In order to investigate the characteristic species and the relative importance of selected environmental conditions of rocky bottom communities in coastal waters and to estimate their richness, 27 sites in the Brest area were surveyed by diving. The abundances of underwater species, from a check-list of 115, were plotted as number of individuals or colonies in m2 or in percentage cover of the rock, against the environmental conditions (depth, bedrock slope, substrate type and sediment nature of the nearest soft bottom). Raw data were converted to biovolume expressed as mm3 m–2 and expressed as log 10 (x + 1).

Various correspondence analyses were applied to these data: the first included bedrock slope (lit/dark surfaces) and takes into account the four biological formations according to the depth. It shows zonation with depth and decreasing light as factor 1, hydrodynamic conditions (waves or current) as factor 2, mixing of estuarine and oceanic waters as factor 3 and turbidity as factor 4. Four species assemblages emerge from these four axes, for which the main species contributing to the four axes may be considered as characteristic species. These correspond well to four broad communities described in British waters: very exposed to wave-action, semi-exposed to wave-action, exposed to strong tidal current, very sheltered sites. The second analysis, in which lit and dark surfaces are distinguished, but some very close sites are fused together, shows in detail the photophilous or sciaphilous nature of the species. Values of hydrodynamic conditions and percentage of surface light plotted on the 'stations-points' of the graphs allow drawing of a factorial network which may be used as hydrodynamic and illumination scales.

In an earlier paper (Prandle, 1978b) estimates were made of the monthly-mean residual flows through the Dover Strait for the period 1949–72. This time series has proven to be of some interest to marine biologists (Colebrook, Reid & Coombs, 1978; Reid & Budd, 1979; Taylor et al. 1981). This short additional note extends this time series up to 1980 (Table 1).

Other model studies of wind forcing in this region have been published in recent years.

Organic production in the sea can be measured by studying the changes in phosphate throughout the water column. Results obtained by this method are compared with estimates of carbon uptake using 14C made on the Fladen Ground during 1955 and 1956. There is good general agreement between the two methods but some differences in the vertical distribution.

The results are also used to calculate filtering rates of phytoplankton and sinking rates of zooplankton, and to compare observed and predicted vertical distributions of chlorophyll.

During investigations into the endocrinology of Leander ( =Palaemon) serratus (Pennant) several differences in physiology (which will be reported in this Journal at a later date) have been found between the prawns from Plymouth and those from Roscoff on the north coast of France. These experiments involved the repeated handling and the close examination of about a thousand prawns from Roscoff and many more from Plymouth. Increasing familiarity with these animals led to the realization that the two samples could readily be distinguished by eye. It was not always possible to determine the provenance of a single individual in this way, but any group of five or six could be told at a glance. A detailed examination of the external morphology showed that the characteristic differences by which the provenance of these animals could be determined lay not in any anatomical feature but in the disposition and arrangement of the chromatophores which form the pattern on the dorsal side of the cephalothoracic shield and the anterior part of the abdomen. Great individual variations were to be seen, but differing trends of development of the patterns were found in the two populations. There was some degree of overlap between the populations, but only about 15% of the prawns lay in this region of overlap and thus failed to bear the marks of their locality; the remaining 85% could be assigned to either Roscoff or Plymouth with little difficulty. Recently I have been able to examine about forty prawns from Concarneau, on the Atlantic coast of France, and these again are mostly different from either of the other two samples.

This study provides a baseline describing natural small scale variability of Symbiodinium density in the sentinel coral Acropora globiceps during the summer, under non-bleaching conditions. Spatial scales investigated range from the colony scale (1–10 cm, i.e. among branches of the same colony) to the reef scale (1–10 km, i.e. among stations distributed over several locations and depths), at Moorea Island, French Polynesia. The coral–Symbiodinium symbiosis is a key process in scleractinian coral physiology, and Symbiodinium density provides an easy-to-measure and inexpensive biomarker of this symbiosis health. Spatial variability of three major environmental factors: light intensity, sedimentation and water motion was also assessed to evaluate their potential link with Symbiodinium density. Density of Symbiodinium did not significantly differ within colonies or among colonies within a station. However, a marked depth gradient was observed, showing increasing density with increasing depth and decreasing light intensity. These observations provide an interesting reference for forthcoming comparisons with disturbed conditions, such as bleaching events.

The digestive system of 36 paralarvae and 150 juvenile Dosidicus gigas were analysed to determine the diet. The early life stages were collected in the central and south region of the Gulf of California during different years and ranged in dorsal mantle length (ML) from 2.8 to 120.5 mm. The food content was separated first into identifiable material (IM) and non-identifiable material (NIM). All paralarvae contained only NIM stored mainly in the caecum rather than stomach. Juvenile squid feed on nine different prey types: euphausiids, copepods, amphipods, unidentified crustaceans, fishes, cephalopods, pteropods, bivalves and polychaetes. The IM were found mainly in the stomachs of juveniles with increasing number and diversity of prey in a function of increasing squid body size. In fact, juveniles from 60 to 120 mm ML had high stomach fullness percentages in half full and completely full stomachs suggesting improvement of swimming and hunting behaviour as they grow.

Digital image analysis was applied to quantify the degradation of muscle in sea bass Dicentrarchus labrax (Pisces: Moronidae) larvae. The measure obtained was the percentage muscle fibre separation (MFS). This measurement was compared to that obtained through classical scoring. The percentage MFS classified correctly a larger number of larvae from different feeding treatments (Fed, Starved and Delayed treatments) and paralleled nutritional condition, both by age and by size. It also yielded a significant correlation with the survival of the Starved larvae. The onset of the mass mortality of Starved larvae was used to define a critical value (Mmax) of 6% MFS which would severely handicap survival. We regard MFS as a useful contribution to the determination of condition in fish larvae. It is a relatively fast quantitative method, and its use would reduce the bias caused by discrete grading (scores) and by differences in individual expertise.

Calyptogena gallardoi is a vesicomyid bivalve inhabiting a methane seep area located at a depth of 740–870 m off the Bay of Concepción, Chile. Vesicomyids host chemoautotrophic sulphide-oxidizing endosymbiont bacteria and are always found associated to reducing environments. In this study, the gonadal structure and the gametes produced by C. gallardoi are described. Light microscopy is used to examine serial histological sections of the gonads, and scanning electron microscopy is used to visualize the external morphology of gametes. The gonads of both males and females are organized in ramified tubular acini. In males, mature sperm are stored near genital openings in acini lined with a secretor epithelium that resembles a seminal receptacle. Spermatozoids have bullet-like heads with an average length of 30.3±2.6 μm (mean±1 SD). In females, the mature oocytes are driven toward the genital opening through evacuator conduits lined by ‘paddle’ cilia. The average diameter of oogonias is 11.6±2.5 μm and that of mature oocytes is 273.8±23.1 μm, making the size of the mature oocyte among the largest reported for bivalves. In addition, C. gallardoi is shown to have external sexual dimorphism. Shells of males are significantly smaller and more elongated with sloping postero-dorsal margin compared with shells of females. The data are discussed in the context of available information on reproductive biology of vesicomyids.

Despite being an exploited and economically important species, little is known about the reproductive behaviour of Loligo forbesi. During a captive trial performed in a closed seawater system in the Azores, three spawning events were directly witnessed. An account of their main behavioural aspects is given. A number of behavioural components are described for the first time in this species: ‘pair formation’, ‘mate guarding’, ‘egg holding’, ‘egg touching’, ‘white arms’, ‘red accessory nidamental glands’, ‘accentuated testis’, and ‘jockeying and parrying’. The chromatic, locomotor and postural components were very similar to other coastal loliginids observed on spawning grounds. From egg masses recovered on octopus traps, we show that in the Azores spawning activity occurs at least between 25 and 144 m, but greater depths might be expected. We suggest that this squid preferentially deposits egg masses on hard structures probably hiding them in cracks and crevices of volcanic substrata. The existence of spawning aggregations is supported by several factors: (i) these spawning grounds may coincide with the fishing spots, where the exploitation seasonally takes place, given that most individuals caught by fishermen are usually mature (more than 80%); and (ii) mate guarding and jockeying/parrying by males was observed, which is a common feature of spawning aggregation areas, where sperm competition occurs. Furthermore, our results, combined with available published and non-published data further confirm L. forbesi as an intermittent spawner. We estimate that throughout their short life cycle, females of L. forbesi are able to perform up to six spawning events, each composed of an average of ≈2300 eggs.

The larval and post-larval behaviour, growth, colour, and morphology of the brown box crab (Lopholithodes foraminatus) are described for the first time based on laboratory reared animals. A detailed morphological description is provided for 4 zoeal stages, the glaucothoe, and the first crab instar. Selected morphological changes over the remainder of the first year of development are also described. Data are presented on larval growth at 11°C and on zoeal stage durations at approximately 8°C, 12°C and 16°C. While the 4 zoeal stages are planktotrophic, the glaucothoe does not feed; a life history character that has been termed ‘secondary lecithotrophy’. Growth of L. foraminatus larvae and post-larvae is generally similar to that of other North Pacific lithodids with planktotrophic zoeae. Zoeal stage durations decrease with increasing temperature. This relationship levels off at approximately 16°C, a higher temperature than in lithodid species from colder regions. Carapace morphology is suggested as a diagnostic character of larval and post-larval stages of Lopholithodes foraminatus. Secondary lecithotrophy may be widespread or even universal among lithodids and also occurs in pagurid hermit crabs. If the family Lithodidae is indeed nested within the Paguridae, as suggested by recent phylogenetic hypotheses based on molecular evidence, secondary lecithotrophy may be plesiomorphic in lithodids.

The tidal streams in the Channel Islands region are rotary anticlockwise. At spring tides anticlockwise Eulerian residual currents of about 20 cm s–1 develop around Guernsey which indicate that frictional effects exceed those due to the Earth's rotation in the generation of Eulerian residual currents in this shallow-water situation. Lagrangian anticlockwise residual currents can exceed 60 cm s–1 at spring tides, indicating that Stokes-induced currents are larger than the Eulerian residual currents around Guernsey. Remote sensing studies show anticlockwise-directed jets which also indicate an anti-clockwise circulation around the island. A tidal circulation pattern for the Channel Islands area is presented based on anticlockwise gyres around all the major topographic features in the region. This pattern off low is consistent with the formation of the well-known front between Guernsey and Jersey and the residual currents derived from a numerical model.

In the Colombian Caribbean Sea a shallow water commercial shrimp fishery has been developed, targeting mainly Farfantepenaeus notialis. Yet, similarly to so many fisheries around the world, the exploitation of this shrimp is not regulated, and a significant depletion has resulted. This study investigates new fishing areas, exploring the poorly understood deep-sea habitats in the Colombian Caribbean Sea, to determine the potential for a viable deep shrimp fishery, studying their abundance and spatial distribution. We found high abundances for giant red shrimp (Aristaeomorpha foliacea) and royal red shrimp (Pleoticus robustus), both important commercially. The higher biomass of these two deep-sea shrimp species were found mainly in the northern zone of the Colombian Caribbean Sea, where the local oceanography is modulated by the seasonal upwelling with high productivity. The size-structure following depth strata showed that A. foliacea increase in size with the depth and the contrary for P. robustus. The majority of adult individuals in these two deep-sea shrimp species reflect the non-fished populations in the study area. However, more scientific assessment is necessary to determine life cycle population parameters of deep-sea shrimps and associated biodiversity before initiating a new commercial shrimp fishery.

Distribution and structure of intertidal macrobenthic communities in the Zwin nature reserve, a lagoonal inlet consisting of marsh and tidal flat habitats, was investigated using univariate and multivariate analyses. Macrobenthos community structure was related to environmental characteristics and discussed in the framework of the implemented extension of the nature reserve.

Based on explorative multivariate techniques, five different sample groups (SGs) were distinguished, which were, in general, located in different habitats of the Zwin nature reserve. The ecologically most important SGs consisted of the highest macrobenthic density, diversity and highest densities of Nereis diversicolor and Scrobicularia plana; these important prey species for wading birds and fish occurred in the deep tidal inlet channels. This habitat was characterized by fine to medium sand sediment and strong tidal currents, guaranteeing water renewal at each high tide. Other SGs were found in less and erratically submersed and thus stressed areas (i.e. tidal pond, salt pans and shallow flats). These assemblages were characterized by typical r-strategists (i.e. Capitella capitata and Polydora cornuta) and typical supralittoral, mobile species (i.e. Orchestia gammarellus and Collembola spp.). Being ecologically most important, the extension of wide, tidal creeks should be a prime target within the future development and management of the nature reserve.

The humpback whale (Megaptera novaeangliae) population that uses Abrolhos Bank, off the east coast of Brazil as a breeding ground is increasing. To describe temporal changes in the relative abundance of humpback whales around Abrolhos, seven years (1998–2004) of whale count data were collected during July through to November. During one-hour-scans, observers determined group size within 9.3 km (5 n.m.) of a land-based observing station. A total of 930 scans, comprising 7996 sightings of adults and 2044 calves were analysed using generalized linear models that included variables for time of day, day of the season, years and two-way interactions as possible predictors. The pattern observed was the gradual build-up and decline in whale counts within seasons. Patterns and peaks of adult and calf counts varied among years. Although fluctuation was observed, there was generally an increasing trend in adult counts among years. Calf counts increased only in 2004. These fluctuations may have been caused by some environmental conditions in humpback whales' summering grounds and also by changes in spatial–temporal concentrations in Abrolhos Bank. The general pattern observed within the study area mirrored what was observed in the whole Abrolhos Bank. Knowledge of the consistency with which humpback whales use this important nursing area should prove beneficial for designing future monitoring programmes especially related to whale watching activities around Abrolhos Archipelago.

The wide variety of reproductive patterns and behaviour in the many species of Nereidae already studied clearly justifies further research. But the life history of Nereis fucata (Savigny) is not only of interest from the comparative point of view. Its commensal habit (it occurs within shells occupied by hermit crabs) immediately gives it a special importance. This alone warrants a detailed study, particularly as no commensal polychaete has yet been reared through to metamorphosis and settlement on its host (Davenport, 1955; Davenport & Hickok, 1957). The numerous interesting problems which arise, and the experimental methods needed to study them, are, however, beyond the range of a paper on nereid development. It is therefore proposed to confine the present account to the reproduction and development up to the time when the larvae settle on the bottom. The complete life cycle, the mechanism of host-adoption, and related topics, will be reported in later papers.

In spite of a specialized shell structure and an obligate coral-inhabiting mode of life, B. anglicum retains a generalized balanoid operculum, cirri and mouthparts. These are used to capture and ingest live planktonic prey such as nauplii. Prolonged cirral extension is a preliminary to prey capture but the capture process itself involves the beating down of the prey by a series of up to six contractions and extensions of the cirri in 7–10 s. The prey is then grasped by the extended third maxillipeds (cirrus III) and drawn into the mantle cavity. An antenniform exopod of cirrus I is extended and detects the prey at the beginning of the capture sequence. The exopods of cirrus I are also used in the rejection of any unwanted particles grasped and taken in by the third maxillipeds.

The number of non-indigenous aquatic species (NIS) has rapidly increased globally. The majority of published evidence on the effects of NIS on local communities is from single species studies in which the interactive effects of NIS are not considered. Here we present experimental evidence of separate and interactive effects of two widespread non-indigenous benthic predators, the round goby (Neogobius melanostomus) and the North American mud crab (Rhithropanopeus harrisii) on benthic invertebrate communities in a shallow coastal ecosystem of the Gulf of Riga, the Baltic Sea. The two species have recently colonized multiple sub-basins of the Baltic Sea and due to their rapid range expansion, increasing densities and local functional novelty, they are expected to have strong separate or interactive effects on native communities. Our laboratory experiment demonstrated that round goby and mud crab exerted a significant predation pressure on different benthic invertebrate species and the effects of the studied predators were largely independent. Predation was stronger at higher temperature compared with low temperature treatment. Among the studied invertebrate species gammarid amphipods were consumed the most. Interestingly, round goby did not prey on the mud crabs despite a large size difference of the studied predators.

Heterodontus portusjacksoni was obtained from the catches of commercial trawl, gillnet and longline fisheries operating in south-western Australian waters, in which this shark is an abundant bycatch species. Ninety per cent of the H. portusjacksoni caught by commercial trawling in a marine embayment were <400 mm in total length, whereas 99 and 100%, respectively, of the individuals taken by commercial gillnet and longline outside that embayment were >400 mm. Although the differences between the size compositions in the catches obtained by trawling vs both gillnetting and longlining, which were similar, are partly attributable to gear selectivity, they also reflect a use by juvenile H. portusjacksoni of protected nearshore waters as nursery areas and a tendency for larger juveniles and adults to occupy reef/rock habitats in a range of water depths. The fact that all but one of the numerous H. portusjacksoni >800 mm were females is reflected in the ratio of females to males differing significantly from parity in the gillnet and longline samples. Yolked oocytes usually take one year to develop to ovulatory size. Ovulation occurs in late winter to early summer and hatching takes place a year later when the embryo is 180–220 mm. The claspers of males commence rapid growth at a total length of ~450 mm, coincident with the onset of clasper calcification and gonadal maturation. The rate of clasper growth relative to total length reached a maximum at ~570 mm and then declined precipitously as the claspers approached full calcification. Based on gonadal criteria, the L50 at maturity for females (805 mm) was nearly 40% greater than that for males (593 mm). Values of the deviance information criterion and marked overlap in their 95% confidence intervals demonstrate that the L50 of 581 mm derived for males using full clasper calcification as the index of maturity was equally valid as the above L50 derived for males at maturity using gonadal criteria. The capture of substantial numbers of juveniles by trawling and of females <L50 at maturity by gillnetting and longlining may be having localized effects on the population structure of H. portusjacksoni in south-western Australian waters.

The present study reviews Perinereis Group 2 species from the Eastern and South-eastern Asian seas based on morphological analysis of the types, non-types and original descriptions, and the use of molecular evidence (COI and 16S rDNA) from newly collected material. These species are characterized by having two bar-shaped paragnaths on pharyngeal area VI, which are often deemed conical when small and pointed, triggering misidentifications as to Neanthes species. New terminology and definition for this particular type of bars are proposed, and the generic position of some resembling Neanthes species is also re-assessed. Five species are transferred to Perinereis: Perinereis babuzai comb. nov., P. belawanensis comb. nov., P. kinmenensis comb. nov., P. shigungensis comb. nov. and P. vitabunda comb. nov. ‘Perinereis aibuhitensis’ species group is newly proposed by encompassing species having proximal dorsal ligule similar throughout the body, dorsal cirri short, and blades of heterogomph falcigers straight with long terminal tooth forming a distinct tendon. Perinereis belawanensis comb. nov., P. linea and P. vitabunda comb. nov. are redescribed. Perinereis linea is regarded as a senior synonym of Nereis (Neanthes) orientalis and Perinereis vancaurica tetradentata based on type material, whereas its exotic status in the Mediterranean Sea is questioned. An identification key to all currently valid species within Perinereis Group 2 is also provided.

Brown crab contributes to small-scale fisheries in the Isle of Man and landings (495 t) were worth in excess of £0.5 million in 2012. The present study sought to fill evidence gaps needed to improve the scientific understanding of this fishery. Observer data were collected to examine the spatial and temporal variations in the size distribution and sex ratio of crabs around the Isle of Man. This study also aimed to evaluate the catch characteristics of brown crab using logbook data (2007–2012), observer data (2012–2013) and questionnaire survey data (2013). The sex ratio is highly variable in different areas across seasons and was perhaps indicative of migration patterns in relation to mating. This change was most notable with a strong increase in the proportion of females to the south and west of the Isle of Man in the autumn months. The depth and pot volume were important factors that influenced the catch per unit effort (CPUE). Future survey designs would need to ensure adequate spatial coverage of the east and west coast of the Isle of Man together with a seasonal sampling regime that captures the spatial change in the distribution and abundance of male and female crabs.