The fatty-acid compositions of tissue lipids of Asterias rubens L., Echinus esculentus L. and Holothuria forskali Delia Chiaje were determined by means of gas-liquid chromatography. Considerable proportions of branched-chain, normal odd-numbered and eicosatetraenoic acids occur in the latter two animals. Tissues of all three animals were incubated with 1−14C-acetate. The relative specific activities of fatty-acid fractions isolated by thin-layer chromatography upon AgNO3-impregnated silica gel G fell in the order: saturates > monoenes — dienes > polyenes. The fatty-acid compositions of the alkoxydiglyceride, triglyceride and phospholipid classes of A. rubens hepatic caecal lipid were also determined.

Blood from Arenicola marina has been shown to contain an active catalyst of sulphide oxidation. This activity is associated with the respiratory pigments. Purified native haemoglobin and oxyhaemoglobin from this animal have similar activity in this respect to the analogous mammalian respiratory pigments and to mammalian hemiglobin. The oxidation product of Arenicola haemoglobin (the brown pigment) which is formed under conditions which might be expected to produce a hemiglobin is, in contrast, a very active catalyst of sulphide oxidation.

The genus Epizoanthus Gray is represented in the north-east Atlantic by three species, all of which live commensally with pagurid crabs. The shallowest-living of the three, Epizoanthus incrustatus (Duben and Koren) occurs with Anapagurus laevis (Bell) within the depth range 20–200 m (Manuel, 1981). Epizoanthus paguriphilus Verrill and Epizoanthus abyssorum Verrill are associated with Parapagurus pilosimanus (Smith), the former within the depth range 600–1550 m and the latter at 3500–4350 m.

Terebellomorpha is a clade of predominantly tube-dwelling polychaetes, some of whose species are very abundant and whose habitats range from shallow to very deep waters. The group contains five families (Terebellidae, Ampharetidae, Pectinariidae, Trichobranchidae and Alvinellidae). This study of their inter-relationships uses DNA sequence data from five gene segments. Including outgroups, sequences were available for 15 species for 15 U2 snRNA, 14 for Histone H3, 23 for the D1 expansion region of 28S rDNA, 15 for the D9-10 region of 28S rDNA and 17 for subunit I of cytochrome oxidase. Outgroups included representatives of the polychaete families Cirratulidae, Sabellidae and Siboglinidae, and the clitellate Lumbricus. These sequences include eight GenBank entries for 28S D1 and one for CO1.

Generally, and in all analyses restricted to the data collected in this laboratory, but including all of these, Terebellomorpha is monophyletic. Within Terebellomorpha, the single maximum parsimony tree indicates that Alvinellidae (all data from GenBank) belongs to a clade with Terebellidae and some Trichobranchidae, contradicting morphological expectations. Terebellidae is paraphyletic with respect to Trichobranchus, this being associated with the subfamily Thelepodinae. The second trichobranchid genus Terebellides (for which only 28S D1 data is available from GenBank) is topologically very distinct to Trichobranchus. Additional data are needed to establish the family's monophyly. Also within Terebellidae, subfamily Terebellinae is paraphyletic with respect to Polycirrinae, supporting the suggestion that this subfamily's morphological simplicity is derived.

The reproductive features of four commercially important species of the Diplodus genus were studied in the Gulf of Tunis to contribute to better fisheries management on the local scale. The study was specifically aimed to estimate sex-ratio and size at first maturity, to determine spawning season, to analyse hepatic and muscular energy reserve changes and to highlight possible regional difference over the Diplodus geographical distribution. A total of 570 Diplodus vulgaris (two-banded seabream), 428 Diplodus annularis (annular seabream), 350 Diplodus sargus sargus (white seabream) and 218 Diplodus puntazzo (sharpsnout seabream) were collected from the commercial catches of the artisanal fleet between October 2004 and June 2006. Male:female ratio was initially skewed in favour of females for the four Diplodus species and especially among larger-sized individuals. Length and age at first maturity was 17.4 ± 0.2 cm total length (TL) (4 years) for D. vulgaris, 9.7 cm TL (2 years) for D. annularis, 21.0 ± 0.3 cm TL (4 years) for D. s. sargus, 21.5 ± 0.2 cm TL (3 years) for D. puntazzo and a recommendation is made for the increasing of the captured length. According to the monthly succession of gonad maturity stages and the yearly gonadosomatic index (GSI) fluctuation, the spawning season of Diplodus species present a temporal succession along the year. The two-banded seabream has a winter spawning period, the white seabream is mainly a spring spawner, the annular seabream spawns essentially in summer months and the spawning of sharpsnout seabream takes place in autumn. Generally, hepatosomatic index presented an inverse trend to GSI in relation to the breeding activity. The condition factor showed significant monthly variations affected by the sexual cycle of the Diplodus species.

Pelagic zooplankton and fish release faecal material which rapidly sinks through the water column and contributes various amounts and types of organic and other chemical constituents to bottom sediments. The major importance of this process in linking biological events in the water column with inputs to sediments has been well demonstrated in a number of sea areas through the use of field experiments with pumps or traps (Bishop et al. 1977; Gagosian, Volkman & Nigrelli, 1983; Honjo, 1978; Knauer, Martin & Bruland, 1979; Prahl, Bennett & Carpenter, 1980; Wakeham et al. 1980; Wakeham, Farrington & Volkman, 1983). In general, field studies have shown that the deposition of organic matter of pelagic origin occurs with considerable alterations both quantitative and qualitative (Gagosian, Nigrelli & Volkman, 1983; Prahl et al. 1980; Wakeham, 1982). Such studies, however, have not clearly defined how individual biological processes competing in the water column influence the overall composition of organic matter in vertically transported paniculate material.

1. The volumes of Balanus balanoides, at three levels of the shore, have been observed for a year.

2. The young barnacles grow very much faster than older ones.

3. The growth rate varies greatly with age, season and tidal level, but in general there is a period of maximum growth in the summer, and very little growth in the winter.

4. Growth, except during the first year, is greatest higher up the shore.

5. Young barnacles, which settle too late in the year, have their growth retarded by the summer heat, but almost catch up in size the earlier settled spat, by the beginning of the next year.

6. The growth rates found are intermediate between those recorded from Herdla (near Bergen), and those from near St. Malo.

7. Most of the lower- and middle-zone barnacles die in their third year, but those from the extreme top zone may live for five years or more.

The lessepsian migrant Siganus luridus appeared along the shallower waters of the Pelagie Islands (central Mediterranean Sea). This is a new record of the species based on the capture of 40 specimens in Linosa Island during the summer of 2003. Some biological data are given and the relevance of this finding from the Sicily Strait is discussed.

The lumpsucker or lumpfish, Cyclopterus lumpus L. (Cyclopteridae, Scorpaeniformes), is a cottoid teleost, and, like other fish in its family, exhibits many characteristics of a coastal, bottom-dwelling fish. It is globiform, has no swimbladder, possesses a large abdominal sucker (formed from the pelvic fins), and lays demersal eggs which are brooded by the male parent for many weeks (Fulton, 1907; Cox & Anderson, 1922; Yesipov, 1937; Zhitenev, 1970; Mochek, 1973). The species spends the breeding season in shallow water, where both sexes may be seen attached to the rocks by their suckers. Early researchers (Couch, 1863; Day, 1880–4; Smitt, 1892) believed that the adults retreated to rocky bottoms in deep water after breeding. However, later workers (Cox & Anderson, 1922; Saemundsson, 1926, 1949; Andriyashev, 1954; Bagge, 1964; Blacker, 1983; Daborn & Gregory, 1983) have demonstrated that the lumpsucker spends much of its larval and adult life living epipelagically and in mid water in coastal and oceanic areas upon macrozooplankton (e.g. ctenophores, mysids). The term ‘semi-pelagic’ seems the most appropriate label for its mode of life.

The vertical distribution of Calanus finmarchicus adults in the daylight in the Plymouth region as shown by stramin ring-trawl catches in described for the period April to September in 1926. The general results confirmed the indications given in 1925 that there is a, gradual descent of the region of maximum abundance from about 10 metres in April to-metres in June, with a definite rise towards the surface ia July, August, and September.

2. The rise towards the surface was evident on sunny days as well as dull, indicating that the suggestion that dull weather and low light intensity was its cause in 1925 may possibly have been incorrect.

Measurements of the total lengths of Calanus were made which showed a seasonal change, a brood of small adults occurring in July, August, and September, as opposed to a brood of large adults whichdominated in the spring.

It is suggested that possibly these two broods are physiologically different, and that the small type of adult prefers a higher light intensity and lives nearer the surface than the large type.

The males and females differed in their behaviour, the males being always slightly deeper in the water than the females.

Some indications are given of the course of the life-cycles of Calanus in the Plymouth area.

While from April to the end of June the abundance of the last copepodid stage (Stage V) rarely exceeded more than 20% of the total Calanus in any one catch, they became very much more abundant in July, August, and September, reaching even 60% and 70%.

The spawning of Paracentrotus lividus has been determined on the basis of the annual gonad index cycle at three sites in the Algiers area presenting low, intermediate and strong hydrodynamism. Three biotopes (Posidonia oceanica beds, rocky substrate with photophilous algae and overgrazed rocky substrate) and two depths (1–3 m and 6–10 m) were considered at these sites, the sex-ratio was always strongly in favour of females (2:1 to 3:1). In all sites but one, there were marked differences in the gonad index and the spawning period between sites; the gonad index reached its maximum value at the site with the weakest hydrodynamism, and the minimum value at the site with the strongest hydrodynamism. Spawning took place in April–May and August–September at the site with the weakest hydrodynamism, in April–June and October–December at the site with intermediate hydrodynamism and only in winter at the site with maximum hydrodynamism. The coexistence, on regional scale, of these reproductive cycles might enable Paracentrotus lividus to compensate the mortality during planktonic larval phase by the fact that spawning of this sea urchin occurred in all seasons.

Closed circuit underwater television observations showed that, in summer, large numbers of Carcinus maenas performed daytime tidal migrations up and down a small mudflat in the Menai Strait, North Wales. At the observation point, 25 m above mean low water mark of spring tides, numbers of crabs moving upshore on flood tides averaged 84 m—1 of tideline, ranging from 48 to 126 m—1. Most crabs were of 20–50 mm carapace width (1 and 11 groups); none smaller than 15 mm was seen. Peak movements occurred in at least 0.5 m depth of water. Over the high tide period, most crabs were dispersed over the upper half of the mudflat where crab population densities of 1·8–2·5 m—2 were indicated by diving observations.

Three new examples of cleaning symbiosis are recorded among the British labridae, Crenilabrus melops, Ctenolabrus rupestris and Centrolabrus exoletus. The first two have only been seen in aquaria although parasites in the stomach of C. melops caught offshore suggests cleaning activity occurs in their natural environment. C. melops has been observed in the public aquarium taking parasites from the bodies of a number of host fish most commonly the pink bream (Pagellus centrodontus). Most cleaning activity occurs after the lights are first turned on when the hosts remain stationary to be cleaned. At this time the incidence of parasites on their bodies is most obvious. Certain areas of the body are cleaned in preference to others. Details are given of cleaning symbiosis by the pipe fish Enterlurus aequoreus, Syngnathus typhle and S. acus.

This study examined the inter-relationships between molluscs, heavy metal concentrations and trematode parasites. Littorina littorea (Mollusca: Gastropoda) were sampled seasonally from two sites in a tidal lagoon. Site A was close to the inflow of a polluted stream whilst site B was at the opposite end of the lagoon. The samples were analysed for lead, iron, copper and nickel. Metal concentrations in L. littorea varied with site, season and parasite infection, and exceeded comparative non-polluted concentrations for all metals in some samples. Parasitized periwinkles consistently had significantly lower levels of iron, copper and nickel than uninfected periwinkles.

Along the central coast of Rio de Janeiro State (22°25′S–23°00′S), south-eastern Brazil, the marine tucuxi dolphin (Sotalia guianensis) feeds on neritic prey that are distributed through the water column and are abundant all year round. The most frequently found species were the teleost fish Trichiurus lepturus, Cynoscion guatucupa, Isopisthus parvipinnis and Porichthys porossisimus. Fish species were more important than cephalopod species in the diet of the marine tucuxi. Back calculations of prey sizes indicated that they feed mainly on young specimens. The present study provided additional information on the feeding habits of the marine tucuxi dolphin.

The morphology of a complete series of developmental stages of Lernaeocera branchialis is described. Seven stages are passed through before reaching the gadoid (final) host.

The structure of the mouth tube and appendages is discussed in detail and compared with those of related genera in which the resemblances are close.

The free single nauplius and copepodid stages are immediately followed by four chalimus stages on Pleuronectes flesus; these show some dedifferentiation though segmentation is not lost. An explanation is given for the peculiar suspensory mechanism of the chalimus.

A second dedifferentiation follows the second well-developed pelagic phase in which the adult form is attained and copulation takes place. Some irregularity is noted in the details of the retrogressive metamorphosis of the maturing female on the gadoid host.

The rate of increase in body length in Lernaeocera decreases regularly up to the assumption of the adult form (stage VII). In this respect it is similar to the free-living copepods Diaptomus, Eurytemora and Calanus, but is in strong contrast to Caligus centrodonti which has an increasing growth rate up to the fourth chalimus stage. In the latter at this stage there is a marked acceleration in the growth rate unaccompanied by any change in shape or any other discontinuity, whereas in Lernaeocera there are early discontinuities in development, yet the growth rate is continuous when expressed graphically: it is a straight line rather than a logarithmic curve as would be expected from our knowledge of the higher Crustacea.

The size of the female is greater than that of the male: that of the female overlapping the male of the succeeding stage. Variations in size of the larvae in a stage group are not seasonal, and an explanation is offered for giant larvae.

Similar lernaeocerid larvae and males to those of Lernaeocera branchialis on Pleuronectes flesus were found on Solea solea and Cyclopterus lumpus. No characters of generic or specific significance could be found which would serve o t separate them from Lernaeocera branchialis so that their identity is not determined.

The ostracods have been analysed from a day and night series of horizontal tows taken near the Island of Fuerteventura (Canaries). Thirty-five species were identified. Nineteen species were sampled in large enough numbers to describe their depthe distributions and the ranges of their vertical migrations. Seven species were too small to have been adequately sampled by the methods used, and the remaining nine species were too rare to draw any firm conclusions as to their depth ranges.

Interannual variability of the primary production in the middle Adriatic Sea for the period 1961–2002 was examined and correlated to the various atmospheric and oceanographic parameters. The sequential t-test analysis of regime shift (STARS) method and locally-weighted scatter plot smoothing (LOWESS) method were applied to the primary production, revealing the new regime with significantly different mean productivity ranging from 1980–1996. Moreover, this period with the highest primary production, consists of the two distinguished sub-periods: periods of increasing (1980–1986) and decreasing (1987–1996) primary production. Whereas in the first period the ecosystem was under the influence of warmer and nutrient richer Levantine Intermediate Water (LIW) intrusions into the Adriatic, in the second period, which started with a cold winter in 1987, the Eastern Mediterranean Transient (EMT) occurred. The EMT established a new circulation regime which prevented the LIW intrusions in the Adriatic, causing its reduced productivity. Reduced LIW inflow in the Adriatic was evidenced in the lower than normal sea temperature, salinity and oxygen concentrations below the thermocline depth. Precipitation and wind regime also arose as important local factors for the primary production variability. Our analysis connected the shifts in primary production with hemispheric and regional scale climate variations, and supports the hypothesis that atmospheric variability can trigger the ecosystem changes.

The free-living benthic copepods and nematodes in samples of decaying leaves and sediment, from a Rhizophora apiculata-dominated mangrove forest bordering the Sungai Merbok Estuary in north-western peninsular Malaysia, were identified to putative species. Analyses of community structure of these taxa revealed that both are concentrated within the surface layers of the sediment; communities associated with decomposing leaves are distinct from those associated with the sediment surface; and variation between physically similar sites within the forest is relatively small. It is suggested that the meiofaunal communities in tropical soft sediment mangrove estuaries respond primarily to salinity and exposure gradients as in temperate non-vegetated estuaries. Copepod communities of the Merbok mangrove system appear to be much more diverse than those in estuarine and saltmarsh habitats in other climatic regions, and detailed faunal analysis suggests that there is a high degree of species endemism, particularly in genera which are only found on decaying plant material.

In this research we studied the diet of Enteroctopus megalocyathus from three principal locations of the octopus fishery (Ancud, Quellón and Melinka) in southern Chile. The gastric contents of 523 individuals, collected between October 1999 and September 2000, were examined and statistically analysed. Diet composition was described using detrended correspondence analysis and analysed as a function of predator gender, body size and fishing area. Food items were found in ~50% of the octopuses examined and a total of 14 prey items were recognized. The diet of E. megalocyathus consisted primarily in brachyuran and anomuran crustaceans, fish and conspecifics. The diet differed in composition between fishing zones and mantle length of the specimens and size of octopuses varied between locations. After adjusting for octopus mantle length, diet composition was found to be different between fishing areas. Large octopuses fed on large crabs at Ancud, while in Quellón and Melinka small octopuses fed mainly on small crustaceans. There were no differences in prey composition between the gender and the size of octopuses was a better predictor of the variance in the diet composition (16%) than the fishing zone (6%). Cannibalism may become an important issue when food is scarce and/or at high population density.