bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Fish Assemblages Sampled by a Shrimp Trawl and a Fish Trawl in St Vincent Bay, New Caledonia
Authors: Wantiez Laurent
Published: May 2009

The spatial and temporal patterns of variation of a tropical soft-bottom fish community sampled by a shrimp trawl and a fish trawl were compared at two sites, North and South Bay, of St Vincent Bay, New Caledonia. Results indicated that the species richness and particularly the species composition were related to the type of trawl. However, the overall density and biomass, species diversity, and evenness did not vary significantly as a function of gear type. The same species dominated the catches of the two trawl types, but differences appeared between density, biomass and mean weight of particular species, calculated from the shrimp and the fish trawl catches. The spatial variations of the community structure were comparable between the two gear types, though the composition of the species assemblages were not the same. Differences appeared for the temporal structures. These differences were insignificant in one of the sampled sites (North Bay), but more important in the other site (South Bay), where species diversity, size range of the individuals, and shape diversity of fishes were more important. However, the major differences between the community structures remained the same, independent of sampling gear type. These results validate studies comparing spatial and temporal patterns of variations in general characteristics (i.e. number of species per haul, density, biomass, species diversity and evenness) of tropical soft-bottom fish communities determined by shrimp and fish demersal otter trawls. This also validates the determination of species assemblages especially spatial assemblages. However, important problems may arise when more particular points are studied, such as species composition of the communities, determination of the characteristic species of the assemblages, or study of a particular species.
Acoustic Assessment of Populations of Common Dolphin Delphinus Delphis In Conjunction With Seismic Surveying
Authors: Goold John C.
Published: May 2009

Common dolphin, Delphinus delphis (bairdi), were monitored acoustically across a survey area of 2747 km2 during a three month period before, during and after an oil industry two dimensional (2D) seismic reflection survey. Over 900 h of audio survey data were collected and analysed, along with GPS positional data, to reveal trends in presence and distribution of animals. The presence of dolphins was determined from vocalization events on the survey recordings. Dolphin presence was assessed by a system of percentage acoustic contact. This was highest before and after the seismic survey, with common dolphins showing a clear south-westerly skew within the survey area and a probable south-westerly migration of animals between September and December. Acoustic contact with dolphins during the seismic survey also showed a south-westerly skew within the survey area, although percentages were lower. Monitoring during the period of seismic activity was restricted to the immediate vicinity (1–2 km) of the seismic vessel, so percentage contact most likely reflects the response of dolphins to such immediate activity. The overall result suggests an avoidance reaction by common dolphins to air gun emissions, although certain observations suggest tolerance to these sounds outside a 1 km radius of the guns.
On the ecology of a dense bed of the brittle-star Ophiothrix fragilis
Authors: Warner G. F.
Published: May 2009

INTRODUCTION

The occurrence of dense beds of the brittle-star Ophiothrix fragilis (Abildgaard) in certain localized areas around the British Isles has been reported by several authors (Allen, 1899; Vevers, 1952; Cabioch, 1961; Holme, 1961; Brun, 1969), with population densities varying from 340/m2 (Vevers, 1952) to 2196/m2 (Brun, 1969). These populations seem to be permanent features of the sea bed since the aggregation sampled by Allen was in the same position as that photographed by Vevers fifty years later.
The biology of Paramysis arenosa [Crustacea, Mysidacea]
Authors: Mauchline J.
Published: May 2009

INTRODUCTION

Paramysis arenosa (G. O. Sars) occurs quite commonly in sandy bays on the west coast of Scotland. It is common in Kames Bay, Millport, Brodick Bay on Arran and on Fairlie Sands in the Firth of Clyde. It has been taken in Loch Crinan, Argyll and at Ganavan Sands and Loch Nell Bay, both north of Oban, Argyll. It is common in Firemore Bay, Loch Ewe and in Gairloch and Gruinard Bay in Wester Ross.
The biology of Neomysis integer [Crustacea, Mysidacea]
Authors: Mauchline J.
Published: May 2009

INTRODUCTION

There are more than twenty species in the genus Neomysis Czerniavsky, of which the only British representative is N. integer (Leach). This is one of the commonest species of mysids round the coasts of Britain. It lives in estuarine, brackish-water situations and Tattersall & Tattersall (1951) have summarized its distribution. The present investiga- tion has added many records from the west coast lochs of Scotland: Lochs Striven, Riddon, Fyne, Gilp, Ranza in the Firth of Clyde; Lochs Craignish, Feochan, Etive, Creran, Shuna, Linnhe, Eil and Torridon farther north. The biology of Neomysis species is much better known than that of species in other genera:N. americana (Smith) has been studied by Cowles (1930), Whiteley (1948), Hulburt (1957) and Hopkins (1965); the biology of N. awatschensis (Brandt) has been examined by Ii (1964) and Turner & Heubach (1966), that of N. czerniawskii Derjavin and N. intermedia (Czerniavsky) by Ii (1964), that of N.japonica Nakazawa by Ishikawa & Oshima (1951) and Ii (1964), that of N. rayii (Murdoch) and N. spinosa Nakazawa by Ii (1964).
The meiofauna off the coast of Northumberland. II. Seasonal stability of the nematode population
Authors: Warwick R. M. , Buchanan J. B.
Published: May 2009

INTRODUCTION

In an earlier paper (Warwick & Buchanan, 1970) the structure of the nematode communities at three stations off the Northumberland coast was compared. It was shown that the offshore mud community at station ‘C’ was faunistically the most homogenous. This station has been selected for a more intensive investigation of meiofaunal production since it provides the simplest situation for study, and furthermore the type of nematode community found here is thought to be of common occurrence in similar sediments round Northern Britain.
Intertidal activity, breeding and the floating habit ofHydrobia ulvaein the Ythan estuary
Authors: Anderson A.
Published: May 2009

INTRODUCTION

Ecological studies of EiderSomateria mollisima, ShelduckTadorna tadorna, RedshankTringa totanus[Aves], and FlounderPlatichythys flesus[Osteichthys], in the estuary of the River Ythan, Aberdeenshire, have entailed investigations of their food requirements, and there is evidence to suggest thatHydrobia ulvae[Gastopoda], as a numerous food item common to all, may in some instances have influenced their breeding success and numbers in some years. In order to get an index of abundance ofHydrobia, the Ythan population has been sampled four times a year since May 1963. The full results of this sampling programme are being published separately. At the same time data on the annual cycle ofHydrobiawere collected from one area (transect number 3, Fig. 1), on the assumption that breeding onset and intensity would be the same in other parts of the estuary in any one year.
Terpenoid quinones and steroids in the nutrition ofOxyrrhis marina
Authors: Droop M. R. , Pennock J. F.
Published: May 2009

INTRODUCTION

Oxyrrhis marinaDujardin is among the few phagotrophic micro-organisms, and the only dinoflagellate with this mode of nutrition, to have been cultivated under axenic conditions. In common with most other phagotrophs studied,Oxyrrhishad to be supplied with a natural source of lipid growth factors for axenic cultivation, lemon rind or grass extracts in this instance (Droop, 1959). The eventual replacement of these natural sources by ubiquinone (Droop & Doyle, 1966) cleared the way for the development of a completely denned culture medium forOxyrrhisand the completion of the nutritional study, the water-soluble nutrients having been fully worked out previously (Droop, 1959). However, identification of this requirement immediately raises two questions. The answer to the first, whether ubiquinone is the only lipid required, appears to be in the negative, and the details of an additional, fairly specific, steroid requirement are presented in the second part of this paper. The other question concerns the specificity of the quinone requirement. Is the quinone merely a convenient source of the benzene ring – mammals require at least one aromatic compound in the diet – or does it act as a true growth factor, in which case the requirement would be unique and would have more than protozoological interest?
On the occurrence of detached spherical colonies of the hydroids Sarsia tubulosa and Tubularia larynx in morecambe Bay
Authors: Clare J. , Jones D. , O'Sullivan A. J.
Published: May 2009

While it is known that the hydroid Clytiajohnstoni (Alder) may get broken off and drift in the plankton (Russell, personal communication), rounding off into pelagic colonies, there is, however, no record of the hydroids Sarsia tubulosa (M. Sars) and Tubularia larynx (Ellis and Solander) living under similar conditions.
The Gaia Hypothesis - Fact or Fancy?
Authors: Craik J.C.A.
Published: May 2009

Many large-scale properties of the biosphere are affected or determined by the activities of living organisms and are maintained at remarkably constant values over long periods. For example, the oxygen content of the atmosphere appears to have been maintained near its present value for hundreds of millions of years, despite the rapid flux of oxygen between production by plants and consumption by animals and decomposing microorganisms. (In this article, I shall use 'biosphere' to denote the whole of the concentric shell of the planet Earth which holds life, and 'biota' to mean all living organisms. Others have sometimes used 'biosphere' to mean the latter.) Lovelock was the first to show clearly how the composition of the Earth's atmosphere, unlike that of Mars or Venus, was held well away from thermodynamic equilibrium by the activities of living organisms (Lovelock, 1983). Other biospheric properties, such as temperature and oceanic pH and salinity, have similarly remained fairly constant despite the existence of large perturbing influences (Lovelock, 1979).
Morphology of the Nervous System of Barnacles: the Median Ocellus ofBalanus Hameri (=Chirona Hameri)(Crustacea: Cirripedia)
Authors: Clare A.S. , Walker G.
Published: May 2009

The barnacle cypris larva possesses a pair of laterally placed compound eyes and a median nauplius eye which is tripartite in structure. Concomitant with the metamorphosis to the juvenile is the loss of compound eyes and the nauplius eye separates into its three constituent parts (Walley, 1969). The two dorsolateral components of the nauplius eye come to lie under the rostral shell plates, whereas the ventral component forms the median ocellus which underlies the mantle flaps of the scutal plates at the posterior margin of the adductor muscle (Figure 1).
In SituForaging and Feeding Behaviour of Narcomedusae (Cnidaria: Hydrozoa)
Authors: Larson Ronald J. , Mills Claudia E. , Harbison G. Richard
Published: May 2009

Narcomedusae are a small and mostly oceanic group of hydromedusae whose tentacle morphology and comportment sets them off behaviourally and perhaps ecologically from most other medusae. Their tentacles are relatively few in number (2–40), stiff, and noncontractile, with points of insertion located well above the bell margin. Eleven species representing eight narcomedusan genera (Aegina, Aeginura, an undescribed aeginid,Cunina, Pegantha, Solmaris, Solmissus, andSolmundella) were observed and collectedin situin the NW Atlantic, Arctic and Antarctic, using scuba and manned submersibles. In life, the tentacles of narcomedusae are nearly always held upwards over the bell or projected laterally. The major prey were other gelatinous zooplankton, especially salps and doliolids. In the laboratory, these relatively large prey were caught on the tentacles which bend inward and coil at the tips to bring food to the mouth. By extending the tentacles perpendicular to the swimming path, these medusae achieve a relatively large encounter area, thus increasing the probability of contact with prey, for the amount of protein invested in tentacles.
Laboratory Studies on the Development of Nephrops Norvegicus Larvae
Authors: Thompson Brenda M. , Ayers R.A.
Published: May 2009

Nephrops norvegicus (Linnaeus, 1758) is a valuable commercial shellfish species. UK landings in 1986 totalled 25,515 tonnes with a market value of over £39 million. It is difficult to estimate stock abundance using trawl surveys because of seasonal changes in the availability of females which tend to remain in their burrows whilst berried (ovigerous) (Chapman, 1980). An alternative method is to assess the number of mature adults in the stock using fecundity data and abundance estimates of larvae derived from plankton surveys (Thompson et al., 1986; Nichols et al., 1987). Estimates of the age of larvae are necessary to enable daily and seasonal production rates to be calculated from abundance data. Water temperature causes considerable variations in the development rate of planktonic Crustacea (Winberg, 1971; Thompson, 1982), and reliable estimates of larvae production therefore require knowledge of the relationship between stage duration and water temperature. This paper describes the results of laboratory experiments carried out from 1984 to 1986 to study this relationship in the three free-swimming stages referred to as zoea I-III by Farmer (1974). Stage IV is generally accepted as the first juvenile stage (Anger & Püschel, 1986). The morphology and general biology of Nephrops larvae are described by Farmer (1975) and Nichols et al. (1987); these authors comment on the scarcity of data concerning the effect of temperature on stage duration.
Rearing herring larvae to metamorphosis and beyond
Authors: Blaxter J. H. S.
Published: May 2009

The use of natural plankton and other foods, and of transfer techniques during phases of mortality before metamorphosis, has made it possible for substantial numbers of herring larvae to be reared beyond this stage, thus supplying requirements for experimental work. A survival to and beyond metamorphosis of over 10% of larvae passing the yolk-sac stage (3–4% of hatched larvae) has been obtained.
Seasonal changes in the calcium content of the blood of arctic cod
Authors: Woodhead P. M. J.
Published: May 2009

A well-marked seasonal cycle in the total calcium content of the plasma was shown to occur in adult cod,Gadus morhuaL., of both sexes: these changes were not found in juvenile, immature cod. The changes in concentration of plasma total calcium appeared to be associated with gonadal maturation, the period of hypercalcaemia coinciding with the maturation cycle and the plasma calcium falling to a resting level again after spawning. Seasonal changes were greatest in the female cod and it is suggested that the raised level of calcium is associated with vitellogenesis in the ripening ovary, probably under the influence of oestrogens. The cycle in the male is not yet fully understood.
Observations on the keeping of adult female Pseudocalanus elongatus under laboratory conditions
Authors: Corkett C. J. , Urry D. L.
Published: May 2009

Stocks of adult female Pseudocalanus elongatus have been kept for the past 6 years in a laboratory remote from the sea. The techniques used in maintaining these stocks are described.

The most suitable temperature for keeping the copepods has been found to be 10 °C.

The control of pH has not been necessary.

Although an allowance of 30 ml. of sea water for each copepod is recommended, it has been found that survival is not affected by densities of up to 1 copepod/10 ml.
Photochemical combustion of organic matter in sea water, for nitrogen, phosphorus and carbon determination
Authors: Armstrong F. A. J. , Tibbitts Susan
Published: May 2009

A photochemical reactor, using a medium power mercury arc lamp for oxidation of organic matter in sea water, is described. The decomposition of some known compounds in distilled water and in sea water, using a 380 W lamp, was followed. First order kinetics with rate constants in the range 0·2–4·0 h−1 were observed. All the nitrogen compounds tested, including urea and some of its derivatives, were oxidized quantitatively. Breakdown of phosphorus compounds was rapid, but polyphosphate esters yielded polyphosphate ion which was only slowly hydrolysed to reactive orthophosphate. If polyphosphate is to be determined, hydrolysis by heating with acid should follow the irradiation. Some samples of English Channel water contained 0·02-0–05 fig-axom P/1. as organic polyphosphate.
Micro-organisms attached to marine sand grains
Authors: Meadows P. S. , Anderson J. G.
Published: May 2009

The distribution, abundance, and types of micro-organisms attached to littoral and sublittoral sand grains have been described. Micro-organisms are present in colonies, ranging from 5 to 150 cells per colony. Many colonies consist of one species. Some colonies are in or surrounded by staining material, others are on flat unstained surfaces. Colonies in staining material often occur in hollows. Large areas of surface between the colonies and staining material are completely bare. Evidence suggests that abrasion may stop micro-organisms colonizing flat or convex surfaces. On grains from the sediment surface, bacteria, blue-green algae (Cyanophyceae), and diatoms (Bacillariaceae) are common. The microbial flora may alter only slightly to depths of 15 cm below the sediment surface, or may change within a few mm. It is sparse towards high water, but differs little between lower littoral and sublittoral sands. The results are discussed in relation to substrate selection by marine invertebrates.
Temporary adsorption on a substrate of an oil-spill remover (‘detergent’): tests with larvae of Sabellaria spinulosa
Authors: Wilson Douglas P.
Published: May 2009

Sand was soaked for 90 min in sea water containing the ‘detergent’ BP 1002 in concentrations of 1000 and 100 ppm (= mg/1.) and then thoroughly washed. Larvae crawling on it soon afterwards were damaged, but the toxic effect disappeared after some days.
Histology, histochemistry and enzyme biochemistry of the digestive glands in the tropical surf barnacle Tetraclita squamosa
Authors: Johnston D. J. , Alexander C. G. , Yellowlees D.
Published: May 2009

The tropical surf barnacle Tetradita squamosa (Bruguière) (Crustacea: Cirripedia) has a pair of lobulate digestive glands each connected to the dorsal surface of the foregut by a single duct. These glands have a central lumen surrounded by columnar epithelial cells and are the primary site of enzyme synthesis and secretion within the alimentary tract. A number of carbohydrases and proteases were detected, all of which exhibited optimal activity at an acidic pH. Gland cells discharge secretory products into the foregut ventriculus via apocrine secretion and this process is continuous; it is not correlated with tidal and subsequent feeding cycles. Possible reasons for the absence of feeding and secretory co-ordination are discussed.
Ionic regulation and buoyancy in some planktonic organisms
Authors: Newton C. , Potts W. T. W.
Published: May 2009

Magnesium/chlorine and sulphur/chlorine ratios have been measured in the body fluids of some planktonic organisms by x-ray emission analysis of frozen hydrated specimens in a scanning electron microscope.Homarus vulgaris(Anthropoda: Decapoda) larvae excluded Mg2+and SO42-ions from the haemolymph, but to a lesser extent than does the adult lobster. Bipinnaria larvae ofAsterias(Echinodermata) excluded Mg2+and SO42-ions from the coelomic fluid.Obeliamedusae excluded Mg2+and SO42-ions from the mesogloea but concentrate them in the gastrovascular system. The high concentration of sulphate in the gastrovascular fluid of medusae has been confirmed by rhodizonate titration inCyaneaandRhizostomajellyfish. Some implications of magnesium and sulphate regulation are discussed.
Population biology ofMeiogymnophallus minutus(Trematoda: Gymnophallidae) in cockles from the Exe Estuary
Authors: Goater Cameron P.
Published: May 2009

Spatial, seasonal and age-related differences in infection of the cockle,Cerastoderma edule, with the trematodeMeiogymnophallus minutuswere studied on the Exe Estuary, England. Prevalence of infection was 100% across all samples with mean abundances between approximately 300 and 1000 larvae per host (maximum=4930 larvae). Aggregration of M.minutusin cockles was extremely high (variancermean ratios >100) and increased linearly as abundance increased. Mean abundance was highest in cockles collected from muddy substrates where the average age of cockles was high. In summer, numbers of larvae fell to less than half of spring levels and then increased after infection by a new wave of cercariae in August. Cockles accumulated larvae for up to 2 y but not thereafter, and levels of aggregation fell in the oldest age class. A peaked pattern of mean abundance and aggregation with age may be a result of parasite-induced death of older hosts or may be due to the inability of cercariae to establish in older hosts.
First Record of the American Jack Knife ClamEnsis Directuson the French Coast of the North Sea
Authors: Luczak C. , Dewarumez J.-M. , Essink K.
Published: May 2009

Ensis directus(Bivalvia: Solenidae) was noted for the first time along the French coast of the North Sea in June 1991. High numbers of post larvae after a period of northerly winds indicate that settled larvae originated from adult populations in Belgian or Dutch coastal waters. Future dispersal ofEnsis directuscould be used as a biological tracer of coastal water movements between the Southern Bight of the North Sea and the English Channel.

The American jack knife clam,Ensis directus(Conrad, 1843), synonymEnsis americanus(Binney, 1870)sensuvan Urk (1964,1972), was discovered in Europe in the German Bight for the first time in June 1979 (Von Coselet al., 1982). This species is assumed to have been transported in its larval stage by a ship containing ballast water. Considering the dimensions of the specimens, this probably happened in the first half of 1978 (Von Coselet al., 1982; Mühlenhardt-Siegelet al., 1983). Since then this species has spread rapidly in the North Sea in subtidal and intertidal areas. Dense populations were found along the German coast within a few years (Von Coselet al., 1982; Mühlenhardt-Siegelet al., 1983; Swennenet al., 1985). In 1986 Ensisdirectuswas reported from the north and east Danish coasts as far as the Belgian coast (Kerkhof & Dumoulin, 1987) (Figure 1). Since then no new records have been reported.
The spatial and temporal development of the spring bloom during the JGOFS North Atlantic Bloom Experiment, 1989
Authors: Weeks A. R. , Fasham M. J. R. , Aiken J. , Harbour D. S. , Read J. F. , Bellan I.
Published: May 2009

The south to north development of the spring bloom in the North Atlantic Ocean was observed during four cruises from April to August 1989. Transects with towed undulating instrumentation packages and CTD profiles on station were made between 42°N and 54°N, along 17°W and 20°W in April and between 47°N and 60°N along 20°N in May, June and July/August, giving vertical sections of temperature and chlorophyll concentration derived from in vivo fluorescence. These sections show the relationship between the onset of seasonal stratification and the initiation of the spring bloom. Supporting data from microscopic analysis of the major phytoplankton species show that the seasonal succession commenced with diatoms, followed in turn by coccolithophores, flagellates and dinoflagellates. During the development of summer stratification the mesoscale distribution of chlorophyll was strongly determined by the depth of the mixed layer, but once stratification had been firmly established higher chlorophyll values tended to be found within the warmer eddies (meanders). One possible explanation of this result is that phytoplankton growth is higher in the warmer eddies.
Settlement and growth of the intertidal gastropod, Melarhaphe neritoides, on the south coast of Ireland
Authors: Myers A. A. , McGrath David
Published: May 2009

Settlement and growth of Melarhaphe neritoides (L. ) were studied on two rocky shores, at Carnsore Point, County Wexford and Tragumna, County Cork, on the south coast of Ireland during the years 1977–1978 and 1983–1991 respectively. Settlement occurred in each year but varied in timing and density, with maxima of 30,000 m-2 at Tragumna and 3,800 m-2 at Carnsore Point. Recently settled individuals occurred in pools in the Verrucaria zone and on open rock below this level. Growth of the 0+ and 1+ cohorts was determined by analysis of length frequency distributions. Growth of older snails was estimated by measuring growth increments in marked animals. Recruits grew to less than 2 mm in shell height in their first year. Larger snails (>2 mm shell height) grew 0. 2–0. 3 mm shell height per year. It is estimated that M. neritoides takes over five years to reach a shell height of 3 mm at Tragumna.
Density-dependent growth in cockles (Cerastoderma edule): evidence from interannual comparisons
Authors: Jensen K. Thomas
Published: May 2009

To examine density-dependent effects on growth in Cerastoderma edule (L.) (Bivalvia), growth rates of individual cockles established by chance at high and low densities on the same intertidal mudflat in two different years (1984 and 1989) were compared. Two-year-old cockles occurring at high densities (>2000 individuals m-2 in 1984) attained mean lengths from 16.1 to 18.8 mm on the lower shore at the end of their third growing season, while low-density cockles (<50 individuals m-2 in 1989) of the same age reached mean lengths in the range of26.5 to 30.3mm. In terms of individual weight the difference between cockles from the two periods was even more striking, as the flesh ash-free dry-weight of a cockle from 1984 constituted only 7% of that from a 1989 cockle. During both periods growth in cockles increased with the duration of tidal submersion, but the interannual growth differences exceeded by far the effect of differences in submersion time.
Mesacanthion Diplechma (Nematoda: Thoracostomopsidae), a Link to Higher Trophic Levels?
Authors: Hamerlynck Olivier , Vanreusel Ann
Published: May 2009

The nematode Mesacanthion diplechma Southern is relatively rare in sediments of the Southern Bight of the North Sea and the Dutch Delta. Strangely, it is about the only free-living nematode found in the stomachs of the sand goby Pomatoschistus minutus Pallas from the same general area and even more peculiarly several hundred animals were found in sand gobies from the central part of the Oosterschelde. The large size of the nematode and its preference for the superficial sediment layers are probable causes for the first observation. For the second observation there is at present no explanation that can be substantiated. Some nematodes are known to aggregate on dead animals and possibly the Oosterschelde gobies may have been feeding on such an aggregation.
Reproductive biology of two epizoic anemones from the deep north-eastern Atlantic Ocean
Authors: Bronsdon S. K. , Tyler P. A. , Rice A. L. , Gage J. D.
Published: May 2009

The reproductive biology of two epizoic deep-sea anemones reveals contrasting reproductive strategies.Amphianthus inornata(Cnidaria: Anthozoa) lives attached to the bathyal gorgonianAcanella arbuscula(Cnidaria: Anthozoa). Females of A.inornataincrease in wet body weight as a result of increased oocyte production until 40% of the body weight is reproductive tissue. The anemone reproduces on a seasonal basis, releasing eggs in the early spring of each year. By contrast,Kadosactis commensalis(Cnidaria: Anthozoa) lives attached to the body wall of the abyssal holothurianParoriza prouhoi(Echinodermata: Holothurioidea). This anemone is a protandric hermaphrodite, females being found only at the anterior end of the holothurian, whilst males are found at any point on the host. Females have a significantly higher wet weight than males and neither sex shows any reproductive seasonality.
Food of striped dolphin, Stenella coeruleoalba, in the Ligurian Sea
Authors: Würtz M. , Marrale D.
Published: May 2009

The stomachsof 23 striped dolphins (Stenella coeruleoalba Meyen, 1833, Cetacea), stranded along the Ligurian coast (western Mediterranean Sea), contained 32 species of cephalopods, crustaceans and fishes, totalling an estimated 2,723 prey specimens representing about 36 kg in weight. Cephalopods and bony fishes were equally important in the diet (50%). Todarodes sagittatus (34.5%) and Micromesistius poutassou (25.9%) were found to be the most important food species. Other species belonging to six cephalopod families, three crustacean families and nine bony fish families, contributed to the diet with variable numbers, weights, and occurrences, demonstrating the opportunistic character of striped dolphin feeding.
Planktonic ciliates in Southampton Water: quantitative taxonomic studies
Authors: Leakey R. J. G. , Burkill P. H. , Sleigh M. A.
Published: May 2009

The species-specific abundance and biomass of marine planktonic ciliates were determined at monthly intervals at two stations in Southampton Water between June 1986 and June 1987. The two stations, an outer one at Calshot and an inner one at north-west Netley, were subject to differing marine and terrestrial influences. A total of 55 ciliate taxa were recorded during the sampling period; of these 34 taxa were identified to genus and 16 to species. The heterotrophic ciliate community at both stations was dominated by aloricate taxa which comprised >90% of the community abundance and biomass during some months. The loricate tintinnids were also common, especially at Calshot, during winter months. Oligotrichs dominated the aloricate community at both stations with haptorids prominent at north-west Netley. At Calshot,Strotnbidiumsp. dominated the heterotrophic community abundance and biomass throughout the study period, whileAskenasiasp.,Strobilidiumsp. andTintinnopsissp. were also common.Strombidiumsp. also contributed most to heterotrophic community abundance at north-west Netley.Balanionsp. andTintinnopsissp. were also abundant. However,Cydotrichiumsp. andDidiniuntsp. dominated community biomass at this station. Most taxa exhibited a seasonal cycle with low winter and high spring and summer abundances. Some taxa reached abundances of >2000 l1However, maximum abundance of one species ofTintinnopsiswas found during winter months. The autotrophic ciliate,Mesodinium rubrum, was also recorded at both stations achieving densities >105l1at north-west Netley during ‘bloom’ conditions.
A new species of Clausophyes (Siphonophorae, Clausophyidae), with a redescription of C. galeata and C. moserae
Authors: Pugh P. R. , Pagés F.
Published: May 2009

A new species of the genus Clausophyes (Siphonophora, Calycophora) is described from four anterior nectophores collected in the Southern Ocean. This species is distinguished from others in the genus by the presence of a large, undivided mouth plate on the anterior nectophore. However, in order to establish the distinctiveness of two other species in this genus, namely C. moserae and C. galeata, which a recent author has suggested should have only sub-specific ranking, the anterior and posterior nectophores of those species are redescribed.
Astomonema southwardorumsp. nov., a gutless nematode dominant in a methane seep area in the North Sea
Authors: Austen M. C. , Warwick R. M. , Ryan K. P.
Published: May 2009

A new species of mouthless and gutless free-living marine nematode,Astomonema southwardorumsp. nov., the dominant species from a methane seep pockmark in the North Sea, is described and illustrated. The new species is distinguished by its combination of short cephalic and cervical setae, with the latter being sparsely and irregularly distributed, and also in male specimens by its arrangement of precloacal and caudal setae and its postcloacal papillae. The genusAstomonemaOtt, Rieger, Rieger & Enderes, 1982, is rediagnosed.Astomonema brevicauda(Vitiello, 1971) Vidakovik & Boucher, 1987, is considered to be aspecies inquirenda.
Cadmium in the gastropod Littorina littorea
Authors: Nott J. A. , Bebianno M. J. , Langston W. J. , Ryan K. P.
Published: May 2009

Tissues of Littorina littorea (Mollusca: Gastropoda) were processed for electron microscopy with an aqueous fixative which included hydrogen sulphide to precipitate intracellular cadmium. The procedure retained cadmium in the cytosol, where it was below the detection limit for x-ray microanalysis, but it did not increase the retention of the metal within lysosomes and other sites of accumulation where it was detectable. Aqueous fixation caused extraction of labile elements, particularly magnesium and potassium, and this effect was increased by the use of hydrogen sulphide. Cadmium and hydrogen sulphide had disruptive effects on the fine structure of cells. It is concluded that cytological fixatives should not include hydrogen sulphide, and that cryo-fixation is required for x-ray microanalysis of intracellular elements.
A Male genital defect in the dog-whelk, Nucella lapillus (Neogastropoda), favouring survival in a TBT-polluted area
Authors: Gibbs P. E.
Published: May 2009

Tributyltin (TBT) pollution has exterminated populations of the dog-whelk Nucella lapillus along most of the north Kent coast (Thames Estuary) but the species survives as a small enclave around the North Foreland. Males in this enclave exhibit an unusual defect involving the non-development or partial development of the genital system: about 10% lack penes, or have undersized penes, and their gonoducts (vas deferens and prostate) are incompletely developed; in some cases, spermatogenesis appears to be retarded. Laboratory-bred animals display the same characters. This deficiency (‘Dumpton Syndrome’) is manifest also in the atypical development of male sex organs on the females (‘imposex’) induced by exposure to tributyltin (TBT). The evidence points to Dumpton Syndrome being a genetic disorder which has lessened the sterilizing effect of imposex and thereby has permitted the survival of this isolated enclave in an area of high TBT pollution.
The appearance of rods in the eyes of herring and increased di-docosahexaenoyl molecular species of phospholipids
Authors: Bell M. V. , Dick J. R.
Published: May 2009

The retina of larval herring (Clupea harengusL.) contains only cones, with rods recruited progressively from about eight weeks onwards. The molecular species composition of phospholipids from the eyes of herring of different ages was determined to find whether the appearance of di-docosahexaenoyl molecular species (di22:6n-3) of phospholipids, which are characteristic of rod outer segment membranes in higher vertebrates, coincided with the appearance of rods. In the eyes of larval herring (cone-only retina) di22:6n-3 molecular species comprised 25.9% of phosphatidylethanolamine (PE), 22.9% of phosphatidylserine (PS) and 4.2% of phosphatidylcholine (PC). In the eyes of adult herring (rod:cone ratio of about 20:1) the proportion of di22:6n-3 molecular species had increased to 49.5%, 39.0% and 16.8% in PE, PS and PC, respectively. Juvenile herring had intermediate values of di22:6n-3 phospholipids. The results confirm the hypothesis that the amounts of di22:6n-3 molecular species of phospholipids in retina increase during development as rods appear, and also show that cones contain smaller amounts of these unique lipids. Three other molecular species containing docosahexaenoic acid, 16:0/22:6n-3, 18:1/22:6n-3 and 18:0/22:6n-3 were also major components of eye phospholipids, emphasizing the important role of 22:6n-3 in vision.
Developmental Biology of Marine Organisms
Authors: Brownlee C.
Published: May 2009

In contrast to the situation found in the bivalves Barnea Candida and Spisula solidissima prophase arrested oocytes of Ruditapes philippinarum cannot be fertilized when extracted from the ovary. They must first undergo germinal vesicle breakdown (GVBD) under the influence of the neurohormone serotonin (5-HT) which drives them to a second block occurring in metaphase of the first maturation division. We used Fluo-3 to investigate the possibility that calcium was involved as a second messenger in controlling this first step in meiosis reinitiation. Our data showed that, in addition to 5-HT, ionophore, thapsigargin and the weak bases ammonia and procaine could induce prophase-arrested oocytes of Ruditapes to resume meiosis.
Mobility in Lepadomorph Barnacles
Authors: Kugele Michael , Yule Andy B.
Published: May 2009

Circumstantial evidence of mobility by the lepadomorph barnacle genus Pollicipes in the literature is supported by observations at Menai Bridge which indicate that the phenomenon is real. Although slow, movement may be in response to gravity, as a positive taxis, or light, as a negative taxis.
Intraskeletal Matrix Proteins in Echinodermata
Authors: Polson E. S. , Robbins L. L. , Lawrence J.
Published: May 2009

An intraskeletal soluble matrix protein of 83 kD was isolated from the calcareous skeletal elements of living specimens of two asteroid species, one echinoid species, and an early Pleistocene fossil specimen of an extant echinoid species. Characterization of this protein by sodium dodecyl sulphate - polyacrylamide gel electrophoresis, reverse phase liquid chromatography, and amino acid composition analysis confirms its similarity to matrix proteins from other phyla. It is composed of a relatively high percentage of the acidic amino acids especially aspartic acid. The 83 kD protein stains only faintly with silver stain and not at all with Coomassie blue, as is typical of matrix proteins. As this protein occurs in both living and fossil echinoids, its analysis may provide information about phylogenetic relations.
The Size of Diatoms IV. The cell diameters in Rhizosolenia styliformis var. oceanica
Authors: Wimpenny R. S.
Published: May 2009

Consideration has been given to the cell diameters of twenty-four samples of Rhizosolenia styliformis var.oceanica from a wide range of latitude together with material from eleven other collections already briefly recorded in Part II of this paper.

It was found that the cells of the smallest diameter occurred in high latitudesand that the average values were greater at lower latitudes.

More auxospore generations were present simultaneously in higher latitudes. An interpretation of these observations is that the prevalence of smaller cell diameters and the simultaneous presence of more auxospore generations in high latitudes could be due to relatively lighter grazing by herbivorous zooplankton in these regions.

Measurements of a few samples of a form of Rhizosolenia styliformis (Bright-well) which I called var. oceanica have been published earlier (Wimpenny, 1946), and auxospore formation was recorded from the Faroe-Shetland area. Since that time, owing to the kindness of the late Dr Vedel Taning, I have been able to see sixteen samples taken in the North Atlantic by the Danish research ship 'Dana' in1948. Mr J. Corlett of the Fisheries Laboratory, Lowestoft, has also been good enough to have made available to me three collections containing this variety from the Weather Ships 'Jig' and 'Item' in 1950 and two from the west ofBear Island in 1952. Finally, I have to add two samples of 33 and 50 specimens fromthe northern North Sea area made available to me many years ago by the late Miss Ogilvie and another sample from which I have been able to measure 100 specimens givenme by Dr James Fraser (E 34, 1934).
Vitamin A compounds and lipids in the blood of the Cod Gadus morhua from the Arctic, in relation to gonadal maturation
Authors: Plack P. A. , Woodhead P. M. J.
Published: May 2009

Cod (Gadus morhua L.) from the Arcto-Norwegian stock that spawns off northern Norway were caught at various times during the course of their gonadal maturation cycle, and plasma samples were collected for the determination of vitamin A compounds and lipids.

The main changes found concerned vitamin A aldehyde, which increased from a resting level of2μg/100 ml. plasma for adult females caught in September to 10 μ/100 ml. in ripe females caught in January-March approaching their spawning grounds; by contrast little change was observed in the males. In the fish of both sexes caught in September, just prior to the onset of maturation, dehydroretinal formed about 38 % of the total aldehyde, but in the plasma of ripe females the proportion was only 16 %. In both sexes there was a fairly steady decline in the levels of vitamin A esters and alcohol in the plasma during the winter. Similarly, the concentration of plasma lipids fell during the winter in the male cod, but in the adult females, during the period of ovarian maturation, the concentration of lipids increased and was maintained at about 0·5 g/100 ml. higher than in the males; in spent fish the concentration of lipids fell to the same low levels in both sexes.

It was considered that the changes in vitamin A aldehyde, and also of blood lipid, in the females were directly linked with sexual maturation, these compounds being transported to the developing eggs in the ovary. On the other hand, the general decline of vitamin A esters and alcohol in both sexes, and of lipids in the males, was probably due to the obligatory winter starvation which occurs in this stock.
Determination of nitrate in sea water by cadmium-copper reduction to nitrite
Authors: Wood E. D. , Armstrong F. A. J. , Richards F. A.
Published: May 2009

An accurate, dependable determination of 0–60 μg-at./l. of NO−3-N in sea water has been developed. The sample is treated with tetrasodium ethylenediaminetetraacetate solution and passed through a column of copperized cadmium filings. A nearly quantitative reduction of nitrate to nitrite results. Nitrite is then determined by a diazotization method. Neither sulphide nor high nitrite concentrations interferes. Approximately eight samples per hour per column can be analysed with a standard deviation of 0.12 μg-at./l. at the 20 μg-at./l. level.

Introduction

Accurate determinations of nitrate ions in sea water have been difficult, especially under shipboard conditions.

The colorimetric method described by Harvey (1926, 1930) and improved by Cooper (1932), Zwicker & Robinson (1944), and others uses strychnidine in concentrated sulphuric acid to produce a red colour. The reagent lacks reliable sensitivity, because it is dependent on the rates of mixing and cooling.

In a method by Armstrong (1963), the absorbance of nitrosyl chloride in the UV region is measured with a spectrophotometer. While the method is good for small samples containing high concentrations of nitrate, the use of concentrated sulphuric acid and lack of sensitivity limit its use in routine analysis.

A method in which nitrate is quantitatively reduced to nitrite would be advantageous, because nitrite can be readily determined by the sensitive diazotization method proposed by Griess (1879). Several such methods have been proposed. FØyn (1951), Vatova (1956), and Chow & Johnstone (1962) used zinc powder for the reduction, but the reduction is sensitive to temperature, and it is necessary to centrifuge or filter each sample.
Carotenoid pigments in sabella penicillus
Authors: Lee Welton L. , Gilchrist Barbara M. , Dales R. Phillips
Published: May 2009

The pigments of the polychaete Sabella penicillus L. were reinvestigated. In addition to zeaxanthin and traces of lutein, a series of carotenoids which may represent steps in the formation of canthaxanthin have been found. These are β-carotene, isocryptoxanthin, echinenone, 4-hydroxy-4′-keto β-carotene and canthaxanthin. No astaxanthin was found. In two other sabellids, Myxicola infundibulum (Renier) and Megalomma vesiculosum (Montagu), astaxanthin was confirmed as the major pigment and the presence of echinenone was established. Attention was drawn to the similarity of the pigments of Sabella penicillus with those of other invertebrates and it has been suggested that in invertebrates a common pathway for the formation of canthaxanthin may exist.
Physiological ecology ofPatella. II. Effect of environmental acclimation on the metabolic rate
Authors: Davies P. Spencer
Published: May 2009

The physiological basis for the previously reported differences in the rate of respiration between high-shore-level and low-level populations ofPatella vulgatain the summertime has been investigated in relation to distribution differences between this species andP. aspera.

The respiration rate of bothP. asperaand low-levelP. vulgatais low in the winter but increases in the spring to a level which is maintained until the post-spawning period in the autumn. The respiration rate of high-levelP. vulgatadoes not increase in the spring but remains at the low winter level. The inter-population difference in rate of respiration therefore appears in the spring and is maintained until the autumn.

The difference in rate of respiration cannot be accounted for by differences in the amount of non-respiring tissue in equal weight individuals and is phenotypic and not genotypic, as indicated by transplantation experiments. These experiments also rule out the possibility of differences in age of equal weight individuals from the two populations being responsible.

Respiration rate was found to be a function of both intertidal height and of the abundance of algal food in the habitat. It is suggested that the low-level population ofP. vulgatashould be regarded as the normal form and that the low respiration rate of high-level limpets in the summer represents a form of adaptation to the stresses of their habitat. It is possible that both nutritional level and temperature acclimation are important in this, and it is speculated that inability to reduce the level of metabolism may be one factor preventing the colonization of high-shore-level habitats byP. aspera.
Cryptic polymorphism in the cirratulid polychaete,Cirriformia tentaculata
Authors: George J. David
Published: May 2009

Investigations showed that populations ofCirriformia tentaculata(Montagu) at Plymouth, Coverack and Salcombe produce both free-swimming and demersal larvae from single egg batches. The proportion of free-swimming to demersal larvae varies from one brood to another but is constant in different cultures from a single brood. Control of the proportion in which the two behavioural types are produced appears to be genotypic and not phenotypic. The larval types could not be separated morphologically but additional evidence for the existence of polymorphism in the species was provided by the variation of esterase pattern between adults. The population that existed in Southampton water previous to the winter of 1962/63 and which produced only demersal larvae was probably genetically isolated from other populations of the worm and showed behaviour atypical of the species as a whole.

Introduction

Since the publication of a note reporting behavioural differences existing between the larval stages ofCirriformia tentaculata(Montagu) from Southampton Water and from Plymouth Sound (George, 1963), continuing investigations have shed more light on the problem. Observation of the Southampton population from 1959 to 1962 showed that demersal larvae were produced throughout the breeding season, from May to September (George, 1964a), whereas Wilson (1936) found that a population from Drake's Island, Plymouth Sound, produced a free-swimming larval stage in July of 1928 and 1933. It is known that some species of polychaete produce pelagic and non-pelagic forms according to the time of year (Mesnil & Caullery, 1917; Thorson, 1946). The Plymouth population was therefore re-examined to determine whether free-swimming larvae were produced during the entire breeding season.