The capture of a remarkable viviparous deep-sea jellyfish, Stygiomedusa fabulosa, has already been reported (Russell, 1959). We have now had an opportunity of making a more detaileexamination of the specimen, which has been added to the collection of the British Museum as the type specimen under the catalogue number B.M. 1960.4.7.1.

A survey of benthic communities found in a heavily fished scallop ground was undertaken in July 1993. Two main faunal assemblages were identified from samples obtained with fine-meshed scallop dredges, which were grouped either in gravelly sand sediments or sandy sediment, which was generally furthest offshore in deeper water. A third assemblage was found in either sandy or gravelly muddy sand sediments. The highest abundance of small and large size-classes of scallops were associated with the assemblage containing the greatest number of species and individuals in sandy sediments. This assemblage had the greatest biomass of emergent fauna such as hydroids and Alcyonium digitatum. Data acquired from a RoxAnn™ acoustic signal processor were able to differentiate between the substratum or biotopes associated with the greatest abundance of scallops. This may provide a useful tool for refining surveys of commercial stocks or mapping suitable habitats.

The mobility and quantity of retinula cell proximal screening pigment, and the liability of the eyes to light-induced damage, were investigated in the Norway lobster, Nephrops norvegicus (L.), obtained from three separate populations from depths of 18, 75, and 135 m.

During the morning after capture, the migration of the proximal pigment in response to the onset of illumination below the threshold for damage varied between the three populations. In the eyes of deep water N. norvegicus, the proximal screening pigment was located close to or below the basement membrane when dark-adapted and rose to a position midway up the rhabdoms when light-adapted. In the dark-adapted N. norvegicus from shallow water the proximal pigment was located more distally than in eyes of deep water animals. After the onset of illumination, the pigment migrated distally to completely cover the rhabdoms. The amount of retinula cell proximal screening pigment was found to decrease linearly with depth.

When dark-adapted individuals from each depth were exposed to light a positive correlation was obtained between the photon fluence rate (PER) and the proportion of the retina damaged. For a given light exposure the amount of damage was highest in animals from deeper water. The PFR causing 25% damage was approximately 1 log unit higher in animals from 18 m compared to those from 135 m.

The amount of damage varied with the delay between capture of the animals and exposure to light. When exposed 2 h after capture significant differences between depths were seen but the results were influenced by the incomplete dark adaptation of some specimens.

The common phenomenon of sublethal predation in soft-bottom bivalves usually involves nipping of siphons. Here we show that foot cropping, hitherto documented only in Donax spp., is widespread in the New Zealand cockle Austrovenus stutchburyi (Veneridae). Depending on the locality, cropping frequency ranged between 14 and 34% of cockles, and the average proportion of the foot area cropped ranged between nine and 21%. Estimates of biomass lost to croppers at the time of sampling varied between 235 and 2040 mg ww m−2. It is emphasized that foot cropping in Austrovenus is likely to affect the population dynamics of the cockles.

The relationships between phytoplankton pigments, optical properties and photosynthetic parameters for different phytoplankton functional types (derived by diagnostic pigment indices, DPI) were determined from data acquired in the Benguela ecosystem and the offshore region in October 2002. We observed robust inter-pigment relationships: total chlorophyll-a (TChla) was highly correlated with total pigment (TP) and accessory pigment (AP). However, the regression equations for stations dominated by flagellates differed from the equations for stations dominated by diatoms and dinoflagellates. The pigment ratio TChla/TP and the optical ratio a676/a440 were not constant but increased non-linearly with increasing TChla or TP; complimentarily the AP/TP and a490/a676 ratios decreased. There were significant non linear relationships between the photosynthetic parameters Fv/Fm or σPSII measured by Fast Repetition Rate Fluorometry and TChla or TP. Pigment ratios, optical ratios, Fv/Fm and σPSII were all inter-correlated with high significance. We determined the distinctive bio-optical properties associated with dominant phytoplankton functional types (derived by DPI) that conformed to the classical partitioning: flagellates (nano-plankton, comprising several taxa) had low biomass,low TChla/TP fraction and low Fv/Fm and high σPSII; diatoms and dinoflagellates (micro-plankton) had high biomass, pigment ratios, Fv/Fm and low σPSII.

Seasonal changes in the diet composition and trophic niche overlap were examined for the dominant members of the fish assemblage of the turbid low-salinity zone of the Scheldt estuary (Belgium). Samples of fish were taken in the cooling water of a power plant. Juveniles of eight species dominated the fish assemblage: two goby species, herring, sprat, bass, flounder, eel and pikeperch. Together, they had preyed upon 31 different prey taxa. Calanoid copepods and hyperbenthic mysids were the most important prey items with macrobenthic invertebrates being largely ignored. Pair-wise comparisons of trophic niche overlap showed that, in general, niche overlap between individuals of the same species was significantly higher than overlap between individuals from different species, suggesting that the available food resources were partitioned. The total annual prey consumption by the dominant fish species was estimated at 610 mg ash-free dry weight m−3.

This paper presents the first record of Ceratothoa steindachneri from Cornwall, making it the first resident species of the fish–parasitic isopod family Cymothoidae in Britain. The host is Echiichthys vipera (Trachinidae) the lesser weever fish, the isopod attaching to the host tongue. A complete redescription and reillustration for C. steindachneri is given, and a neotype is selected for the species Ceratothoa parallela. A key to the north-east Atlantic and Mediterranean species of Ceratothoa is included, with a brief illustrated account for each species.

A revision of the check-list of the red (Rhodophyta), green (Chlorophyta) and brown (Ochrophyta, Phaeophyceae) seaweeds of Britain has been compiled and revealed 644 taxa, mostly at species level but including infraspecific taxa: 348 reds, 110 greens and 186 browns. There were 30 additions to the list, notably five newly described species and five new non-native additions. In addition to the check-list, an updated list of non-native species was compiled based on a stringent review of the available evidence. We have listed 31 non-native species (~5% of the flora), although the numbers may be considerably higher and probably include species that are effectively naturalized and perceived to be part of the indigenous flora. The check-list is discussed in relation to the impact of molecular techniques on the identification, taxonomy and phylogeny of species, and points to the need for a comprehensive, in-depth study on the identity and relationships of the seaweeds of Britain.

This study evaluates the influence of man-made activities on the benthic environment at two different marinas: Southsea Marina on the south coast of England, and Minimes Marina on the Atlantic coast of France. We assessed the differences in: (1) sediment percentage organic matter, particle size and heavy metal concentration, using copper (Cu), cadmium (Cd), zinc (Zn) and lead (Pb) as contamination indicators; (2) sediment elutriate toxicity (LC50) using algal (Fucus serratus) bioassay; and (3) benthic community characteristics (number of species, abundance, most contributing species (SIMPER) and biotic index (AMBI)). Canonical correspondence analysis (CCA) was performed to relate the abundance of species to the environmental variables. At both marinas, we observed an increasing gradient of contamination from outside to the innermost sites. At both marinas, the lowest macrofaunal abundance was recorded at the innermost sites and differences in benthic community structure were observed between sites. At Southsea Marina, the cirratulids Tharyx marioni and T. killariensis and the cossurid Cossura pygodactylata dominated sites outside, while the opportunistic species Capitellides girardi dominated the innermost sites. At Minimes Marina, the cirratulid Streblospio shrubsolii was abundant outside and at the middle sites but was almost absent at the innermost sites. The biotic index—AMBI—indicated that sediments in the innermost sites were heavily disturbed at Southsea Marina and slightly to moderately disturbed at Minimes Marina. In Southsea, the AMBI was positively correlated to the sediment metal concentrations (Cu, Zn and Cd) and elutriate toxicity (LC50), while in Minimes the AMBI was positively correlated to the % of sediment fine particle and elutriate toxicity (LC50).

The predatory action of the pink shrimp (Farfantepenaeus brasiliensis and Farfantepenaeus paulensis) trawling fishery in south-western Brazil affects populations of some benthic species and Hepatus pudibundus is an abundant by-catch in this fishery. Individual growth and mortality of H. pudibundus were studied by taking monthly samples for a year from the by-catch of the pink shrimp fishery in the Ubatuba region. The von Bertalanffy growth model described growth of H. pudibundus (K=2.73 y-1, CW∞=82.97 mm; K=2.62 y-1, CW∞=66.72 mm, for males and females respectively). Modal progression of the monthly average sizes was related to increasing values of relative condition index. The instantaneous coefficients of total, natural, and fishing mortality were: males, Z=7.62 y-1; M=1.80 y-1; F=5.83 y-1; females, Z=7.36 y-1; M=1.80 y-1; F=5.56 y-1. Length composition and mortality analysis suggest that H. pudibundus in the Ubatuba region might be overfished.

The ecdysteroids ecdysone (E), 20-hydroxyecdysone (20E) and ponasterone A (PoA) were measured in the haemolymph, hepatopancreas and oocytes of female shore crabs Carcinus maenas during the moulting cycle and during oocyte maturation using HPLC-MS. In the haemolymph, ecdysteroid titres varied over the moulting cycle with high levels during premoult and low levels during postmoult and intermoult, however, no significant change in haemolymph ecdysteroid titres was observed in relation to oocyte development. In the hepatopancreas, PoA levels were high during premoult but low during postmoult and intermoult. This is in contrast to E and 20E where levels remained high from early intermoult (C1) until late premoult (D3) and only decreased during postmoult. In the oocytes, ecdysteroid levels were low during postmoult and for 20E and PoA also during late premoult D2 and D3. In contrast, all three ecdysteroids were observed to increase in the oocytes during oocyte development, in particular E and PoA. The present study demonstrates that changes in haemolymph ecdysteroid titres relate to changes in moulting status and not to changes in oocyte development. Also, the study indicates that the hepatopancreas is involved in the metabolism of ecdysteroids related to the moulting cycle but may also be involved in ecdysteroid metabolism during oocyte development. Furthermore, the pronounced increase in oocyte ecdysteroids during oocyte development during periods where haemolymph ecdysteroids titre is low, indicates that the oocytes are capable of de novo synthesis of the three ecdysteroids investigated.

Of a wide range of algae tested, juvenile Convoluta roscoffensis ingested only Platymonas convolutae, the natural symbiont; related species of the genera Platymonas, Prasinocladus and Tetraselmis; and Chlamydomonas coccoides. Platymonas convolutae was not ingested to a greater extent than Prasinocladus marinus, Tetraselmis tetrathele and Tetraselmis verrucosa, or taken up in preference to T. verrucosa when animals were exposed to a choice between the two species. Convoluta ingested fewer cells of C. coccoides than P. convolutae and related species. Uptake of P. convolutae was not affected by pretreatment of the cells with lectins or proteases, incubation in media of pH 5·0–9·0 or inhibition of algal photosynthesis, but was substantially reduced if the algae were killed.

Cells of P. convolutae, Pr. marinus, T. tetrathele and T. verrucosa persisted and divided in juvenile Convoluta. The algal population in the worms started to increase 2–3 d after ingestion and within 15–20 d the animals were uniformly green. These algae formed a viable symbiosis with Convoluta and promoted the growth of the animals. In contrast, C. coccoides cells did not persist in Convoluta for more than 12–24 h a nd were probably disrupted.

P. convolutae cells lost their thecae within a few days of ingestion and before migration from the central to sub-epidermal region of the animal. Animal vacuoles surrounded recently ingested thecate algae. Structural studies of the adult symbiosis suggest that the algae were also intracellular and enclosed in vacuoles.

It is proposed that Convoluta discriminates against algae unrelated to P. convolutae on initial contact and in the central region of the host. The nature of the recognition mechanism(s) has not been established.

Electrical responses were obtained from the utriculus of the sprat (Sprattus sprattus L). during stimulation by bursts of oscillatory pressures ranging in frequency from 2·5 to 880 Hz and in amplitude from 0·12 to 220 N m−2 (28–93 dB above threshold). These responses had double the frequency of the stimulus and we argue that they were given by two major groups of utricular receptors, one group (decompression or d-receptors) responding to movements of the utricular floor away from the fenestra of the auditory bulla, the other group (compression or c-receptors) responding to movements of the utricular floor towards the fenestra. These groups were identified with oppositely oriented groups of utricular hair cells coupled mechanically by the rigid base on which they lie. Responses grew with increasing stimulus strength over a range of over 100 dB, the slope of the log-log relation decreasing with the larger stimuli. Above 40 Hz the delays between responses and mechanical displacements were very small and the amplitude of response depended only on the amplitude of displacement and not on frequency. Below 40 Hz the sensitivity declined more steeply with reduction of frequency than would be expected from the mechanical responses of the utricular floor. When stimulating frequencies were mixed the responses were not those expected on the hypothesis that different groups of receptors were excited by the different frequencies but those expected if all displacements of the utriculus towards or away from the fenestra from a rest position gave responses in either one or other of two major groups of receptors. The response to mixed frequency pressure waves was such that high peaks were exaggerated and information about polarity preserved. The response of the utriculus to the first cycle of a burst of sinusoidal pressure stimuli was usually larger than that to subsequent cycles.

The feeding habits and host specificities of the Pycnogonida are poorly known. These usually small, cryptically coloured animals are difficult to observe alive and are mostly collected fortuitously in gross samples taken from trawls and dredges. Any association between the pycnogonids and their food is disrupted in the trawl. Further, the possibility that some of the pycnogonids may have been captured in the water column rather than on the bottom cannot be ascertained from trawl and dredge samples. King (1973) lists only twelve records of pycnogonids actually seen browsing on food organisms. Most occur on hydroids and other cnidarians, and all are from benthic habitats. In more recent papers, Stock reports a pycnogonid seen on a brittle star in the Seychelles (1979), feeding preferences of pycnogonids on benthic cnidarians (1978), and an association between a pycnogonid and a starfish from the Philippines (1981).

Analyses of the relationship between the size and the number of eggs per female in various decapods, isopods, cumaceans and mysids were made by Jensen (1958) based upon personal research and information from available literature. Regression analyses indicated that the number of eggs per female is related to the cube of the body length.

The morphology of burrows constructed by the upogebiid mud shrimps Austinogebia narutensis and Upogebia issaeffi was studied using resin castings of burrows in situ on Mukaishima Island, Seto Inland Sea, Japan, where the two species occurred sympatrically. The burrow structure of both shrimps is a relatively simple Y-shaped pattern, which is typical of the family Upogebiidae. Total burrow length, and length and overall width of the U-shaped section of A. narutensis were greater than those of U. issaeffi, possibly because A. narutensis is the larger species. When the ratios of the burrow measurements to the mean burrow diameter were compared to exclude possible size effects, the burrows of A. narutensis had a wider and shallower U-shaped section than those of U. issaeffi. Because the casts were made where the two species occurred sympatrically, the differences in the burrow morphology were not due to the differences in environmental factors but to the difference in the shrimp species, whether they are adaptive or not.

Stolonica socialis (Hartmeyer) and Distomus variolosus Gaertner are two species of styelid ascidians with a capacity for budding and colony formation, found on both sides of the western end of the English Channel. Distomusoccurs immediately below the level of extreme low spring tides, commonly encrusting the sides of rocks and laminarian bases. Stolonica is more usually found by dredging in deeper water, on the upper sides of stones or gravel bottom. Their external appearance and general internal anatomy have been well described and beautifully illustrated in the monograph of Lacaze-Duthiers and Delage (1892), while the process of budding has been investigated by Selys-Longchamps (1917).

The commercially important chokka squid Loligo reynaudii occurring in South African waters is currently managed on a single-unit stock hypothesis. We tested this assumption through a spatial comparison of the morphology throughout the distributional range of the species. Forty-three morphometric characters were measured from 1079 chokka collected off the south coast of South Africa, the west coast of South Africa, and southern Angola. While no significant differences were found in the hard body parts, results from classification analysis showed that though all four types of morphometric attributes (soft body parts, beaks, statoliths, sucker rings) resulted in some separation, the most consistent separation of samples from the three regions was based on soft body part morphometric characters. On average, though dependent on the model, the overall correct classification rate ranged from 0.68–0.99 for males and 0.7–0.99 for females in all three regions. Previous DNA analysis had revealed some genetic differences between west coast and south coast samples, suggesting the confluence of the cold Benguela and warm Agulhas current may act as the approximate point of a phenotypic and possible genetic breakpoint. Finer scale genetic analysis of samples collected across the Benguela–Agulhas confluence reported no significant genetic structuring in this area suggesting environmental heterogeneity and not restriction of genetic flow/isolation as the primary driver of the observed phenotypic divergence.

The exact form of the taxonomic relationship between the common or blue mussel, Mytilus edulis L., and Mytilus galloprovincialis Lmk, the Mediterranean mussel, has been the subject of considerable scientific interest in recent years (for a review see Gosling, 1984). While the origins of this separation into two species rests with the original descriptions by Linnaeus and Lamarck (e.g. Soot-Ryen, 1955), interest was stimulated in recent times through the discovery by Hepper (1957) of an ‘unusual’ type of mussel at Padstow in Cornwall which, on the basis of morphological criteria, he identified as M. galloprovincialis (see also Lewis & Seed, 1969). This discovery was followed by a series of electrophoretic investigations providing evidence that the so-called ‘Padstow mussel’ exhibits genetic affinities with M. galloprovincialis from the Mediterranean (Ahmad & Beardmore, 1976; Skibinski, Ahmad & Beardmore, 1978; Skibinski, Cross & Ahmad, 1980). In her recent review paper on the systematic status of M. galloprovincialis in western Europe, Gosling (1984) considers information from morphological, cytological, immunological, electrophoretic and hybridization studies and concludes that M. galloprovincialis is a ‘form’ or ecotype of M. edulis.

Infanticide is considered a conspicuous expression of sexual conflict amongst mammals, including bottlenose dolphins. Although reported previously in this species, confirmed cases of infanticide and associated epimeletic behaviour are very rare and their socio-behavioural context remains poorly understood. Here, we provide evidence of epimeletic and infanticide behaviours in free-ranging bottlenose dolphins in Galicia, NW Spain. After describing the observed events, we include a complete description of the post-mortem examinations (where the carcasses were recovered) in order to confirm the cause of death. With evidences of blunt trauma in two of the presented cases, we confirm that the calves were intentionally killed by adult individuals. The aggressive interaction between adult individuals and the neonates together with the observed ante-mortem injuries bore a strong resemblance to the behaviours and traumatic injuries described in other cases of violent dolphin interactions in other parts of the world. The circumstances under which these infanticides occurred at our site fit the conditions proposed under the sexual selection hypothesis. The difficulties for researchers to observe this type of behaviour in the field and to find carcasses in good enough condition to determine the cause of death, emphasizes the importance of this type of study.