Despite the hydroid fauna of the Mediterranean Sea being considered one of the best known in the world, the eastern basin of the Mediterranean Sea remains nearly unexplored. This paper reports on 38 species collected along the Levant Sea coast (mainly Lebanon), of which three are new records for the Mediterranean and nine for the Levant Sea. Six alien species, i.e. Eudendrium carneum, Sertularia marginata, Sertularia techocarpa, Macrorhynchia philippina, Diphasia digitalis and Dynamena quadridentata, are described in detail and illustrated on the basis of Levant Sea material. The last four species are considered as immigrants from the Red Sea. The synonymy of Sertularia stechowi, described from Japan, with S. techocarpa is established. Taken as a whole, the collection comprised a majority of circum-(sub)tropical species, and a reduced proportion of Atlantic–Mediterranean elements and Mediterranean endemics. The ecology (seasonality, depth distribution and habitat preference) of the indigenous species resulted similar to what is known for the more studied western Mediterranean, with some exceptions. Adding the present species inventory to the scanty published information, the total of hydroid species known from the Levant Sea rises to 70, indicating the need for future investigation in this sector of the Mediterranean Sea.

This study reports for the first time on the whole epibiont fauna of loggerhead marine turtles, Caretta caretta, in the western Mediterranean, analysing the factors that account for the predictability and composition of the assemblage. A total of 104 loggerhead turtles stranded along the coasts of eastern Spain during 1995–2006 were surveyed for epibionts. A total of 39 epibiont taxa were identified, three of them being new records for loggerhead turtles: Bittium sp., Idotea metallica and Jassa sp. The assemblage was composed of a group of 27 facultative taxa that use turtles as any inanimate buoyant substrate, and 12 taxa that have developed more specific associations to marine turtles, including six species that occur in marine turtles exclusively, two that dwell also on other hosts, and four that can also survive as free-living forms but have developed a strong association with marine turtles. Hierarchical clustering and Similarity Profile Analysis based on the occurrence of 166 epibiont taxa from nine available surveys indicated that the epibiont assemblages from loggerhead turtles in the western Mediterranean (WM) are similar to those from Central Mediterranean (CM), but significantly different from turtles surveyed in the eastern Mediterranean and the Atlantic. The subset of epibionts occurring on WM and CM turtles is defined by a combination of geographic factors (exclusive Mediterranean epibiont taxa) and ecological factors (relative absence of littoral-benthic taxa). Loggerhead turtles from WM and CM apparently exploit both pelagic and benthic habitats in similar fashion, representing a homogeneous unit for epibiont recruitment.

Digenean trematodes are omnipresent in the cockle Cerastoderma edule, a common coastal bivalve of (semi-)sheltered north-eastern Atlantic coasts. They can use their host as a second intermediate host where they remain in a relatively latent stage as metacercariae. Cockle population dynamics and trematode parasite load were monitored for two years in two sites, Arcachon (France) and Merja Zerga (Morocco) for the cockle cohort of 2005. Individual growth was slightly higher at Arcachon than at Merja Zerga (Von Bertalanffy parameters: K = 1.5 yr−1 in both sites but L∞ = 31.2 mm at Merja Zerga against 38.3 mm at Arcachon). Production during cockle life was twice as high at Merja Zerga (48.5 compared to 22.2 gDW.m−2 at Arcachon). Elimination compensated production at Merja Zerga while elimination was low at Arcachon (8.1 gDW.m−2) due to sediment dynamics which concentrated cockles within the sampling area. P/B was similar in both sites (2.4–2.6 yr−1) while E/B was higher at Merja Zerga (2.2 yr−1 versus 1.0 yr−1). Trematode communities were similar in both sites in terms of species and abundance. During the cockle cohort lifespan, there were 3 to 5 events in the parasite abundance survey that suggested parasite-dependent mortality. At Merja Zerga, trematodes metacercariae did not affect P/B (2.4 yr−1) but increased E/B (+14%). At Arcachon, they also had no effect on P/B (2.6 yr−1) but on the contrary increased E/B (+20%). The threshold of metacercariae abundance beyond which cockles are affected was lower for Echinostomatid trematodes at Merja Zerga, suggesting an interaction with other factors such as temperature which is higher at the southern limit of cockle distribution.

The previous work on spontaneous activity in ascidians is briefly reviewed: there is clear evidence for the existence of spontaneous contractions of the siphons of certain monascidians but no function has been ascribed to this activity. Phallnsia mammillata exhibits spontaneous contractions of its siphons at intervals of 6-9 min. over long periods in Plymouth tank sea water. The siphon contractions are synchronous. The frequency of the contractions may shift fairly quickly under constant conditions to a higher or lower rate which is usually twice or one half the normal rate.

A method of recording the volume of water propelled by spontaneous activity is described. The method also records the ciliary through-current at the same time as the squirts.

The frequency of the squirting is increased during a period of partial or complete starvation. It is reduced again by adding food cultures to the water.

The physiological mechanisms involved in the spontaneous activity are investigated and comparisons are made with the spontaneous activity exhibited by Metridium senile and Arenicola marina. It is finally suggested that the spontaneous squirting of certain ascidians is an integral part of their feeding mechanism.

An ex-Royal Navy frigate, HMS ‘Scylla’, was placed on the seabed in Whitsand Bay, south Cornwall on 27 March 2004. After five years, the reef supported a mature steel wreck community. The colonization of the reef showed wide fluctuations in species abundance in the first two years but, by 2006, most species that dominated or characterized the reef after five years had settled. Significant colonization events included settlement of barnacles, tubeworms and hydroids within a month and remarkably high settlements of the sea urchin Psammechinus miliaris and the queen scallop Aequipecten opercularis in the first year together with starfish Asterias rubens, solitary sea squirts and ephemeral algae. The plumose anemone Metridium senile, a characteristic species of wrecks, arrived in late summer 2004 but the widely distributed dead man's fingers Alcyonium digitatum was not observed until spring 2005. Wrasse were slow to colonize the reef but were established in small numbers by the end of 2007. Sea fans, Eunicella verrucosa, were first observed in August 2007. The species count for the reef stood at 263 taxa by the end of March 2009. The inside of the reef remained poorly colonized even after five years. Areas coated with tributyltin (TBT) antifouling paint only had colonization where the paint had flaked-off or on non-toxic paint markings, but with some indication that colonization may be occurring by a very few species especially near to non-TBT areas. Many species characteristic of natural reefs had not settled and neither do they occur on older wrecks including branching axinellid sponges, some cushion sponges and the yellow cluster anemone Parazoanthus axinellae. The artificial reef developed a community that was distinctly different to nearby natural rock reefs and such artificial structures should not be considered as a replacement for damaged or destroyed natural habitats.

Cetacean stranding reports in the North Aegean Sea were recorded since 1998 from Strimonikos Gulf in Chalkidiki up to Alexandroupoli on the Turkish border and in a few northern Aegean islands. On site, the specimens were examined to identify species, gender, approximate age and, when possible, cause for stranding. A total of 26 filled stomachs of five cetacean species collected since 2002 were analysed: bottlenose dolphins Tursiops truncatus (N = 8), common dolphins Delphinus delphis (N = 8), harbour porpoises Phocoena phocoena (N = 5), striped dolphins Stenella coeruleoalba (N = 4) and Risso's dolphins Grampus griseus (N = 1). From the analysed stomachs it was found that the bottlenose dolphins fed mainly on snake blenny Ophidion barbatum (34%), bogue Boops boops (22%) and round sardinella Sardinella aurita (13%); common dolphins on round sardinella (17%), picarels Spicara spp. (10%) and Cocco's lantern fish Lobianchia gemellaris (9%); harbour porpoises on Gobidae (four-spotted goby Deltentosteus quadrimaculatus 41% and black goby Gobius niger 37%) and round sardinella (7%); striped dolphins on Myctophydae (Madeira lantern fish Ceratoscopelus maderensis 51%), and on Pfeffer's enople squid Abraliopsis morisii (10%) and bogue (8%); and Risso's dolphin exclusively on Teuthidae (31%), the umbrella squid Histioteuthis bonellii (30%) and the reverse jewel squid H. reversa (14%). The present work represents the first attempt to investigate the diet up to species level for several cetaceans in Greek waters and for harbour porpoises stranded in the Mediterranean Sea.

In North Wales settlement and metamorphosis of Balanus balanoides occur in May and the animals breed for the first time in the following November. Three weeks after metamorphosis the oviducal glands appear as epidermal invaginations in the basal segments of the first pair of cirri. At first there is no lumen or external duct but these develop during the next fortnight. The wall of the gland is a columnar epithelium which increases in height as the gland increases in size. During mitosis this epithelium exhibits the pattern of cell movements characteristic of similar epithelia in vertebrate embryos.

The reproductive biology of the lane snapper, Lutjanus synagris, was evaluated from 770 specimens (434 females and 336 males) obtained on the Abrolhos Bank, eastern Brazil, between May 2005 and October 2007. Total length ranged from 14.7 to 56.0 cm for females and from 16.5 to 54.3 cm for males, with size composition not varying significantly between sexes. Five distinct maturity stages were identified based on macroscopic and histological examination of the gonads. Mean value of the gonadosomatic index (GSI) for females peaked in September and October, with a secondary peak in February and March. Histological analyses confirmed the reproductive cycle inferred by GSI variation. Asynchronous-type ovarian development was observed, and batch fecundity ranged from less than 104,743 oocytes for a 25.5 cm female of to 568,400 oocytes for a 56.0 cm female (250.0 and 2260 g, respectively), with an average of 345,700 oocytes. The reproductive parameters obtained for L. synagris in the Abrolhos Bank were similar to those reported in studies in northern Brazil and the north-west Atlantic. The species is an important fishery resource in the study region, and management measures are needed before the species becomes overfished. Exploitation occurs largely during spawning aggregations, a situation that has caused other lane snapper populations (and congeners) to decline acutely elsewhere. Our results provide support for size limits and seasonal spawning closures on the Abrolhos Bank, a region that sustains artisanal fisheries involving >20,000 fishermen.

The present list of diatoms may be considered an extension of the recent check-list of British marine algae by Parke (1953). It includes not only truly marine species, both sessile and planktonic, but also species inhabiting brackish waters with a few fresh-water species that manage to live, though somewhat precariously, in estuarine conditions.

It has been compiled for the following reasons: (1) to indicate the extent of the diatom flora around British coasts, so that comparisons may be made with that of the other countries; (2) to assist workers in the identification of material by indicating the size of any genus known to inhabit our shores; (3) to check the arrival of new entrants to the British flora; and (4) to provide a basis for a more detailed work, now in preparation. The check-list does not presume to lay down finalized decisions on the taxonomic rank ascribed to any organism or to consider the criteria upon which such ranks are based.

This is one of a series of four papers dealing with vertical distribution of cephalopods in the North Eastern Atlantic at six stations near 20° W and at about 10° intervals from 60°N to 11° N (Clarke & Lu, 1974, 1975 a; Lu & Clarke, 1975). The present study is based upon a series of hauls made at discrete horizons between o and 2000 m with opening-closing nets during both daylight and darkness. The collections were made for the ecological programme of the National Institute of Oceanography, Wormley, Surrey, England (now part of the Institute of Oceanographic Sciences).

If Arion hortensis be fed on a diet which contains 90Sr, autoradiographs show that the isotope istaken up by the digestive and lime cells of the digestive gland. From the former it passes to th haemocoel; in the lime cells it is concentrated around the calcium spherules. Some of the tracer enters the body through the wall of the intestine. Calcium stores which surround blood vessels and calcium cells in the mantle also concentrate the tracer.

In Aplysia.punctata 90Sr from the surrounding water passes through the surface of the body, and especially the gill; in Acanthodoris pilosa ions which enter the tissues from the sea water accumulate around the numerous calcium concretions in the mantle. These marine molluscs obtain cations directly from the water as well as by way of the food.

There is a slow uptake of strontium ions by the ctenidia of Mytilus edulis, though, even in filtered sea water, the gut is the more important area for their ingress to the body. It is possible that they enter with the mucous feedingsheets. They pass readily into the cells of the digestive gland. Some of the isotope taken in with the food is absorbed by the wall of the intestine; this also occurs in Patella vulgata, in which the intestine provides a much larger area, and in Lepidochitona cinereus.

Mytilus placed in filtered sea water which is activated with 90Sr, so increasing the strontium content by 007%, show the tracer localized for excretion within 10 hr. Ions are aggregated in the pericardial glands, not in the kidney.

At Aberaeron, Dyfed, mid-Wales, the two trochid species, Monodonta lineata and Gibbula umbilicalis breed during the summer months. M. lineata showed a discrete spawning period in late July in both 1980 and 1983, whilst G. umbilicalis spawned in August in both years, though with gamete release prolonged into September in 1980. In both species gonad development begins in April/May, and by June the characteristic bimodal oocyte diameter distribution of mature females has been established. Vitellogenesis and the development of a jelly coat around the oocyte begin when the oocytes have a diameter of 70–80 μm, with mature oocytes reaching 140–180 μm in diameter, excluding the jelly coat.

Continuous observations on the Upper Fal Estuary oyster beds during the years 1925, 1926, and 1927 have established the fact that 0. edulis exhibits on these beds two definite periods of shell-growth, i.e. increase in shell-area, in one year; one period of general shell-growth occurs in the spring, beginning early in April, and the other in autumn at the end of September or early in October. There is some evidence-but as yet incomplete-that internal shell-growth occurs solely and simultaneously with the deposition and thickening of the new shell-shoots in a period of one to two months.

These general bursts of shell-growth occur in the pre-breeding and post-breeding part of the season

Similar periods of shell-growth occur on beds in the River Blackwater (AVest Mersea), and also occur mainly in the pre-breeding and postbreeding part of the season; but shell-growth begins in the spring in April-May on these beds, a few weeks later than on the Upper Fal Estuary,and in the autumn in August-September a few weeks earlier than on the Upper Fal beds.

Spring and autumn periods of shell-growth are also known to occur on many other estuarine beds.

The food and feeding habits, and general biology of the commoner gadoids in Manx waters have been studied. During the pelagic phase the diet of the gadoids showed a great similarity, consisting mainly of various abundant calanoid copepods. The larger pelagic post-larvae supplemented this basic diet with the inclusion of euphausiid ‘furcilia’ larvae and (in whiting) the amphipod Hyperia. Whiting, cod and pout were often found associated with medusae: the whiting, 21–53 nun long, were taken in large numbers, and their diet was found to be modified as a result of this association.

Young gadoids in a shallow sandy bay showed a great similarity in their basic diets, which typically consisted of various small, swarming mysids, amphipods and isopods. This habitat was a nursery area for many of the gadoids.

The larger fishes fell into two groups: (i) those that were characteristically feeders on the infauna and large, slow-moving epifauna; such fish being provided with stout barbels, well equipped with taste-buds, e.g. cod; (ii) those that feed largely, on the smaller active epifauna and nektonic prey, and possessed no, or only rudimentary, barbels, e.g. whiting.

The larger gadoids showed a concentration after spawning on a shallow, submarine shelf (the Warts Bank) to the south of the Isle of Man. Here the spent fish fed on an abundant and localized food, sand eels. The gadoids were found in this habitat from March to September, and were the object of a local fishery.

There was evidence that the gadoids exercised choice of food from that potentially available from the four primary food sources in each habitat; but if their favourite food was scarce or lacking, they would take substitute food by exploiting sources otherwise normally neglected.

Infection of Nephrops norvegicus by a dinoflagellate parasite belonging to the genus Hematodinium, is reported in populations of Nephrops from the Irish Sea. Diseased animals are recognized by an opaque vivid body colour and high densities of parasites in the haemolymph. Infection causes a general morbidity of the host along with a reduction in swimming performance, which eventually leads to the death of the host lobster. Research vessel cruises performed over the period 1994–2001 have shown Hematodinium to occur in populations of Nephrops from the Irish Sea throughout this period. High infection prevalence during the month of April and negligible levels during October agree with published data on seasonal infection levels in Scottish Nephrops stocks. Data on spatial and temporal infection prevalence are presented for the first time for the Irish Sea and show variation between stations and between years. Mean infection prevalence peaked at 18% of captured Nephrops during April 1996 and was followed by a downward trend to 2001. Infection predominates in small Nephrops (<30 mm carapace length) and in females is normally associated with immature animals. Although a positive correlation with seawater salinity was noted, preliminary analysis did not show a relationship between prevalence and other environmental factors.

Early development in the north-west Atlantic awning clam, Solemya velum (Solemyoida: Solemyidae) was examined by light and scanning electron microscopy. Embryonic and pericalymma larval stages, typical of protobranch bivalves, developed within individual adhesive gelatinous egg capsules and offspring emerged at hatching as benthic crawl-away juveniles. Fertilized eggs were light orange in colour, spherical, and had a yolk-mass diameter of approximately 190 μm. Entirely ciliated cylindrical pericalymma larvae, with a length and width of 318 μm and 208 μn, respectively, were obtained within 24 h. These larvae lacked an apical ciliary tuft, possessed nine rows of calymma cells, and actively rotated within the egg capsule. During metamorphosis, which occurred within 48 h of fertilization, the transitory larval ectoderm was entirely ingested. The prodissoconch measured roughly 320 μm in length by 215 μm in height. The foot and ciliated gill buds were well developed by four days after fertilization and subsequent growth contributed to the dissoconch or adult shell. Hatching began at 13 d after fertilization when the shell measured approximately 402 μm in length by 251 μm in height. Actively crawling and burrowing juveniles were cultured for six months after fertilization and an ontogenetic sequence of encapsulated and juvenile shell morphology was obtained for identification purposes. Current contradictory hypotheses regarding the phylogeny of marine bivalve develop-mental types are reviewed in light of new information on the Order Solemyoida.

Forty-three species of choanoflagellates were seen during a study of the heterotrophic nanoflagellates in Southampton Water, between 1991 and 1994. The majority of the species were loricate choanoflagellates (Acanthoecidae), and this group accounted for –8% of the total heterotrophic nanoplankton during the period of study. Aloricate choanoflagellates (Codosigidae and Salpingoecidae) were less diverse, and accounted for only 3–4% of the heterotrophic nanoplankton. The seasonal occurrence of loricate choanoflagellates was studied using light microscope whole mounts, whilst more detailed studies of lorica structure were made using electron microscope whole mounts. Two new species, described in this paper, had a markedly seasonal occurrence and were only recorded during a period of 6–10 weeks each spring.

The diet and functional biology of the digestive system of the cephalaspidean gastropod Haminoea orbygniana was investigated by gut content analysis of animals collected in the Ria Formosa, a coastal lagoon in southern Portugal. The results show that this species is herbivorous, stenophagic and probably non-selective, feeding mainly on diatoms (67·61%) and occasionally on vegetal detritus (4·16%) and Foraminifera (0·04%), but also including sand grains as an important part of the gut contents (28·34%). The role of the gizzard plates in the fragmentation of diatom frustules was demonstrated and is discussed. Data reveal that this process, although possibly important for the digestion and assimilation of food, seems not to be crucial. The role of sand as an additional food source and as an accessory tool complementary to the gizzard plates is discussed. A general review of the diet within the family Haminoeidae is presented, with all recent work indicating that they feed on diatoms and green algae.

The pulsed-Doppler flowmeter permits continuous, non-invasive measurement of blood flow through several arteries simultaneously. Summation of volume flow rates through all arteries leaving the heart allows determination of cardiac output, stroke volume, and the percentage of cardiac output delivered to each region of the body. The use of this system for investigating changes in arterial perfusion as well as its calibration in situ are described.

Dense aggregations of echinoderms on the sea bed have been described from various parts of the world. Reese (1966) considered that such an aggregation ‘is a response to one or more essential environmental factors such as food or substratum, and does not reflect social behaviour per se’ Observations by Warner (1969, 1971) and by Brun (1969) suggested that, in aggregations of the brittle-star Ophiothrix fragilis, individuals may respond to conspecifics rather than solely to food or the substratum. On an apparently uniform substratum, some areas are covered with a dense bed of brittle-stars while other adjacent areas are devoid of brittle-stars. Warner (1971) pointed out that the aggregations are advantageous to the species so it seems possible that the animals might aggregate actively rather than coming to a suitable feeding area by chance. The aims in this study were to investigate the responses shown by Ophiothrix fragilis to its physical surroundings, to some of the other organisms living near it and, especially, to conspecifics. The animals studied are in dense aggregations off Berry Head in Southern England and all observations were made underwater in the natural habitat.