bluuebunny/crossref_metadata_2025 huggingface dataset:
The biology of Isancistrum subulatae n.sp., a monogenean parasitic on the squid, Alloteuthis subulata, at Plymouth
Authors: Llewellyn J.
Published: May 2009

A new species of a monogenean Isancistrum subulatae (Gyrodactylidae) has been discovered on the arms and tentacles of the cephalopod mollusc Alloteuthis subulata at Plymouth and I. loliginis, on the gills of the same host, has been re-discovered for the first time since its original description in 1912. I. subulatae, like other gyrodactylids, is viviparous, and has been shown by experiments to transfer to new hosts by contagion. In nature such transfers probably take place during copulation of the hosts and since the parasite may occur in numbers of several thousands per host, it may thereby constitute a venereal disease.
Changes in plant lipids during passage through the gut ofCalanus
Authors: Prahl F. G. , Eglinton G. , Corner E. D. S. , O'Hara S. C. M. , Forsberg T. E. V.
Published: May 2009

By means of capillary gas chromatography (GC) and capillary gas chromatography'mass spectrometry (GC/MS), the aliphatic hydrocarbons, fatty acids, fatty alcohols and 3ß-sterols were identified in saponified lipid extracts of the green alga,Dunaliella primolecta, the copepod,Calanus helgolandicus, and faecal pellets released by the animal when fed in the laboratory on the algal diet. Comparison of the lipid data for faecal pellets with those for the plant showed that marked changes to dietary lipids occur during passage through the gut of the copepod: (1) 17:2, 17:1, and 17:0 hydrocarbons are completely eliminated; (2) polyunsaturated fatty acids (e.g. 16:4 and 18:3) are significantly reduced relative to total fatty acids; (3) evidence of the conversion of phytol to dihydrophytol is observed; (4) C28 and C29 sterols with Δ and Δ nuclear unsaturation are selectively removed from the diet relative to Δ components. The Δ sterols are released unchanged as faecal lipids. Cholest-5-enol, absent from the original diet, is also released in the faecal pellets. These observations illuminate the fate of specific dietary lipids inCalanusand the contribution copepod faecal pellets can make to the overall lipid composition of bottom sediment in many marine environments.
The sterol chemistry of salps: the occurrence and distribution of saturated sterols
Authors: Morris R. J. , McCartney M. J. , Bone Q.
Published: May 2009

Three species of salps(Pegea confoederata, Salpa maxima,and S.fusiformis)from the Western Mediterranean have been analysed for their general biochemical composition and their detailed sterol chemistry. In particular the distribution of saturated sterols in various tissues of the salps has been studied. The results suggests that dietary phytoplankton exerts a major influence on the tissue sterol composition of the salps, although the presence of occelesterol and saturated sterols in the salps cannot be explained on the basis of diet. Possible explanations for the occurrence and distribution of the saturated sterols are considered.
A revision of the North-east Atlantic species of Ericthonius (Crustacea: Amphipoda)
Authors: Myers A. A. , McGrath D.
Published: May 2009

Seven species of the amphipod genus Ericthonius are described and figured from the North-east Atlantic and associated seas and a key to their identification is provided. West Atlantic material is also considered where relevant to the taxonomy of East Atlantic species. Two species are re-established after a long period of submersion in synonymy, and one species new to science is described. The previous confusion in the literature of some of the species is discussed, and a synonymy of species described in key works is provided.
The herring swimbladder: loss and gain of gas
Authors: Blaxter J. H. S. , Batty R. S.
Published: May 2009

The herring is a physostome with no gas secretion mechanism in the swimbladder. The swimbladder volume was measured in fish from about 3–33 cm in length. It was rarely large enough to give the fish neutral buoyancy at the sea surface. Swimbladder volumes were also measured after periods of up to 1 week at pressures from 1·9 to 5·5 ATA (0·9–4·5atm above atmospheric pressure) in a laboratory pressure vessel and in a sub-surface cage in the sea. The swimbladder gas was lost within a few hours in the larval herring and in a few days in smaller juvenile fish; no change was found in older fish under experimental conditions. The findings were in accord with measurements of the guanine content of the swimbladder wall which was low in those fish which lost gas quickly. This supports the view that gas diffusion is limited by guanine crystals. While it seems likely that larger fish can exist for several weeks without the need to replenish the swimbladder gas some large spawning herring were caught at sea with empty swimbladders, suggesting a long stay near the sea bed. Analysis of swimbladder gas showed that oxygen tended to diffuse out more quickly than nitrogen. Behaviour experiments showed that fish with artificially emptied swimbladders could refill them by swallowing air at the surface, in some cases very quickly and efficiently. Fish with empty swimbladders and no access to the surface suffered a high mortality. The ecological implications of these results and their relevance to the interpretation of sonar ‘target strength’ measurements are discussed.
Reproductive and nutritional periodicities in the starfish,Marthasterias glacialis, from Plymouth Sound
Authors: Nichols D. , Barker M. F.
Published: May 2009

The gonadial, pyloric caecal and somatic cycles over three consecutive years in a subtidal population of the starfishMarthasterias glacialisfrom Plymouth Sound are described. The study area lies towards the eastern limit of the up-Channel range of this species, and this is reflected in only partial reciprocity between gonadial and pyloric indices, and also by the apparent utilisation of somatic material during the build-up of gametes. The sequence of events at the cytological level during gonadial build-up is described.
The benthos of a coastal power station thermal discharge canal
Authors: Bamber R. N. , Spencer J. F.
Published: May 2009

Kingsnorth Power Station, on the River Medway Estuary, Kent, discharges cooling water into a canalcomprising a 4 km creek system. A comprehensive investigation of the sublittoral benthic fauna of the discharge system was undertaken from January 1979 to September 1981. The benthic macrofauna was sampled monthly at five stations along the system and a sixth in the River Medway adjacent to the creek mouth (DC4); salinity, sea-bed temperature, sediment particle size, sediment redox potential, residual chlorine and meiofaunal numbers were measured. The macrofauna is significantly suppressed at sites along the discharge canal, representing a community with half the number of species as at station DC4, comprising dense populations of a few dominant opportunistic species tolerant of thermal stress (e.g.Tubificoides, Cauleriella), and not those characteristic of organic pollution stress communities. The latter are regular summer immigrants in the creek, but persist only in low numbers if at all in the winter (e.g.Polydora ciliata). This suppression is the result of a 10°C temperature front between the heated discharge water and ambient estuarine water, passing over the sea bed with the ebbing and flooding tide four times each day. The residual gradient of mean temperature along the discharge canal causes some changes in the dominance of those species not eliminated by the temperature front. These temperature effects are expected to be localized, mainly in the area of sea-bed impingement of the discharge water; they are predicted to occur at any thermal discharge in tidal waters where the heated effluent contacts the sea bed.
Electrophoretic comparison of the Antipodean cirripede, Elminius modestus, with immigrant European populations
Authors: Flowerdew M. W.
Published: May 2009

Elminius modestus Darwin 1854 is a small, estuarine barnacle, until 1940 found only in New Zealand and southern Australia but now well established in Europe. Using electrophoresis, 22 enzymes were compared between 10 populations of E. modestus from Europe and three populations from the Antipodes. Fourteen enzymes gave consistent, scorable results at 19 loci, of which 10 were monomorphic. Contingency comparisons of allele frequencies at the polymorphic loci showed no significant difference within the European samples, within the Antipodean samplesand between the European and Antipodean samples. These results were discussed in the context ofboth the history of the spread of the species and its planktonic larval phase. It seems likely that the species spread to Australia by remote dispersal from New Zealand before 1832, and thatthe initial settlement in U.K. waters in the 1930s must have been large enough to establish thespecies successfully with a genome representative of that of the mother population, at least atthe loci examined.
The distribution of benthic hydrographic indicator species in Svalbard waters, 1978–1981
Authors: Dyer M. F. , Cranmer G. J. , Fry P. D. , Fry W. G.
Published: May 2009

Fourteen species of benthic invertebrates, found to be indicators of hydrographic conditions by Blacker (1957), were recorded during research cruises between Finmark and north Spitsbergen during the summers of 1978, 1979, 1980 and 1981. The distributions were compared with those found during surveys carried out between 1949 and 1959.Both Atlantic and Arctic species were found to the north of Bear Island and along the west coast of Spitsbergen, and the temperature ranges at which they were found were greater than those found by Blacker (1957).

Introduction

During the past century the annual mean temperature of the Arctic regions has undergone a considerable change. The warming of the regions began about 1885 (Willett, 1950) and peaked around 1938, when the mean air temperature of Spitsbergen was nearly 6 °C warmer than at the turn of the century (Hoel, 1953). The warming of the seas in the region seems to have started later - Jensen (1939) suggests 1917 - and sea temperature changes were detected north of Spitsbergen in 1921 (Schokalsky, 1936). This warming resulted in the reappearance of cod in great quantities on the Bear Island Bank, after the absence of any sustained quantities for about 40 years (Blacker, 1957).

The marine benthos of Svalbardf was surveyed during the latter part of the last century and the first half of this century (1878–1914,1923–31) when the benthos was recorded during several cruises in the region (see Blacker (1957) for review). The benthos was again recorded between 1949 and 1955 (Blacker, 1957) and 1955 and 1959 (Blacker, 1965); see Fig. lA.
Observation on the Biochemical Composition of an Unusual Diatom Bloom
Authors: Morris Robert J. , Carre Claude
Published: May 2009

The development of a unispecies bloom of phytoplankton in the Rade de Villefranche (N.W. Mediterranean, near Nice) during June 1982 coincided with the disappearance of salps from the area. A phytoplankton haul was taken on 24 June and examined in detail. The sample consisted of virtually a unispecies diatom population; Rhizosolenium spp., together with a few small medusae and crustaceans. The diatom cells were unusual in that they appeared to be associated with large amounts of extracellular mucus.

The appearance of this virtually monospecies bloom provided a rare opportunity to examine in detail the biochemical composition of a natural field diatom species (see discussion in Ballantine, Lavis & Morris, 1979 and Morris, 1984). After removal of zooplankton the phytoplankton were collected on a 30 μm clear nylon filter. A detailed biochemical analysis was carried out as previously described (Morris, McCartney & Robinson, 1983; Morris, 1984).

The Rhizosolenium spp. sample was composed of almost equal amounts of lipid (23 mg), insoluble carbohydrate (19 mg) and protein (24 mg) with much smaller amounts of soluble carbohydrate (009 mg). The lipid was composed mainly of polar lipids (70% total lipids), neutral glycerides (20% total lipids) and sterols (8% total lipids). The detailed fatty acid and sterol composition of these major lipid fractions are shown in Tables 1 and 2.
Monthly-Mean Residual Flows Through the Dover Strait, 1949–1980
Authors: Prandle D.
Published: May 2009

In an earlier paper (Prandle, 1978b) estimates were made of the monthly-mean residual flows through the Dover Strait for the period 1949–72. This time series has proven to be of some interest to marine biologists (Colebrook, Reid & Coombs, 1978; Reid & Budd, 1979; Taylor et al. 1981). This short additional note extends this time series up to 1980 (Table 1).

Other model studies of wind forcing in this region have been published in recent years.
Predation of Sagartiogeton Laceratus Upon Aurelia Aurita in Shallow Water
Authors: Berryman John
Published: May 2009

Sagartiogeton laceratus Carlgren. was observed in 1979 in large numbers (11–20 m) in shallow water (5 m below chart datum Sullom Voe) at Whaal Firth, Yell, Shetland, at a site named Stany Pund. It was recorded at a nearby site, Poita, at a lower density (1–2 m) in deeper water (6–8 m below CD.), and was also recorded as ‘common’ at the shallow head of the firth.

Very large numbers of Aurelia aurita (L.) were observed within the sheltered, shallow arm of the firth, within the upper few metres of water.

Each year since 1979 the same occurrence has been noted, and in the summer of 1980 the predation of Sagartiogeton upon Aurelia was observed and photographed on several occasions. These observations were repeated in 1982.

Sagartiogeton laceratus is found attached to shell fragments in silt, the column inclined towards the current. During ingestion the tentacles shorten, and the mouth, disc, and column, distend many times their normal dimensions. (Estimated to be 400% for the column, disc.)

It seems likely that the occurrence of both species in sufficiently large numbers to make predation noteworthy is due to the position and depth of Whaal Firth. It forms a north facing ‘trap’ on the eastern side of Yell sound through which ebb and flood tides move rapidly. The total length of Whaal Firth is approximately 7 km of which 4 km are relatively exposed, and 3 km sheltered.
A Note on Feeding inLeptopentacta (=Cucumaria) Elongata
Authors: Douglas McKenzie J. , Picton B. E.
Published: May 2009

Conflicting opinions exist as to the method of feeding employed byLeptopentacta elongata(Dub. and Kor). Orton (1914) and Mortensen (1927) suggested that it may be a deposit feeder. Chia & Buchanan (1969) noted that post larval specimens up to 1 year old deposit fed. Fankboner (1981), in a short study, concluded that the adults were cryptic deposit feeders. Hunt (1925) and Fish (1967), however, observed what they concluded was suspension feeding. All the above observations were the result of aquarium studies. Fish (1967) also demonstrated thatLeptopentactahibernated between October and April or May both in the field and in aquarium. He also observed that hibernation could be induced in the summer months by reducing water temperature to 8°C but that winter hibernation could not be curtailed by raising the water temperature.

Obsevations made by one of us (B.P.) while diving indicate thatLeptopentactasuspension feeds. This behaviour has been observed on several occasions from several sites around the Irish coastline with specimens then being caught and their identity confirmed. While feeding the tentacles are held clear of the substrate to intercept suspended material.

These observations clearly do not support the description ofLeptopentactasolely as a cryptic deposit feeder, indeed the evidence for the adults deposit feeding at all is weak. Orton (1914) and Mortensen were only speculating onLeptopentactabeing a deposit feeder based on the observation that specimens in aquaria spent much of their time completely buried. Hibernation, as shown by Fish (1967), is a possible explanation for this.
Acanthonotozoma Serratum, an Arctic Amphipod New to Britain
Authors: Moore P. G.
Published: May 2009

The amphipod family Acanthonotozomatidae was represented hitherto in British waters by the generaIphimedia Rathke (includingPanoploea Thompson) andOdius Lilljeborg; Acanthonotozoma Boeck being unrecorded (Lincoln, 1979).

Material referable toAcanthonotozoma serratum (O. Fabricuius, 1780) is here reported from the East coast of Scotland. Two specimens (1 juvenile,ca. 7 mm long and 1 immature female, broken in half, estimated length 85 mm) were taken by Dr R. Earll by diving (his sample no. CR2, St. 4/3) from amongst tubes occupied by the amphipodEricthonius rubricornis Stimpson attached to boulders amongst coarse sand, depth 345 m, at Coldingham Bay, St Abbs, Berwickshire, Scotland (55° 53' 30": 2° 5' 36") on 17 August 1982. Dr Earll kindly made over his amphipod material to me for identification.

Just (1978) has reviewed the genusAcanthonotozoma and has commented on the variability of both morphology and coloration ofA. serratum from Greenland, Iceland, Spitzbergen, Russian Kara Sea, N. Norway and the Skagerrak. The Scottish material has Norwegian rather than Greenlandic characteristics. Thus the dorsal tooth on peraeonite 5 is lacking, giving the dorsum a 4-dentate appearance. Coxal plate 3 is bluntly tapered distally. Coxal plate 4 is squarish and coxal plate 7 has the posterodistal corner unproduced. The posterodistal projections of the third epimeral plate are short with a wide angle between them. The basal articles of peraeopods 57­ have a square, less sharply produced posterodistal corner.

Mouthparts and anterior peraeopoda have been dissected from the right side of the female and mounted on three slides in polyvinyl-lactophenol. No significant differences are apparent in mouthpart morphology compared with fig. 4 in Just (1978).
Observations on the Bottom Fauna Near Plymouth During a Dinoflagellate Bloom in 1982
Authors: Forster G. R.
Published: May 2009

In July and August 1982 a bloom of Gyrodinium aureolum spread from its normal mid-Channel position to inshore waters off Plymouth. During some particularly calm weather in July and early August the presence of this bloom coincided with aberrant behaviour and some mortality of the bottom fauna. From previous observations in 1978 (Forster, 1979) it seemed probable thatthese damaging effects were related to the presence of the bloom. As soon as possible diving was carried out on positions where mortalities of affected species had been reported, or where previous observations had been made so that any changes could be easily recognized.
A Note on the Distribution of Metacercariae of Maritrema Arenaria in Balanus Balanoides at a Site on the North-East Coast of England
Authors: Mitchell J. B. , Dessi J.
Published: May 2009

The survey of Balanus balanoides (L.) for metacercarial cysts of Maritrema arenaria Hadley and Castle, 1940, on the east coast of Northern Ireland by Irwin & Irwin (1980) prompted us to carry out a similar survey in the north-east of England. The site we selected was a rocky shore at Whitburn, Sunderland (Grid Ref. NZ411 613) from which six separate batches of 100 barnacles, B. balanoides, were examined. The results were as in Table 1.
Microzooplankton Community Structure in the North-Eastern Atlantic: Trends with Latitude, Depth and Date, Between May and Early August
Authors: Sleigh M.A. , Edwards E.S. , John A.W.G. , Burkill P.H.
Published: May 2009

Microzooplankton from water samples collected from depths of between 10 and 50 m at four stations between 47° and 60°N along the 20°W line of longitude during each of three cruises were classified into taxonomic groups and measured to estimate their abundance and biomass. Metazoan members of the microzooplankton were rarely found and their overall biomass was negligible in comparison with protists. The mean numbers of protistan microzooplankton cells >15 μn ranged between 3 and 11 cells ml-1, with mean biomass values between 2 and 14 μgC 1-1. Numbers and biomass increased towards midsummer and then decreased again, except at the most northerly station where the values were highest in the early August sample. The ratio of dinoflagellate to ciliate biomass tended to increase through the summer to levels of three or four and then decrease again, with later changes further north; this ratio also tended to be higher at deeper levels than in the mixed layer. Gymnodinioid forms usually dominated dinoflagellate numbers and biomass, but they were overshadowed by Protoperidinium and others at the two southern stations in June and July samples. Strombidium species were the dominant ciliates, commonly providing 25–50% of total microzooplankton biomass, while predatory haptorid ciliates were occasionally numerous, but tintinnids never formed more than 10% of the biomass.
Bait-Attending Amphipods in the Deep Sea: A Comparison of Three Localities in the North-Eastern Atlantic
Authors: Christiansen Bernd
Published: May 2009

Scavenging amphipods were studied at three locations along the 20°W meridian in the north-eastern Atlantic using vertical arrays of baited traps. The sampling sites had several features in common. All amphipods captured belonged to the superfamily Lysianassoidea. Generally, highest densities of amphipods were found in the bottom traps. Abundances as well as species diversity were strongly reduced in traps exposed from 8–500 m above bottom. However, differences between stations occurred in standing stocks, decreasing from north to south, in the taxonomic composition of the bait-attending amphipods and in the vertical distribution and size structure of the giant amphipod Eurythenes giyllus.. Possible reasons for the differences between the locations are discussed and the establishment of at least two provinces in terms of bait-attending amphipods in the eastern North Atlantic is suggested.
Zonal Orientation and Spectral Filtering inTalitrus Saltator(Amphipoda, Talitridae)
Authors: Ugolini A. , Vignali B. , Castellini C. , Lindström M.
Published: May 2009

Adult individuals ofTalitrus saltatorwere tested for celestial orientation in a plexiglass bowl covered with colour filters of different wavelengths. Results show thatT. saltatorcan recognize the sun and use it for orientation only at γ <450 nm. At γ >500 nm, the sight of the sun (and sky) only induces phototactic behaviour. It has also been confirmed that an important celestial orienting factor is perceived in the UV range. Variations in populations from diversely oriented coastlines are discussed. Preliminary results of electroretino-graphic responses indicate the presence of at least two visual pigments in the eye and a steep decrease in sensitivity for γ >500 nm.
Vertical Changes in Density, Size Structure and Shell Shape of the Bivalve Lasaea Undulata Within Intertidal Mussel Beds
Authors: Iwasaki Keiji
Published: May 2009

Vertical changes in density, size structure and shell shape of Lasaea undulata (Bivalvia: Galeommatoidea) inhabiting intertidal mussel beds were studied at Wakayama Prefecture, Japan. At the study site, where two mytilids Septifer virgatus and Hormomya mutabilis formed vertically contiguous mussel beds, Lasaea density decreased downshore within the S. virgatus bed of the upper and mid zones. Few individuals were found within the H. mutabilis bed of the lower zone. Multiple linear regression analysis revealed that shore height was the only factor which showed a significant, positive correlation with density. Size structure differed between the upper and lower parts of the S. virgatus bed, suggesting that reproductive periods or growth rates of L. undulata differed with shore height. Prodissoconch length and shell shape were also different among shore heights. Number, size and shell shape of juveniles brooded within parents indicated that this species releases its young as non-planktotrophic, crawl-away juveniles. There was no significant difference in density of recruits between artificial mussel clumps of S. virgatus and H. mutabilis within enclosure cages, and no specific association was detected between L. undulata and either of the two mussel species.
Synchronous Penis Shedding in the Rough Periwinkle,Littorina Arcana
Authors: Dytham C. , Grahame J. , Mill P. J.
Published: May 2009

Penis size and morphology of an oviparous species of rough winkleLittorina arcanaHannaford Ellis (Gastropoda: Prosobranchia) was studied at Robin Hoods Bay on the English east coast. Monthly collections were made over a two year period from August 1987 to August 1989 and again from May to December 1993. Number of penial glands was recorded and a six point scale was used to quantify penis maturity. Results indicate that maleL. arcanashed their penes in summer and regenerate a new one during the following 12–20 weeks. MaleL. arcanain captivity shed penes in July but not in November. The significance of penis shedding and the differences in reproductive seasonality betweenL. arcanaand its ovoviviparous sibling speciesL. saxatilisis discussed.
Seasonal Variations in Fecundity and Egg Size of The Common Goby, Pomatoschistus Microps
Authors: Rogers S.I.
Published: May 2009

The common goby Pomatoschistus microps (Krøyer), is a small and abundant brackish water fish, which becomes sexually mature after the first winter of life and usually survives for only a single breeding season (Miller, 1975). During a protracted breeding season from approximately mid-April to August or September, the goby can produce up to 9 or 10 separate batches of eggs. It is therefore considered to be an iteroparous species, but because of the short adult life-span during which spawning occurs, this species has been termed an abbreviate iteropare (Miller, 1984). The nest-building activities of the male fish, courtship behaviour and subsequent brood-care are well documented (Vestergaard, 1976).
Photomorphogenesis in Early Development of Tilopteris Mertensii (Tilopteridales: Phaeophyceae)
Authors: Kuhlenkamp Ralph
Published: May 2009

The Tilopteridales are an order of three filamentous benthic Phaeophyceae found in North Atlantic and Arctic waters (Hooper et al., 1988). Detailed life history studies are reported for Haplospora globosa Kjellm. and Tilopteris mertensii (Turner, in Smith) Kutz. (Kuhlenkamp & Müller, 1985).
The Shell ofCardium Edule, Cardium GlaucumandRuditapes Philippinarum:Organic Content, Composition and Energy Value, As Determined by Different Methods
Authors: Goulletquer P. , Wolowicz M.
Published: May 2009

The organic content of the shells of molluscs can represent a significant fraction of the total organic content (Bernard, 1974) but it is often neglected in calculations of energy budgets in these animals. This may be in part due to uncertainty about the true values, since published estimates of the organic content of shells show quite wide variation. The species examined and also the provenance of the selected samples contribute to this variation as does also the method of measurement. The methods principally used have been by ignition at various temperatures from 400 to 550°C for various durations between 2 and 36 h (see Shumway & Newell, 1984; Jørgensen, 1976; Mohlenberg & Kiorboe, 1981; Vahl, 1981; Shafee, 1979; Priceet al, 1976) or by acid extraction using different extraction proceedures (see Ivell, 1979; Dame, 1972; Horn, 1986; Griffiths & King, 1979). To calculate the energy content of the organic component some investigators have used the Hughes (1970) coefficient of 5.037 cal mg-1, while others have used Paine's (1971) protein coefficient of 2.39 J g-1. Wilbur & Saleuddin (1983) have called attention to the need for more study of these analyses. We present here the results of a study of the shell organic content of three species of molluscs, using two methods for the measurement and giving data on biochemical composition and energy value.
On the Muscle Fibres and Locomotor Activity of Doliolids (Tunicata: Thaliacea) Q. Bone
Authors: Bone Q.
Published: May 2009

Doliolids are pelagic tunicates which swim by very rapid contractions of the muscle bands that encircle their barrel-shaped bodies; the resulting jet pulses drive them forwards at instantaneous velocities up to 50 body lengths s-1(Bone & Trueman, 1984). The obliquely-striated muscle fibres within the bands have the unique feature that they lack any kind of sarcoplasmic reticulum or sub-sarcolemmal vesicle system (Bone & Ryan, 1974). Most stages of the rather complex life-cycle of doliolids (Braconnot, 1971a) are small animals, less than 4 mm long; but in one of the species examined the largest may be up to 40 mm. This paper shows that external Ca2+is required for contraction of the locomotor muscle fibres and that the decremental muscle potentials preceding contractions are carried by Ca2+. In younger stages, the muscle fibres within a band are electrically coupled to some extent, but in older animals, the degree of coupling decreases
Modelling of Phytoplankton Population Dynamics in an Enclosed Water Column
Authors: Andersen Valerie , Nival Paul
Published: May 2009

To understand the working of the marine pelagic ecosystem one needs to study the logical frame of the complex food web. This study is much easier in an enclosed water column than in the open sea where biological interactions are often concealed by physical events.
Escape Responses of Herring Larvae to Visual Stimuli
Authors: Batty R.S.
Published: May 2009

Predation is now considered the main cause of mortality in larval and juvenile fish (Hunter, 1984) and is therefore the most important factor controlling recruitment to the adult population. Marine fish larvae are prey for many different types of predator including medusae, crustaceans and larger fish. When predatory attacks are sensed both adult and larval fish may respond by making a 'C-start', a very fast, simultaneous contraction of the trunk musculature that deforms the body into a C-shape within 20 ms (Eaton & Hackett, 1984). This startle response is mediated by the Mauthner cells, a pair of prominent neurones in the hind brain or by other reticulo-spinal cells located in the same region. As a result of reciprocal inhibition and decussation of the cell axon, stimulation on one side of the body results in contraction of all the muscle on the contralateral side.
Extended Pre-Feeding Period in Planktotrophic Larvae of the Bathyal Echinoid Aspidodiadema Jacobyi
Authors: Young C.M. , Cameron J.L. , Eckelbarger K.J.
Published: May 2009

The long-standing hypothesis (Thorson, 1946, 1950; Mileikovsky, 1971; Jablonski & Lutz, 1983) that deep-sea invertebrates should reproduce by direct development or by non-feeding (lecithotrophic) larvae is beginning to fall in the light of recent data. Traditional reasoning maintained that planktonic food should be limiting at great depths, and that microscopic, ciliated larvae should be incapable of migration to the euphotic zone. However, in recent years, planktotrophic larvae of two deep-sea gastropods have been collected in surface waters, and planktonic larval development has been inferred from shell morphology and chemistry in several other species (Bouchet & Warren, 1979; Killingley & Rex, 1985). Planktonic larvae have also been collected in the water column of the deep sea (Berg et al., 1985; Smith, 1985; Berg & Van Dover, 1987), particularly near hydrothermal vents. Relatively diverse benthopelagic plankton populations relying primarily on suspended detritus for food are now known from the benthic boundary layer of the deep sea (Wishner, 1980a, b; Gowing & Wishner, 1986). Thus, it is increasingly apparent that planktotrophy may be a common option for deep-sea larval development.
Will Deep Subtropical Ring ‘Storm Physallv’ Cross the Mid Atlantic Ridgea and Reach America?
Authors: Pingree R.D. , Sinha B. , New A.L. , Waddington I. , Head R.N. , Nechvolodov L.V.
Published: May 2009

A short research cruise was planned to trace the movement of a discrete body of water in the subtropical eastern North Atlantic Ocean. A subtropical ring or deep eddy called STORM was found budding off the Subtropical Front (STF) south-west of the Azores. A physical, chemical and biological survey to depths of 3·5 km was made of this 400 km scale body of water which was spinning cyclonically (anticlockwise). The azimuthal transport or the amount of water swirling in the eddy was 45 Sv. Storm was ‘hooked’ with ten drogued Argos buoys and a further five subsurface Alace floats were deployed. Storm is moving westward at ~3 km a day and is expected to reach the Mid Atlantic Ridge in rather less than a year unless it is destroyed by typography or reabsorbed into the Azores Current. With current technology, Storm's evolution and westward progress can be observed and analysed remotely, at a distance of ~3000 km in the laboratory. Realtime position data means that future sea surveys can be planned.
A Time-Series Study of Foraminiferal Assemblages of the Plym Estuary, South-West England
Authors: Castignetti Paul
Published: May 2009

Monthly samples retrieved from the previously unstudied Plym Estuary, from January 1994 to November 1994, were analysed for living and dead Foraminifera. An assemblage composed of three hyaline species; Haynesina germanica, Elphidium williamsoni and Ammonia beccarii var. batavus, was identified. Further samples were taken to assess depth distribution, microdistribution and lateral distribution, to compliment the original sample suite. A comparison of the dead assemblage to the live assemblage revealed similar species proportions in both assemblages, reduced test abundance in the dead assemblage, and the presence of rare estuarine and marine species in the dead assemblage. This study has revealed a complex interplay of species resulting in several foraminiferal blooms throughout the year; the largest occurring in May.
The Lipid Composition of the CoccolithophoreEmiliania Huxleyiand Its Possible Ecophysiological Significance
Authors: Pond D.W. , Harris R.P.
Published: May 2009

The lipid class and fatty acid composition of eight geographically disperse isolates ofEmiliania huxleyi, grown under 12 h L:D cycles and harvested during logarithmic and stationary growth phases, were examined. Cell size and chlorophyll content tended to decrease from logarithmic to stationary growth phase, Methyl and ethyl ketones were the dominant lipid classes, although proportions exhibited no clear pattern either between strains or growth phases. Neutral lipid hardly accumulated over the course of the growth experiments, and triacylglycerol was either absent or only present at low levels. In all strains with the exception of a South African isolate, levels of total fatty acid per cell decreased markedly between logarithmic and stationary phases, primarily attributable to reductions in the levels of saturated and monounsaturated fatty acids. Major fatty acids in all strains during both growth phases were 14:0,16:0,18:1 (n-9), 18:4 (n-3), 18:5 (n-3) and 22:6 (n-3). Although all strains were rich in polyunsaturated fatty acids (47–72% of total fatty acids) stationary phase cultures consistently contained the highest proportions. The polyunsaturated fatty acid docosahexanoic acid (22:6, n-3) was the most abundant fatty acid in all strains, comprising a maximum of 38·4% of total fatty acids in strain M 181 during stationary phase. Multivariate analysis (PCA) allowed logarithmic and stationary phase cultures to be distinguished although no obvious intra-isolate variability was apparent. The results are discussed in terms of the importance of lipids for the ecophysiology of E.huxleyiand the role of this dominant coccolithophore in the marine food chain.
The Occurrence of the Estuarine PolychaeteLycastopsis Littoralis(Namanereidinae: Nereididae) in the Ria De Bilbao, Northern Spain
Authors: Gibbs P.E. , Salinas J.I. Saiz
Published: May 2009

Namanereids are an interesting group because of their success, remarkable amongst polychaetes, in colonizing freshwater habitats, particularly damp-terrestrial situations in tropical rainforests (see reviews by Feuerborn, 1932; Corrêa, 1948; Wesenberg-Lund, 1958; Hartman, 1959). Species assigned to the subfamily Namanereidinae Hartman, 1959 are now known from world-wide localities but there are few records from European waters.
Allozyme Evidence of Genetic Differentiation Between Populations ofHediste Diversicolor(Polychaeta: Nereididae) from the Western Mediterranean
Authors: Abbiati M. , Maltagliati F.
Published: May 2009

The occurrence of genetic differentiation among western MediterraneanHediste diversicolor(Polychaeta: Nereididae) populations was assessed by allozyme electrophoresis on cellulose acetate. Seventeen loci were analysed in four populations. The level of the genetic variability was markedly low (mean HLrange: 0.014–0.034), but comparable to that of other brackish water nereidids. The values of Nei genetic distance index (D) confirm the existence of genetic differentiation between the geographically isolated populations at Venice, Elba, Navicelli and Serchio D range: 0.128–0.356). However, the two samples from Serchio and Navicelli, ~15 km apart, were not genetically different (D=0·00005). The level of genetic differentiation inH. diversicolorpopulations followed the isolation-by-distance model. Reduced gene flow amongH. diversicolorpopulations may be explained by its limited dispersal capacity and the eco-physiological barriers that occur between different brackish habitats.
The Effects of Dissolved Sugars Upon the Temporary Adhesion of Barnacle Cyprids
Authors: Neal A.L. , Yule A.B.
Published: May 2009

The effects of pentoses, hexoses and uronic acids upon the temporary adhesion of cypris larvae of five barnacle species from four families has been studied. A common, concentration dependent, inhibitory effect of D-glucose was observed for the five species, with maximum inhibition (to 60% of control levels) occurring at 10−8M glucose. UsingBalanus perforatuslarvae, glucose was shown to be acting at the antennular surface, most probably by interacting with polar groups associated with the temporary adhesive. The pentose, D-arabinose, was less active than glucose, reducing temporary adhesion to only ∞80% of control levels. D-glucuronic acid was more active, decreasing adhesion to 60% at 10−9M, whilst two other hexoses, D-mannose and D-galactose, showed similar activity to glucose. We suggest that hexoses interact with the same polar groups in the adhesive, glucuronic acid with the higher activity because of its more polar nature. The pentose possibly interacts with a different, less common, group. Our results suggest that the chemical identity of bacterial exopolymers, particularly in respect of their pentose: hexose and neutral suganuronic acid ratios, may be an important factor in determining the strength of temporary adhesion shown by barnacle cyprids towards bacterial films.
Mysids of the GenusBoreomysisfrom Abyssopelagic Regions of the North-Eastern Atlantic
Authors: Hargreaves P.M. , Murano M.
Published: May 2009

The geographic and vertical distribution in the world oceans of species ofBoreomysishas been summarized by Mauchline & Murano (1982). Various authors including Birstein & Tchindonova (1958) discussed the vertical distribution of abyssalBoreomysisspecies in the Pacific Ocean. Relatively little is known about Atlantic populations ofBoreomysisat depths >2000 m, though there have been a few reports of occurrences in abyssopelagic zones (Nouvel, 1942, 1943; Tattersall & Tattersall, 1951; Lagardère & Nouvel, 1980; Lagardère, 1985; Hargreaves, 1985). The aim of this paper is to present distribution data on five lesser-known species ofBoreomysisfrom depths >2000 m in the north-eastern Atlantic Ocean at ~30° -42°30′N and to describe in more detail, aspects of their morphology.
Validation of Rapid Assessment of Damage in Urban Mangrove Forests and Relationships With Molluscan Assemblages
Authors: Skilleter G.A.
Published: May 2009

Six mangrove forests in the urban region of Sydney, Australia, were examined to determine whether there were relationships between levels of human-induced damage and the structure of molluscan assemblages, the first stage in the validation of a technique for rapid assessment of the impacts of anthropogenic disturbance in urban mangroves. All six mangrove forests showed some damage but the amount varied considerably among and within each forest. Significant correlations between the levels of damage and abundance of different taxa, and changes in the structure of the molluscan assemblage along gradients of damage, suggest that indices based on measures of damage have the potential to provide a means for the rapid, wide scale evaluation of mangroves affected by impacts associated with human activities in urban areas.
An Interpretation of the Taxonomic Relationship Between the LimpetsPatella Rusticaand P.Piperata
Authors: Côrte-Real H.B.S.M. , Hawkins S.J. , Thorpe J.P.
Published: May 2009

The taxonomic relationship between the limpetsPatella rustica(Mollusca: Archaeogastropoda) andP. piperatais unclear with controversy as to whetherP. piperatashould be given specific status. The problems stem from its similar morphology but different biogeographic range fromP. rustica. Individuals from seven populations ofP. rusticaand three ofP. piperatawere analysed for a combination of morphological and genetical characters. Morphological analyses of shell shape and radular morphology revealed differences between species for radular length, higher inP. rusticathan inP. piperata, and the shape of the pluricuspid teeth of the radula with a well-developed internal cusp inP. piperatabut not inP. rustica. Electrophoretic results based on 11 allozyme loci, however, did not distinguish the two species clearly. The overall genetic identity value between the two was 0·861, a value which lies within the range for conspecific populations of other patellids. It is proposed thatP. piperataon the basis of the genetic data obtained, may represent a subspecies ofP. rusticathat is in the process of diverging due to its geographic isolation.
Vertical Distribution Correlates With Pressure Tolerances of Early Embryos in The Deep-Sea Asteroid Plutonaster Bifrons
Authors: Young Craig M. , Tyler Paul A. , Gage John D.
Published: May 2009

The astropectinid asteroid Plutonaster bifrons (Wyville Thomson) occurs on the continental slope of the north-east Atlantic between 1000 and 2500 m depths. As in most deepsea animals, the factors limiting bathymetric distribution of this species are unknown. Eggs were fertilized in vitro and incubated through the early embryonic cleavage stages at pressures that correspond to depths from 0 to 3000 m. The highest percentage of normal development occurred near the peak of the species distribution (2000 m), and virtually no normal development occurred at a pressure corresponding to 3000 m depth. Develop-mental rate was retarded at pressures higher and lower than those found near 2000 m. These experiments indicate that embryonic pressure tolerances could determine both the upper and lower bathymetric limits of distribution for this species.
Antibacterial and Antisettlement Activity of the Dogfish (Scyliorhinus Canicula) Eggcase
Authors: Thomason J.C. , Marrs S.J. , Davenport J.
Published: May 2009

The dogfish eggcase protects the developing embryo for up to a year against predation and fouling. The mechanical protection is provided by the strength and resilience of the case. The aim of this study was to determine the mechanisms underlying the case's antifouling proficiency. The eggcase is constructed of oxidatively cross-linked proteins, which are primarily collagen. Two main hypotheses were examined, firstly that the egg case scavenges heavy metals and these act as deterrents. Secondly, the tanning agents, particularly dihydroxyquinones, through reaction with Fe2+, produce hydroxy radicals that act as deterrents. This process is called the Fenton reaction. Using ten different species of marine bacteria,Semibalanuscyprids andEnteromorphazoospores, a variety of experiments were conducted to examine the effect of surface chelation, iron loading, changing the surface roughness, different collagen types and quinones, and the presence of antioxidants. The results suggest that the photoactivated generation of free radicals is partially responsible for the antifouling mechanism of the eggcase. Collagen and quinone chemistry and surface integrity are also considered to be important in the antifouling process.
Oxygen consumption and osmoregulation in the shanny,Blennius pholis
Authors: Milton P.
Published: May 2009

INTRODUCTION

It is well known that littoral teleosts, such asBlennius pholis, are on occasions subjected to considerable and abrupt variations in the salinity of their environment. Smith (1930) constructed a tentative model of the processes involved in the osmoregulation of teleosts; quantification of the various components of the Smith model has been extensive, but little attention has been paid to the respiratory stresses undergone by teleosts in fluctuating salinities.
The epizoic fauna of Flustra foliacea [Bryozoa]
Authors: Stebbing A. R. D.
Published: May 2009

INTRODUCTION

Various authors during the last century (Johnston, 1847; Hincks, 1868, 1880) and more recently (D. Eggleston, unpublished†) have recorded a number of species as epizoites on the perennial bryozoan Flustra foliacea (L.) (Table 1); but the ecology of the ‘community’ (Hedgpeth, 1957) of epizoites and their interaction with the living substratum has never been studied. The sessile fauna of Flustra fronds includes species of seven different phyla, but it can be said of only a few that the fronds provide their typical habitat. For example, the barnacles are never very numerous and the lamellibranchs rarely reach adult size. This paper is concerned mainly with the most common epizoites: the hydroids and bryozoans. The distribution and orientation of some of these species on the fronds are of ecological interest.
Variations in the relationship between oxygen consumption, body size and summated tissue metabolism in the winkleLittorina littorea
Authors: Newell R. C. , Pye V. I.
Published: May 2009

INTRODUCTION

A considerable amount of data now exists on the relationship between metabolism and body size in a wide range of organisms from bacteria and protozoans through to large mammals. Much of this information has been reviewed by Kleiber (1932, 1947), Brody and Procter (1932), Brody (1945), Zeuthen (1947, 1953), Hemmingsen (1950, i960) and Bertalanffy (1957). In general the metabolism has been shown to be proportional to a fractional power of the body weight thus eggs, the larger metazoan poikilotherms and even homoiotherms is proportional to a constant power of the body weight. This factor has been shown to be 0.751 ± 0.015 by Hemmingsen (i960). Superimposed upon this general relationship are variations according to the weight range of the organisms concerned. Thus both Zeuthen (1953) and Hemmingsen (i960) have shown that the value of the constantbfor unicellular organisms is approximately 0.7 (Zeuthen, 1953) or 0.751 (Hemmingsen, 1960), whilst that for small metazoans is 0.95 (Zeuthen, 1953) or 1.0 (Hemmingsen, 1960). Finally, the slope of the line relating the metabolism to body size in larger metazoans is 075 (Zeuthen, 1953) or 0.751 (Hemmingsen, 1960). That is, the value forb— 1 in equation (2) is likely to be between -0.3 and -0.249 in unicellular organisms; 0 and -0.05 in small metazoans and approximately -0.249 in larger metazoans.

Despite this apparently fundamental relationship between metabolism and body size, there are many instances where for a particular species the relationship may not apply. Indeed in some species the metabolism may vary in its relationship to body weight according to conditions such as salinity, shore level, experimental temperature and acclimation temperature.