A method for a qualitative analysis of sea urchin diet is based on the characterization of the photosynthetic pigment indices of the major algal groups in the sea urchin gut. The pigments were separated by reverse-phase high performance liquid chromatography (RP-HPLC). This study demonstrated that HPLC is a better method to estimate chlorophyll-a in the gut contents than the conventional spectrophotometric methods which overestimate the amounts by including chlorophyll-a breakdown products. Three sea urchins species, Paracentrotus lividus, Psammechinus miliaris and Sphaerechinus granularis, settled on the loose-lying coralline algae (maerl) in the Bay of Brest (France), were used in this study. The algal pigments identified within the gut contents included chlorophylls-a, -b, -c, fucoxanthin, lutein, βε-carotene and ββ-carotene. The presence of chlorophylls and carotenoid biomarkers was used to characterize the three algal groups: Rhodophyceae, Chlorophyceae, Phaeophyceae in estimating sea urchin diet. The pigment analysis reported here demonstrated that the three species of sea urchins investigated mainly consumed Rhodophyceae which dominate the epibenthic flora in the study area.

The morphology and stomatogenesis of the marine scuticociliate Pseudocohnilembus hargisi collected from a shrimp culturing pond in Qingdao, China, were studied using pyridinated silver carbonate and Chatton–Lwoff silver impregnation techniques. The result shows that the Qingdao population of this species possesses typical characteristics of the genus Pseudocohnilembus: the buccal apparatus consists of three highly specialized membranelles; membranelle 1 comprises a single row of kinetosomes, is parallel to membranelle 2, and lies anterior to the paroral membrane; membranelle 2 is longer than membranelle 1 and also comprises one row of kinetosomes; membranelle 3 is located near the middle of the paroral membrane and comprises three rows of kinetosomes. The silverline system is similar to that of P. persalinus. During stomatogenesis, the parental scutica proliferates and becomes the primordial field. This subsequently develops in two separate parts, the anterior part eventually disappears while the posterior part forms membranelle 3 of the opisthe. The secondary proliferated field, which derives from the zigzag configuration of parental paroral membrane, also develops in two parts, with the anterior becoming the paroral membrane and scutica of the opisthe and the posterior part developing into membranelles 1 and 2 of the opisthe. The remnants of the parental paroral membrane give rise to the paroral membrane and scutica of the proter.

Habitat mimics were used to investigate the role of coralline algal frond length in determining spatial patterns in diverse gastropod assemblages on a rocky shore near Sydney, Australia. Frond length represents the vertical scale component of habitat structure, which is rarely experimentally manipulated. Length of fronds did not explain differences between gastropod assemblages at different tidal heights or among patches of turf separated by tens of metres in mid-shore areas. In contrast, changes in frond length caused large differences in the structure of gastropod assemblages in low-shore areas. Contrary to previous studies, the total abundance and diversity of gastropods was greater in turf with short fronds than with long fronds. Possible mechanisms for this negative relationship are discussed. Overall, the vertical scale component of habitat structure can have strong effects on associated faunal assemblages, but the magnitude of these effects depend heavily on local environmental conditions (e.g. different tidal heights).

The reproductive cycle and size at sexual maturity of the commercial whelk Buccinum isaotakii in Funka Bay, southern Hokkaido, Japan, was examined using monthly samples of individuals collected from May 1999 until October 2000. Female and male sexual maturity was determined based on reproductive organ sizes and histological examination, and sex ratios did not differ from parity. There were parallel annual cycles in the size of the ovary and pallial oviduct, and an inverse cycle for the digestive gland. The testis and seminal vesicle showed inverse cycles. The peak in seminal vesicle size was at the same time as the peak in ovary and pallial oviduct. The size of the male digestive gland exhibited no evident cycle. Males were mature from May to October 1999 and from April to October 2000, and spent individuals first appeared in September 1999 and then decreased in numbers until June 2000. Sperm content and epithelium in seminal vesicle indicated that the copulating period started in March and lasted until August 2000. Ovarian maturation and oogenesis occurred from October 1999 onwards and peaked in January 2000, with egg laying occurring from May until September. An increase in temperature coincided with the advancement of spermatogenesis and the egg laying while the transfer of the sperm from the testis to the seminal vesicle in males and the maturation of ovaries in females coincided with a decrease in temperature.

The mating behaviour of the helmet crab, Telmessus cheiragonus, was observed in the laboratory to obtain information of its fishery management and seed production. Females always moulted before copulation and all moulting females copulated with their mates, while males performed precopulatory guarding before their mates moulted. The average duration of precopulatory guarding was 11.8±5.0 SD days. Sex ratios in experimental tanks did not influence the first guarding duration of male but diminished the female's guarded duration under female-biased treatment. Competition among males for females was observed; larger males appeared to have a competitive advantage. Males started copulation in 41.2±10.9 SD min after females moulted and the copulation lasted for 110.6±6.6 SD min. Postcopulatory guarding duration was 4.0±6.6 SD h. Small males tended not to guard and to copulate with females larger than themselves. Common features and differences in mating behaviour between T. cheiragonus and Erimacrus isenbeckii is discussed.

The type specimens of the common tropical intertidal barnacles Chthamalus malayensis and C. moro, were re-investigated and compared with other specimens of Chthamalus from the Indian Ocean, Indo-Malaya, northern Australia, Vietnam, China and the western Pacific, using ‘arthropodal’ as well as shell characters.  Chthamalus malayensis occurs widely in Indo-Malayan and tropical Australian waters. It ranges westwards in the Indian Ocean to East Africa and northwards in the Pacific to Vietnam, China and the Ryukyu Islands. Chthamalus malayensis has the arthropodal characters attributed to it by Pope (1965); conical spines on cirrus 1 and serrate setae with basal guards on cirrus 2.  Chthamalus moro is currently fully validated only for the Philippines, Indonesia, Taiwan, the Xisha (Paracel) Islands, the Ryukyu Islands, the Mariana Islands, the Caroline Islands, Fiji and Samoa. It is a small species of the ‘challengeri’ subgroup, lacking conical spines on cirrus 1 and bearing pectinate setae without basal guards on cirrus 2. It may be a ‘relict’ insular species.  Chthamalus challengeri also lacks conical spines on cirrus 1 and has pectinate setae without basal guards on cirrus 2. Records of C. challengeri south of Japan are probably erroneous. However, there is an undescribed species of the ‘challengeri’ subgroup in the Indian Ocean, Indo-Malaya, Vietnam and southern China and yet more may occur in the western Pacific. The subgroups ‘malayensis’ and ‘challengeri’ require genetic investigation.  Some comments are included on the arthropodal characters and geographical distributions of Chthamalus antennatus, C. dalli and C. stellatus.

Barnacle encrustation negatively influenced every aspect of swimming in the scallop Chlamys hastata measured in this study. Scallops swam significantly longer, travelled further and attained greater elevation once epibiotic barnacles had been removed. Shell morphometry of barnacle-encrusted scallops was similar to shells of unencrusted scallops. Specifically, shell length was positively allometric with shell height and shell mass was negatively allometric. However, adductor muscle mass scaled isometrically to shell height, in contrast to unencrusted scallops. In the laboratory, the drag coefficient (Cd) of barnacle-encrusted scallops decreased after barnacle removal, in contrast to sponge-encrusted scallops in which no decrease in Cd was detected when the sponge was removed from the scallop's valves. Furthermore, scallops swimming with barnacle encrustation required more energy than did unencrusted scallops. Although there was no significant difference in aerobic energy expenditure between swimming barnacle-encrusted and unencrusted scallops, differences in anaerobic energy expenditure were detected. Specifically, barnacle-encrusted scallops required more arginine phosphate than unencrusted scallops to swim to exhaustion although octopine levels were similar. Thus, barnacle encrustation dramatically decreased a scallop's ability to swim, partly by increasing the drag coefficient experienced by the scallop and the energy required for swimming.

Only one specimen of Architeuthis dux was previously reported from the southern Indian Ocean. The present work adds ten new records of giant squid in the area. Two remains of fresh specimens have been collected from La Réunion Island (21°S) and Amsterdam Island (38°S) in tropical and subtropical waters, respectively. Eight other squid were identified from beaks found in stomach contents of sleeper sharks caught in Kerguelen waters (47 to 48°S) located in the southern Polar Frontal Zone. These new data together with published and unpublished information on the food of seabirds and marine mammals indicate that giant squid have a wide distribution throughout the southern Indian Ocean.

Stomatogenesis of the marine scuticociliate Metanophrys sinensis, collected from a molluscan culturing pond in Qingdao, China, was studied using protargol impregnation method. The morphogenetic sequence develops in the proter: the remnant of parental paroral membrane gives rise to the paroral membrane and scutica, and the three parental membranelles were inherited. In the opisthe: the paroral membrane, membranelles 1, 2 and the scutica originate from the parental paroral membrane, while parental scutica gives rise to the membranelle 3. This suggests that M. sinensis has a relatively similar morphogenetic pattern to the members of the genus Uronema.

Seasonal variations in the gonad index and the biochemical composition of gonad and gut tissue of the sea urchin, Paracentrotus lividus (Echinodermata: Echinoidea) were determined. Samples were collected from Lorbé (Galicia, north-western Spain) between November 1994 and October 1995. The gametogenic cycle of the sea urchin was annual, with a long, single spawning period from May to August 1995. Most of the biochemical components in gonad showed clear seasonal variation, which was related to the gonad cycle. The main component was protein, which ranged between 36 and 60% of the dry weight, with maximum levels coinciding with the minimum levels of glycogen. Gonad glycogen therefore seemed to be the energy source employed for protein synthesis during gametogenesis. Seasonal variation in total lipids in the gonad was less evident; the main lipidic component was triacylglycerol (around 10% of the dry weight), whereas total cholesterol accounted for less than 1%. The gut does not seem to act as a storage tissue in P. lividus and seasonal variation in biochemical components may be a consequence of fluctuations in the availability of food.

The distribution of molluscan assemblages across and along a vertical rocky cliff near Otranto (southern Adriatic Sea, Italy) was studied. Sampling was undertaken in May and November 2000 at three sites approximately 100 m apart. Three depths (5, 15, 25 m) were sampled at each site, by scraping off three replicate 20×20 cm quadrats. Samples yielded 6722 specimens, referred to as 133 species. Multivariate analyses showed that the structure of the assemblages significantly differed among depths with a clear gradient of distribution from shallow to deep stands. However, a considerable variation in the structure of the assemblage was also observed among sites at each of the three depths. The species contributing most to characterize depths and/or differentiating sites at each level of the shore were identified. Some potential causes of the observed differences are discussed.

The effects of the multiple autotomy on epibiosis infestation on embryos, on the survival of embryos, and on brooding care behaviour were examined in females of Cyrtograpsus angulatus, a south-western Atlantic intertidal and subtidal crab. The population of C. angulatus in Mar Chiquita, a coastal lagoon, presents a high incidence of limb autotomy. Newly laid embryos of both healthy and autotomized females were immediately colonized by bacteria and filamentous fungi, peritrichid ciliates, and few small animal species, while detritus was accumulated. The periphery of the embryo mass was more infested by epibionts and accumulated more detritus than the central region. Multiple autotomy in female C. angulatus increased the epibiosis and detritus accumulation in embryos and pleopods, decreased the chance of embryos to complete their development. The following behaviours related to brooding care were observed in both healthy and autotomized females: standing, chela and pereiopod probing, abdominal flapping, pleopod beating and maxilliped beating. However, the time devoted to standing and abdominal flapping was significantly higher in healthy and autotomized females, respectively. Brooding care behaviour in non-ovigerous females and in females with early and late embryos, suggests the presence of different signalling systems that trigger them. We propose that multiple autotomy modifies brood care, decreases the success of embryonic development and, consequently, reduces the contribution of autotomized females (approximately 30% of the potentially reproductive females of C. angulatus in Mar Chiquita) to the following generation.

Tributyltin (TBT) leaching from the antifouling paint on hulls of pleasure craft eliminated a population of dog-whelks Nucella lapillus from Watermouth Cove in the Bristol Channel but outside the Cove the number of snails was apparently unaffected. Following the ban on TBT in antifouling paints, the species has recovered most of its former range in the Cove. It is postulated that the recolonization was from a subtidal population of unusually large and elongated individuals. It was observed that it had taken some 13 years to recolonize a distance of 30 metres.

Age, growth and maturation of the temperate ‘mini-maximalist’ Idiosepius notoides from Tasmania is described and compared with those of its tropical congener Idiosepius pygmaeus. Using statolith increment analysis, growth of I. notoides was best described by a power curve with a maximum age of 115 days recorded. Males have a shorter lifespan than females, however growth rates were similar between the sexes. Idiosepius notoides grows to a larger size than its tropical counterpart. Onset of maturity in I. notoides occurred at an age of approximately 68 days for males and 88 days for females compared to 45–60 days for I. pygmaeus. Size at onset of sexual maturity was analogous between the two species, with males mature at approximately 6·5 mm mantle length (ML) and females at 14·0 mm ML. Idiosepius notoides, like I. pygmaeus, is a small short-lived sepioid with significant gender dimorphism and the capacity to spawn multiple times throughout its short life. This research supports the concept of similar cephalopod species living longer and growing larger in cooler environments.

The presence of two dinoflagellate species of the genus Asterodinium, which are a priori representative of warm waters, is reported for the first time in the western Mediterranean Sea. Asterodinium libanum was identified in the Bay of Villefranche-sur-Mer (Ligurian Sea), while Asterodinium gracile is reported in the Tyrrhenian Sea. These findings are discussed in the context of the progressive warming of Mediterranean waters.

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.

Maerl grounds are comparable to sea grass beds in terms of their high biodiversity, and are characterized by abundant juveniles of species such as the queen scallop, Aequipecten opercularis. Maerl grounds impacted by towed demersal fishing gears are structurally less heterogeneous than pristine, un-impacted maerl grounds, diminishing the biodiversity potential of these habitats.

The dynamics and feeding biology of a population of Marthasterias glacialis (Echinodermata: Asteroidea) was examined over a two-year period from 2000–2002 at Lough Hyne Marine Nature Reserve, Co. Cork, Ireland. A multivariate approach was used and both multiple factors and multiple interactions between factors were found to influence population structure. These included time of year, site, individual sea-star size, depth, and predator density. Individuals belonging to the smallest size-classes (0–50 mm and 51–100 mm) were most abundant amongst boulders in shallow water (0–1 m), while larger individuals were primarily found in water below 1 m in depth on finer grade substratum and shell debris. Dietary composition was also found to differ with depth; sea-stars in the immediate subtidal had an opportunistic diet, and fed on a variety of taxa, whilst those M. glacialis from 1–6 m were more selective and restrictive, feeding chiefly on bivalve prey. We propose that spatial partitioning of different size-classes and a generalist feeding strategy may account for the success of M. glacialis at Lough Hyne.

Feeding and vertical distribution of pelagic chaetognaths were studied at coastal and open-sea stations in the northern part of the South Adriatic Pit during five cruises from April 1993 to February 1995. Chaetognaths were more numerous in the upper 100 m, decreased conspicuously with depth, and were captured only rarely between 600 and 1000 m. Copepods were the main food for the most abundant species in all layers. Cannibalism was evident in all species. Feeding on fertilized chaetognath eggs by Pseudosagitta lyra and Mesosagitta decipiens is reported for the first time. The food containing ratio (FCR) and number of prey items per chaetognath (NPC) of Flaccisagitta enflata were highest during the reproductive period. Higher FCRs and NPCs for M. decipiens and P. lyra were noted below 100 m, where the contribution of older specimens increased with depth and the abundance of copepods decreased.

The diets of scaldfish Arnoglossus laterna, dab Limanda limanda, lemon sole Microstomus kitt, long rough dab Hippoglossoides platessoides, solenette Buglossidium luteum, thickback sole Microchirus variegatus, plaice Pleuronectes platessa, witch Glyptocephalus cynoglossus and Dover sole Solea solea in the Irish Sea were determined for March and October 1997 and 1998 and compared. Similarities in diets were examined using multivariate analyses. In general, there were differences in diet between species and generally the diets were similar within a species. Smaller individuals tended to have a similar diet. There were seasonal changes in the diets of individual species. Likewise, the overlap in diets between species changed between seasons and to a certain extent between sediment types.