Epibenthic macroalgae were observed to grow more abundantly on the upper surface of the Japanese scallops Patinopecten yessoensis (Bivalvia: Pectinidae) than on other available substrate. A field experiment to examine the hypothesis that colonization of live scallops protects macrophytes from grazing by sea urchins Strongylocentrotus nudus and S. intermedius was performed. Algal growth in the areas with urchins was compared with that in the enclosures without urchins. Each enclosure contained two live scallops, two empty shells, and one rock similar to scallops in size and shape. Twenty live scallops, 16 empty shells and ten rocks were marked and left outside the enclosures. After three months there was no difference in macrophyte mean percentage cover on live scallops inside and outside the enclosures. Percentage cover of macrophytes on dead scallop shells and rocks was significantly lower outside the protective enclosures as compared to unprotected areas. The results support the hypothesis that scallops serve as mobile refugia for macroalgae from urchin grazing.

This study explores whether timing adjustment in ocypodid waving also occurs between heterospecific pairs. Analysis of the dyadic interactions between neighbouring males of Ilyoplax pusilla and Uca lactea in the field showed that the former tended to wave with some delay after each U. lactea wave, while the latter was little influenced by I. pusilla waves. The heterospecific wave timing of I. pusilla by U. lactea waves can be viewed as a weakened form of the conspecific wave timing mechanism in this species.

Aberrant statolith microstructure was observed in an immature female of the squid Todarodes sagittatus (Cephalopoda: Ommastrephidae) caught in the Moroccan shelf. The paralarval statolith, (a central part of adult statolith that developed at paralarval stage), showed the first 12 growth increments outside the nucleus was reversed to the posterior side of the adult statolith, and its main axis was turned perpendicularly to the main axis of the adult statolith. However, further statolith growth followed the common pattern, and the statolith acquired its normal shape at the level of 55–60 growth increments. Such aberrance in a direction of the paralarval statolith can be explained by its complete detachment from the macula statica princeps (MSP) during strong impact to the head of the paralarva (e.g. by a predator) and further occasional re-attachment of the statolith to the MSP again.

Respiration rates during late embryonic development and hatchlings of Octopus vulgaris were measured at 20 °C. Oxygen consumption rates increased suddenly at hatching, in response to the increase in energetic expenditure due to their constant swimming activity by means of jet propulsion. Estimates indicate that hatchlings consumed three times more oxygen than the embryos at late stages. Chemical composition analysis revealed a relatively high nitrogen content (11%) in O. vulgaris hatchlings with an energy content of 1.09±0.03 J mg dry matter−1. Specific oxygen consumption in unfed O. vulgaris hatchlings reached values around 0.18 nmol O2 μg−1 h−1. It was estimated that the oxygen consumption of a medium-size egg mass of O. vulgaris is approximately twice than the oxygen uptake of the respective brooding female.

The stranding of a female specimen of the genus Architeuthis, a species not previously recorded in the Mediterranean Sea, is reported from the southern Spanish coast (Alboran Sea, western Mediterranean). The geographical distribution of the species is discussed.

The systematic position of the giant squid Architeuthis remains unresolved but comparison of beak morphometrics is an approach that has not been attempted before. Additional data for the relationship between mantle length (ML) and lower beak rostral length (LRL) suggest that Architeuthis sp. in the North Atlantic, South Africa and New Zealand are parts of the same asymptotic relationship. Comparison of beak dimensions of Architeuthis from the North Atlantic, South Africa and New Zealand with those of two distinct species of Todarodes, from the Mediterranean and southern Africa, indicate that there may be only one species of Architeuthis in these three regions. No consistent morphological evidence has yet been found to indicate more than one species of Architeuthis in the Atlantic or in the southern hemisphere.

Two types of infectious agent within rootlet cells of the parasitic barnacle, Sacculina carcini have been recognized by transmission electron microscopy. The rootlets were dissected from the common shore crab, Carcinus maenas, collected from two locales—Plymouth and Pwllheli. Yeast cells were identified within cells of S. carcini rootlets from crabs collected at both locations and an iridovirus was also found, but only in rootlets from Plymouth crabs. These infectious agents were never found co-occurring in the rootlets from Plymouth crabs. Both agents, when present in rootlets, were also present in the respective host crab tissues. It is therefore concluded that S. carcini rootlets are susceptible to invasion from natural infectious agents of the host crab.

The first record of the genus Stylopoma (Bryozoa: Cheilostomatida) is reported from the Mediterranean Sea with the description of Stylopoma inchoans sp. nov. from a single specimen collected in the 19th Century. Its affinities to recently described Indo-Pacific species are discussed.

The prey size of young cuttlefish was investigated by measuring the size of entire animals, carapace, periopods, and otoliths in the stomach contents of specimens from Morbihan Bay in 1994–1996. The young of the Sepia species consumed a wide range of prey sizes. The size of all isopods and amphipods was less than the 50% of those of the Sepia. The size ratio of brachyurans varied between 14 and 37% of the dorsal mantle length of the cuttlefish. The young could catch fish species which were three times larger than itself.

This paper reports, for the first time, the existence of external digestion of decapod larvae by the common octopus, Octopus vulgaris (Mollusca: Cephalopoda), paralarvae. Zoeae of three crab species were externally digested, leaving a whole and empty exoskeleton. The attack sequence on these prey is also described, and divided into the same three phases (attention, positioning and seizure) already known for Sepia hatchlings.

Loxosomella tonsoria (Entoprocta: Loxosomatidae) was found associated with the polynoid polychaete Lepidonotus clava collected among the algae and debris scraped from the intertidal level at the rocky shore of Limens (Pontevedra, Spain). New features are added to the original description, together with the first description of its buds. Host specificity of the genus and distribution of this species are discussed.

The intertidal insect Anurida maritima (Apterygota: Collembola) has a circatidal rhythm of locomotory activity on the soil surface which was observed during both the day and the night. The main function of this activity was foraging for food. When a superabundant food supply was provided on the upper shore, this completely repressed the usual migration to the lower shore. There was a clear rhythm in feeding activity which was highest shortly after the sea uncovered the insects' shelters and declined rapidly during the intertidal period. The circatidal rhythm of locomotory activity persisted in the laboratory in constant light for seven days (15 cycles). A free-running rhythm underlying the degree of aggregation was also detected.

Length composition, maturation and growth of the ommastrephid squid Todaropsis eblanae were studied using length–frequency distributions (LFDs) and statoliths of squid caught off the north-west African coast. Length–frequency distributions were quite similar in all seasons studied, indicating all year round spawning. However, both high proportions of mature squid in the winter and the hatching peak of squid from our sample in spring suggested the winter–spring peak of spawning. Immature and maturing squid had rather high growth rates, attaining 140—150 mm of dorsal mantle length (ML) by the age of 160—170 d. Todaropsis eblanae is likely to have an annual life cycle on the north-west African shelf.

The occurrence in the Strait of Sicily of the saddled snake eel, Pisodonophis semicinctus (Osteichthyes: Ophichthidae), a rare finding for the Mediterranean Sea, is confirmed on the basis of one specimen caught off the northern coast of Tunisia in 1991. The specimen, 800 mm in total length and 457 g in body weight (preserved condition), was captured during a commercial bottom trawl hauled at 30 m next to Cape Bon (north of Tunisia). This represents the second and fourth documented record of this Atlantic intruder within the Strait of Sicily and the Mediterranean Sea, respectively.

The egg mass of the diamond-shaped squid, Thysanoteuthis rhombus (Oegopsidae: Thysanoteuthidae) was sighted in surface waters off south-east Sulawesi. It was a sinuous hollow tube-like structure about 2 m long and 0·15 m diameter. It was estimated to contain in the order of 180,000 purple eggs of 1 mm diameter with little or no yolk. Development of the embryos from early differentiation to hatching took between 47 and 57 h at about 28°C.

The early benthic phase (EBP) European lobster Homarus gammarus, and the habitat to which it recruits, remains largely undiscovered. Following reports that juvenile lobsters were being located within an intertidal lobster fishery in Johnshaven, Scotland, a three day census was undertaken. The shore consisted of a wave cut platform with a red sandstone/cobble conglomerate substratum. Three juvenile lobsters of 28, 32 and 45 mm carapace length (CL) were located in a crevice type habitat. It is hypothesized that in some areas of coastline, intertidal crevices act as a peripheral habitat for juvenile lobsters.

Over the period 1—4 April 1999 a large number of dead asteroids were washed ashore at the northern end of the Isle of Man. The area is commonly used for public recreation and the stranding prompted numerous alarmed telephone calls to various bodies. Initially, disease or pollution were suspected, but a more detailed examination of the circumstances indicated that the mass stranding was probably a result of tides and weather conditions. The stranding occurred on the east coast of the Isle of Man from about 100 m to the south of the Point of Ayre, which is the northernmost point of the Isle of Man, and extended southwards for ≈600 m. This is a highly exposed shore with a strong tidal flow, subtidally it is shallow, with coarse gravel and exposed bedrock, and extensive mussel (Mytilus edulis) beds, which may be expected to attract large numbers of predatory starfish.

A description is given of Alcyonidium reticulum sp. nov. (Bryozoa: Ctenostomatida), a smooth-surfaced species found encrusting intertidal stones and on Fucus serratus in south-west Britain. It is distinguished from two superficially similar congeners, A. gelatinosum and A. mytili.

Basking shark (Cetorhinus maximus) movement patterns and growth rates over annual cycles remain entirely unknown. Here the re-sighting of a female identified by a highly distinctive first dorsal fin, after a 3·1 year period is described. Our results show this individual foraged at the surface in coastal areas off south-west England in at least two of four summer seasons and increased in total length by 2·4 m over this period. The growth increment observed was similar to that predicted from the growth model for this species.

The diet of Dipturus chilensis was composed mainly of the nototheniid fish Patagonotothen ramsayi, squid Illex argentinus, hake Merluccius hubbsi, serolid isopods, and crustaceans. Our results suggest that D. chilensis feeds selectively on some teleosts and rejects eel-like fishes. Total length of consumed P. ramsayi was significantly correlated with the skate's mouth width.