An analysis of species composition of the zooplankton, macrobenthos (two stations) and demersal fish from Northumberland (north-west North Sea) are reported. The four time-series show synchronous changes in species composition. While some of these changes coincide with changes in climateological variables, others do not. The degree of synchrony implies that either all the time-series are responding to a single set of extraneous forcing factors, or that food chain links, rapidly translate the signal through all ecosystem components.

A new barnacle, Chthamalus neglectus sp. nov. is described from Hong Kong. Light microscopy and scanning electron microscopy investigations of adult morphology show obvious differences from previously recorded Chthamalus species, and that this species belongs to the ‘C. challengeri group’ of Chthamalidae.

Caprellid amphipods, Caprella danilevskii were exposed to tributyltin (TBT) (100 ng 1−1) for ten periods after eggs were deposited in the brood pouch. Brood loss during incubation was found in six exposure periods between 12 and 72 h after spawning, although no brood loss was observed in the control. It was suggested that exposure to TBT half a day after spawning might be sufficient to damage reproduction during the caprellid's embryonic life. The female percentage was 38.7% in the control, whereas it was gradually increased to 60.0–71.4% in the four exposure periods between 12 and 48 h after spawning.

Two distinct forms of the megrim, Lepidorhombus whiff-iagonis (Walbaum), exist, a southern form which ranges from the Mediterranean to the British Isles and a northern form which ranges northwards from the north of Ireland and the North Sea (Richardson, 1860; Kyle, 1913; Furnstein, 1935; Dwivedi, 1964). Kyle and Richardson considered these forms to be separate species. The southern form of megrim extends into the English Channel with Start Point, 3° 40' W, the approximate eastern limit of its distribution (Cligny, 1905). However, this fish is common only at the western entrance of the Channel since it is abundant only in depths below loom (Dwivedi, 1964). Little is known of the separate megrim populations in the geographical range of the southern form. Studies of meristic characters indicate the existence of at least three populations, one in the Mediterranean and along the coast of Portugal, another in the Bay of Biscay and the third south of Ireland and in the entrance to the English Channel (Cligny, 1905; Dwivedi, 1964).

Limpet populations of the genus Patella from the south-west coast of England were examined by means of gel electrophoresis in order to settle debate on the specific status of the three Patella forms. Populations varied morphologically along an east-west gradient, from three distinct forms in the west to continuous intergradation in the east, in accord with earlier studies. Patella collected were divided into three groups on the basis of a complex of external features described by earlier workers, corresponding to the morphologically defined taxa P. vulgata Linn., 1758, P. aspera Röding, 1798, and P. depressa Pennant, 1777. These groups were electrophoretically distinct in five of seven enzyme systems examined, with no hybrids or intermediates. Incomplete speciation and hybridization can be ruled out as possible causes of the observed morphological variation.

Leptogorgia ignita is a new gorgonian species characterized by its conspicuous bright orange colour, irregular branching pattern and combination of sclerite types in the coenenchyme, all of the same orange colour, with abundance of capstans and blunt spindles, and less abundant acute spindles. The species was found in a shallow water coral community, 4–12 m deep in Samara Bay, Pacific Costa Rica. Morphologically, L. ignita belongs to the L. rigida-group comprising eight species for the group; 13 Leptogorgia species are known for Costa Rica, and 23 for the entire eastern Pacific. The new species is described, illustrated and compared to the other valid taxa of the group.

It is well known that the smooth adductors of lamellibranch molluscs can hold the shells closed against the tension exerted by the elastic hinge ligament for prolonged periods without visible signs of fatigue. Two opposing hypotheses have been put forward to explain this phenomenon. One postulates that tonic contraction is a tetanic phenomenon and that the economy of lamellibranch smooth muscles is due to their slow speed of relaxation (Ritchie, 1928); whilst the other proposes the existence of a ‘catch mechanism’ which enables tension to be maintained without expenditure of energy, so that no excitation is needed during tonic contraction (Jordan, 1938).

Thirteen species of Amphipoda have been recorded from the stomachs of plaice and 11 species from dabs, with Perioculodes longimanus the most notable prey oedicerotid in both flatfish species sampled from the shallow sublittoral zone (<-6 m depth) at Kames Bay, Millport. Plaice took mostly bivalve siphon tips (Angulus sp.). Polychaetes were more numerous in larger plaice. Sand gobies specialized on small crustaceans, taking 13 amphipod species inter alia (with P. longimanus again the most notable oedicerotid). Amphipod numbers in sand goby stomachs increased with the length of the fish. Neither dabs nor sand gobies consumed bivalve siphon tips and only rarely consumed polychaetes. Although amphipods formed only a minor part of the diet of plaice, at the population density known for this species in this bay, its depredations would still constitute an important selective agency governing patterns of activity in epibenthic oedicerotids.

The palatability of organic chemical extracts from ten of the most abundant sponge species along the Israeli (shallow) coast, eastern Mediterranean Sea (Axinella sp., Axinella polypoides, Chondrilla nucula, Ircinia sp., Psammocinia sp. 1, Psammocinia sp. 2, Psammocinia sp. 3, Psammocinia sp. 4, Sarcotragus sp. and Tetilla sp.) was tested. To examine the generality of the phenomenon, it was evaluated with two types of potential predators, a fish and a gastropod. It was determined that the extracts of only two species (Psammocinia sp. 1 and Psammocinia sp. 3) deterred feeding of the omnivorous ornate Mediterranean wrasse Thalassoma pavo. On the other hand, extracts of five other sponges (Chondrilla nucula, Axinella sp., Ircinia sp., Sarcotragus sp. and Psammocinia sp. 2) were non-palatable to the omnivorous gastropod Strombus persicus (the extracts that deterred the fish did not deter the gastropod and vice versa). We also determined the capacity of extracts from six Red Sea sponges to deter T. pavo, and compared it with these extracts' effect on the Red Sea wrasse T. klunzingeri. All the extracts that deterred the Red Sea wrasse (from Amphimedon chloros, Crella cyatophora, Negombata magnifica and Theonella swinhoei) were also non-palatable to the Mediterranean wrasse. In addition to these four species, also Diacarnus erythraenus deterred Thalassoma pavo while being palatable to T. klunzingeri, whereas food pellets with extracts of Niphates rowi were eaten by both wrasse species.

The cheliped stridulatory structures are described for Trizopagurus strigimanus, T. melitai, T. tenebrarum and T. strigatus.

Sound in T. strigimanus is produced during reciprocal flexion and extension of the carpo-propodite and mero-carpopodite joints of tightly apposed chelae. These underwater sounds occur as syllables, each of which is composed of damped pulses with a repetition rate of 36–303/s and a within-pulse frequency of 6–8 kHz. The maximum sound pressure level (peak to peak) 15 cm from the source was 24 dB re: 1 Pa.

The gastropod shells inhabited by T. strigimanus had a weak effect (5% pressure difference) on directional radiation of sound in the near field (5 cm) and no effect beyond 20 cm from the crabs.

Cavity resonance of the shells was predicted from a mathematical model, but only appeared important at a fundamental frequency of about 4 kHz, when tested in animals partially removed from their shells. A more significant effect was low-frequency vibration (100–300 Hz) imparted to the shells through direct contact by the hermit crab inhabitants.

Behavioural experiments suggested that the function of T. strigimanus stridulation is defensive, particularly against conspecific aggressors. This may reduce intraspecific competition for shells in Trizopagurus.

Amphipods of the genus Phronima are known to make a barrel-shaped house from the gelatinous matrix of pelagic tunicates or siphonophores. Among the seven barrels examined here, one barrel of Phronima curvipes was supposed to be made from a swimming bell of a siphonophore based on its morphology, while the other six barrels made by P. sedentaria were immunochemically and/or morphologically identified as tunicates (i.e. Thetys vagina, other salps and pyrosomas). Histological observation showed that the phronimids had completely eaten the animal tissues other than the gelatinous matrix (i.e. tunic or mesoglea). Tunic cells were found in the tunicate barrel and some were probably tunic phagocytes that appeared to be alive and functional. In the tunicate barrels, cuticular layers of the tunic were found on both the outer and inner side of the barrel wall. Tunic cuticle would be regenerated on the inner side after the epidermis was grazed by the phronimids. The cuticular layers would protect the tunic matrix from the invasion of microorganisms. In the barrel supposed to originate from Thetys vagina, there are minute protrusions on the tunic cuticle as found in the intact tunic of this species. In the barrel from a siphonophore, neither cells nor cuticle regeneration were found. No bacteria were observed in the barrel, suggesting that the barrel has some antibiotic system.

The mudskipper Boleophthalmus pectinirostris maintained territories in farming ponds during the cold season between November and February. There were two types of territory, one was surrounded by mud-walls, and the other was without mud-walls. Both types of territory were entirely covered by shallow water. The area of walled territories was significantly bigger than that of non-walled ones. The nearest neighbour distance of walled territories was significantly shorter than that of non-walled territories. In January, fish surface activity occurred between 1200 and 1500 hours at which time the territorial water temperature reached a maximum, being significantly higher than that of the air, mud surface or deep burrow. The territorial sediments exhibited a significantly greater benthic microalgal biomass (chlorophyll-a and total chlorophyll-a) as compared to the non-territorial sediments. The present study indicates that B. pectinirostris forms a territory during the cold season to keep a pool of water that encourages diatom growth and enables the fish to engage in surface activity.

The limpet Patella vulgata is a key species of northern Atlantic rocky shore-associated communities, and is commonly considered to be important in regulating populations of canopy-forming Ascophyllum nodosum, through consumption of propagules and young recruits. Although P. vulgata is usually regarded as a non-selective epilithic biofilm grazer, a role in the collapse of established A. nodosum through grazing of adult plants has been repeatedly suggested. Factors controlling the preference of P. vulgata for epilithic biofilm or adult algae are still not clearly established. Here, we test the hypothesis that the diet of P. vulgata is mainly driven by the local availability of food sources. Limpets were sampled along the first 6 metres of an A. nodosum bed–bare rock gradient. Stable isotope ratios of their muscle tissue and digestive glands were measured. The contribution of A. nodosum to the diet of limpets was the highest in the immediate vicinity of macroalgae beds, which confirmed our initial hypothesis. However, the contribution of epilithic biofilm did not match our hypothesis, being the lowest for limpets colonizing bare rock. Instead, these limpets relied on a wide array of sources, including ephemeral green algae, biofilm and drifting A. nodosum fragments. Overall, our results indicate that A. nodosum can be readily grazed by limpets, which challenges the hypothesis that these macroalgae dominate rocky shores due to the absence of strong top-down control exerted by herbivores. Our results also highlight the need to consider the small spatial scale to understand the dynamic of herbivore–algae interactions in natural environments.

New Zealand rattail fish are of great interest both to biologists who study their phylogenetics and in fisheries. In contrast, their morphological evolution is little studied and poorly understood. Geometric morphometric methods based on scale shape were applied in this study to determine differences among species and genera. Scale shapes were described using seven landmarks, the coordinates of which were subjected to a generalized Procrustes analysis, followed by a principal components analysis. A cross-validated discriminant analysis was applied to assess and compare the size-shape (centroid size plus shape variables) efficacy in the species and the discrimination of the genera. Two main phenetic groups were identified: cluster no. 1 with eight species and cluster no. 2 with six species. Coelorhinchus aspercephalus and Mesovagus antipodum were more separated from the other species in the first cluster. The cross-validated canonical discriminant analysis correctly classified 74% at the genus level, with most misclassifications occurring between Coelorhinchus and Coryphaenoides, whereas the best classified genera were Mesovagus and Trachyrincus. The discrimination of correctly classified species ranged from 41.2 to 100%. The highest correct classification rates were recorded for Coryphaenoides armatus, Coelorhinchus innotabilis, Trachyrincus longirostris and Mesovagus antipodum.

Small boat surveys were organized to study cetaceans of the Marquesas (9°S and 140°W) and the Society Islands (17°S and 150°W) in French Polynesia. Prospecting took place from 12–15 m sailboats, between 1996 and 2001 with systematic visual searching. Boats moved according to sea conditions, at a mean speed of 10 km/h. Effective effort of 4856 km in the Marquesas and 10,127 km in the Societies were logged. Relative abundance indices were processed for odontocetes using data obtained with Beaufort 4 or less. In the Marquesas, 153 on-effort sightings were obtained on 10 delphinids species including the spotted dolphin, spinner dolphin, bottlenose dolphin, melon-headed whale and rough-toothed dolphin. In the Societies, 153 sightings of 12 odontocetes included delphinids (spinner, rough-toothed and bottlenose dolphins, short-finned pilot and melon-headed whales, Fraser's dolphin, Risso's dolphin and pygmy killer whale) and two species of beaked whales, the sperm whale and dwarf sperm whale. Relative abundance indices were higher in the Marquesas than in the Societies both inshore (0.93 ind/km2 against 0.36 ind/km2) and offshore (0.28 ind/km2 against 0.14 ind/km2). Differences in remote-sensed primary production were equally important, the Marquesas waters featuring an annual average of 409 mgC.m−2 · day−1 and the Societies of only 171 mgC · m−2 · day−1. The presence of a narrow shelf around the Marquesas also accounted for differences in odontocete populations, in particular the delphinids.

The rayed trough-shell Mactra corallina Linnaeus 1758 is a surf clam that inhabits the Atlantic Ocean, Black Sea and Mediterranean Sea and represents a commercially important bivalve. This species is present with two different and well-defined sympatric morphotypes, which differ mainly for the colour of the shell (white in the corallina morph, and brown-banded in the lignaria morph). The aim of this work is to resolve the confused and contradictory systematics of the bivalves belonging to M. corallina putative species by analysing molecular and morphological features. Fifteen specimens of M. corallina corallina (white variant) and 19 specimens of M. corallina lignaria (brown variant) were collected in the North Adriatic Sea and analysed by four molecular markers (12S, 16S, 18S and COI genes, partial sequences). Genetic analyses clearly support the presence of two different species, which were previously ascribed to M. corallina. In addition, 35 specimens identified on a morphological basis as M. c. corallina and 28 specimens identified as M. c. lignaria collected in the same area were used for a morphometric analysis. A positive correlation was found between the maximum width of shell (W), antero-posterior length and between W and the height of specimens from umbo to ventral margin, thus adding to molecular data.

The present notes (see also Wilson, 1949, 1953) are mainly concerned with the breeding habits of two fishes commonly kept in marine aquaria. These habits may be familiar to keepers of other large marine aquaria, but I have failed to find any account of them in scientific literature other than a very brief and inadequate description by Raffaele (1898, p. 328) of the nesting of Cantharus vulgaris (= Spondyliosoma cantharus) in the aquarium at Naples. The scientific names of species mentioned follow the Plymouth Marine Fauna third edition (Marine Biological Association, 1957)

Bottom trawling is a large-scale fishing activity along the Brazilian coast, but its effects on benthic infauna are still poorly known. This is the first experimental evaluation of benthic responses to bottom trawling along the Brazilian coast. We tested the effects of trawling on macroinfaunal assemblages on the inner continental shelf off Paraná (southern Brazil) by using a sampling design with adjacent trawl and control areas. We hypothesized that if trawl fishing has a negative effect then we should expect lower numbers of species and lower benthic densities after an experimental trawling. Sampling was conducted at adjacent sites within each area to minimize confounding due to spatial variation. Five sites were sampled at a control, and five at an experimental area for infaunal and sedimentological variables. Sampling was carried out just before and one hour after experimental trawling. Multidimensional scaling followed by a PERMANOVA did not show any clear variation tendencies in the structure of the benthic assemblages in the impacted area before and after trawling. However, variance analysis showed a significant and unexpected increase in infaunal total density, in the density of the numerically dominant species (except for the polychaetes Capitella sp. and Loandalia tricuspis) and in species richness in the experimental area. Conversely, no significant variations were recorded in the control area. We suggest that the overall increase in benthic density after a disturbance is correlated with the reworking of the sediment matrix and benefits the suspension-feeders after sediment resuspension.

A new species of the genus Golfingia (phylum Sipuncula), belonging to the subgenus Phascoloides Fisher, is described from the Plymouth area.

Studies of the local populations of G. (Golfingia) elongata have shown the species to vary considerably in some important taxonomic characters, in particular, the number of retractor muscles: over 13% have only two or three retractors instead of four.

Notes on, and a key to, the species of Golfingia found around the British Isles are given.

Elminius modestus cyprids settle readily in contact with adult barnacles in the field, and do not discriminate between conspecific and alien adults. This settlement strategy is contrasted with that previously shown to be employed by Balanus balanoides.