Meiofauna, macro-infauna and epifauna were sampled at two offshore sandbanks in the southern North Sea in 2006. The epifaunal and infaunal communities in the dynamic environment of the sandbank crests were species poor, with lesser weever, solenette, Crangon crangon, amphipods and deposit-feeding polychaetes the predominant benthic taxa. Abundant early life-history stages (24–39 mm) of the lesser weever Echiichthys vipera on the sandbank crests indicated that these habitats may be important nursery grounds for this species. Species diversity of infauna and epifauna was greater in the deeper waters parallel to the sandbanks. Contrasting patterns were evident for meiofaunal nematodes, where communities collected on the sandbank crests were more diverse than those recorded in the deeper off-bank sites. The fauna of sandbank crests is composed of a restricted range of the fauna typically associated with sandy habitats, particularly taxa adapted to live in this dynamic environment.

Eyeshine brightness was measured in a number of species of oplophorid shrimps and one sergestid. Eyeshine varies in a systematic way across the eye. Forward and downward looking parts of the eye often have the brightest eyeshine. In many cases eyeshine is graded in the horizontal and vertical axes. Eyeshine brightness can be explained in terms of underlying tapetal morphology. These features of the decapod eye can be rationalised in terms of the normal irradiance distribution in the sea and the need for certain parts of the eye to have enhanced sensitivity. Contrary to the expected results, when six species of oplophorid were compared there was a clear trend of decreasing brightness with depth at whichthey occurred. In a number of species the tapetum is incomplete with distinct holes. Such holes occur in the dorsal region of two species of oplophorid. In one deep-water species the central tapetum is lacking. This feature, and the observed decrease in eyeshine with depth, may be adaptations to reduce the signal that eyeshine provides to potential predators.

The movement and activity patterns of the nurse shark, Ginglymostoma cirratum, a vulnerable species off Brazil, were investigated using mark-recapture and acoustic telemetry at an oceanic insular Marine Protected Area, the Fernando de Noronha Archipelago, Brazil. A total of 93 sharks were captured and tagged, ranging from 82 to 265 cm of total length (TL). Nurse sharks were captured throughout the year, and all life-stages used the insular shelf. Fifteen sharks (16% of the total) were recaptured after periods at liberty ranging from 3.5 h to 705 days, and the distances between tag and recapture locations ranged from 0.07 to 3.5 km. Site fidelity and movements of 10 sharks ranging from 107 to 265 cm TL were investigated for 18 months with an array of automated telemetry receivers. The mean period of detection of the monitored sharks was 66 days, ranging from 13 to 119 days. One individual 158 cm TL was monitored with active tracking for 17 days, with distances between daily locations ranging from 0.84 to 3.32 km, exhibiting movements similar to those of sharks monitored by automated telemetry. Despite remaining motionless or exhibiting short range movements for several hours or days, nurse sharks can be relatively wide-ranging, and protected areas alone cannot be the only conservation measure used to protect this species, which requires a set of protective measures, including fisheries management.

A study of the polychaetes living on isolated seamounts was undertaken to give data on marine biogeography and the dispersal of marine invertebrates. The data from the Meteor and Josephine seamounts came from Hartmann-Schröder and Rosenfeldt's work in the 1980s. Data from Hyeres came from Bellan's work in the 1960s, and data from the Atlantis and Hyeres seamounts were obtained during the Seamount 2 French expedition on board the ‘Suroît’ in 1993. Thirty-five sites from 280 to 2205 m were sampled: 16 on Atlantis (13 with polychaetes), and 19 on Hyeres (16 with polychaetes). In all 84 polychaete taxa from four seamounts were studied: Atlantis, 36; Hyeres, 33; Josephine, 34; and Meteor 50, but data analysis was based on the following number of taxa: Atlantis, 31; Hyeres, 29; Josephine, 34, and Meteor 48. Two groups of sites were identified by cluster analysis: I, Atlantis and Hyeres; and II, Josephine and Meteor. Only seven species were present at all sites. Nine families were present only in group I and six other families only in group II. Hesionidae (three species) occurred in group I, conversely Syllidae (16 species) were sampled only in group II. Some of the species were cosmopolitan (31%), 49% had a large distribution in the Atlantic, 11% were lusitano–mauretanian species, and only 6% were endemic; 51% of the species have direct development against 46% of the species which had a planktotrophic development and 3% a lecithotrophic development. Results of the biogeographical distribution and reproductive patterns of the polychaetes collected on these four sites were compared.

Knowledge about the diet of fish-eating predators is critical when evaluating conflicts with the fishing industry. Numerous primary studies have examined the diet of grey seals Halichoerus grypus and common seals Phoca vitulina in a bid to understand the ecology of these predators. However, studies of large-scale spatial and temporal variation in seal diet are limited. Therefore this review combines the results of seal diet studies published between 1980 and 2000 to examine how seal diet varies at a range of spatial and temporal scales. Our results revealed extensive spatial variation in gadiform, perciform and flatfish consumption, likely reflecting variation in prey availability. Flatfish and gadiform consumption varied between years, reflecting changes in fish assemblages as a consequence of factors such as varying fishing pressures, climate change and natural fluctuations in populations. Perciform and gadiform consumption varied seasonally: in addition there was a significant interaction between season and seal species, indicating that grey and common seals exhibited different patterns of seasonal variation in their consumption of Perciformes and Gadiformes. Multivariate analysis of grey seal diet revealed spatial variation at a much smaller scale, with different species dominating the diet in different areas. The existence of spatial and temporal variation in seal diet emphasizes that future assessments of the impact of seal populations should not be based on past or localized estimates of diet and highlights the need for up-to-date, site specific estimates of diet composition in the context of understanding and resolving seal/fisheries conflict.

Thysanoessa raschii is a regular inhabitant of the Firth of Clyde. Adults are found throughout this area, generally in waters not less than 40 fms. deep. Those of large size, 23–25 mm., are apparently consistently found from year to year in Loch Striven in large numbers from October to January within 10 fms. from the bottom in waters of 40 fms. depth. Throughout the rest of the year they occur in small numbers in the tow-nets, and are seldom found at all during the summer months. On one occasion, however, February, 1926, several hundreds were fished in addition to large numbers of Meganyctiphanes norvegica at 40–60 fms. in the Cumbrae Deep.

The swimming and burrowing habits of four species of the genus Bathyporeia have been examined and shown to be alike, and similar to B. robertsoni as described by Schellenberg.

Swimming is effected by the pleopods working in a metachronal rhythm, drawing water along a ventral groove formed by the coxal plates of the second peraeopods and the expanded bases of peraeopods 3, 4 and 5.

The main water current enters anteriorly between the second gnathopods and is filtered by a series of feathered bristles borne on the basis of this appendage; a subsidiary current enters between the second and third peraeopods.

Burrowing is effected mainly by the sweeping action of the second gnathopods and first two pairs of peraeopods, aided by the first and second uropods as soon as they can obtain a purchase on the sand. The adaptation of these three pairs of appendages to burrowing is explained.

Although cadmium concentrations of unpolluted sea water are low, ranging from 0.01 to 0.41 µg/1 (Goldberg, 1965; Preston, 1973; Chester & Stoner, 1974; Kremling & Petersen, 1977) concentrations in estuaries are from 10 to 100 times higher, as reported by Butterworth, Lester & Nickless (1972) for the Severn and Eustace (1974) for the Derwent estuaries. Unusually high cadmium concentrations of 50 µg/1 have been found by Chan, Cheung & Li (1974) in Hong Kong harbour water. The cadmium in the drinking water (225 µ/l) and the food (rice) of Japanese farmers is believed to have caused the ‘itai-itai’ disease (Kobayashi, 1971), a pathological syndrome characterized by kidney damage with bone disease.

The anthozoan Actinostella flosculifera, the polychaete Lygdamis wirtzi, the decapods Gnathophyllum americanum and Periclimenes platalea, the phoronid Phoronis australis, the holothurian Euapta lappa, and the asteroid Goniaster tesselatus are recorded from São Tomé Island for the first time. The marine zoogeography of the area is briefly discussed, with special emphasis on the high proportion of amphi-Atlantic species.

The results of a short investigation of the population of ormers (Haliotis tuberculata) are described and discussed. The average number of ormers found by diving between 0–5 fm. below low tide was 2·4 per m2. The catches were measured, but no separation of year-groups was found.

To elucidate the sulphur sources for chemoautotrophy by the symbiotic bacteria of a vestimentiferan tubeworm, Lamellibrachia satsuma, living in Kagoshima Bay at depths of 80–100 m, we analysed the sulphur isotopic ratios of the animal tissues and compared them with environmental sulphur species collected in the field. Animals that had been maintained in an aquarium for over a year and supplied a known sulphur source were also investigated. The gas emitted from volcanic source in Kagoshima Bay contained rather heavy sulphide (+12·7 to +22·9‰ δ34S) compared with deep-sea hydrothermal vent systems (0 to +5‰). The tissue of the tubeworms contained very light sulphide (−21·5 to −25·9‰). It is inferred from the analysis of the aquarium-maintained specimens that the fractionation by the tubeworm or its symbiont was <1·5‰. The sulphur source assimilated by the tubeworms in the field is therefore inferred to have δ ratio −19·1 to −24·6‰. This means that only 9·7 to 25·0% of the sulphur in the worm tissues can be derived from the volcanic gas and the rest must come from other sources, such as microbial activity in the bottom sediment.

The extrinsic nerves of the stomach of dogfish and skates regulate the frequency and amplitude of contraction by inhibition followed by rebounds. By contrast the nerves of the spiral intestine are excitatory.

Stimulation of the vagus nerve of the ray produced slight reduction in the amplitude of spontaneous contractions of the cardiac stomach. Much greater inhibition was produced by stimulation of the sympathetic nerves and was followed by large rebound contractions. These effects were imitated by adrenalin and serotonin which altered the frequency and amplitude of contraction in various ways. These actions were not blocked by either propranalol (1–5 × 10−5 M) or phentolamine (2 × 10−5 M) and indeed were often increased. The excitatory response to adrenalin was not blocked by TTX even after this had blocked the response to the nerve. Responses both to the nerve and adrenaline were blocked by trazodone. Acetyl choline caused some contraction of the stomach but only at high concentration.

Muscles of the spiral intestine of Raja or Scyliorhinus were activated by stimulation of their sympathetic nerves and by adrenalin. These responses were not blocked by phentolamine and only reduced by propranalol They were blocked by trazodone. The response to adrenalin continued after the nerve was blocked by TTX. Acetyl choline had very little effect on the spiral intestine.

The striking differences between the responses of the stomach and intestine are probably related to the fact that the plexus in the latter contains no nerve cells. The neurons in the stomach are therefore presumbly connected with the inhibition and large rebound contractions.

The observations recorded form preliminary studies which it is hoped will be useful in special investigations on the physiology of shell-depositions in oysters. The distribution of chalky shell-deposits on the internal faces of the valves in young and old O. edulis and O. angulata has been studied, and its average distribution determined in shells of O. edulis of jnedium age from West Mersea and the Fal Estuary.

The distribution of this material in the shells of young O. edulis and in O. angulata is such that there can be little doubt that the function of the chalky deposit is to fill in rapidly grooves, hollows, and other spaces, which are inimical to efficient functioning in the changing needs of the individual.

In O. edulis of medium age large deposits occur regularly in the shell adjacent to the exhalent chamber and smaller ones on the border of the shell in the region of the inhalent chamber. The hypothesis is advanced that these regular deposits can be explained in the same way as those more easily understood by assuming that in a high percentage of shells of medium age, the contour of the shell in the region of the exhalent chamber and other parts is such that rapid extension and contraction of the mantle cannot be effected; deposition of chalky shell-material modifies this contour of the shell with certainty in some cases, but hypothetically in others, so that the mantle can be extended and retracted with a maximum of efficiency.

Several strains of Stichococcus bacillaris Naeg. and of the marine S. cylindricus Butcher were all found to fit morphologically in Naegeli's species. Both the marine and non-marine strains grow well in either fresh- or sea-water media. S. cylindricus must therefore be regarded as a synonym of S. bacillaris. Three marine Chlorella strains including C. ovalis Butcher and C. stigmatophora Butcher were also found to be quite unexacting about salinity. The significance of small differences, particularly of growth rate, is discussed with regard to non-sexual organisms. In general, widely based species are advocated for such organisms, with the clonal lines, where appropriate, designated by the reference number of a recognized culture collection.

Oval squid Sepioteuthis lessoniana hatchlings originated from maternally identical egg strings were incubated under constant temperature and examined with special reference to statolith formation. Statoliths of a hatchling already had an adult-like shape, and some increments were observed. In spite of the maternally identical origin and constant incubation temperature (25°C), dorsal mantle length and statolith length of the hatchlings varied from 4.70 to 6.26 mm and 320 to 410 μm, respectively (N=14). These variations had a positive correlation with the embryonic duration ranging from 22 to 27 d, which means that the size of body and statolith becomes larger in hatchlings hatching later.

In an earlier study Pingree, Pennycuick & Battin (1975) used a diffusion model to study the monthly temperature distribution and heat exchange in the English Channel. This showed that the diffusion would have to be adjusted according to the tidal ellipses for an improvement in the predicted temperature distributions, and that advection was probably an important factor at certain times of year. An attempt to use the same model for prediction of the salinity distributions was unsuccessful due partly to lack of information on run-off, precipitation and evaporation. The present study is an attempt to provide an overall monthly mean heat and salt budget for the eastern English Channel and Southern Bight of the North Sea which could serve as a preliminary to a two-dimensional mixing/advection model in which the horizontal eddy diffusion is represented as a tensor based on the tidal ellipse properties (Hunter, 1975).

First observations on reproduction of Neorossia caroli from the southern Sardinian sea are reported, based on the analyses of an egg clutch and specimens collected by bottom trawl on sandy and muddy grounds. The egg clutch, consisting of 13 white eggs of 9 mm length with embryos at an advanced developmental stage, was found at 1200 m depth, attached to a piece of hard substrate. Adult specimens were collected in a depth range between 400 and 1600 metres. DNA sequences indicated that embryos, spermatangia and adults belonged to the same species, the carol bobtail squid, N. caroli. Fecundity analysis made on 40 females showed a variable number of eggs (20–611) in the ovaries, with the combined presence of advanced and developing oocytes, and few smooth eggs ready to be spawned in the oviducts of mature females. Several sperm reservoirs (spermatangia) were embedded in the mantle of some of the females, in the anterior ventral area overlying the oviduct.

The spiny dogfish Squalus acanthias is widely distributed in Atlanto-Mediterranean regions, being captured off the Languedocian coast (southern France, northern Mediterranean), despite a decline of landings. The male and female sexually matured between 635–700 mm and 860–880 mm total length (TL), respectively. The largest male and female were 800 mm and 1110 mm TL, respectively and weighed 2220 g and 8900 g, respectively. There was a significant relationship for total mass versus TL, and liver mass versus TL between males and females. The diameter of the largest yolky oocytes ranged between 43 and 47 mm (mean 45.08 ± 0.98), while the mass ranged between 29.5 and 37.4 g (mean 31.79 ± 2.20). Near- term embryos ranged from 245 to 271 mm TL (mean: 258.85 ± 7.28) and weighed from 47.5 to 55.9 g (mean 53.35 ± 2.26). Ovarian fecundity ranged from 6 to 15 (mean = 10.38 ± 2.66). Uterine fecundity or litter size ranged from 4 to 12 (mean = 8.15 ± 2.07). Both fecundities showed a positive relationship with TL of females. A chemical balance of development based on mean dry masses of yolky oocytes and near-term embryos was 0.87 and suggested that S. acanthias is a pure lecithotrophic species. Hepatosomatic index (HSI) and gonadosomatic index (GSI) significantly increased with size in both males and females. HSI reached the highest values in both sub-adult and adult specimens, reflecting the role of the liver in the gonadal production as well as in buoyancy, while in the GSI the highest values were observed in pregnant females. Vitellogenesis proceeds in parallel with embryonic development. Near-term females were captured in different months of the year while a short period of resting could not be excluded between parturition and the beginning of a new pregnancy, so it appears difficult to delineate the length of gestation. However, a reproductive cycle with a wide range from 18 to 24 months remains a suitable hypothesis.

The occurrence of most species is linked to the distribution of specific combinations of environmental variables that define their occupied niche. As a result, the relationship between environmental variables and species occurrence can be used to model species distribution. However, when collecting data to construct such models, it is preferable to ensure that the survey coverage is representative of all available habitat combinations within the area as a whole to ensure that the model does not under- or over-estimate the actual species distribution. By using multi-variate statistical techniques, a habitat representativeness score (HRS) can be calculated to provide an objective assessment of whether a specific survey coverage will collect (or has collected) data that are representative of all available habitat variable combinations in an area. To demonstrate this approach, HRSs calculated using principal component analysis were used to assess the minimum number of evenly-spaced parallel north–south surveys required to adequately survey two study areas with differing levels of environmental heterogeneity for all available combinations of four habitat variables. For the more environmentally homogeneous study area, the HRS suggests that for this survey design a minimum of five evenly-spaced parallel transects, covering around 5% of the study area, would be required to obtain representative survey coverage for these four variables. However, for the more heterogeneous study area, at least eight evenly-spaced parallel transects, covering around 9% of the study area, would be required. Therefore, for a given survey design, more survey effort is required to obtain a representative survey coverage when the survey area is more variable. In both cases, conducting fewer surveys than these minimum values would produce an unrepresentative data set and this could potentially lead to the production of species distribution models that do not accurately reflect the true species distribution.

The ontogeny of evasive behaviours was examined in Atlantic menhaden (Brevoortia tyrannus, Clupeidae) and bay anchovy (Anchoa mitchilli, Engraulidae), with supplemental data for scaled sardine (Harengula jaguana, Clupeidae). Predicted relationships between ecology and behavioural ontogeny were tested using the different patterns of inshore vs offshore habitat utilization displayed by these species. In two of the species, menhaden and anchovy, the roles of vision, mechanoreception, and audition in evasive behaviours were examined ontogenetically and compared to the morphological development of these sensory systems. Anchovy early larvae were more responsive to a predatory stimulus than were menhaden; sardine early larvae were intermediate in responsiveness. By the end of the larval period most individuals tested in all three species responded. These results matched the pattern predicted by larval habitat. Ontogenetic trends in reactive distance did not match predictions based on habitat for these species but instead appeared to be more dependent upon changes in sensory morphology. In menhaden, ontogenetic changes in responsiveness were more dependent upon neuromast proliferation and cephalic lateral-line canal formation, while in anchovy these behavioural changes were more dependent upon ontogeny of the retina. Auditory stimuli were not implicated for either menhaden or anchovy in responding to the stimulus used.