Sporelings of the marine red alga Plumaria elegans, grown under continuous illumination from a fluorescent tube, show a maximum rate of cell production at a light energy flux of 10 ergs/sec/mm2 in the range 380—720 mμ. This amount of light energy is low, but compares closely with that illuminating Plumaria in its natural habitat at Wembury during the period of the year when the plant is producing spores.

Benthic phases of aCricosphaera sp. (Plymouth Culture Collection no. 156), and of a coccolithophorid obtained from a filamentous plant found growing in the region of high-water mark at Borth, Cardiganshire, have been subjected to a variety of experimental conditions, and viability assessed in terms of their ability to release again the motile cells.

Survival of the benthic cells has been observed in a salinity range of 3–236% with liberation of coccolithophorids directly into the medium at salinities between 3–90 ‰ In the salinity range 90–207% liberation of coccolithophorids was observed on returning the benthic cells to 'normal' sea water after protracted periods of immersion in the media of higher salinities. Benthic cells were found to survive after slow evaporation of the medium and crystallization of the salt around them. Liberation of coccolithophorids has also been obtained after ageing of the culture (e.g. the motile cells have been obtained from an 11-month-old culture). Continued growth of coccolithophorids has been observed at salinities between 6‰. Continued formation of the benthic cells in media of high and low salt concentration resulted in a tendency for the release of coccolithophorids to occur over more restricted salinity ranges.

There is now considerable evidence that benzo[a]pyrene hydroxylase (aryl hydrocarbon hydroxylase: AHH) is involved in the metabolism of petroleum hydrocarbons by several species of marine fish (see review by Varanasi & Malins, 1977), as well as by certain species of marine invertebrates, including crabs and lobsters (Payne, 1977). Several workers (Payne & Penrose, 1975; Payne, 1976, 1977; Bend, James & Dansette, 1977) have found increased activities of this enzyme in fish previously exposed to petroleum hydrocarbons and related compounds: similar findings have been made in a study using two species of polychaete (Lee, Furlong & Singer, 1977 a). No evidence of such enhanced activity, however, has been found in experiments with crabs and lobsters (Payne, 1977).

In order to gain a general understanding of the problems of fish locomotion and appreciate them in an evolutionary context, it is important that we have information available on the kinematics, hydrodymamics and energetics of the swimming of as wide a range of fish as possible. At present, most of our knowledge of fish locomotion is restricted to the swimming of streamlined, pelagic and nektonic teleosts, capable of high speeds and accelerations, that are either neutrally buoyant or have a buoyancy close to neutral (see Lighthill (1969), Webb (1975), Bone (1975) for reviews).

The general biology of the gadoid fishes of the North Sea after recruitment to the demersal fisheries has received considerable attention, but little is known about their behaviour patterns during the period between metamorphosis and assumption of the demersal habit. In the summer of 1969 the Marine Laboratory, Aberdeen, began a series of annual midwater trawling surveys of the northern North Sea (Hislop, 1970, 1972a, b; Hislop & Bailey, 1971, 1975). During the surveys observations were also made on various aspects of the biology of the species caught. This paper describes the results of a series of trawling experiments carried out on a cruise of F.R.S. ‘Scarba’ (ex ‘Scotia’) between 12 and 29 August 1971.

Changes in four macrobenthic assemblages of the muddy-fine sand Abra alba community along the north-west French coast were compared using several numerical analyses (distogram, Eigen vector filtering, clustering and multi-dimensional scaling). The faunistic composition of these four assemblages continuously changed during the 1978–1992 period. These modifications are characterized by more or less rapid and abrupt successions of distinct groups of species, but the amplitude and the frequency of these changes are different between sites. Comparison of the results provided by different analyses also reveal that these four macrobenthic assemblages did not fluctuate in parallel, and that local conditions might play a key role on their temporal variations. However, it is shown that a major mesoscale climatic event, the alternation of mild and cold periods, probably also influenced the temporal variations of these four macrobenthic assemblages. Thus it is likely that there is a combination of both local and mesoscale events influencing these communities. In certain cases, changes in local conditions were the major source of variations. Sometimes the impact of the mesoscale conditions was more apparent, especially at the northern sites where the amplitude of the variations of temperature was greater.

The hydrothermal-vent barnacle Vulcanolepas osheai of the subfamily Neolepadinae is one of the most conspicuous organisms at the Brothers Caldera, south Kermadec Arc, New Zealand. Like a neolepad species found in the Lau Basin, V. osheai harbours filamentous bacteria on its elongated cirral setae. To define the phylogenetic affiliation of the epibiotic bacteria and the nutrition of the barnacle host, we conducted molecular phylogenetic and isotopic analyses. Analysis of 16S rRNA gene sequences of microbial communities on the cirral setae showed that among 91 bacterial sequences investigated, 28 sequences were related to the ɛ-proteobacterial endosymbiont of Alviniconcha aff. hessleri; 11 sequences were related to the epibiont of the bresiliid shrimp Rimicaris exoculata. Fluorescence in situ hybridization showed that in contrary to results from the 16S rRNA gene-sequence library, approximately 80% of the filamentous bacteria hybridized with a probe targeting the sequences related to the epibiont of the bresiliid shrimp R. exoculata. The fatty-acid profiles of the filamentous bacteria and the host barnacle both contained high levels of monounsaturated C16 and C18 fatty acids, and the carbon isotopic compositions of the biomass and monounsaturated C16 and C18 fatty acids of both the bacteria and barnacle were nearly identical. This would suggest that the nutrition of the barnacle is highly dependent on bacteria thriving around the barnacle, including the epibiotic bacteria.

The diet and feeding pattern of scyphomedusa Stomolophus meleagris (Rhizostomeae) was studied, by comparing stomach samples from different developmental stages and environmental zooplankton with the aim to determine diet composition, trophic niche breadth, selectivity and feeding overlap of this edible jellyfish species. Samplings were performed during April and December 2010 and in January 2011, in the coastal lagoon Las Guásimas (27°49′–27°54′N 110°40′–110°35′W), central Gulf of California, which consisted of zooplankton tows and jellyfish collections for stomach content. More than 39 prey items were identified in the gut contents (N = 69), from which eight taxa formed over 90% of the total. Fish eggs were considered main prey (58.6%), copepods (10.8%), veliger larvae of gastropod (13.0%) and bivalve (12.7%) were secondary prey while cirriped and decapod larvae were incidental prey (<3%). However, these proportions varied significantly between small, medium and large size classes of medusa as well as number and type of prey increasing as a function of medusa size. Values of Levin's index confirmed S. meleagris is a specialist predator and Pearre's index showed positive selection of fish eggs, gastropods, bivalves and cirripeds while selectivity was negative for copepods and appendicularians. The relative timing of these changes suggests that ontogenetic processes are closely related with shift in the diet, which indicates increasing predation pressure during development of the medusoid stage of this species, thus emphasizing their ecological importance in coastal ecosystems.

The diets of scaldfish Arnoglossus laterna, dab Limanda limanda, lemon sole Microstomus kitt, long rough dab Hippoglossoides platessoides, solenette Buglossidium luteum, thickback sole Microchirus variegatus, plaice Pleuronectes platessa, witch Glyptocephalus cynoglossus and Dover sole Solea solea in the Irish Sea were determined for March and October 1997 and 1998 and compared. Similarities in diets were examined using multivariate analyses. In general, there were differences in diet between species and generally the diets were similar within a species. Smaller individuals tended to have a similar diet. There were seasonal changes in the diets of individual species. Likewise, the overlap in diets between species changed between seasons and to a certain extent between sediment types.

During 1992–2002 approximately 110 strandings of minke whales Balaenoptera acutorostrata were recorded in Scotland (UK). Most strandings were recorded between April and November, with a peak of strandings of males in July and August. There were two length modes at 4–6 m and 7–10 m. Stomach contents samples were obtained from ten animals. The diet comprised mainly sandeels (Ammodytidae, around two-thirds of the diet by number or weight) and clupeids (herring Clupea harengus and sprat Sprattus sprattus). Results on diet are consistent with results from whaling catches in the North Sea. The possibility that minke whales compete with fisheries is discussed.

Stage V copepodites of Calarms finmarchicus collected from the Firth of Clyde during April–August 1978 and October 1979–January 1980 moulted to adults in the laboratory. The interval between capture and ecdysis was longer on average and less variable during the months July–November (when overwintering stocks build up in the Firth) than April–June. Overwintering Stage V copepodites moulted earlier in the laboratory than in the sea; this is not associated with differences in environmental factors known to affect developmental rate and may have been induced by stress associated with capture or handling. A similar induction of moulting is not evident in spring and summer generations.

The occurrence of imposex in Adelomelon brasiliana during two consecutive years near to Mar del Plata (the principal fishery port of Argentina) and its relation to tributyltin (TBT) and dibutyltin (DBT) content in muscle tissue and digestive gland was investigated using gas chromatography. Percentage of imposex affected females increased to over 80% in spring and summer of both years. However, its intensity, given by the relative penis size index (RPSI), fluctuated around low values. Adelomelon brasiliana digestive gland samples showed a very low concentration of TBT (36–46 ng/g dry weight). Egg capsules presented normal viable embryos, which had TBT concentrations similar to the capsule wall (15 ng/g) while the intracapsular liquid was only 2 ng/g, similar to the sediment concentration. The proportion and distribution of butyltin compounds (BTs) in sediments indicate a major contamination event.

Further tests on the settlement reactions of Ophelia bicornis larvae have shown that both Bullhill Bank and Salthouse Lake sands are less favourable to the larvae after sterilization than they are when fresh and untreated. The effect of a large variety of treatments of both sands has been investigated under conditions where the larvae were free to choose between two or more samples of sands presented together in the same dish. Results from these experiments, taken in conjunction with results obtained using conical vessels, show that sands may be classed as attractive, neutral or repellent with intermediate grading between these three main categories. It is concluded that organic material, living or dead, on the sand grains plays an important role in rendering a sand attractive or repellent to the larvae.

A detailed account of sponge knowledge in Greek antiquity is given on the basis of their records in the written documents of the historical periods it comprises. The analysis of the examined material revealed interesting information on various aspects of sponge biology, more or less consistent with their present scientific knowledge. The value of sponges for man at that time was evident in many of his activities, such as household, personal hygiene, pain relief, disease treatment, art and war enterprises. The significant role of sponges in medical practice is illustrated by the high number of their records in the medical works of the studied historical period. Furthermore, sponges appeared in legends, as well as in similes and metaphors that attributed their special qualities to human behaviour, various body parts or objects.

The genus Princaxelia, Pardaliscidae, is a rarely recorded, infrequently collected and hitherto observed benthic amphipod, typically found at hadal depths (>6000 m) in the Pacific Ocean trenches. Little is known about the behaviour or physiology of this genus. Using a baited camera lander, observations of Princaxelia jamiesoni were made in the Japan Trench (7703 m) and Izu–Ogasawara Trench (9316 m) and of Princaxelia aff. abyssalis in the Kermadec Trench (7966 m) and Tonga Trench (8798 m). These amphipods rapidly intercepted the bait and preyed upon smaller lysianassoid amphipods. Mean absolute swimming speeds for P. jamiesoni and P. aff. abyssalis were 4.16 cm.s−1 ± 1.8 SD and 4.02 cm.s−1 ± 0.87 SD respectively. These amphipods have the capacity for long range swimming, high manoeuvrability in close range, and efficient predatory behaviour. Burst swimming speeds for P. aff. abyssalis were 9 and 10 cm.s−1 with accelerations up to 22–25 cm.s−2.

Since 1971 the macro-benthic infauna at Station P, 18.5 km off the Northumberland coast (central western North Sea), have been sampled by grabbing each January/February. The data series now includes over 260 taxa from 173 genera. The most abundant taxa are Heteromastus, Levinsinia and Priospio which between them account for nearly 45% of the individuals recorded while the top 10 ranked taxa between them include almost 70% of the individuals recorded. Both total abundance and genera richness have varied through the 36 year series, particularly during the late 1980s–early 1990s but there was no trend and values in the 2000s are similar to those at the start of the series. However, MDS ordination of the entire genera abundance series shows a trend in composition of the macrobenthos through time. There is evidence that the changes in composition were driven by fishing impacts, but also influenced by the trend in climate warming and altered fluxes of phytoplankton to the benthos. Given that the dominant taxa have not changed and the total abundance and richness are similar this implies a turnover and redistribution of individuals across many taxa and raises the possibility of shifts in the ecological functioning of the system.

Two new deep-sea barnacles (Cirripedia) are described. The first, from approximately 5200 m in the Southwest Atlantic, belongs to the most generalized genus of the order Ascothoracica, Synagoga. The two previously known species, S. mira from the Mediterranean and S. metacrinicola from Japan, are from relatively shallow water. The new species is not only more generalized than either of these, but it exceeds previous depth records for any ascothoracican by more than 1000 m. It is apparently a sequentially protandric hermaphroditic ectoparasite, knowledge of which helps clarify difficulties in interpreting the life histories of certain more highly evolved endoparasitic forms. On the other hand, its markedly generalized features bear heavily on considerations of the origin of the Maxillopoda.

The second new species, from approximately 1500 m in the Bay of Biscay, belongs to the most generalized genus of the order Acrothoracica, Weltneria. It is closely related to W. hessleri known from 1000 m off Bermuda and the two are unique in being the only true deep water members of the order. The new species is remarkable in inhabiting a friable, clayey substrate - all other acrothoracicins are known to burrow only in relatively solid forms of calcium carbonate. However, both have a calcified rostral plate, and this indicates that the Acrothoracica stem from scalpellid rather than cyprilepadid or iblid Lepadomorpha.

Acetylcholinesterase (AChE) activity, a marker of neural differentiation, was histo-chemically localized in embryos and larvae of Mytilus galloprovincialis Lamarck and M. edulis L. (Mollusca: Bivalvia). The results show that: (1) the first AChE-active cells develop as two bilaterally symmetrical, postero-dorsal pioneer sensory neurons and their supporting superficial cells; (2) the pathways of their pioneering longitudinal axons are the same as those of two bilaterally symmetrical nerve cords which differentiate later in a postero-anterior direction; (3) in the conchostoma larva the posterior neurons and their associated superficial AChE-active cells give rise to two ciliary sensory-like organs which are the earliest rudiments of pedal ganglia and primary byssus glands; (4) three pairs of posttrochal gangliar rudiments, most probably visceral, parietal and pleural ganglia, develop on the same longitudinal nerve cords in the trochophore larva; (5) starting from the veliger stage, the presumptive foot rotates on the ventral side and migrates forwards, so that this gangliar chain is bent and the viscero-parietal ganglia become localized dorso-posteriorly to the pedal ganglia; (6) the cerebral ganglia differentiate together with the apical organ and the nerve network of the velum after the first pedal nerve rudiments have been detected.

Two members of the scallop genus Pecten (Bivalvia: Pectinidae) occur in European waters. Pecten maximus is largely an Atlantic species whilst Pecten jacobaeus is almost completely confined to Mediterranean waters despite slight overlap of distributions in the western Mediterranean. Genetic distances between these species were estimated using both allozyme electrophoresis and mitochondrial DNA PCR–RFLP and shown to be of a similar magnitude to intraspecific values, considerably lower than expected for congeneric species. These data are discussed in the light of recognised morphological differences, hybrid rearing trials and previous studies examining genetic distance by allozyme methodologies.

Arbacia punctulata and Lytechinus variegatus are widely distributed echinoid species in shallow water in the western Atlantic Ocean, Caribbean Sea and Gulf of Mexico that seem to have different life history strategies. We evaluated the effect of two types of stress (high temperature and starvation) on gonad production and scope for growth. We hypothesized that A. punctulata has a stress tolerant life strategy and would be more tolerant to stress and L. variegatus has a competitive–ruderal strategy and would be less tolerant to stress. Gonad production by A. punctulata was not as greatly affected by temperature as L. variegatus, suggesting the hypothesis was correct. Arbacia punctulata had a significantly higher excretion rate indicating greater energy allocation to maintenance than production. Lytechinus variegatus had a significantly greater consumption rate but did not absorb significantly more energy. Arbacia punctulata compensated for its lower food consumption by a higher absorption efficiency. Measured energy expenditure and calculated scope for growth did not differ. However, the percentage change in energy absorbed and energy expenditure was greater for L. variegatus than for A. punctulata with a change in temperature. Feeding had a greater effect on production than temperature suggesting that the biotic stress of low food availability is more important than an abiotic stress such as temperature on energy budgets.