Larvae of Stenorhynchus seticornis were reared in the laboratory in a factorial experiment employing three temperatures (22, 25 and 28°C) and three salinities (30, 35 and 40‰) to determine the effects of these variables on the survival and duration of the larval stages. Larvae from five females were subdivided in six groups of 10 and reared in glass bowls containing 125 ml filtered and UV-irradiated seawater at different temperature–salinity combinations. Larvae were transferred daily to clean bowls with newly hatched Artemia nauplii, and the number of moults and mortality within each bowl was recorded. Complete larval development of S. seticornis occurred under all experimental conditions, except at temperature 28°C and salinity 35‰. Salinity affected percentage survival of the two zoeal stages, but not that of the megalopa. Survival of the second zoeal stage, the megalopa, and the complete development to the first crab was affected by temperature, with the greatest survival occurring at 25°C. Duration of the two zoeal stages, the megalopa, and development to the first crab stage showed a gradual reduction with increasing temperature. Development from hatching to the first crab stage required 17 to 31 days and was inversely related to temperature, averaging 26.9 days at 22°C, 21.0 days at 25°C and 19.7 days at 28°C. Salinity affected the duration of the first zoeal stage only.

Otoliths from the stomachs of 138 by-caught grey seals (Halichoerus grypus) from the west coast of Ireland were compared with otoliths from the stomachs of 364 commercially caught cod(Gadus morhua) to determine if there were any overlaps in type, number and size of prey that might be attributable to secondary ingestion. A total of 19 species/groups were common to both cod and seal stomachs accounting for 99·6% and 95·8% of the otoliths from cod and seal stomachs respectively. There were significant differences between the otolith/fish lengths of all six species/groups compared but there were overlaps in the size distributions. Analysis of the diet composition of the cod stomachs suggested that larger cod consumed mainly fish and smaller cod consumed mainly crustaceans. Cod and seals were utilizing the same fish prey but the seals were generally consuming larger fish. Overlaps between the size distributions of prey species/groups suggest that secondary ingestion was possible and should be considered in future seal diet studies.

Using depth-telemetering, sonic tags orally inserted into the stomachs of Gadus morhua (Pisces: Gadiformes) found over-wintering in Trinity Bay, Newfoundland, the movements of individual fish were observed as surface waters warmed in early spring. Physiological measurements (antifreeze protein levels in the blood) indicate that many cold-adapted, bay cod change their thermal regime at this time. Fish acclimatized to subzero water temperatures enter the newly-formed thermocline and become available to a cod trap fishery. Most sonically-tagged fish resided in 0–1°C waters along the shoreline. Tracking data confirmed indications from declining antifreeze protein levels that cold-adapted cod, having moved into shallow waters in early spring, do not return to deeper, subzero-temperature waters for any appreciable time. At night some cod swam pelagically near the surface. Fish moved at times in the same direction as the tidal current, but ground speeds were several times greater than current velocities. Nocturnal pelagic swimming was also observed during the summer when temperatures within the thermocline exceeded 10°C.

Based on material collected during oceanographic campaigns in the western Atlantic from 1958 to 2011, two species of primnoid octocorals belonging to the genus Callogorgia were identified: Callogorgia americana and Callogorgia arawak sp. nov. These species are described and illustrated herein and their geographic and bathymetric are given. This is the first record of the genus in the south-western Atlantic. Additionally, the elevation of C. americana americana and C. a. delta to species level is proposed, keeping Callogorgia gilberti, C. delta and C. americana as separate species.

Large-scale green tides of Ulva prolifera occur repeatedly in the Yellow Sea, and the microscopic propagules of U. prolifera play a critical role during the development of green tides. Ulva prolifera propagules and microalgae are both present in seawater and share similar niches, but their potential interactions are poorly understood. Nine species of microalgae were selected to study their interactions with the propagules of U. prolifera (gametes) in laboratory. The results showed that settlement of gametes could be inhibited by some microalgae, such as Alexandrium tamarense, Prorocentrum lima and Karenia mikimotoi, at the cell density of blooming (102–103 cells ml–1). Inversely, the germlings germinated from U. prolifera gametes had negative effects on the microalgae, the inhibition rate ranged from 28 to 66%. Our results demonstrated the complex interactions between microalgae and propagules of green algae, which may influence the formation of green tides and their ecological consequences in the Yellow Sea.

The Black Sea subspecies of the bottlenose dolphin (Tursiops truncatus ponticus) is threatened and has a small range. Its population structure is little known: it possibly includes a few local coastal populations. We assessed connectivity between coastal groupings in six localities along 800 km of the coastline based on records of photo-identified animals between 2004 and 2014. Abundance of these groupings, as estimated, ranged between 76 and 174 individually distinctive dolphins. In total, there were 350 identified individuals, of which 91 (26%) were resighted within the same areas. However, only three cases of individual movements between local coastal populations were recorded at the distances between 135 and 325 km. Therefore, despite the absence of physical barriers, the coastal Black Sea population is fragmented into numerous resident or locally migrating groupings with site fidelity. These local populations are loosely connected to each other with rare movements between them. This fragmentation can be a factor contributing to short-term fluctuations in abundance of Black Sea bottlenose dolphins and their decline in some localities, despite the potentially high population growth rate.

Macrobenthic infauna was sampled in Mevagissey Bay, off the south coast of Cornwall, England, when the bay was receiving fine-grained mineral waste from the china clay industry at a rate of about 450000 tons per annum. Quintuplicate 0·1 m2 grab samples, washed on a 0·5 mm mesh, were taken on 15 occasions over two years at a station about 1 km from the outfall and at a water depth of 13 m. The fauna had a range of density of 755–2144 individuals/0–5 m2 and in composition resembled a partially impoverished Echinocardium cordatum/Amphiurafiliformis community. Population densities of Goniada maculata (Polychaeta), Cingula semicostata (Gastropoda), Nucula turgida, Mysella bidentata, Venus striatula and Tellina fabula (Bivalvia) showed no clear trends during the two years' sampling. Magelona filiformis (Polychaeta), Abra alba and Phaxas pellucidus (Bivalvia), Acrocnida brachiata and Amphiura filiformis (Ophiuroidea) declined in abundance, whereas the densities of Nephtys hombergi (Polychaeta) and Labidoplax digitata (Holothurioidea) increased. L. digitata became the commonest species, with a peak density of 708 individuals/0·5 m2. A month after sampling began the rate of waste discharged was reduced from 700000 tons per annum, but this did not appear to improve conditions for the benthic community. Total faunal density remained relatively stable but species diversity declined. It is argued that the suspended solid concentration was unlikely to have adversely affected the predominantly deposit-feeding community, but that persistent sediment instability continued to be a source of stress. Nevertheless, the observed major changes of community structure were similar to natural fluctuations of coastal soft-bottom populations resulting from species interactions and differences of larval success.

Earlier descriptions showed that the community of appendicularians off the British coast was mainly composed of Oikopleura dioica (Appendicularia; Müller, 1846) and Fritillaria borealis (Appendicularia; Lohmann, 1896), rarely by Oikopleura fusiformis (Appendicularia; Fol, 1872) and Fritillaria pellucida (Appendicularia; Quoy & Gaimard, 1833) and exceptionally by Oikopleura longicauda (Appendicularia; Vogt, 1854). Based on weekly samples collected during 1989 at a single station off the coast of Plymouth, we describe the first complete seasonal cycle of appendicularians in this area. The results suggest that rather than being occasional visitors, O. fusiformis, F. pellucida and O. longicauda are consistently present and abundant from mid to late summer. Moreover, the seasonal shifts in structure of the community of appendicularians in the area, as depicted by multivariate analysis, are consistent with those of the more southerly central Cantabrian coast (Spain). This suggests that they are viable populations rather than occasional expatriates from other areas.

In this study randomly amplified polymorphic DNA (RAPD) fingerprinting is proposed for species identification of Gammarus, based on the electrophoretic position of amplified DNA bands. Three common marine amphipods of European estuaries—G. chevreuxi, G. insensibilis and G. locusta—were profiled using ten RAPD primers, accompanied by a careful morphological identification. Nine of these primers produced a very distinct species-specific RAPD profile, allowing unambiguous differentiation of amphipod species assayed. The RAPD fingerprints were here characterized by 8–12 amplicons for each primer. Each amplicon was visualized as a band of known molecular length, with characteristic band thickness and density. A total of 78 diagnostic bands, based on the most robust and evident amplicons found for each primer and species, are proposed for identification of the Gammarus species analysed. These results allowed us to identify an unknown amphipod species from a previous study as G. insensibilis, only based on the RAPD fingerprint. One primer was sufficient for this identification. A taxonomic identification system integrating molecular and morphological tools is proposed for Gammarus.

Detailed molecular data of Artemia (Crustacea, Anostraca) from South Africa are scarce. Here, we provide for the first time genetic data on the species status and phylogeography of Artemia from this region after an extensive sampling expedition. Our 16S rRNA RFLP analysis of 27 Artemia populations, including seven from South African sites, provides evidence for the presence of a mixed bisexual and parthenogenetic component in this area. Phylogenetic and network analyses reveal that three (out of seven) Artemia populations from South Africa belong to the invasive A. franciscana, two of them belong to A. salina while the last two contain both parthenogenetic and bisexual (A. salina) individuals. From a total of 18 haplotypes identified, seven were recorded from South Africa. To our knowledge, this is the first confirmed report of A. franciscana in this region. Its invasiveness is reaffirmed by evidence for the complete replacement of the native A. salina population from Velddrif Saltworks. However, in other cases, parthenogens seem to modify the capacity of A. franciscana to replace natives. Results on the genetic identification of South African Artemia provide insights into the dynamics of invasion and co-occurrence and highlight effects on species interactions and on biodiversity in inland aquatic invertebrates.

The ctenostome bryozoan Alcyonidium diaphanum is widespread and abundant in the coastal waters of the British Isles. During the Centre for Environment, Fisheries and Aquaculture Science groundfish surveys some atypical colonies were found and subsequent histological and genetic analyses have shown that these represent two previously undescribed species of erect subtidal Alcyonidium. They are described here fully and named Alcyonidium condylocinereum and Alcyonidium hydrocoalitum. Comparisons with further museum specimens of erect Alcyonidium species have shown that A. proliferans, A. topsenti and A. gelatinosum form lacourti can be synonymized with A. diaphanum. The northern and southern limits of A. diaphanum are here more clearly defined; however, the identities of Arctic erect Alcyonidium species have yet to be fully investigated using histological and genetic methodologies. It is clear from this study that gross colony morphology is not a good indicator of species identity, but that tentacle number and reproductive mode can be useful taxonomic characteristics in these species.

Determinations have been made, by neutron activation analysis, of the concentrations of tantalum in the tissues of some common crustaceans, molluscs, echinoderms and tunicates of coastal waters of southern England. The concentrations ranged from less than 0·01 ppm dry weight in the muscle of Mytilus edulis to 2 ppm dry weight in Neomysis integer. Two ascidian species showed concentrations of about 0·2 ppm dry weight in the whole organism. The measurements support the generalised concentration factors which have previously been assumed in assessing the radiobiological significance of discharges of radioactive tantalum to the marine environment.

The surface-swimming duration of basking sharks (Cetorhinus maximus) was determined in the western English Channel from May to July over a five-year period. Surface duration showed marked variation from 0·17 to 1·45 h over the short time period from late May to mid-June. Stepwise multiple regression was used to identify any relationships between surface-swimming duration and time of day, daily sea surface temperature (SST), and zooplankton density. There was no support for any effects of SST or two measures of zooplankton density (median and maximum densities). However, there were significant relationships for surface duration with time of day and minimum zooplankton density (r2=0·50) indicating basking sharks respond to the abundance of prey and its temporal availability. This suggests that the probability of sighting sharks at the surface will vary depending on the diel period and the surface abundance of zooplankton.

This short note describes the in situ activity cycles of Galathea squamifera and G. strigosa (Crustacea: Decapoda) through SCUBA diving observations in south-west Ireland. Both species exhibited nocturnal activity peaks, although they were not exclusively nocturnal. Fluctuating tidal current strength and direction had no discernible influence on either species’ activity cycles. It is suggested that shelters, particularly in terms of both predator avoidance and as foraging areas, play an important role in the ecology of both species.

Both the anomuran decapod crustaceans Galathea squamifera Leach and G. strigosa (L.) are widespread throughout the rocky subtidal of the north-west European coastline. In contrast to the general body morphology and the structure of the mouthparts which have been well studied (Nicol, 1932; Pike, 1947), the biology and ecology of the genus Galathea remains poorly studied. These morphological studies have shown that the mouthparts are ill-adapted to living on muddy substrates, essentially restricting the distribution of both G. squamifera and G. strigosa to rocky areas, where their food is obtained by detrital deposit feeding and scavenging. Turner & Warman (1991) have studied the activity patterns of the genus Galathea at Lough Hyne, southwest Ireland and concluded that the genus exhibits nocturnal activity peaks. However, the different species were not distinguished, nor was the potential effect of the aberrant tidal patterns in the area considered. As at least three species (G. squamifera, G. strigosa, G. intermedia) are known to occur at the study site (Holmes, 1985), the present study was initiated to elucidate the activity cycles at a species-specific level.

The expected allometry between the linear cirral length and animal volume or weight for isometry should be 0·33; similarly the rate of beating, db/dt, might also be expected to increase as −0·33 with volume. The average allometry index of cirral length is less in both Balanus balanoides (0·22–0·23) and in Elminius modestus (0·27–0·32). The segment numbers also rise less than expected.

The rate of beat in Balanus balanoides correlates well with size (-0·28) and with temperature with a correlation coefficient of 0·898, significant for both variables. For a group of 11 species the relation between maximum rate of beating and size over 5 decades gives an approximate allometry of −0·24 which is also less than the expected −0·33 for an isometric linear appendage moving at constant velocity. It is suggested that the approximately reciprocal allometry index between cirral beating rate (−0·28) and cirral length (+0·22) may be mutually compensating, resulting in the cirri moving through the water at a constant rate during the growth of the animal. This rate may maximise the chance of prey being captured.

The three common blennies of Plymouth are the Shanny, Blennius pholis, the Gattorugine Blenny, Blennius gattorugine, and the Butterfly Blenny, Blennius ocellaris. These have their habitat from just below high-water mark downwards. Thus, B. pholis inhabits the rocky pools from near high-water mark to the regions left dry by the tides; B. gattorugine is also to be found between tide-marks, but not so high up as B. pholis, and is more frequent in those parts uncovered by the spring tides; whereas B. ocellaris inhabits the deeper water and is always covered by the tide; it is frequently to be found on the dredging grounds in the region of the Mewstone and beyond the Breakwater.

In the course of dredging for the rich epifauna of the continental slope near 48° 30′N., 10° W. (Southward & Southward, 1958b) in May 1957, several hauls were made by chance on a muddy bottom at 500–700 fin. depth. At the time, these hauls were examined only cursorily after sieving, and the con-tents immediately preserved. One of the hauls contained several damaged siliceous sponges, and a recent careful examination disclosed a number of pogonophore tubes entangled among the threads and spicules of the sponges.

During the autumn of 1954 plankton samples were taken in the northern Irish Sea and the North Channel from R.V. Clupea (Scottish Home Department) as part of a larger survey of the distribution of herring larvae. At the same period similar samples were taken in the central Irish Sea from R. V. William Herdman (Marine Biological Station, Port Erin). The present paper concerns the distribution, as shown by both sets of samples, of a few selected species.

I am indebted to all those on both vessels who assisted in taking the samples and to the Marine Laboratory, Aberdeen, for lending me for analysis the samples taken from R.V. Clupea.

Temperatures and salinity, phosphate, total phosphorus and silicate analyses of water from the International Hydrographic Station E1 during 1955 are discussed. The seasonal variation is shown, and it appears that consumption of nutrients by plants in the spring was: phosphate 0·42 μg atom P/L, ‘total phosphorus’ 0·40 μg atom P/l., silicate 2·43 μg atom Si/1., these being means for the whole water column. Some irregularities are pointed out; they are probably attributable to changes in the water mass.

The ectoparasitic gastropod genus Cerithiopsis Forbes & Hanley, 1850 was nominally based on Murex tubercularis Montagu, 1803. We have used the DNA barcode COI sequences to assay sympatric samples of morphotypes recently described as distinct species of the Cerithiopsis tubercularis-complex. Our results demonstrated that, in the Croatian waters, the gastropods usually called C. tubercularis in fact comprise a complex of cryptic species, which can be reliably diagnosed only by examining the soft parts. In the present study we have demonstrated that the colour pattern of the head-foot is diagnostic at the species level in this complex and, coupled with genetic data, may provide a sounding base for a revision of the cerithiopsids of the European coasts.