It has been shown that the main factor which influences the local distribution of the lugworm at Whitstable is the depth of the muddy sand overlying the clay stratum below.

In places this clay is furrowed by straight channels which are revealed only by the arrangement of the lugworm castings. These are more numerous along the channels.

Migration of adult lugworms has been shown to occur, most freely in the spring.

In a four year study of bottlenose dolphins along the southern shore of the outer Moray Firth we show that whilst dolphins were encountered along the majority of the survey area, there was a significant preference to the western section, which is the area directly adjacent to the current Special Area of Conservation (SAC). We also show that 80% of all groups encountered (N = 62) included calves, and that neonates were seen throughout the months of July, August, September and October. The mark–recapture abundance estimates for the southern outer Moray Firth were variable, with a highest annual estimate of 108 (95% CI = 79–129), which is similar to previous estimates for the number of animals using the entire Moray Firth. In contrast, the lowest annual estimate of 61 (95% CI = 48–74) suggests that not all individuals regularly use the entire geographical range of the population and that individual ranging patterns may vary across years. The findings of this study indicate that the southern outer Moray Firth is an important area for this population and that it should not simply be considered as a corridor to other areas of more importance. For this reason, we believe that further consideration of the current management of this population in areas outside the existing SAC is necessary.

The upside-down jellyfish Cassiopea is a benthic scyphozoan, considered a non-indigenous invasive species in the Mediterranean, forming large blooms in eutrophic areas. Taxonomy of the genus Cassiopea is extremely difficult because morphological/meristic characters used are variable within the same species, overlapping among different species, and cryptic species have been identified by molecular markers; nine Cassiopea species are recognized on the basis of molecular study. Mediterranean records of Cassiopea have been ascribed to andromeda species on the basis of a hypothesized invasion pathway from the Suez Canal. In the current study, an analysis of the main morphological characters of the sampled Cassiopea jellyfish from Palermo (Tyrrhenian Sea) was carried out and subsequently, molecular analyses were performed by using COI barcode in order to identify the species. Molecular data were compared with published information in GenBank. Morphological characters were highly variable, but molecular analyses confirmed that Mediterranean Cassiopea specimens belong to andromeda species. Moreover, high values of sequence divergence were found between Mediterranean Cassiopea and the other C. andromeda from the Red Sea, Hawaii and Florida. These results lead to a discussion of possible explanations linked to life history features of the species. Two different explanations are proposed; the first is that Mediterranean C. andromeda, finding a suitable ecological niche good for colonization and proliferation, could have been isolated in Palermo Harbour. The second considers the possibility of multiple introduction events by human transport as demonstrated for other non-indigenous jellyfish; in this case Cassiopea genetic differences increased in the invaded area.

The reef-building fire coral Millepora alcicornis is reported from Ascension Island (South Atlantic). This record, based on a recent expedition to Ascension, is the first in which the identification of a Millepora coral is supported by photographic evidence from the field and by morphological and molecular analyses of collected specimens. This finding is discussed in relation to earlier Millepora records from Ascension and the biogeographic range of this particular species in the Atlantic.

Studying interactions between cetaceans and humans is fundamental to assess their ecological significance and the impact of human activities on marine wildlife. Delphinids have historically been associated with human maritime activities, and while evidence suggests that such interactions are becoming more frequent worldwide, these remain poorly studied. Areas of potential interaction and differences in dolphin affinity to interact with humans were used to test hypotheses about the spatial distribution and temporal variation in dolphin–fisheries interactions off the highly productive Alvarado lagoon, in the western Gulf of Mexico. Line-transect surveys yielded 928 dolphin, 980 vessel, and 320 fishing gear target records, the latter involving mostly the shrimp fishery. No temporal differences were found in daily relative abundance of dolphins ( = 8.1 h−1, SD = 9.7), vessels ( = 7.8 h−1, SD = 5.9) or fishing gear ( = 2.4 h−1, SD = 2.6) between two consecutive years. Non-random spatial distributions indicated higher target concentrations at the lagoon entrance; however, dolphins and fishers were found to evade each other, possibly to prevent competition; dolphins only interacted with gillnets (28.6% of vessels and 22.6% of fishing gear). We observed small areas of potentially intentional and random encounters outside the entrance of the lagoon and low or null potential for interactions elsewhere. Only 18.9% of dolphin schools (44.8% of the 172 photo-identified animals) interacted with fisheries mostly by chance. Resident individuals (N = 23) tended to avoid humans, likely in response to negative reinforcement caused by aggressions from fishers. Hence, the potential intentionality of a few individuals to interact with fisheries, show they bare higher risks while attempting to benefit from gillnetted prey. This research unveils the chronic and acute exposure of the dolphin community to artisanal fisheries within the area, having important reciprocal consequences on their distributions and activities.

A population of the supralittoral Orchestia gammarellus (Pallas) (Amphipoda: Talitridae), living in a percolating filter of a sewage treatment works has been studied over 12 months. The population showed a seasonal pattern of occurrence, few animals being collected during the winter. The sex ratio was biased significantly to females except during the breeding season when it did not deviate significantly from 1:1. Ovigerous females, never collected in high numbers (1–14 per month), were found from April to August, with peak occurrence in May/June. Juveniles were present throughout the year, but peak recruitment occurred in summer, following the period of reproduction by females. The smallest ovigerous female had a body length of 12.6 mm and the largest measured 20.0 mm. Egg numbers (5–31 per brood) increased with increasing female size and egg volume more than doubled during embryonic development. These findings are discussed in relation to the possible methods of colonization of this unique habitat and the influence of sewage on crustacean life-history traits.

The present study investigates hourly variation in nocturnal abundance fluctuations in a tropical, Caribbean sea grass bed. As expected, results indicate that significant diel variation is present. In addition all dominant species show an abundance peak shortly after sunset, with numbers gradually declining throughout the night. It is therefore suggested that nocturnal samples are not only incorporated into any sampling regime, but that nocturnal samples are taken within two hours after sunset.

Stilifer stylifer (Turton) has been recorded from Plymouth many years ago living on Psammechinus miliaris (=Echinus) and Echinus esculentus; also from several other British localities (see Jeffreys, 1867, IV, p. 196). Jeffreys describes the spawn and larvæ hatched from it, but apparently these have never been figured. It had not been rediscovered at Plymouth until 1931 when in August Mr. A. D. Hobson found several specimens of Psammechinus miliaris from deep water beyond the Eddystone with these small commensal molluscs on them. In the first lot of about a dozen Psammechinus, three were covered; with the spawn of Stilifer, one having one mollusc and two having two. In a second lot taken a few days afterwards, five were covered with spawn, one having one mollusc, two having two, and two having three. These were placed in a plunger-jar, but unfortunately most of the Stilifer left the Psammechinus and were presumably eaten by them as pieces of their shells were found. They probably did not like their surroundings. Some of the spawn was removed from the Psammechinus and placed in a fresh plunger-jar with some Nitzschia where some of the larvæ hatched out. A Psammechinus was introduced in the hope that the larvæ might settle down, but they all died after living only a few days.

Records are given of Kinorhyncha from muds at 101–140 m depth off the Scottish east and west coasts. All three suborders of Kinorhyncha are represented, and one new species and two new larvae are described.

Six colour varieties were recognized in an intertidal population of Amphipholis squamata from Normandy (France). Each variety exhibits its own capacity to produce light, the light emitted by the most luminous variety being 500 times more intense than that emitted by the least luminous one. Differences in luminescent capabilities observed between varieties do not seem to be due to differences in pigmentation or to be of exogenous origin. It was shown that the capability to produce light changes according to whether individuals are brooding or not, brooding individuals emitting a more intense light than non-brooding ones. This supports the defensive use of luminescence generally associated to ophiuroid production of light. However, light capabilities differ so much between A. squamata colour varieties that bioluminescence could also be associated with another role in the species.

The cirratulid polychaete Cirriformia tentaculata (Montagu) may be found in gravelly mud or sand often beneath large stones in pools between tide marks. It is usually associated with reducing conditions indicated by blackened mud or sand and the distinctive odour of hydrogen sulphide. It occurs also in crevices that retain stagnant water at low tide. The worm does not make a permanent burrow but lies in different postures to enable the branchiae and feeding tentacles to be extended on to the surface, where they are bathed by the overlying water. The mucus-lined burrow is not irrigated.

Cirriformia tentaculata encounters two respiratory problems. When covered by water the branchial filaments can take up oxygen which is then circulated by means of the well-developed vascular system with blood containing haemoglobin in solution. While the branchiae may lie in a well-oxygenated medium the main body of the worm lies in a highly reducing substrate. The sediment immediately surrounding the worm is commonly black and there is no oxygenated layer as occurs in burrows which are irrigated and provide an envelope separating the animal from a potential oxygen-sink. If exposed by the tide the branchiae are withdrawn or clump together and cannot function effectively. Even when covered by the tide the branchiae can be rapidly with-drawn, presumably to avoid loss by predation, and under all these conditions the animal must experience hypoxic or anoxic conditions of varying duration of up to several hours.

We have examined the ability of Cirriformia tentaculata to maintain oxygen uptake under decreasing oxygen tension, the oxygenational properties of the haemoglobin, the oxygen capacity and blood volume.

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.

The paired excretory organs or maxillary glands of the adult barnacles, Balanus balanoides and Balanus hameri, lie within the posterior part of the body below and to either side of the foregut. Each organ has an end sac linked to an efferent duct via a valve. The sac-shaped efferent duct connects with a relatively short terminal duct, opening out at the base of the second maxilla. The end sac consists of podocytelike cells having marked morphological and cytochemical similarities to the equivalent region of other Crustacea and to the vertebrate glomerulus. The main cells of the valve contain extensive apical secretion. They rest upon a series of modified end-sac cells projecting into the efferent duct. The efferent duct is composed of a uniform flattened epithelium which is cytochemically unreactive. The cells are lined by a short microvillous border, below which is a series of tubules which appear to be invaginations of the apical membrane. The morphology of efferent duct cells is not indicative of a highly active solute reabsorptive epithelium, but secretion of membrane-bound bodies into the efferent duct lumen was observed. The terminal duct is a relatively short, cuticle-lined ectodermal infolding. The parenchyma cells surrounding the efferent duct exhibit a marked affinity for certain dyes when injected into the haemolymph, indicative of a possible role in the elimination of material. The excretory organ is surrounded by a network of elastic fibres and is suspended within the body by strands of connective tissue and a complex series of tendon-muscle connexions. The end sac is well supplied with haemolymph from the scutal sinus but the supply to the efferent duct is more restricted.

Idotea metallica Bosc occurs occasionally in plankton from waters off the west coast of Britain, but since it does not seem to be a British resident it was excluded from a recent review of the genus Idotea (Naylor, 1955 a). Accounts of the distribution of /. metallica seldom distinguish between occasional records and resident breeding localities, and this note attempts to explain its occasional occurrence in Britain.

The pattern of somatic energy storage, measured as body lipid proportion, was investigated in the grass goby Zosterisessor ophiocephalus, by comparing the per cent lipids across three reproductive groups—large males (territory holding, caring for eggs, males), small males (sneaker males) and females—and across a seasonal phase including the entire breeding season and a post-reproductive period. Furthermore, the pattern of some indicators of somatic and reproductive investment, such as gonadosomatic index (GSI) and liversomatic index (LSI), was investigated, as well as the relationship between lipid content and fish body size was studied over time in both sexes. Results showed that the amount of somatic lipids depends largely on the different levels of reproductive investment shown by the breeding individuals. Females had the lowest levels of somatic lipids at the beginning of the breeding season when large males reached, by contrast, the highest levels. Large males showed a strong decrease in their reserves as the breeding season proceeded, and their replenishment was significantly slower than that of smaller males, which had relatively high levels already in September. Analysis of the trends of GSI and LSI revealed that the difference between females and males in the primary reproductive investment (gonadic mass) can explain most of the differences in the levels of somatic energy storage. The relationship between body size and lipid content changed over time, being positive and statistically significant at the beginning of the breeding season for each reproductive group, indicating that during these phases all the breeding individuals had accumulated energy in their tissues and that the breeding season reduced their somatic energy storage although with different intensity.

The gonadial, pyloric caecal and somatic cycles over three consecutive years in a subtidal population of the starfish Marthasterias glacialis from Plymouth Sound are described. The study area lies towards the eastern limit of the up-Channel range of this species, and this is reflected in only partial reciprocity between gonadial and pyloric indices, and also by the apparent utilisation of somatic material during the build-up of gametes. The sequence of events at the cytological level during gonadial build-up is described.

The luminescent material emitted from the post-cleithral organ of searsid fishes is in the form of granule-packed cells. From this material a partially purified extract may be prepared which shows some of the properties to be expected from a photoprotein. The purified material luminesces on treatment with hydrogen peroxide and, specifically, ferrous iron. The properties of the luminescent system appear similar to those of material isolated from the luminous polychaete Chaetopterus.

The following three species of grey mullet (Mugilidae) are recorded by Wheeler (1978) for the waters of north-western Europe: thick-lipped mullet, Chelon labrosus (Risso, 1826); thin-lipped mullet, Liza ramada (Risso, 1826) and golden mullet, Liza aurata (Risso, 1810). Liza ramada was obtained in relatively large numbers during the course of extensive sampling of the material collected on the intake screens of power stations in the Bristol Channel and Severn Estuary (for details of other studies see e.g. Claridge & Gardner, 1977, 1978; Titmus, Claridge & Potter, 1978; Abou-Seedo & Potter, 1979; Claridge & Potter, 1983, 1984). Since there is apparently no detailed information on the biology of the thin-lipped mullet in the estuaries of north-western Europe based on regular frequent collections, the power station material was used to provide data on seasonal and annual abundance, size composition, growth and lip depth of this species in the Severn Estuary and Bristol Channel. Comparisons have been made between these data and those obtained for C. labrosus from the same environments and more particularly from outside the area at Pembroke where much larger collections of this latter species were taken.

The bluespotted cornetfish (Fistularia commersonii) is an Indo-Pacific species that in the last ten years colonized a large part of the Mediterranean basin. The aim of this study was to sequence some portions of the mitochondrial DNA (D-loop II, 16S, 12S and Cyt b) of this fish from different localities of the Mediterranean Sea, in order to evaluate the level of its genetic variability in this area. The genetic analysis performed on specimens from seven localities of Sardinia, Tunisia and Libya revealed the presence of at least five mitochondrial lineages. The results obtained, compared with previous studies, indicate that the use of a sufficient number of mitochondrial regions may allow a more accurate estimate of genetic variability in lessepsian invasions.

Bathymetric range, substrate, colony density, colony size, and some zoarial features (form of the colony and branches) of the carbonate reef building cheilostome bryozoan Pentapora fascialis (Pallas) were recorded from 15 localities along the western coast of Italy. A wide range in the depth distribution of colonies was observed (11 to 60 m). Colonies occurred on several different types of substrate including gorgonians, sponges, bedrock and rock boulders, in current swept areas. Density was approximately 1 colony/m2. The most frequent colony size-class was 10 to 20 cm in diameter and was typically found growing epizoically on gorgonians. Ellipsoidal colony forms with expanded, foliaceous laminae were characteristic of larger colonies; these frequently grew on rock substrates. Subspherical colonies with a diameter less than 20 cm grew as epizoans and had a narrow branches structure. This information will help to inform decisions on taxonomic discrepancies within the Pentaporidae. In addition the data provide a useful baseline for the future estimation of a carbonate budget in the region.