The macrofauna of samples collected with a box-corer from northern Adriatic Sea muddy bottoms in five survey campaigns from 1985 to 1993 has been analysed separately in sediment strata of varying depth. Samples were collected before, during and after the dumping of large amounts of inert particulate material that covered the seabed and caused an almost total defaunation. After this disturbance the seabed was recolonized by a new community. This new community differed from the original one mainly on account of the abundance of Mysella bidentata, a small bivalve filter or surface deposit-feeder. In the original community M. bidentata was confined to the more superficial sediment layers (0–5 cm) at low population density. In the new community it was very abundant and evenly distributed even in the deep layers (5–20 cm). Analysis of species association performed on data from each of the 54 corer samples collected in the last sampling period, points to a marked association between M. bidentata and Nephtys incisa in deeper sediment layers. Deep layer colonization by Mysella in association with the burrowing polychaete N. incisa suggests a case of commensalism between these two species.

The macrofauna of molluscs associated with soft bottoms in the Bay of Cádiz (southern Spain) was studied monthly from February 1994 to January 1996. The number of species (63) is high for a soft bottom and is related to environmental characteristics (growth of macrophytes) and the biogeographical setting of the studied area. Corbula gibba (∼90%) was the dominant species in this taxocoenosis together with the gastropod Nassarius pygmaeus and the bivalves Pandora inaequivalvis, Parvicardium exiguum and Macoma melo. The most frequent species during the two years was also the bivalve Corbula gibba (100%) followed by the gastropods Nassarius pygmaeus, Tricolia tenuis, Rissoa membranacea and the bivalve Macoma melo. Total abundance of the taxocoenosis in both years reached higher values in spring. The dynamics of the ecological indices such as diversity or evenness, and the species richness showed a similar pattern in both years, with low values of diversity and evenness together with high species richness in spring and summer months and the reverse in autumn and winter. The qualitative correspondence analysis of monthly samples shows an ordination related to seasonality in both studied years, however the values of Jaccard's coefficient do not indicate significant boundaries among the monthly samples. The quantitative correspondence analysis shows an ordination and grouping of samples related to the biology of species, particularly with the recruitment of C. gibba, the dominant species. The existence of similar trends in the structure of the taxocoenoses over both years, and the seasonality highlighted by the qualitative correspondence analysis, seems to indicate a certain stability of the ecosystem.

Mercury determinations were carried out in mussels (Bathymodiolus azoricus) from three Mid-Atlantic Ridge hydrothermal vents (Lucky Strike, Menez Gwen and Rainbow) and shrimps (Rimicaris exoculata and Mirocaris fortunata) from Rainbow. Among the three hydrothermal vents, mussels of Menez Gwen show the highest levels of total Hg and comparing mussels and shrimps from Rainbow the former show more Hg than shrimps. Mussels from different hydrothermal vents are exposed to different kinds of environment which may result in distinct bioaccumulation processes. Detoxification processes in shrimps are related to the low concentrations found. When compared with coastal species from unpolluted sites, mussels show higher concentrations of total Hg and shrimps lower levels. The methyl-mercury concentrations found were very low, not exceeding the detection limit of the technique.

Mats of articulated coralline algal turf are common on many rocky intertidal shores. The dense fronds provide a habitat for extremely diverse and abundant macrofaunal assemblages. Despite a large contribution to faunal biodiversity of rocky shores, little has been published about these assemblages. This study describes patterns of distribution and abundance of macrofauna in coralline turf on rocky shores around Sydney. In addition, the potential of environmental variables (sediment, epiphytes, length and density of coralline fronds) for determining these patterns was also investigated. Relatively consistent differences were found between macrofauna in low- and mid-shore areas at all times of sampling and on all shores. Although there was some variation among shores, there was generally significant variation in macrofauna between sites separated by tens of metres. Generally, a relatively small number of taxa were responsible for the great majority of dissimilarity between assemblages. Apart for the small bivalve Lasaea australis, however, these taxa varied between heights on the shore, among times of sampling and among shores. These data illustrate the important contribution that coralline turf has for biodiversity of faunal assemblages on rocky shores around Sydney. They also provide a basis for investigating biological processes and physical factors responsible for structuring patterns of biodiversity of macrofaunal assemblage in coralline turf.

The coexistence of three taxa of Codium (Chlorophyta: Codiaceae) was examined on wave-swept shores of western Ireland: the introduced macroalgae Codium fragile ssp. atlanticum and ssp. tomentosoides and the native Codium tomentosum. In spring 1999 and 2000, four sites were monitored to evaluate whether past predictions regarding temporal changes and species replacement occurred. Introduced and native species of dichotomously branching Codium occurred at four tidal levels: in tidepools in (i) the upper barnacle zone; (ii) the mid barnacle/fucoid zone; (iii) the mussel zone, and (iv) on emergent substrata in the red algal turf/kelp zone. Codium fragile ssp. atlanticum and ssp. tomentosoides grew together in 11·9% of surveyed pools containing Codium. Compared to 1971 censuses, C. fragile ssp. atlanticum had increased in relative abundance at all tidal levels, and the dominance of C. fragile ssp. tomentosoides had declined. The native C. tomentosum constituted the same percentage of the population as it did in 1971. Pool availability and primary rock surfaces were not limiting at most sites, indicating that inter-subspecific and inter-specific competition could not account for temporal changes in Codium distribution on Irish shores. Ecological constraints other than intra-generic competition may have contributed to the purported long-term changes in Codium abundance.

Two developmental stages of the micromorph rhynchonellid Tethyrhynchia mediterranea (Brachiopoda: Tethyrhychiidae) are described using scanning electron microscopy (SEM). They were found in niches of the mantle cavity of adult females, as T. mediterranea broods its offspring between the protecting valves of the shell. The developmental stages of T. mediterranea are very small (∼120 μm), but relative to adult body size of up to 1·2 mm in length they are larger than any other lecithotrophic brachiopod larva. Dispersal ability and phylogeography of T. mediterranea in the Mediterranean Sea is discussed.

A new species of Chalinula (Haplosclerida: Chalinidae), C. saudiensis, is described from the coral reefs of the Red Sea off Jeddah. The new species is remarkable in its vivid blue colour and its bioactivity. Its description includes cytological features in transmission electron microscopy.

Samples were collected from six pools in order to examine the distribution, body length, base colour and phenotypic diversity (chromatophore pattern) of Idotea granulosa populations on five different species of algae (Ceramium, Corallina, Chondrus, Fucus and Enteromorpha), on each of two shores. Holbeck (HOL) pools had significantly higher habitat heterogeneity in terms of algal species diversity than did those on the more exposed Filey Brigg (FB). Idotea densities were significantly higher and mean body size significantly smaller on Corallina than the other algal species. Isopods were significantly larger on Fucus. There was no significant difference in base colour frequencies between shores but there was a positive association between the brown base colour and Corallina and the green colour and Fucus.  The commonest chromatophore pattern morph was the granulosa-maculata that occurred in 44% of the isopods sampled and five out of ten chromatophore patterns accounted for <10% of the population. The uniformis morph was rare on both shores. There was no significant difference in chromatophore pattern frequency between the sexes. The lineata-maculata morph and maculata morphs showed a positive association with Corallina and Fucus respectively. There was a significant difference in chromatophore pattern frequency between adults and juveniles. The uniformis and maculata patterns occurred in higher frequencies than expected in the adult population whereas the reverse was true of the granulosa-maculata and lineata-maculata morphs.  A total of 85 different phenotypes were recorded from both shores, with 51 of these being exclusively found in HOL pools. Holbeck pools had a significantly higher isopod phenotypic diversity than did those from FB. There was no significant difference in phenotypic diversity between adult and juvenile Idotea at HOL, however juveniles had a significantly higher phenotypic diversity than did adults at FB. Overall, there was a significant positive correlation between rockpool algal diversity and isopod phenotypic diversity.

The population of Paguristes erythrops (Crustacea: Anomura) was studied based on seasonal abundance, size–frequency distribution, sex ratio and reproductive period (percentage of ovigerous females). Specimens were collected monthly by SCUBA diving in the infralittoral area of Anchieta Island, Ubatuba. A total of 543 individuals was analysed. Animal size (minimum and maximum shield length, respectively) was 1·7 and 11·8 mm for males, 1·7 and 10·3 mm for non-ovigerous females, and 3·2 and 7·8 mm for ovigerous females. The sex ratio was 0·91:1. Sexual dimorphism was recorded by the presence of males in the largest size-classes. The absence of ovigerous females during winter months (June to August) and their high incidence from January to March indicated discontinuity in the reproductive cycle, suggesting that females become ovigerous and breed in the summer, with the spawning period lasting from spring to autumn. This strategy of reproduction probably was based on competition with other coexisting species in this area.

Three species of microgastropods, Eatoniella atropurpurea, Eatonina rubrilabiata and Amphithalamus incidata, are common in various habitats at mid to low levels on intertidal shores in New South Wales, Australia. These habitats include patches of sediment, pebbles and algal turf. These species are very patchy, varying in abundance within and among habitats at scales of centimetres to many metres. This study describes laboratory experiments which tested hypotheses about differences in mortality and growth rates for each species in three different habitats: sediment, pebbles and coralline turf. There was greater mortality in coralline turf without sediment for E. rubrilabiata and A. incidata, whereas Eatoniella atropurpurea showed a greater mortality in sediment. Moreover, Eatonina rubrilabiata had a faster rate of growth in sediment, whereas Eatoniella atropurpurea grew more rapidly in coralline turf. The different rates of mortality and growth for these species in different habitats provide mechanisms which may partially explain the patterns of abundance in the field.

Littoraria ardouiniana and Littoraria melanostoma are common snails in Hong Kong, living and feeding on mangrove trees. Gut content and stable isotopic analyses were conducted to investigate the littorinid's diets. Gut content analyses revealed these snails ingested bark, epidermal plant cells, fungi, and microalgae, but that broken plant cells were the most abundant food items in the stomach and faecal contents. The gut contents of the two littorinid species, either from the mangrove trees Kandelia candel or Aegiceras corniculatum, were similar and showed little temporal variation throughout the year. Dual stable isotopic analysis, which investigated the δ13C and δ15N values of the littorinids and their potential food items, indicated that these littorinids might feed on mixed diets composed of parts of the mangrove trees and other items available on the trees such as phylloplane fungi, microalgae and cyanobacteria. These epiphytic mangrove littorinids are generalist grazers which graze on the substratum non-selectively as they are constrained on their host trees, and their diets are, therefore, dependent on food availability on the trees themselves.

A comparative study of some tagging methods for the great scallop (Pecten maximus) is reported and intended to increase reliability and reduce costs associated with tagging. Tags were tested for ease of application, legibility, visibility and retention prior to a 17-month study of Pecten maximus in suspended (pearl net) culture. Of the six adhesives tested (standard epoxy resin, rapid epoxy resin, underwater epoxy resin, dental cement, cyanoacrylate fluid and cyanoacrylate gel), rapid epoxy resin and both cyanoacrylates were successful, bonding strongly and quickly to scallop shells. Of the three tag types used, Shellfish Tags (Hallprint) were favoured because they were simpler to apply, more visible, easier to read, and held more data than both Micromarkers (Brady) and engraved codes. In long-term trials 550 scallops were double tagged with Shellfish Tags using cyanoacrylate gel. Loss rates were 16% for tags on the umbo and 0·4% for tags positioned in grooves near to the shell margin. Loss rates did not increase over the 17-month period.

Feeding behaviour of the Japanese pygmy cuttlefish Idiosepius paradoxus, inhabiting sea grass beds, was observed in captivity. Pygmy cuttlefish preferred to feed on crustaceans and the feeding behaviour consisted of two phases, namely, attacking and eating. The sequence of attacking behaviour is divisible into three stages, namely attention, positioning and seizure. In the eating process, pygmy cuttlefish insert buccal mass into the exoskeleton of the captured crustacean. In this action the buccal mass elongates to a similar length to the first arm, and moves in various directions inside the exoskeleton and flesh is ingested as this behaviour proceeds. As a result, the empty exoskeleton remained intact when the pygmy cuttlefish finished feeding.

The relationship between sperm reservoir and total spermatophore length among 168 spermatophores from 44 species in 11 genera has been considered. Bivariate plots show that four Atlantic species of the genus Eledone produce spermatophores with relatively large sperm reservoirs that differ from all others. Measurements of the remaining spermatophores are so tightly correlated that a single equation explains over 96% of the variation. Functional constraints on gross spermatophore morphology may be so strong that males cannot manipulate sperm reservoir size independently of spermatophore size to maximize the sperm delivered at a single copulation. Alternate means to assure male paternity may have evolved in the group as a result. Despite the overall uniformity of the relationship among all species other than those of Eledone in the Atlantic, these measurements distinguish the overtly similar species Octopus bimaculatus–Octopus bimaculoides and separate Benthoctopus januarii from all others.

Bryozoans were collected from nine stations between 569 and 1278 m depth on the Hebridean continental slope north-west of Lewis. The 21 species recorded from 1544 colonies included three species new to the British fauna. The bryozoan fauna, growing on pebbles, cobbles and small boulders, was dominated by species with encrusting, spot or ribbon-like colony morphologies. The few erect species were rare. Colony density on available rock substrata declined from 569 to 855 m, but was high at 1278 m, where the nodular species Turbicellepora boreale occurred on pebbles as small as 1 cm diameter. Cyclostomates made up >90% of the colonies in the shallowest sample and were present in lower numbers to 855 m. None were recorded at 1278 m. In the 569–855 m depth range, diversity and evenness were lowest at 569 m but relatively constant at the other stations. A species accumulation curve suggests that the 20 species recorded is a good estimate of the total fauna in this depth range.

Two species of bryozoan cyphonautes larvae are described and illustrated from plankton tows made among coral heads in shallow waters at Lizard Island, Great Barrier Reef, Australia. Individuals of both species settled and metamorphosed, and their ancestrulae and early astogeny are also described and illustrated. One is recognized as a formerly unknown species of Conopeum, C. ponticum sp. nov., the other is attributed to Biflustra reticulata.

The taxonomic identity of the common subtidal ctenostomate bryozoan Alcyonidium diaphanum is resolved using comparative morphological and molecular genetic techniques. The newly recognized lectotype series and topotype specimens are described and illustrated. The incorporation of spicules and foreign particles during colony growth is described. Colony morphology and genetic characters of the three commonly occurring morphotypes are examined, showing that just a single genetic species may be recognized, based on the 12s rRNA and CO1 mtDNA genes. Mitochondrial haplotypes show no general correlation with either colony morphotype or geographical location.

The metazoan parasites of 101 lesser-spotted dogfish Scyliorhinus canicula from locations off the coast of England (Plymouth and the eastern Solent) and Wales (Cardigan Bay) were surveyed and assessed for their potential as stock discrimination tools.  A total of ten parasite species was found using a relatively rapid host examination technique suitable for non-parasitologists. On the basis of established criteria, larval anisakid nematodes and the copepod Lernaeopoda galei were selected as being potentially useful as stock discrimination tools. The monogeneans Leptocotyle minor and Hexabothrium appendiculatum may be suitable as markers following further investigation of their response to handling stress.

Spiny dogfish Squalus acanthias and narrowmouth catshark Schroederichthys bivius are the only two shark species commonly inhabiting the Falkland Islands shelf. The present study was undertaken to investigate their feeding habits and possible dietary overlap between the species. The diet of the spiny dogfish was dominated by Falkland herring Sprattus fuegensis and squid Loligo gahi, though it also preyed on a wide range of other fish and invertebrates. Catsharks showed a preference for invertebrates. The diet of both species showed marked variations with season, and ontogenic shifts were also evident. Dietary overlap was minimal in winter (15·4%) and maximal in spring (61·1%), the latter being due to both species preying upon spawning aggregations of S. fuegensis.

Aspects of the reproductive biology of two exploited deep water sharks, Centroscymnus coelolepis and Centrophorus squamosus were investigated, based on trawl and longline surveys of the continental slopes and commercial samples from fishing vessels. Gravid Centrophorus squamosus were totally absent from this area, but analysis of uterine width data showed that small numbers of post-natal females were present. Mature males and pre-ovulatory females predominated in the middle of the bathymetric range for both species, indicating that mating occurs at these depths. Gravid Centroscymnus coelolpeis occurred only in waters shallower than 1200 m, though peak abundance of the species was between 1300 and 1400 m. There was no obvious bathymetric segregation of male Centrophorus squamosus, contrary to Centroscymnus coelolepis, where immature males occurred deeper than 1100 m, and the proportion of mature males increased up-slope. Centroscymnus coelolepis apportions twice the resources to gonadal tissue as Centrophorus squamosus. Hepatosomatic index declined during vitellogenesis in Centroscymnus coelolepis. Both species have low reproductive outputs and commercial exploitation should proceed with caution.