This study examined the role of predation in restricting early benthic phase (EBP) lobsters to shelter-providing substrata. In the field, the survival of animals provided with cover in the form of cobble and gravel substrata was significantly higher than unsheltered controls. Small benthic fish, particularly gobies Pomatoschistus minutus and rockling Ciliata mustela were the primary predators subtidally while crabs Carcinus maenus appeared to be the dominant intertidal predator. Predatory attack primarily occurred within minutes of the lobsters being deployed. The study reinforces the role played by predation in restricting EBP European lobsters to shelter-providing substrata.

Published information on the diet of Cuvier's beaked whales Ziphius cavirostris (Odontoceti: Ziphiidae) is reviewed and new information on the stomach contents of three animals: two stranded in Galicia (north-west Spain) in February 1990 at A Lanzada, and in February 1995 at Portonovo; and the third stranded in February 1999 in North Uist (Scotland), is presented. The whale stranded in 1990 was a male; the other two were adult females. All animals were >5 m long.  The limited published information on the diet of this species indicates that it feeds primarily on oceanic cephalopods although some authors also found remains of oceanic fish and crustaceans.  Food remains from the three new samples consisted entirely of cephalopod beaks. The Scottish sample set is the largest recorded to date for this species. The prey identified consisted of oceanic cephalopods, mainly squid (Cephalopoda: Teuthoidea). The most frequently occurring species were the squid Teuthowenia megalops, Mastigoteuthis schmidti and Taoniuspavo (for the Galician whale stranded in 1990), Teuthowenia megalops and Histioteuthis reversa (for the second Galician whale) and T. megalops, Gonatus sp. and Taoniuspavo (for the Scottish whale). Other prey included the squid Histioteuthis bonnellii, Histioteuthis arcturi and Todarodes sagittatus as well as Vampiroteuthis infernalis (Cephalopoda: Vampyromorpha), Stauroteuthis syrtensis and Japetella diaphana (Cephalopoda: Octopoda). The squid eaten (estimated from the measurement of the lower beaks) included juvenile and mature individuals of the most important species (Teuthowenia megalops, Gonatus sp.).  The range of species found in the diet of Z. cavirostris is greater than that reported for sperm whales and bottlenosed whales in the north-east Atlantic.

The vent mussel Bathymodiolus puteoserpentis, a large vesicomyid clam and a smaller thyasirid were collected from an area of sediment subject to diffuse hydrothermal flow. The mussels live on the surface, the vesicomyids are partly buried and the thyasirids burrow in the sediment. The fine structure of the gills differs in the three bivalves. Bathymodiolus puteoserpentis hosts two types of bacterial symbiont, one methanotrophic, and another probably thiotrophic. The other two bivalves have single types of symbiont of different shapes. Stable isotope ratios of carbon and nitrogen indicate thiotrophy in the vesicomyid and thyasirid, but a predominance of methanotrophy in the mussel. This is the first time that such an assemblage has been found at a hydrothermal site on the Mid-Atlantic Ridge (MAR), with the different faunistic elements exploiting different energy resources.

Ectoparasitic crustaceans (Copepoda: Caligidae) occurred at considerable frequency in stomach contents of young specimens of Diplodus sargus and Diplodus puntazzo (Pisces: Sparidae) from two central Mediterranean coastal lagoons. This finding suggests that the ectoparasites might give a non-negligible contribution to the diet of the studied fish species and reveal a certain adaptive advantage of cleaning behaviour in coastal environments.

The genus Trachytedania Ridley, 1881 (Porifera: Poecilosclerida), includes those tedaniidae sponges characterized by the presence of acanthostyles. To date, only five species of the genus Trachytedania have been described of which only three actually belong to this genus. Other species described as Tedania could be considered as Trachytedania because of the presence of acanthostyles in their skeletons. Some authors propose retaining Trachytedania as a subgenus of Tedania because of its skeletal structure. In this work, a taxonomic revision and consideration of the validity of the genus is provided. The morphology and anatomy of Trachytedania ferrolensis sp. nov. from the Ría de Ferrol (Spain, north-east Atlantic) are described in detail, and the types of the three valid species described as Trachytedania to date: Trachytedania spinata, Trachytedania patagonica and Trachytedania biraphidora are studied. A key to this genus is provided.

In 1999 divers discovered a population of the burrowing mantis shrimp Rissoides (Meiosquilla) desmaresti (Crustacea: Stomatopoda) east of the St Tudwal's Islands, North Wales. This species has only sporadically been recorded in UK waters and commonly occurs in the Mediterranean. In summer 2000 the burrow morphology and distribution of these shrimps in the area east of the St Tudwal's Islands was investigated. Burrows were found at ten of the 15 sites investigated in a survey area measuring ∼18 km2. Burrow density varied from one to 11 burrows per 100 m2. The burrows were always recorded in sediments consisting of a mixture of mud, sand and gravel but were not present at sites with a high proportion of mud (>70%) or sandy sediments with very little mud ([les ]2%). Resin casts of six burrows revealed that these have a simple elongated U-shape, with an average length of ∼450 mm and depth of ∼160 mm. The average diameter of the burrow entrance was 19±2 mm and the diameter of the burrow along the horizontal section varied between 18 and 38 mm with a distinct constriction part way along.

The distribution of sole (Solea solea) eggs and larvae were described from two cruises conducted in April and May 1995 along the French coast of the eastern English Channel and the Belgian coast of the Southern Bight of the North Sea. Sole migration was investigated using larval stages and univariate spatial analysis as geostatistics (variograms). Important environmental parameters were selected by comparison with larval distribution. Path analysis was used to remove spatial correlation and to define links between abundance and environmental variables.  Sole larvae were found to be coastal throughout their development. Strong links between larval distribution and environmental parameters were identified, particularly for the younger stages which were found in higher abundance in areas of high chlorophyll-a concentration. The association was not direct, suggesting that the larval spatial distribution was influenced by an undetermined, intermediate variable, such as larval prey. Sole larvae are retained in the coastal area throughout ontogeny despite the strong hydrodynamics which characterize the region. Larval distribution resulted from behavioural mechanisms as well as environmental influences.

A female Octopus macropus, the first ever observed spawning, attached eggs (4·0×1·2 mm, with a chorion stalk 4 mm in length) individually or in clusters to a hard substrate, and brooded them till hatching. Hatchlings measured 4·0 mm in dorsal mantle length, 5·5 mm in total length and were planktonic; their short arms had seven suckers each, the outer demi-branch of each gill had ten lamellae. The chromatophore pattern confirmed an earlier identification of young individuals from the plankton (Naef, 1923).

The Mediterranean parrotfish Sparisoma cretense is reported for the first time along the south-eastern coasts of Apulia (Ionian Sea, south-east Italy). Only juvenile specimens of S. cretense were observed during visual census surveys carried out in late August 2000, whereas adults were never observed in, or reported from, this region. Juvenile parrotfish were 3–4-cm long (TL), with a light-grey livery, pale-yellow heads and marked yellow margins around the eyes. They were recorded at 5–15 m depth, whereas they were absent near the surface (0–2 m depth) and in deeper areas (25–28 m depth). The possibility that climatic changes occurring in the Mediterranean basin (i.e. water warming) would be involved in the spreading of S. cretense outside its typical distribution range is discussed.

Phenoloxidase (PO) has been shown to be present in both invertebrates and vertebrates, yet little is known about the PO in Branchiostoma belcheri tsingtauense. The present study demonstrated that the PO activity existed histochemically the epithelial cells of the gill bar and intestine of adult animal, producing brown to black melanin deposits. Ultrastructural examination revealed that PO reaction products were localized in the cytoplasmic granules of the epidermal cells, the epithelial cells of gill bar and intestine and most of them were electron-dense and homogenous. Frequently, the PO reaction products were also observed in the secondary lysosomes.  The mucus from the body surface had little antibacterial activity against Escherichia coli, but it enhanced the antibacterial activity of L-dopa and the enhancement was suppressed by PTU, a PO specific inhibitor. This indicates that the active material inhibiting the E. coli growth in the mucus is PO.

A new version of a technique, based on telemetric devices, to monitor temporal aspects of the activity of homing species of limpets and the parallel recording of sea level oscillations is described. The home/away status of individual limpets was continually assessed by means of a magnetic reed switch. Signals from the reed sensors were transmitted to a distant automatic scanner/receiver, located away from the shoreline. The system can be easily replicated and employed for extensive long-lasting monitoring in the field, even in those cases where previous versions, based on cable connections, were unsuitable.

Dynamics of the Abra alba muddy fine sand community of the Rance Basin (western English Channel), initially sampled in one station by Retière at the beginning of the 1970s after the tidal power station built at the mouth of the estuary went into service, was reassessed from 1995 to 1997. Results showed a more ‘mature’ community in 1995–1997 with an increase in the number of species. After a short period, in spring 1995, during which the structure of the community was comparable to those described in 1972–1973, the assemblage was characterized by a great interannual structural stability. Densities of dominant species seem to fluctuate around a mean value comparable to the carrying capacity of the biota for these species. The recruitment of the dominant species with a long life span appears low compared to the densities of adults but seems sufficient to assure the replacement of individuals. Our results suggest that the pattern of massive recruitment followed by high mortality rates could not be the general rule and that a pattern of moderate recruitment followed by low post-settlement mortality of recruits should be more frequent.

The spatio–temporal abundance pattern of 0-group sea bass, Dicentrarchus labrax, was investigated between April 1995 and November 1996 by beam trawl surveys. The highest densities of D. labrax were recorded in shallow areas. Dicentrarchus labrax density was also significantly related to water temperature and salinity, but the variation pattern was not linear. The 0-group individuals of this species first occurred on the nursery ground in May and the highest densities were recorded in June. Diet of 0-group D. labrax was mainly composed of crustaceans, the most important food items being Decapoda, Mysidacea and Isopoda. Feeding activity increased during summer. Short-term variations were related to the period of the day and tidal cycle. The growth rate determined for 0-group D. labrax was higher than those reported for the UK and northern France, and was similar to those obtained in eastern Mediterranean.

This study provides a description of the Mediterranean monk seal (Monachus monachus) diet from the Aegean Sea coast of Turkey. A total of 23 prey items belonging to five species were identified from the two stomachs examined. Cephalopods constitute the dominant prey group by weight (94·01%). Sarcotragus sp. (Porifera) and Posidonia oceanica (Magnoliophyta) are assumed to be incidental prey. Of the cephalopods identified, Eledone moschata and Bathypolypus sponsalis were encountered for the first time in a monk seal stomach.

This is the first report of egg release by the oviparous excavating sponge Cliona viridis. Adult specimens of excavating (α) and massive (β) sponge forms for the presence of oocytes were monitored from 11 May to 12 July 2000, in a shallow-rocky coast of the north-west Mediterranean. The immediate environment around the sponge was sampled for the presence of eggs. Spawning occurred synchronously in the study area at temperatures above 19°C. Oocytes were released in clusters enclosed in adhesive maternal tissue. They contained symbiotic zooxanthellae. Free, adhesive egg-masses drifted in the water or adhered to erect algae in the vicinity of the sponge. Morula stages and larval release are described.

Larvae of Chthamalus malayensis (Cirripedia: Thoracica) from Hong Kong were cultured in the laboratory. Larval development includes six naupliar stages and a non-feeding cypris stage. Larvae reached the cypris stage in 20 d at ∼21°C compared to 14 d at ∼28°C. Morphological features including the cephalic shield, frontal horns, labrum, abdominal process, antennules, antennae and mandibles in all nauplius and cypris stages were described and illustrated using a combination of light microscopy and scanning electron microscopy. Attempts were made to compare morphological differences between the nauplii and cyprid of C. malayensis with those of other Chthamalus species including C. stellatus, C. montagui, C. dentatus, C. fragilis, C. dalli, C. antennatus, C. fissus and C. challengeri. The present description of the nauplii of C. malayensis is not in agreement with the previous description of this species.

There are sporadic records of Thia scutellata from Carmarthen Bay, Cardigan Bay and off the north coast of Wales. Relative scarcity of this small burrowing crab is probably due to habitat specialization. It lives in loose very well sorted medium sand, as typically found in parts of sand waves.

Responses of the Antarctic limpet Nacella concinna (Mollusca: Gastropoda) to meltwater exposure were studied at Adelaide Island (67°34′S 68°08′W). Limpets in crevices could be bathed in pure meltwater, though animals in large pools often avoided significant exposure to lowered salinity because of marked halocline formation. Small pools containing limpets showed extremely demanding osmotic environments with fluctuations between salinities of 3 and 30 psu being recorded within 1–2 min because of alternating meltwater and wave action. Analysis of haemolymph osmolarities in animals taken from the field demonstrated significant falls in osmolality (to 600–800 mOsm kg−1) compared with control animals living in seawater (1000 mOsm kg−1). A few moribund animals had osmolarities <600 mOsm kg−1. Nacella concinna are stenohaline osmoconformers with a median lower lethal salinity (96 h) of 20·9 psu and a median lethal time for freshwater exposure of 2 h 18 min. A 1 h exposure to freshwater caused a 14% increase in body volume and a 27% loss of body fluid ions. Nacella concinna responds behaviourally to meltwater by short-term, ineffective, clamp down of the shell, retraction of the head, cephalic tentacles and mantle margin tentacles. On vertical surfaces limpets respond actively to freshwater exposure by rapid detachment; 50% of animals lose adhesion within 5 min. Consideration of tidal regimes at Adelaide Island suggests that an individual intertidal limpet has a risk of being exposed to severe meltwater exposure about once per year.

This study examined the association pattern of two snapping shrimp species that inhabit burrows at exposed rocky shores of the Chilean Pacific coast. The two species Alpheus inca and Alpheopsis chilensis were frequently found to share the same burrows. In most burrows an heterosexual pair of each species was found. A strong positive correlation between the body length of female and male conspecifics cohabiting in a burrow was found both for Alpheus inca and for Alpheopsis chilensis. Similarly, a positive correlation existed between the mean body length of Alpheus inca and that of Alpheopsis chilensis occurring together in one burrow. Thus, a size-relationship between burrow cohabitants exists both in the intra-specific as well as in the inter-specific association of these shrimps. Most females, regardless of their reproductive stage, were accompanied by males. Within a particular burrow, females of the two species often were in the same reproductive stage, i.e. both were with embryos in a similar developmental stage, or both were without embryos. These data suggest that male and female conspecifics, as well as the pairs of the two species, remain together in the same burrow for relatively long time periods. It is proposed that the intra-specific communication system of snapping shrimp facilitates the development of inter-specific associations, such as the one reported herein.

The beryciform fish Hoplostethus mediterraneus (Beryciformes: Trachichthyidae) is a species discarded from the southern Portuguese coastal fisheries. It is taken as by-catch by deep water trawls, at depths of between 234 and 618 m, more than 80% being taken at depths of between 234 and 422 m. Immature fish ranged from 4 to 13 cm in length and were present at all seasons. Of the mature individuals, males ranged from 7 to 17 cm and females from 7 to 21 cm. From autumn until spring, fish with gonads at various stages of maturation were present, although there were no specimens with mature gonads.