The rates of ingestion, egestion, ammonium excretion, and CO2 respiration of Tripneustes gratilla (Echinodermata: Echinoidea) from a shallow water embayment at eastern Mactan Island, central Philippines were examined. There was no significant difference in weight-specific feeding rate with the three macrophytes (Sargassum polycystum, Thalassia hemprichii, and Kappaphycus alvarezii). The power function equation, M=KWb fitted well with the weight-specific egestion rates ((r2=0·93), weight-specific CO2 respiration rates (r2=0·92) and ammonium excretion rates (r2=0·86). Weight-specific egestion rates, CO2 respiration and ammonium excretion were indirectly proportional to body weight. For weight-specific egestion rate (in μg DW faeces/g DW urchin-h), the regression coefficient, b and constant, K were −2·31±0·68 (mean±SE) (P=0·02) and 6359·55±5394·31 (P=0·29), respectively. The b and K for CO2 respiration were −1·28±0·48 (P=0·04) and 39·72±10·59 (P=0·01), respectively. For ammonium excretion, the b and K were −1·03±0·46 (P=0·11) and 262·51±56·89 (P=0·02), respectively.

Ichthyoplankton from an area in the Celtic Sea was studied to provide an insight into the fish larval community structure in March, May and June 1998. Three station groups were defined each month, Neritic, Transition and Oceanic. The Neritic assemblages included larval stages of coastal fish species and the Oceanic assemblages included mesopelagic and high-oceanic fish species which were not recorded from any of the Neritic stations. The Transition stations usually contained species characteristic of both the Neritic and Oceanic assemblages. It is suggested that these broad patterns of larval fish distributions are constant features of the Celtic Sea area, probably related to the spawning location of the adults. The area is, in general, species poor, with the Oceanic stations usually dominated by a single species, indicating the presence of a large spawning school of fish.

Elemental composition and ontogenic change patterns of Sr and Ca were examined in conger eel, Conger myriaster, otoliths. Accumulations of the major elements of seawater, K, Mg, and Na, into otoliths were smaller than the accumulations of 19 other minor elements whose concentrations were determined. Strontium content and Sr:Ca ratios in the otolith fluctuated during the life history transect at 100 to 200 μm from the core of the otolith, indicating a period of metamorphosis. Changes in Sr content and Sr:Ca ratios may be associated with internal physiological factors such as metamorphosis in the early developmental stage in the conger eel.

A local population of the introduced green macroalga Codium fragile ssp. tomentosoides was investigated in Oban in the district of Argyll, western Scotland. Periodic surveys demonstrated that sacoglossan densities (Elysia viridis and Placida dendritica) were unusually high in 1997 and early 1998, slug herbivory noticeably damaged algal thalli, and the local algal population was decimated. These patterns provide indirect evidence of the significance of slug herbivory on the introduced alga.

The effect of water flow rate on the regeneration rate of the temperate sponge Cliona celata was investigated at two sites experiencing fast and slight current flow respectively at Lough Hyne, Co. Cork, Ireland. Faster regeneration rates were found in sponges living in high current areas which may be due to an increased amount of potential food material per unit time and the possibility of entrained water flow.

Several morphological characteristics of the shell in cockles (genus Cerastoderma) were investigated. A significant inverse relationship between rib number and shell curve was revealed in Cerastoderma glaucum. Morphometric and meristic descriptors were correlated with some environmental factors, such as salinity and temperature. Analysis of allometry in C. glaucum and Cerastoderma edule revealed significant differences between the two species. The results are discussed from an adaptive perspective, providing possible hypotheses on the steps which might have driven the evolution of form of the studied species during the process of adaptation to coastal tidal and confined habitats.

Digital image analysis was applied to quantify the degradation of muscle in sea bass Dicentrarchus labrax (Pisces: Moronidae) larvae. The measure obtained was the percentage muscle fibre separation (MFS). This measurement was compared to that obtained through classical scoring. The percentage MFS classified correctly a larger number of larvae from different feeding treatments (Fed, Starved and Delayed treatments) and paralleled nutritional condition, both by age and by size. It also yielded a significant correlation with the survival of the Starved larvae. The onset of the mass mortality of Starved larvae was used to define a critical value (Mmax) of 6% MFS which would severely handicap survival. We regard MFS as a useful contribution to the determination of condition in fish larvae. It is a relatively fast quantitative method, and its use would reduce the bias caused by discrete grading (scores) and by differences in individual expertise.

There are just a few records of giant squid of the species Architeuthis captured alive. Two living sub-adult females of Architeuthis of 180 and 135 cm mantle length with total weights of 148 and 81 kg respectively, were caught 34 miles offshore in northern Spanish Atlantic waters (43°52.54′N–05°18.4′W) in December 1999 and January 2001. From April 1999 to January 2000 in the same area, another giant squid of 102 kg as well as a single tentacle measuring 5 m, and another tentacle of 2 m long were caught. Another five living specimens were captured and 11 more animals were caught dead during the last 15 years in the same area.

This study focused on the breeding period of Stenorhynchus seticornis (Brachyura, Majidae, Inachinae) in the south-eastern Brazilian coast. Monthly collections were accomplished from January to December of 2000. A catch effort of approximately 4 h was allocated to each monthly survey. The breeding intensity was determined as the percentage of ovigerous crabs within the whole adult female population. A total of 204 adult females were obtained, from which 74·5% presented eggs attached to their pleopods. Ovigerous females were observed year-round, usually comprising more than 60% of sampled adult females. The ovigerous frequency was not found to be correlated with either temperature or salinity.

Male and female sharknose cleaning gobies Elacatinus evelynae (Gobiidae) occupying cleaning stations in monogamous pairs differed significantly in cleaning behaviour and diet. Females spent five times longer cleaning, took more bites from clients, engaged in more cleaning events on more client species, and cleaned at a higher rate than males. These behavioural differences tended to be reflected in the diet, with more females ingesting more client-gleaned items than males. These results are consistent with greater energetic requirements for reproduction for females. Male cleaning gobies were frequently absent from cleaning stations, presumably guarding eggs, and their presence at cleaning stations gave rise to foraging conflicts and interactions with females. The cleaning rate of females was significantly lowered by the presence of males, whether cleaning or not, whereas males cleaned for longer and took more bites when females were present. When cleaning the same client, males and females showed priority of first inspection, with females cleaning longer and taking more bites in cleaning events they initiated while males gained similar advantages in client- and male-initiated interactions. Furthermore, females initiated cleaning on larger clients, which may give them a foraging priority on a higher-quality resource since larger clients tend to have more ectoparasites. Finally, from a client's perspective, the cleaning service provided appears better in terms of length of inspection and bites taken when both males and females are at a cleaning station than when a single cleaner is present. However, the foraging differences and interactions between male and female cleaning gobies are of little consequence to clients since the cleaning service provided is simply reapportioned between males and females rather than changed by the interactions between gobies.

Deviation from pentamerism is a rare phenomenon in 5-armed echinoderm species. Qualitative and quantitative data from field observations of 14 populations around the world were used for a biogeographical study of this phenomenon. Four abnormal forms presenting deviation from the classical pentamerism of echinoderms were observed within the brittle-star species Amphipholis squamata (Echinodermata: Ophiuroidea). Although these forms were rare in global populations (0·29%), they can reach important frequencies in some locations. Our results suggest that habitat structure has an influence on the occurence of abnormal forms. Moreover, deviations from pentamerism are not a heritable character but are a consequence of environmental perturbations on the metamorphosis of larvae and/or abnormal regeneration of arms.

Statoliths of the jumbo flying squid Dosidicus gigas (Cephalopoda: Ommastrephidae) in the eastern Pacific in 1995, 1996 (non-El Niño years) and 1997 (El Niño year) were analysed to observe whether unusual temperature increases due to El Niño was recorded in the concentration of trace elements. In addition to calcium (the major element), trace elements of manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and strontium (Sr) were detected. Strontium concentration in the calcified tissue of some aquatic animals changes with environmental variables. However, yearly comparisons revealed that Sr concentration did not significantly differ between the El Niño year and non-El Niño years. Instead, the Sr concentration differed with squid habitats. Strontium concentration in statoliths of D. gigas from Peruvian waters (high salinity) was significantly higher than those from Costa Rican waters (low salinity) regardless of El Niño.

0-group bass were sampled from the shallow creeks of the Tamar and Camel estuaries at regular intervals from May to September in 1981 to 2000 to measure relative year-class abundance. From 1989 onwards classes were generally strong, especially those of 1989, 1992 (Tamar only), 1995 and 1998. Sampling at age-4, before departure from the nursery at the onset of adolescent movements, gave broadly similar relativities. Numbers were greater, and growth faster, in the Tamar than in the smaller and cooler Camel. Temperature was an important factor in both abundance and growth. Occasional major differences in abundance between the two estuaries were reported. Factors which might bias the age-4 result are considered. Other estuaries on the south side of the south-west peninsula, sampled less frequently, reflected Tamar abundances; others on the north side reflected Camel abundances. Limited analysis of stomach contents of older juvenile bass often present in the same habitats revealed no evidence of cannibalism on 0-groups. The shallow creeks of the Tamar and Camel were deserted in winter but a deeper creek on the Taw, frequented throughout winter, was sampled monthly in the 1982–1996 winters to measure losses, if any, in cold periods. In the mainly mild winters, losses were infrequent and small except in the five-week cold spell of early 1986, when the 1985 class suffered an estimated 58% loss in the Taw and possible total loss in the Camel and the Tamar. Sudden heavy flooding of the estuaries caused no apparent losses when they occurred in late summer and autumn but might be damaging if they occur soon after post-larvae arrive.

A new species of the genus Rosacea (Siphonophora: Calycophorae: Prayidae) is described from the Gulf of Oman, where its eudoxid stage was found in abundance. It is distinguished from other Rosacea species by the course of the lateral radial canals on the nectosac of the nectophore, and the shape of the eudoxid bract and the arrangement of its bracteal canals.

The feeding habits of Polyacanthonotus rissoanus, the sixth most abundant species below 1000 m on the deep slope of the Catalan Sea (western Mediterranean), were studied in the Mediterranean Sea. Samples were obtained at depths between 1000 and 2250 m. Diet was analysed for two seasons (summer and autumn) and three different bathymetric strata. The most important food items found were small epibenthic and suprabenthic crustaceans and polychaetes, and occasionally other groups such as Priapulida, Gastropoda and Foraminifera. At 1000–1425 m, the mysids were preferential prey, while in summer at all depths analysed, isopods were a dominant prey. Polychaetes have certain incidence in the diet only at 1000–1425 m, being a dominant prey in autumn. Individuals at the 1000–1425 m depth ingest larger numbers of prey of higher average sizes than those at 1425–2250 m. The scarcity of resources below 1200–1400 m resulted in diversification of diet and encouraged preying on deposited foraminiferans, molluscs or moving copepods.

The present study was carried out during the summer of 1997 in three locations of the western Italian coast (La Spezia, Ligurian Sea; Ischia, central Tyrrhenian Sea; Ustica, southern Tyrrhenian Sea) to investigate variability in abundance and size structure of the labrid fish Thalassoma pavo along a latitudinal gradient and over different spatial scales. Fish abundance and size were estimated by visual census in shallow rocky reefs. Significant differences were detected in average abundances of T. pavo (with and without the contribution of juveniles) among locations (separated by a distance of hundreds of kilometres from each other) and over the smallest scale examined (i.e. among sites located tens of metres from each other). However, most variability was explained considering the largest spatial scale associated with the latitudinal gradient. Average abundances generally decreased from the southern Tyrrhenian to the Ligurian Sea. In terms of frequency, juveniles (<5 cm total length (TL)) increased from north to south, while the largest fish (16–20 cm) displayed an opposite trend. The intermediate size-classes (6–10 and 11–15 cm) did not show any distinct patterns. In terms of abundance, small T. pavo (0–5 cm) showed significantly higher densities at Ustica, followed by Ischia and La Spezia. Fish 6–10 and 11–15 cm long were significantly less abundant at La Spezia than at Ischia and Ustica, while those between 16 and 20 cm TL did not differ numerically among the three locations. The results of the present study provide suggestive evidence that factors acting on a geographical scale are likely to influence distribution patterns of the thermophilic fish T. pavo, although significant effects have been also observed at the smallest spatial scale examined. Climatic conditions (e.g. water temperature along the latitudinal gradient) and substrate features (e.g. macroalgal cover, physical complexity, slope) are thus likely to affect average abundances and size structures of T. pavo populations along the western Italian coast.

Analyses of 13 submersible dives on the continental slope of the Bay of Biscay (north-east Atlantic) showed that: (i) orange roughy formed dense aggregation of more than 4000 individuals per ha close to the bottom of a small underwater canyon. In all other study areas only a few individuals were observed. Orange roughy aggregations are probably associated with areas of high water mass movements and mixing; (ii) most individuals observed within this aggregation or in its peripheral areas were behaviourally inactive and could be approached with the submersible at close distance; (iii) a large number of these orange roughy showed a completely pigmentless white, or weak red coloration, never observed from specimens caught in trawls. Two individuals which were disturbed by the submarine changed from white to the ‘typical’ red coloration.

These observations suggest fine tuning of the foraging strategy and life cycle of the species. It is speculated that, as an active predator of a sparse food resource, orange roughy has developed adaptations to exploit areas with specific hydrological conditions which offer high prey encounter rates and shelter during metabolic relaxation phases between foraging trips.

Stomatolepas elegans on a Dermochelys coriacea is reported at Seiland, Finnmark, northern Norway at the highest latitude recorded for this species or for any members of its subfamily (Platylepadidae), as well as for its turtle host. The distribution of the species of Stomatolepas is given and their taxonomy is briefly discussed. A recording of data on the different species of Stomatolepas gives the distribution on the host as well as the identity and the collecting locality of the latter.

The distribution, abundance and feeding behaviour of sea urchins (Paracentrotus lividus, Psammechinus miliaris, Sphaerechinus granularis) and the macro-algal biomass were assessed in two maerl beds within a north-east Atlantic coastal ecosystem (Bay of Brest, Brittany, France). To study the possible control of herbivorous sea urchins on the macrophytic algae, one maerl bed under the influence of urban sewage (northern site) was compared to one less influenced by urban and industrial outlets (southern site). Macrophytic biomass in the northern site was estimated as 40-fold higher than in the southern site where sea urchins were, on average, 38-times more numerous. Preliminary results support the hypothesis that grazing of sea urchin, even in low densities, can be a factor regulating the macrophytic biomass on maerl beds except in too nutrient enriched environments. So in the northern basin of the Bay, data pointed out the role of anthropogenic impacts on macrophytic biomass increase which was concomitant with the progressive disappearance of sensitive herbivorous species like sea urchins, both processes result in change in the ecosystem.