviour can evolve.

The impact of biofouling by the filamentous bacteria Leucothrix mucor upon the body density and swimming behaviour of the harpacticoid copepod Tigriopus brevicornis was investigated. Biofouled individuals had a greater body density than non-fouled individuals. Biofouled and non-fouled animals swam similar distances and for similar periods of time during trials, but biofouled animals engaged in fewer, but longer bouts of swimming per trial and as a result experienced a lower swimming rate. These observations imply that biofouling has significant implications for the behavioural ecology of T. brevicornis.

Clam species belonging to the family Veneridae (Mollusca: Bivalvia) represent very important marine products, especially in the European countries. The increasing economic interest in marine edible molluscs has strongly enhanced the need for a routine method of unambiguous recognition of species in fresh and preserved material, mainly intended to prevent mislabelling and commercial frauds. Here a procedure for identification of soft parts is proposed, by means of SDS-PAGE total protein patterning. In fresh material, this technique allowed recognition of four main regions of diagnostic bands, which have been named V1 (111–99 kDa), V2 (44 kDa), V3 (33–30 kDa) and V4 (19–13 kDa). The main diagnostic region appears to be the V3 band series. SDS-PAGE analysis allows the same technique to be used with denatured samples, such as cooked and preserved soft parts, giving reproducible results, very similar to those of fresh material.

The effect of two putative tripeptide analogues (isoleucine-isoleucine-arginine [IIR] and valine-leucine-arginine [VLR]) and a reported analogue, glycyl-glycyl-arginine (GGR), of the waterborne cue to settlement of Balanus amphitrite amphitrite Darwin cypris larvae has been investigated. Settlement in the presence of these tripeptides was not significantly different from that in filtered seawater. Because crude waterborne cue and settlement-inducing protein complex both significantly evoked settlement, the cyprids used in this study were competent to respond. The overall results, therefore, demonstrate that IIR, VLR and GGR are not analogues of barnacle waterborne settlement pheromone.

This is the first record of the digenean parasite (Maritrema arenaria) in the acorn barnacle (Balanus perforatus). The seasonal variations in the abundance and prevalence of infection as well as variation of these with tidal level and barnacle scutum lengths are discussed.

In situ seasonal study of siphonal activity in Mya arenaria (ten individuals) was performed using a fixed video camera during nine complete submersion cycles between May and November 1996. Siphonal activity was described by exhalant and inhalant siphon simultaneous closure frequencies (EIC), pseudofaeces production frequencies (PFC) and both siphons opening state duration (OPE). A repeated measure ANOVA model showed a slight OPE increase between May and June and a strong OPE and EIC decrease from October. A non-linear probit model on the proportion of individuals showing PFC events during submersion cycles indicated a progressive decrease of this behaviour with time. The siphonal activity was relatively high until September and then decreased from October suggesting a marked reduction of the feeding activity.