To evaluate the relative importance of tentacular crown and body surface in sabellid respiration, experiments were carried out on Eudistylia vancouveri (Kinberg, 1867), a long narrow worm living in a permanent tube in the intertidal zone. This species irrigates its tube by peristaltic waves, as do most species of Sabellinae and this allows water circulation inside the tube for body surface respiration.

Measurements of oxygen uptake after amputation of the tentacular crown indicated a reduction of about 80% of the total respiration. This value was higher than that found for other Sabellinae studied. Some predictions about other species were made on the basis of the present observations and of comparison with species having similar aptitudes.

The habit of living in a narrow tube protruding from the sea bottom, as occurs among sabellids, implies some adaptations concerning feeding, excretion and respiration. In the order Sabellida, the prostomium is reduced and fused to the peristomium which usually forms a large tentacular crown (Fauchald, 1977) with both feeding and respiratory functions. Its relative importance in respiration, however, is still little known. Survival after crown amputation suggests that this structure is not essential for respiration; moreover some species can autotomize and regenerate it (Berrill, 1931; Okada, 1934). In sabellids, respiration can in fact occur at the level of the body surface and this is made possible by the flux of the water contained in the tube which is generated by the worm itself: i.e. irrigation. Sabellinae species can actively irrigate their tubes by waves of muscular contraction of the body wall in either direction.

The influence of two sea-cage fish farms at Gran Canaria Island (Canary Islands, central east Atlantic Ocean) on the intertidal macrobenthic assemblages was studied. Two controls and two impact locations were established at each farm. The composition and coverage of the macrobenthic assemblages were surveyed every three months using image processing analyses. Significant dissimilarities were found between control and impact locations at both sea-cage fish farms. The presence of: (1) algal species tolerant to pollution (Caulerpa racemosa and Corallina elongata); and (2) filter-feeding fauna (Anemonia sulcata) at impact locations, indicate that the fish farming activity is causing an effect on the surrounding intertidal macrobenthic assemblages of both sea-cage fish farms.

In the flounder adipose tissue forms a padding between the muscles to the dorsal and ventral fins. A little is present under the skin, more especially where the lateral line septa and the myocommata meet the skin. In addition a quantity of fat is associated with the skeleton.

Immature flounders living in the estuaries of the Tamar and Lynher are fattest after intense feeding during the summer, and leanest after the winter fast.

Maturing flounders have a high fat content before going to sea to spawn. While in the sea during the spawning season, February to April, very little feeding takes place and there is a rapid drop in fat content. Spent fish are very lean.

Those females which return to the estuaries after spawning rapidly make good their fat loss.

In 1971 and 1972 during the course of short cruises to the South Biscay area on R.V. ‘Sarsia’ several hauls were made with a 100 hook long-line on the Continental Slope at depths ranging from 800 to 3600 m. The hooks used were of two different patterns (Fig. 1) arranged alternately. The hooks were mounted on wire snoods of about 1 m length which were attached to the line at 10 m intervals by stainless-steel snap-on connectors. The object of this arrangement was to find out if the incurving hook pattern based on a traditional South Pacific type of wooden hook showed any advantage over a normal type of hook.

Measurements of the release of dissolved organic nitrogen (DON) and carbon (DOC) were carried out on an axenic batch culture of the coccolithophorid Emiliania huxleyi. This unicellular marine alga was cultured using a media with nitrate as the sole N source and the changes of DOM concentrations measured over 14 days. Results showed that there was a significant release of DON, i.e.7.6 µM N day−1 during mid-exponential growth phase (days 5–7). The highest release of DOC was also recorded in the same growth phase and accounted for 24.0 μM C day−1.

Three surveys were made in 1963 and five in 1964 in the area of the English Channel between the English and French coasts and between 3° 40' W and 5°10' W. This area had been surveyed in 1961 and 1962. Temperature and salinity were determined at o, to and 50 m and phosphate silicate and nitrate at 10 and 50 m. The results are presented graphically. Temperature and salinity were compared with Lumby's 25–year averages. The year 1963 started with unusually low temperatures and salinities higher than average. Temperature remained low in the spring, but salinity decreased. The year 1964 started with temperatures and salinities above normal, but during the rest of the year values were close to average. Nitrate in January 1964 was higher than in January 1963. Analyses of suspended matter at 12m were made for carbon, nitrogen and phosphorus on most surveys, and mean values for the whole area are given. Suspended carbon was 67 /ig C/l. in January 1963 and 51 /*g C/l. in January 1964, a significant difference. Increases in sus-pended carbon, nitrogen and phosphorus were found in spring and summer 1964.

Egg clutch brooding and larval release behaviour are common among decapods and involve pheromone communication between the developing embryos and the brooding female. We tested caridean shrimps to determine whether their behaviour was similar to other decapods. In tests with aqueous extracts of crushed eggs and peptide pheromone mimic shrimps responded similarly to brachyurans and lobsters. The elongate body form of shrimps enabled us to focally stimulate body locations with the goal of determining the location of pheromone receptors. The receptors for the pheromones are likely located on the bases of the walking legs or on the gills, not on the pleopods, first walking legs, antennae or antennules. Shrimps are another example of organisms that use peptides generated by trypsin-like serine proteases as pheromones and signal molecules.

The olfactory organs in juvenile Dascyllus aruanus and Amphiprion ocellaris, studied by scanning and transmission electron microscopy (SEM and TEM), consisted of two bilaterally radial rosettes per specimen, fan-shaped, located medio-ventrally, one in each of two olfactory chambers. In D. aruanus the rosette comprises six lamellae, three on each side of a midline raphe; in A. ocellaris 12 lamellae, six on each side. In both species, the sensory regions in the lamellae are continuous, except for the margin of the lamellae, and richly covered with stereocilia. Areas with juvenile bipolar receptor cells were observed in both species. Two dissimilar types of olfactory receptor cells in the sensory epithelium: ciliated and microvillous were observed.

A frontal region is predicted in Lyme Bay from a numerical model. A crescent-shaped feature is occasionally identified in the coastal-zone colour scanner imagery for this region. Measurements at sea confirm the development of a frontal zone which can show associated increases in levels of chlorophyll a. The surface distributions of inorganic nutrients indicate that nutrients and light levels are factors controlling the observed variations of surface phytoplankton.

Several specimens of monstrilloid copepods were collected in different localities of Brazil between 1993 and 1997. The taxonomic analysis of these specimens yielded the identification of two new species of Monstrilla. The first one, M. careli sp. nov. can be distinguished by a combination of several characters, including its body proportions, with a very long cephalothorax, by the particularly long terminal segment of the antennules, by the structure of its fifth legs, and by the very long dorsal seta on the caudal rami. The second species, M. brasiliensis sp. nov. can be distinguished by the peculiar features of its fifth leg, with a patch of long and stout hair-like setae along its outer margin; it has also a notched protuberance near the antennule bases. It has a notch on the anterior protuberance of the genital somite, and a ventrally swollen cephalothorax. This species, together with M. inserta Scott bears a pair of enigmatic structures which are either modified sensillae or a vestigial postantennular appendage not previously described in the Monstrilloida.

The taxonomy of Magellanic and Antarctic cadlinids has been for many years in extreme disorder, and the species were not reliably identifiable. Recent collections in Chile and Argentina, mainly by SCUBA, and re-examination of type material provided data for a comprehensive revision. The present study gives new morphological information on all southern species, both by scanning electron microscope examinations of cuticular structures and detailed microanatomical investigation of the genitalia. The high Antarctic Cadlina affinis does not possess an aberrant androdiaulic genital system but, as all other doridoidean nudibranchs, a triaulic system with a separate vagina and nidamental duct. The vaginal duct is short and leaves the vagina distally, distinguishing this species from other known cadlinids. The genitalia of the holotype of C. kerguelensis from Kerguelen Island have been re-examined. In contrast to previous assumptions, it is not conspecific with cadlinids from South Georgia and the Magellanic region because of clear differences in the genital system. The south-western Atlantic C. magellanica is redescribed and considered to be conspecific with the holotype of C. falklandica from the Falklands. A specimen previously assigned to C. falklandica from South Georgia, however, differs from other southern cadlinids due to genital features and is redescribed as C. georgiensis sp. nov. The Argentinian species C. laevigata and C. berghi, cannot be clearly distinguished from C. sparsa, of which a lectotype has been designated and, therefore, are regarded as junior synonyms. Five Cadlina species from the Southern Ocean are regarded to be valid, and their biogeography is briefly discussed.

There is some controversy about the strength of the stock of mackerel in the Celtic Sea and off the coasts of Cornwall and Ireland, and it is difficult to find out if the numbers of mackerel in this area have fluctuated in the past (Johnson, 1977; Lockwood & Johnson, 1976; Lockwood, 1978; Coombs, Pipe & Mitchell, 1977,1979, 1980). The earliest complete survey of the south-west spawning grounds was made in 1937–9 (Steven & Corbin, 1939; Corbin, 1947) and was principally designed to show the seasonal and geographical pattern, not provide a basis for stock evaluation. Nevertheless, this survey is the only information we have about the breeding of mackerel in the days before the war when fishing was performed with drift-nets and lines, a period when we can assume exploitation was very much less intense than today when trawls and purse-seines are used. Attempts to use the 1937–9 data for estimation of the pre-war stock have been regarded as giving unsatisfactory results (Walsh, 1976). The data from the 1937–9 surveys were defective because we did not know the influence of the depth of fishing of the nets in relation to the vertical distribution of the eggs, nor the efficiency and catching capacity of the nets for sampling eggs and post-larvae.

Three new species of free-living marine nematodes Micoletzkyia longispicula sp. nov., Micoletzkyia filicaudata sp. nov. and Micoletzkyia nanhaiensis sp. nov. from the Yellow Sea and the South China Sea are described. Micoletzkyia longispicula sp. nov. is characterized by spicules elongated and straight, 7 a.b.d. long, pear-shaped proximally and pointed distally; gubernaculum conical, without apophysis, and tubular supplement headlike proximally. Micoletzkyia filicaudata sp. nov. is characterized by slender body with relatively long filiform tail (8.1 a.b.d.), spicules elongated and straight (4.4 a.b.d.), cephalate proximally and pointed distally, gubernaculum tubular, with dorsal apophysis. Micoletzkyia nanhaiensis sp. nov. is characterized by spicules slender and curved, 2.5 a.b.d. long, cephalous proximally and chapiter-shaped distally, and gubernaculum with relatively long dorsal apophysis. A key for all known species of Micoletzkyia is proposed.

Stauromedusae are cnidarians that have attracted relatively little ecological study, especially in the southern hemisphere. They are Scyphozoa that develop directly from the scyphistoma, and each consists of a calyx and a more or less distinct aboral peduncle that attaches to the substratum by an adhesive disc. The animals are mobile on the substratum, but have no pelagic phase. The present note originates from observations made on stauromedusae living in intertidal and shallow subtidal waters at Husvik Harbour, South Georgia (54°11′S 38°40′W) in early 1994. The species concerned was identified from Kramp (1961), Carlgren (1930) and Pfeffer (1889) as Haliclystus antarcticus Pfeffer, 1889. This species has attracted little previous study. The most detailed anatomical description was given by Carlgen (1930), while distributional details are given in O'Sullivan (1982) who followed Pfeffer (1889); at present there is no evidence that the species occurs other than at South Georgia.

Medusae were found on two substrata. Large animals (~30mm high, inconspicuous dark brown in colour) were found on the underside of boulders at extreme low spring tide level in a bay on the north of Husvik Harbour about 1·2 km from the whaling station and close to Brain Island. Locally they were common, often being close enough to touch one another. Smaller animals (pink-orange in colour; cryptic on the macroalga) were found attached to the brown macroalga Desmarestia menziesii J. Aghardh (Phaeophyceae) collected at low-water spring tide level from Kanin Point on the southern shore of the harbour. Medusae on boulders were briefly emersed on particularly low tides: they collapsed, hanging from the peduncle, when out of water, but did not risk desiccation as their habitat was wet and not exposed to the sun.

The soft-sediment marine benthos is well-known to be patchily distributed. To test whether this could be caused by individual epifaunal movement, spatial and temporal variation in numbers of adult mudsnails, Hydrobia ulvae, were analysed within an area of 40 m2 on an intertidal mudflat over periods of 4 or 6 d on three occasions, two of spring tides and one of neap. Significant spatial variation was always present, and significant temporal variation occurred during the spring tides. There was no variation dependent on the numbers of replicate samples taken from each station. Furthermore, movement of large, individually marked winkles, Littorina saxatilis, in the same habitat was measured and shown to be significantly directional over three series of spring tides, although the mean angle of movement varied widely between the different tidal series; storm-induced movement was particularly large. Such directional movement could account for the temporal and spatial variation seen in H. ulvae. Distances moved by winkles under permanently submerged conditions, however, did not display any directional component. Estimates of the population density and dispersion of potentially mobile or movable, intertidal epibenthos obtained on a series of individual, widely spaced days must therefore be treated with caution, however much replicated on any given occasion.

In a previous paper (1924) the writer considered the factors which bring about the mixing of surface water, warmed by the sun, with the cooler water below. Observations were cited to show that in the English Channel, between May and September, a warm surface layer may exist, which differs from the deeper water in being more alkaline and poorer in phosphates; both these differences are due to the activity of the phyto-plankton. The reduction in phosphate proceeds in the upper well-illuminated layer till none is left. No further increase in phytoplankton is then possible till phosphate is set free by decomposition or supplied by mixing with the deeper water. The phenomena of thermal stratification are consequently of great importance in the study of the phyto-plankton.

Ontogenic change patterns in otolith Sr:Ca ratios were examined in the Russian sturgeon, Acipenser guldenstadti in the Caspian Sea. Otolith Sr:Ca ratios fluctuated widely during the life history in accordance with the migration pattern from freshwater to brackish water habitats, i.e. all specimens exhibited a typical anadromous pattern in the ratio. Several specimens had two transition points in otolith Sr:Ca ratios from the low ratios to the high indicating that those specimens had a flexible migration strategy in the ambient water and had the possibility of migrating downstream to the Caspian Sea multiple times after spawning in a freshwater habitat.

The population biology and habitat of Haliclystus auricula was studied from samples taken every two months in southern Chile between November 2001 and November 2002. A total of 3790 medusae were collected and examined. The abundance of H. auricula varied seasonally. Maximum densities occurred in summer (1405/m2) and minimum densities during the winter, when the population gradually disappeared. Gonads were observed in medusae starting from a size of 2·0 mm. Stauromedusae were found most often on the red filamentous alga Ceramium rubrum (69%), followed by Gymnogongrus furcellatus (12%) and Ulva sp. (10%). There were highly significant differences in mean abundance of medusae on these three algae (P<0·05). The remaining 9% of medusae were found on other seaweeds. The smallest medusae (0·08–0·9 mm umbrella height) were found exclusively on C. rubrum. The highest densities were recorded in the midlittoral zone.

Killary Harbour is a fjord-like inlet on the west coast of Ireland and is an important site for suspended culture of mussels. As part of a study of the production ecology of the inlet, the zooplankton fauna was sampled quantitatively at two week intervals, between February 1981 and January 1982 using nets with mesh apertures of 90 and 335 μm. The dominant holozooplankton species of Killary Harbour are typical of inshore or neritic waters but there are also representatives of estuarine and oceanic faunas. Inflow of water into the bay below the surface layer of low salinity apparently maintains conditions suitable for neritic species and accounts for similarities between the zooplankton faunas inside and outside the bay. Large populations of estuarine species presumably do not develop because of the variability of freshwater discharge. During September 1981 there was evidence of an intrusion of oceanic water into the bay.

We assessed the distribution, diversity and abundance of corals in Pakistani waters. A total of 29 hard coral species (eight families and 14 genera), one black coral species and eight soft coral species (three families and seven genera) were recorded from 18 dive sites at nine locations along the coastline. Distribution of hard corals was extremely poor at Mubarak Village and Sandspit, and corals were not found at Goth Abdul Rehman, Gadani (Kuchiani) and Buleji. Moderately rich coral communities were recorded at Churna Island and at more exposed sites around Astola Island. By contrast highly diverse hard coral communities, with up to 80% cover, were found only at the northern sheltered side of Astola Island where Favites complanata, Favites pentagona, Coscinaraea monile and Porites nodifera were the most abundant species. Favites complanata was recorded from most dive sites at Astola Island. Porites nodifera and Pocillopora damicornis, and to a lesser extent Porites harrisoni, Leptastrea pruinosa and Psammocora obtusangulata formed large single species stands. No ‘true’ coral reef was found at any dive site; however, the formation of proto-reefs was evident around Astola Island. Soft corals were dominant at most exposed sites, particularly at Ormara (Roadrigues Shoals) and Jiwani. By comparing diversity with other locations in the region, corals distribution and growth appear to be fairly poor in Pakistan.