bluuebunny/crossref_metadata_2025 huggingface dataset:
On the distribution of the intertidal barnacles Chthamalus stellatus, Chthamalus montagui and Euraphia depressa
Authors: Crisp D. J. , Southward A. J. , Southward Eve C.
Published: May 2009

There are three species of chthamalids in Europe. Two of them, Chthamalus stellatus and Chthamalus montagui, overlap extensively in geographic range: they occur together along the whole Atlantic coasts of Britain, Ireland, France, Spain and N. Africa, and both also occur in the Mediterranean Sea. They have almost identical north-eastern limits to their distribution in the English Channel and N. Scotland, but C. stellatus may extend farther south along the W. African coast. These two species also show overlap in their vertical distribution, though C. montagui is usually commoner in the upper barnacle zone while C. stellatus may be dominant lower down. The species are separated by habitat, C. stellatus favouring wave-beaten open coast sites, C. montagui more embayed situations, but there is still extensive overlap. The third European species of chthamalid, Euraphia depressa, has a more restricted vertical distribution and is almost entirely confined to the Mediterranean Sea, where it favours high-intertidal levels in wave-beaten places, and also cryptic habitats.
Visual predation by a marine cyclopoid copepod, Corycaeus anglicus
Authors: Gophen M. , Harris R.P.
Published: May 2009

In an experimental study the cyclopoid copepod Corycaeus anglicus Lubbock was found to ingest Artemia nauplii at much higher rates (up to 15 times) in the light than in the dark. Maximal ingestion rates observed in the light represent daily rations of 70% and 66% of the body carbon for males and females respectively. From experimental observations together with studies of the ultrastructure of the photoreceptors it is suggested that Corycaeus can locate prey visually. This is in contrast to the majority of other copepods which use chemoreceptors and mechanoreceptors.
The effect of algal and artificial diets on the growth and fatty acid composition ofCrassostrea gigasSpat
Authors: Langdon C. J. , Waldock M. J.
Published: May 2009

Crassostrea gigasspat were fed diets ofPavlova lutheri, Dunaliella tertiolectaorTetraselmis suecica. TheD. tertiolectadiet contained no fatty acid longer or more unsaturated than linolenic acid (18:3ω3) and theT. suecicadiet was deficient in decosahexaenoic acid (22:6ω3). The algal diets were supplemented with micro-encapsulated triolein, oyster lipid extract or 22:6ω3. Spat were also starved or fed carbohydrate diets.
Factors influencing shell deposition during a tidal cycle in the intertidal bivalveCerastoderma edule
Authors: Richardson C. A. , Crisp D. J. , Runham N. W.
Published: May 2009

The thin band between growth increments in the shell ofCerastoderma eduleis laid down at the end of the period of emersion, when the pH of the mantle and extrapallial fluids are at a minimum of pH 7·0 and 7·2 respectively. The growth increment is formed during immersion when the pH of the extrapallial fluid is 7·5–7·7 and the mantle 7·6–7·8, which is close to that of sea water (pH 7·8).
Studies of the effects of small-scale turbulence on phytoplankton
Authors: Savidge G.
Published: May 2009

Nutrient-limited batch cultures of two marine phytoplankton have been subjected to aeration and varying rates of mechanical agitation and the effects of growth and uptake of14C and nutrients recorded. In both phosphate- and nitrate-limited cultures the lag period decreased with increasing agitation rate. Cell division times in the exponential phase decreased with increasing agitation of phosphate-limited cultures but increased in comparable nitrate-limited cultures. Division times were increased in all aerated cultures. The final yield of phosphorus-limited cultures was greatest at the highest agitation.
Sterol and fatty acid composition of four marine haptophycean algae
Authors: Volkman J. K. , Smith D. J. , Eglinton G. , Forsberg T. E. V. , Corner E. D. S.
Published: May 2009

The lipids of four marine coccolithophorids (class Haptophyceae),Emiliania huxleyi, Hymenomonas carterae, Isochrysis galbanaandCrystallolithus hyalinus, were examined by capillary gas chromatography-mass spectrometry. Fatty acids ranged from C14to C22and were predominantly of even chain length. The major acids were polyunsaturated C18acids, 22:6 and either 14:0 or 16:0. C20fatty acids were of low abundance. Significant amounts of octadecapentaenoic acid (18:5), previously thought to be unique to dinoflagellates, were identified in three of the algae. A small amount of a di-unsaturated C36 w-alkenoic acid was identified inE. huxleyi, which is the first report of such a long-chain fatty acid in any alga. Traces of wax esters, which are reportedly uncommon inalgae, were found in three of the species. The sterol distributions were very simple, with two or three compounds accounting for > 99% of the total sterols. In each case, the major component was 24-methylcholesta-5,22E-dien-3β-ol.H. carteraeandC. hyalinusalso contained 24-ethylcholesta-5,22E-dien-3β-ol and significant amounts of cholest-5-en-3β-ol were found inE. huxleyiandI. galbana. An unusual sterol, 23,24-dimethylcholesta-5,22E-dien-3β-ol, was identified inH. carterae. These sterols were mostly non-esterified although small amounts of sterol esters were identified inE. huxleyi. The lipid composition ofE. huxleyiis distinctive in that it contains, in addition to the C36fatty acid, novel C37–C39unsaturated ketones and C31–C38alkenes. Of the other coccolithophorids onlyI. galbanacontained small quantities of one of the C3lalkenes.
The barnacle excretory organ
Authors: White K. N. , Walker G.
Published: May 2009

The paired excretory organs or maxillary glands of the adult barnacles,Balanus balanoidesandBalanus hameri, lie within the posterior part of the body below and to either side of the foregut. Each organ has an end sac linked to an efferent duct via a valve. The sac-shaped efferent duct connects with a relatively short terminal duct, opening out at the base of the second maxilla. The end sac consists of podocytelike cells having marked morphological and cytochemical similarities to the equivalent region of other Crustacea and to the vertebrate glomerulus. The main cells of the valve contain extensive apical secretion. They rest upon a series of modified end-sac cells projecting into the efferent duct. The efferent duct is composed of a uniform flattened epithelium which is cytochemically unreactive. The cells are lined by a short microvillous border, below which is a series of tubules which appear to be invaginations of the apical membrane. The morphology of efferent duct cells is not indicative of a highly active solute reabsorptive epithelium, but secretion of membrane-bound bodies into the efferent duct lumen was observed. The terminal duct is a relatively short, cuticle-lined ectodermal infolding. The parenchyma cells surrounding the efferent duct exhibit a marked affinity for certain dyes when injected into the haemolymph, indicative of a possible role in the elimination of material. The excretory organ is surrounded by a network of elastic fibres and is suspended within the body by strands of connective tissue and a complex series of tendon-muscle connexions. The end sac is well supplied with haemolymph from the scutal sinus but the supply to the efferent duct is more restricted.
Geographical variations in the reproduction of the horse mussel,Modiolus modiolus(Mollusca: Bivalvia)
Authors: Brown R. A.
Published: May 2009

The reproductive cycles of four widely separatedModiolus modioluspopulations from W. Sweden, W. and N. Norway, and Northern Ireland were examined in relation to their contrasting temperature regimes. Reproductive condition was analysed on the basis of the degree of development and numerical density of the gametes, and on size-frequency distributions of oocytes.

All the Scandinavian populations had well defined spawnings, those of W. Sweden and W. Norway occurring in June and followed by a period of redevelopment and further gamete release. The N. Norway population spawned in July and subsequent redevelopment was not accompanied by further spawnings. Both Norwegian populations overwintered in a relatively ripe condition, but that from W. Sweden spent the winter in a low state of reproductive development. The N. Ireland population contrasted with the others in being continuously ripe and having no overt spawning, but rather a slow, constant release of gametes throughout the year.

These differences are assessed in terms of the effects of the local temperature regimes on the interacting processes of gametogenesis and spawning. It is concluded that seasonal variability in temperature plays a major role in determining the extent and duration of gametogenesis, whilst spawning is more dependent upon the attainment of a limited range of minimum temperatures. The northern limit ofM. modiolusis therefore more likely to be determined by failure of conditions suitable for spawning and larval development than by a failure of gametogenesis.
Abundance, movements and size of gadoids (Teleostei) in the Severn Estuary
Authors: Claridge P. N. , Potter I. C.
Published: May 2009

Samples collected regularly from the intake screens of power stations between July 1972 and June 1977 demonstrate that the Gadidae is the most abundant and diverse teleost family in the inner Bristol Channel and Severn Estuary. The first records for the Severn Estuary of two cold water species, northern rockling and Norway pout, which were present in appreciable numbers, may be related to the effects of the changes that commenced in south-western English waters during the 1960s. Maximum numbers of the five most abundant gadoids were attained in different years, with the greatest catches being recorded for whiting and poor cod in 1975/6, bib and pollack in 1974/5 and northern rockling in 1976/7. Peak abundance in the middle estuary was reached by whiting, bib, poor cod and pollack in the autumn and by northern rockling in the winter or early spring. The 0 + age class of these species, which was always by far the most predominant category, showed increases in mean length during their relatively short stay in the estuary. Movement out of the shallows of the inner Severn Estuary by whiting and also apparently by some other gadoids occurred when salinities fell below 10‰. The size of poor cod and pollack in the autumn was not as great in 1974 as in 1975 and 1976, presumably reflecting the effect on growth of lower summer temperatures in the first of these years. Poor cod was represented by five age classes and attained at the end of the first to fifth years of life standard lengths of approximately 80 mm (≡4.8 g), 110 mm (≡11.7g), 140 mm (≡23.0 g), 170 mm (≡39.6 g) and 210 mm (≡71.6 g) respectively.
A check-list of monogenean (platyhelminth) parasites of Plymouth hosts
Authors: Llewellyn J. , Green J. E. , Kearn G. C.
Published: May 2009

ThePlymouth Marine Fauna(Marine Biological Association, 1957) list of monogenean parasites of fishes has been increased from 39 to 58 species and in addition 2 species have been recorded from a cephalopod host. The increase in listed species represents an increased ‘parasitological effort’ rather than an influx of new species into Plymouth waters.
Nephtys pente sp.nov. (Polychaeta: Nephtyidae) and a key to Nephtys from northern Europe
Authors: Rainer S. F.
Published: May 2009

Nephtys pente sp.nov. is described. The species is known to occur in shallow waters from the western Baltic to Greenland. It may occur with Nephtys ciliata, which it closely resembles. An amended definition for N. ciliata is proposed. A key is provided for the northern European species of Nephtys.
Cupular growth in herring neuromasts
Authors: Blaxter J. H. S.
Published: May 2009

Using vital staining of neuromasts, followed by recovery, cupular growth rates of 1.4–4.1 μm/h were found in herring (Clupea harengus L.) larvae and 4.0 μm/h in juveniles. It seems likely that the cupulae are continually being shed and replaced.
Cell division and reformation of the amphiesma in the pelliculate dinoflagellate,Heterocapsa niei
Authors: Morrill Lenitac , Loeblich Alfred R.
Published: May 2009

Cytokinesis is described for the first time in a pelliculate dinoflagellate that retains its thecal plates during cell division. InHeterocapsa nieicytokinesis proceeded in a manner that differed from that described for other dinoflagellates. The thecal plates separated along the fission line before the development of a cleavage furrow. A distinct cleavage furrow developed as cytokinesis progressed. The outer membrane and the outer plate membrane expanded during division to enclose the enlarging cell undergoing cytokinesis; however, as the cleavage furrow deepened, these membranes were not continuous with the cytoplasm. The pellicle was occasionally intermittent in the region of the cleavage furrow, possibly facilitating movement of material from the cytoplasm to the developing outer membranes. Thecal plate formation occurred within the thecal vesicle from unrecognizable precursors.
Tracking movements of deep demersal fishes in the Porcupine Seabight, north-east Atlantic Ocean
Authors: Bagley P.M. , Smith A. , Priede I.G.
Published: May 2009

Miniature acoustic transponders wrapped in bait were deployed on the sea floor in the continental rise and slope regions of the Porcupine Seabight during August 1992. These were ingested by Centroscymnus coelolepis (Chondrichthyes, Selachii) at 1517–1650 m depth, Antimora rostrata (Osteichthyes, Moridae) at 2020–2501 m depth, and Coryphaenoides (Nematonurus) armatus (Osteichthyes, Macrouridae) at 2501–4050 m depth. Fish with baits in their stomachs were tracked using a scanning sonar deployed on the sea floor. All fish had moved out of range of the sonar (500 m) within 3–9 h of the bait reaching the sea floor, indicating no site fidelity. Swimming speed of C. (N.) armatus increased with depth from 0056 m s-1 at 2500 m to 0·109 m s-1 at 4000 m. This is partially explained by a bigger-deeper trend in fish size.
Scavenging deep demersal fishes of the Porcupine Seabight, north-east Atlantic: observations by baited camera, trap and trawl
Authors: Priede I.G. , Bagley P.M. , Smith A. , Creasey S. , Merrett N.R.
Published: May 2009

Demersal fishes on the continental rise and slope were sampled by trawl, baited trap and a baited camera. Seventy-one different species were trawled, but only 18 species approached baits. At rise soundings (4100 m to 2250 m) Coryphaenoides (Nematonurus) armatus was dominant at baits and comprised 41·5% of the trawl catch. On the slope (<2250 m) Synaphobranchus kaupi was dominant at baits and comprised 32·7% of the trawl catch. At 1500–2501 m Antimora rostrata competed at baits and comprised 5–10% of trawl catches. At 1500–1650 m Centroscymnus coelolepis also consumed baits but was not captured by trawl. For C. (N.) armatus abundance was proportional to tarr2 (where tarr= arrival time), demonstrating that arrival time of the first fish at baits provides an estimate of population density. Maximum estimated abundance at 2897 m was 877 km-2, more than five times the abundance on the abyssal plain. Halosauropsis macrochir, Lepidion eques, Coryphaenoides guentheri, Gadiculus argenteus and Coryphaenoides rupestris were important in trawl samples but absent or rare at baits.
Fish assemblages on the slope in the Catalan Sea (western Mediterranean): influence of a submarine canyon
Authors: Stefanescu Constanti , Nin-Morales Beatriz , Massuti Enric
Published: May 2009

The analysis of 35 bottom trawls taken on the slope in the Catalan Sea (western Mediterranean) has shown the existence of two different demersal fish assemblages occurring on the upper (350–650 m) and middle (1150–1300 m) slope. The middle slope assemblage is characterized by much higher values in some ecological parameters such biomass and mean fish weight, resulting from the dominance of middle to large size species (e.g. Alepocephalus rostratus, Trachyrhynchus trachyrhynchus, Mora mom). On the upper slope two different stations were considered, one inside and the other outside a submarine canyon. Only slight differences were found in species composition, and hence sample and species were not clearly separated by a correspondence analysis. However, some interesting ecological differences exist between these two stations. Much higher values in abundance and biomass inside the canyon were indicative of higher food availability there. Moreover, a drop in mean fish weight was also noted inside the canyon. The analysis of size distributions in the commonest species along the upper slope showed that the submarine canyon acts as a recruiting ground for some of them.
Abundance, seasonality and size of Atlantic salmon smolts entrained on power station intake screens in the Severn Estuary
Authors: Claridge P.N. , Potter I.C.
Published: May 2009

Atlantic salmon smolts were sampled from the intake screens of the Oldbury power station in the inner Severn Estuary at weekly intervals between July 1972 and June 1977. These catches, and those taken over nearly three years from the nearby Berkeley power station, demonstrated that the abundance of smolts in the estuary peaked in autumn (October) and, to a far greater extent, in spring (April and May). However, small numbers of smolts were occasionally found in all other months of the year except July. Standard length-frequency distributions of smolts remained unimodal throughout the year. Lengths ranged from 76 to 187 mm, mean 130·2 ±1·87 mm (95% CL), and wet weights ranged from 5·4 to 68·0 g, mean 26·9 ±1·17 g. The mean monthly standard length of smolts increased slightly between the autumn of one year and the spring/early summer of the next year, suggesting that, on average, the former were six months younger than the latter. The condition factor was significantly greater in autumn (1·40) than in spring (1·23). It is estimated that the total number of salmon smolts entrained annually on the screens at Oldbury during the five years ranged from 92 to 791, with a mean of 405. Total estimated numbers at Berkeley ranged from 196 to 788 per annum. The numbers at Oldbury are lower than those estimated for the downstream migrants of the Twaite shad, another anadromous species, and far lower than those of the most abundant of the marine fish species that use the Severn Estuary as a nursery area.
Cryptocaryon irrttans (Ciliophora): photoperiod and transmission in marine fish
Authors: Burgess P.J. , Matthews R.A.
Published: May 2009

The ciliate Cryptocaryon irritans Brown, 1951 is a parasite of tropical marine fishes, being recorded chiefly from coral reef species (Laird, 1956; Burgess, 1978; Colorni, 1985). The disease, cryptocaryosis, accounts for fish mortalities in aquaria (De Graaf, 1973) and mariculture systems (Huff & Burns, 1981; Colorni, 1985; Kaige & Miyazaki, 1985; Rasheed, 1989); however, relatively few studies have been undertaken on the biology of C. irritans, as highlighted by Lorn & Dykova (1992). Sikama (1937) described the major features of the life cycle, infection of the fish epidermis alternating with a free-living phase of reproduction within a protective cyst. Most other investigations of C. irritans have been concerned with morphology (Sikama, 1937, 1938; Brown, 1951, 1963; Nigrelli & Ruggieri, 1966; Cheung et al., 1981; Colorni, 1988) with a recent work on the ultrastructure of the pellicle (Matthews et al., 1993). Little is known regarding the behaviour of free-living stages and the possible influence of environmental factors on transmission. Nigrelli & Ruggieri (1966) noted photopositive responses in theronts. The establishment and maintenance of C. irritans in mullet under controlled conditions (Burgess & Matthews, 1994) provided an opportunity further to investigate light in the survival strategy of this fish pathogen.
Competition for Space in encrusting bryozoan assemblages: the influence of encounter angle, site and year
Authors: Turner Stephanie J. , Todd Christopher D.
Published: May 2009

This field study examined competition for space among encrusting bryozoans on artificial panel substrata used to simulate the habitat found on the undersides of boulders. In all 1761 interactions were analysed, involving 16 species of cheilostomes (genera Callopora, Celleporella, Cribrilina, Electra, Escharella, Escharoides, Haplopoma, Membraniporella, Microporella, Phaeostachys, Schizomavella, Schizoporella and Umbonula) and two ctenostome genera (Alcyonidium and Flustrellidra). Neither absolutely transitive nor intransitive arrangements of competitive outcome occurred among the species. Instead, the high incidence of ‘ties’ and reversals of outcome produced a network-like arrangement. In terms of outcome alone Escharoides coccinea (Abildgaard), Membraniporella nitida (Johnston) and Schizoporella unicornis (Johnston in Wood) were apparently ‘overgrowth dominants’, Alcyonidium spp. and Cribrilina cryptooecium Norman were ‘intermediate dominants’ and Callopora lineata (L.), Callopora craticula (Alder), Celleporella hyalina (L.) and Electra pilosa (L.) were ‘inferior competitors’ for space. The effects of four variables on the outcome of specific competitive encounters were assessed in detail and included (i) the identity of the colony encountered, (ii) the angle of contact between the competing colonies, (iii) the location (two sites, on both the east and west coasts of Scotland) and (iv) the year (1983, 1984). Models incorporating these variables were developed, using the Generalized Linear Interactive Modelling System (GLIM), to examine their influence on the outcome of bryozoan encounters. All of these factors contributed to explaining the considerable variability in the outcome of competitive interactions. The species were not, however, affected equally by all the variables, although encounter angle and year were significant for dominants and encounter angle, site and year all were significant for intermediate species.
Growth zones and back-calculation for the sea urchin,Sphaerechinus granularis, from the Bay of Brest, France
Authors: Lumingas L.J.L. , Guillou M.
Published: May 2009

A procedure for accurately determining age and growth of the sea urchinSphaerechinus granularis(Lamarck) (Echinodermata: Echinoidea) in the Bay of Brest (France) is described. Readings of growth lines were made from the longitudinal cross-section of interambulacral oral plates of sea urchins collected in February 1993. These results agree with age estimates calculated using the ELEFAN I programme based on diameter-frequency distributions of sea urchins collected from February 1992 to March 1993. A non-linear regression (monomolecular equation) best describes the relationship between test diameter and plate thickness. The diameter-at-age data can be increased by back-calculation, assuming a constant proportional deviation from the mean size of the test. Although von Bertalanffy growth curves fitted to actual observations were similar to those fitted to back-calculated diameter-at-age data, the latter produced a more adequate curve and increased the quality of the growth parameter estimators. The von Bertalanffy growth curve estimated by ELEFAN I shows a pattern similar to the back-calculated von Bertalanffy growth curve.
The microhabitat and morphology ofGrubea cochlearon the gills of mackerel from lyme bay, Southern England
Authors: Lyndon A.R. , Martinez-Vidal V.M.
Published: May 2009

The microhabitat and morphology ofGrubea cochlear(Monogenea), a rare gill parasite of Atlantic mackerel (Scomber scombrus), were investigated for a sample of fourteen parasite individuals obtained from Lyme Bay, southern England.Grubea cochlearshowed a preference for the inner hemibranch of the fourth gill arch, this localization contrasting with that of the related and sympatric speciesKuhnia scombri. The morphology ofG. cochlearin this sample differed slightly from some of the previously documented specimens, especially with regard to the number of small genital hooks and the relative size of the haptor. It is suggested that geographical morphological variation may occur in this species.
On the Amount of Phosphoric Acid in the Sea-Water off Plymouth Sound. II
Authors: Matthews. Donald J.
Published: May 2009

The amount of phosphoric acid in sea-water off Plymouth was at a maximum of 0.06 mg. per litre of P2O5 at the end of December, 1915, after which it fell irregularly to a minimum of less than 0.01 mg., which extended from the last week of April to the latter part of May; it then increased again and in January, 1917, reached the same value as the average for the first part of the month in the previous year.

This seasonal variation is probably to be attributed to the removal of the phosphates from solution, at first by the fixed algæ, and later in the spring by the diatoms and for a short time by Phcœcyslis. There is also present in sea-water taken near Plymouth another soluble compound of phosphorus which can be converted into phosphoric acid by oxidising agents.
Populations of phytoplankton in the western English Channel between 1964 and 1974
Authors: Maddock Linda , Boalch G. T. , Harbour D. S.
Published: May 2009

Phytoplankton data collected between 1964 and 1974 at three stations in the western English Channel were analysed by the multivariate method of correspondence analysis. The data comprised counts, logarithmically transformed, of 126 taxonomic groups in 700 samples from different depths. The first three axes from the correspondence analysis explained only 17% of the total variation, but the sample positions on these axes showed a clear mean seasonal cycle, slightly different at each station. The species fell into ten groups according to their position on the axes and to their seasonal occurrence. Differences in the position on the axes of samples from different depths on the same occasion correlated well with the temperature structure of the water column. No clear long-term trends were apparent although there were obviously large differences from year to year. The results provide a mean seasonal pattern of species succession on a quantitative basis which can be used to compare counts from different areas or to identify changes in the same area.
An experimental search for phytoplanktonic algae producing external metabolites which condition natural sea waters
Authors: Wilson Douglas P.
Published: May 2009

In a search for phytoplanktonic algae which may condition water masses by excreted metabolites monocultures of 29 species of diatoms and flagellates, also of one sedentary alga, were tested with developing eggs and larvae of two species of sea-urchin and of a polychaete. Results indicated that about half of the algal species examined, using both unfiltered cultures and filtrates from them, probably do not produce metabolites affecting development of the three animal species employed in this work. Others were harmful or favourable to them in various ways. One flagellate species in particular, Olisthodiscus luteus N. Carter was of outstanding interest, with effects on larvae varying from toxic to favourable according to culture density and amount of dilution with normal sea water. Ancillary experiments eliminated the possibility that excessively high or low pH could be responsible for observed effects, while others showed that in a semi-toxic environment crowding of eggs and larvae can be beneficial but not in non-toxic media. In the main experimental search for possible effects of metabolites, eggs and larvae were never crowded.
An Energy budget for a population of the limpetPatella vulgata
Authors: Wright J. R. , Hartnoll R. G.
Published: May 2009

An energy budget has been assembled for a population of the limpetPatella vulgatainhabiting the mid-tide level of a moderately sheltered shore in the Isle of Man. The average biomass during the two year study was 346 kJ m−2, and the energy budget in kJ m−2year−1:
Responses ofcorophium volutatorto sediment sulphide
Authors: Meadows P. S. , Deans E. A. , Anderson J. G.
Published: May 2009

An apparatus has been developed which allows the complete replacement of interstitial water in sediments without disturbance. In principle, it can be adapted to handle sand or mud, different solutions, and different volumes of sediment. The apparatus was tested with 0·05% (wt/vol.) eosin in sea water. After replacement of the interstitial water, the eosin was evenly distributed throughout the sediment. Interstitial water in samples of sediment was replaced by sulphide solutions in sea water, at a range of concentrations. The responses ofCorophium volutatorto these sediments was tested in choice and non-choice experiments. In the choice experiments, animals avoided burrowing in sediments containing sulphide at concentrations greater than about 5·8 × 10−5M. In the non-choice experiments, animals were progressively inhibited from burrowing when the sediment sulphide concentration was greater than about 5·8 × 10−4M. No mortality occurred during the experiments.
Changes in the benthic community of china clay waste deposits in Mevagissey Bay following a reduction of discharges
Authors: Probert P. Keith
Published: May 2009

Macrobenthic infauna was sampled in Mevagissey Bay, off the south coast of Cornwall, England, when the bay was receiving fine-grained mineral waste from the china clay industry at a rate of about 450000 tons per annum. Quintuplicate 0·1 m2grab samples, washed on a 0·5 mm mesh, were taken on 15 occasions over two years at a station about 1 km from the outfall and at a water depth of 13 m. The fauna had a range of density of 755–2144 individuals/0–5 m2and in composition resembled a partially impoverishedEchinocardium cordatum/Amphiurafiliformiscommunity. Population densities ofGoniada maculata(Polychaeta),Cingula semicostata(Gastropoda),Nucula turgida, Mysella bidentata, Venus striatulaandTellina fabula(Bivalvia) showed no clear trends during the two years' sampling.Magelona filiformis(Polychaeta),Abra albaandPhaxas pellucidus(Bivalvia),Acrocnida brachiataandAmphiura filiformis(Ophiuroidea) declined in abundance, whereas the densities ofNephtys hombergi(Polychaeta) andLabidoplax digitata(Holothurioidea) increased.L. digitatabecame the commonest species, with a peak density of 708 individuals/0·5 m2. A month after sampling began the rate of waste discharged was reduced from 700000 tons per annum, but this did not appear to improve conditions for the benthic community. Total faunal density remained relatively stable but species diversity declined. It is argued that the suspended solid concentration was unlikely to have adversely affected the predominantly deposit-feeding community, but that persistent sediment instability continued to be a source of stress. Nevertheless, the observed major changes of community structure were similar to natural fluctuations of coastal soft-bottom populations resulting from species interactions and differences of larval success.
A note on the growth of Arctica islandica
Authors: Forster G. R.
Published: May 2009

In conjunction with a tagging experiment on Callista chione (L.) in 1976, a small number of the large bivalve Arctica islandica (L.) (Family Arcticidae) were also tagged in a similar manner with plastic discs cemented on to the shell with fast-setting cyanoacrylate adhesive. Arctica is less common in Whitsand Bay than Callista but extends into deeper water, 50–60m. Holme (1953) suggested that the species is long-lived and produced spat infrequently. A few young Arctica have been taken in Whitsand Bay (length 29–37 mm) and also, more commonly, specimens of 80–100 mm. In 1976 five Arctica were tagged and relaid, three of these were recovered in 1977 and one in 1978. Three more were tagged in 1978 and searched for without success in 1979. The recovered specimens did not appear to have moved at all. The results of shell length measurements, though meagre, indicated that growth was very slow. For a shell of 82 mm length the increase was 1–5 mm in a year. For a shell of 101 mm there was no increment after two years. For a shell of 102 mm the annual increment was probably 0-1 mm. In this instance it seems likely that the original length should have been 102–3 mm instead of 103–2 which was recorded. For a shell of 108 mm an increment of 0–3 mm was found after 12 months. From these results the average increment of shells over 100 mm length is likely to be of the order of 0-1 mm per year.
Chemoautotrophy in Bivalve Molluscs of the Genus Thyasira
Authors: Dando P. R. , Southward A. J.
Published: May 2009

The bivalves Thyasiraflexuosa and T. sarsi have enlarged gills which contain numerous prokaryotes. Gills from freshly collected animals contain high concentrations of elemental sulphur. Homogenates of gill tissue show activity for ribulosebisphosphate carboxylase, adenylylsulphate reductase, sulphate adenylyltransferase and sulphate adenylyltransferase (ADP), indicating that the prokaryotes are sulphur-oxidizing autotrophs. Both species can burrow to depths of 8 cm below the sediment surface and use their vermiform feet to construct channels penetrating deeper into the sediment. T.flexuosa and T. sarsi are scarce in sediments with high hydrogen sulphide concentrations and are not found in sediments where the sulphide zone is below their burrowing depth.
Food from the Sea
Authors: Allen E. J.
Published: May 2009

…Passing now to the special subject of my address to-night, I will ask your attention in the first place to some general aspects of our Sea Fisheries as a source of national food supply and to the general scientific investigations which have been undertaken in the hope that the yield of the harvest of the sea may be still further increased. In the second place a more detailed account will be attempted of some particular researches bearing upon these matters, which happen to have formed during the past few years the subject of my own special work. If in the course of my remarks you may seem to be asked to follow me in excessive detail into some of the more remote corners of the problems which arise, my excuse must be that, even at the risk of upsetting the balance of the picture as a whole, it is probably possible to speak to more purpose and with a better prospect of stimulating others to fresh efforts, by describing researches with which I have been personally concerned, than by a more general and better proportioned, but necessarily more superficial treatment of the whole subject.
Wing-loading, stability and morphometric relationships in flying fish (Exocoetidae) from the North-eastern Atlantic
Authors: Davenport John
Published: May 2009

‘Four-winged’ flying fish (in which both pectoral and pelvic fins are hypertrophied) reach greater maximum sizes than ‘two-winged’ forms in which only the pectoral fins are enlarged. Exocoetus obtusirostris shows negatively allometric growth in relation to standard length in terms of body mass (b=2·981), and lateral fin area (b=1·834). In consequence, wing-loading rises in positive allometric fashion with standard length (b=l·236). Pectoral fin length cannot be greater than 78–79% of standard length or swimming will be impaired, so the requirement for increased flying speed resulting from increased wing-loading during growth means that lift:drag ratios have to be improved by relatively narrowed wings and tapered wing tips; features which in turn increase wing-loading. Evidence is presented to show that hypertrophied pelvic fins in four-wingers are required to solve problems of stability in pitch, rather than to decrease wing-loading. The ‘non-flying’ flying fish, Oxyporhamphus micropterus, has very high wing-loadings, but the main reason that it cannot fly is that the centre of gravity of the fish is so far behind the pectoral fins that stalling on take-off would be inevitable. Flying fish possess reasonable quantities of red axial musculature, but no more than are used for cruising in fast-moving pelagic fish such as mackerel; it seems probable that acceleration to take-off speed in flying fish requires use of anaerobic white muscles.
Regional morphological variations in the compound eyes of certain mesopelagic shrimps in relation to their habitat
Authors: Gaten E. , Shelton P. M. J. , Herring P. J.
Published: May 2009

The anatomy of the eyes of several species of mesopelagic decapods (family Oplophoridae), obtained from the eastern north Atlantic, is described and related to the unique light environment of the deep seas. The oplophorid eyes are of the reflecting superposition type, but they show a number of regional morphological variations. The main rhabdom, formed by retinula cells Rl to R7, comes in a variety of shapes, from fusiform rhabdoms in the dorsal region of the eyes of Oplophorus spinosus to multi-lobed interdigitating rhabdoms in deepwater species. The distal rhabdom, contributed to each ommatidium by retinula cell R8, gradually increases in size towards the ventral part of the eye in Systellaspis debilis and O. spinosus. Histological examination of the tapetum shows that it is incomplete dorsally in some species from the upper mesopelagic zone (S. debilis, O. spinosus), and that the amount of reflecting pigment in the tapetal cells increases in the ventral part of the eye. The tapetum is complete in some deep-water species (Systellaspis cristata, Acanthephyra kingsleyi, A. pelagica). These adaptations of the rhabdoms and tapeta are thought to be concerned with increased sensitivity to the dim up-welling irradiance and to bioluminescence. A dorsal accessory compound eye consisting of a small group of apparently functional apposition-type ommatidia is described.
Polymerase Chain reaction and 16S rRNA gene sequences from the luminous bacterial symbionts of two deep-sea anglerfishes
Authors: Haygood Margo G. , Distel Daniel L. , Herring Peter J.
Published: May 2009

Sequences of the 16S ribosomal RNA gene of luminous bacterial symbionts from the escas of the deep sea anglerfishesMelanocetus johnsoniandCryptopsaras couesiwere determined by direct sequencing of polymerase chain reaction products. A sequence was also obtained from a strain ofPhotobacterium phosphoreum, the culturable light organ symbiont ofOpisthoproctus grimaldii. Comparison of these and other published sequences showed that the anglerfish symbionts group with the marine luminous bacteria but are not closely related toP. phosphoreum. The two ceratioid symbionts differ from each other at least at the species level.
Some features of the territories in the breeding males of the intertidal blennyLipophrys pholis(Pisces: Blenniidae)
Authors: Almada Vitor C. , Gonçalves Emanuel J. , De Oliveira Rui F. , Barata Eduardo N.
Published: May 2009

In this paper we present data on the organization of the territories in males ofLipophrys pholisduring the breeding season. Data were collected during high tides by skin- and scubadiving and during low tides by direct inspection of nests. Our study area was located at Arrébida, Portugal. The main results are: (i) The territories of the breeding males of this species are temporary, being established each breeding season, (ii) The guarding males stay in the nest holes with the egg masses while the tide is low and are subjected to several hours of emersion in each tidal cycle, (iii) Even when the nests are submerged the fishes stay inside the nest for an average of 92% of the time. All the activities performed outside the nest correspond to an average of 27 minutes per day. (iv) There was a low frequency of territorial intrusions. Conspecific intruders released a significantly higher frequency of agonistic responses than didCoryphoblennius galerita.(v) Removal experiments showed that vacated territories are not occupied by other males during the same breeding season, (vi) Without the presence of the guarding male the eggs are slowly destroyed by predation and infection, but some eggs can still survive and hatch up to five days after the removal of the parental male. The results are discussed in terms of the probable costs and benefits of breeding intertidally.
Larval and early postlarval shell morphology of several venerid clams
Authors: Goodsell J. G. , Fuller S. C. , Eversole A. G. , Castagna M. , Lutz R. A.
Published: May 2009

Shell morphological features of the larvae and early postlarvae of species from two venerid (Mollusca: Lamellibranchia) subfamilies, Chioninae (Mercenaria mercenaria, M. campechiensis, M. campechiensis texana and Chionecancellata) and Pitarinae (Pitar morrhuanus), were examined using scanning electron microscopy. A single elongated fold on the anterior half of the left valve became more robust and a small fold in the centre of the right valve increased in length along the hinge line throughout the larval period. A MANOVA of shell length, shell height and provinculum length detected statistically significant (P) differences between the larval shells of Chioninae and Pitarinae, and within the Mercenaria.
Growth Bands in the sea Urchin Echinus Esculentus: Results from Tetracycline-Mark/Recapture
Authors: Gage J. D.
Published: May 2009

Recoveries of tetracycline-labelled specimens of the sea urchin Echinus esculentus (Echinodermata: Echinoidea) from a wild population marked two years previously indicate very low skeletal growth rates in large adults. The post-tag growth in the test of a smaller specimen showed two clear growth zones in the middle layer of the plates, this conforming to the expectation of a single growth band each year. Merging of the spinochrome pigment bands present in the outer layer near the plate edge in older urchins will probably result in underestimation of age based on counts of these bands.

The large literature on growth banding in the European sea urchin Echinus esculentus L. and other echinoids is reviewed by Pearse & Pearse (1975), Smith (1980) and Gage (1991). Moore (1935) utilised spinochrome pigment banding in the genital (apical) plates of E. esculentus from the Isle of Man (Irish Sea) and Firth of Clyde (western Scotland) in one of the first studies utilising growth bands to interpret the age structure and growth rates of sea urchins. A single band was assumed to be formed each year. Counts of spinochrome bands have been used to obtain nearly all subsequently published age data for this species (Sime, 1982; Nichols et al., 1985; Sime & Cranmer, 1985; Comely & Ansell, 1988).

The present study was aimed at helping to resolve differing interpretations of age and growth rates in Echinus esculentus provided by these studies. This was undertaken by time marking the skeletal plates of a large sample of a wild population accessible by scuba diving on a submerged rock reef at 10–15 m depth off the islet of Eilean Mor near the Dunstaffnage Laboratory.
An Epibiont on the Red-Water Ciliate Mesodinium Rubrum
Authors: Crawford David W.
Published: May 2009

Spherical, opaque bodies (5–10 µm diameter) were frequently observed adhering to cells of the marine ciliate Mesodinium rubrum, particularly towards the end of red-water blooms in Southampton Water. Transmission electron microscope sections revealed these structures to be of biogenic origin, and packed with an amorphous, lipid-like material. No diagnostic features were observed to confirm their identity.

The phototrophic ciliate Mesodinium rubrum (Lohmann) forms recurrent red-tides each summer and autumn in the Southampton Water estuary, UK (Williams, 1980; Soulsby et al., 1984). During a study of the impact of these blooms on the estuary, live cells were routinely observed microscopically. Frequently, but predominantly later in the bloom, numerous individuals posessed spherical, colourless, but opaque bodies, apparently attached or adherent to the outer cell membrane. Cells observed prior to the bloom, or at other times of the year, were never observed o possess such structures.

Cells bearing these bodies were photographed live, or after preservation in Lugol's iodine, using the phase contrast optics of an Olympus BH2 photomicroscope.
Morphological adaptations of Aglaophenia harpago (Hydrozoa: Plumulariidae) to enhance feeding efficiency
Authors: Hughes R. G. , Henderson D. H. J.
Published: May 2009

The pinnate (feather-shaped) hydrocauli (stems) of Aglaophenia harpago are dish-shaped with the food catching hydranths borne on the convex side of the lateral branches, a morphology recognised as an adaptation to feeding from unidirectional currents. A. harpago experience unidirectional currents because the hydrocauli are able to rotate close to their bases on an articulation in the perisarc (the tubular exoskeleton) so that the concave surface always faces into the current and the hydranths face leeward. The structure of this articulation, revealed by light and electron microscopy, is described and its mechanism interpreted. The articulation consists of two oblique grooves of thin flexible perisarc which traverse around the hydrocaulus at an angle of 62–65°. The grooves terminate in areas of perisarc divided into longitudinal lamellae (probably of structural protein). The grooves and lamellae confer the flexibility which allows the hydrocaulus to ‘fold’ up to 90° clockwise or anticlockwise across each groove. The lamellae maintain the longitudinal support necessary to prevent the hydrocaulus collapsing.
Tegumental glands in the paragnaths of Palaemon serratus (Crustacea: Natantia)
Authors: Alexander C. G.
Published: May 2009

The three lobed paragnath of Palaemon serratus (Pennant) contains numerous rosette-type tegumental glands often arranged in clusters of up to ten glands. Each gland is made up of around ten cells most of which stain deeply with toluidine blue and whose contents have a reticulate appearance in electron micrographs. One, or occasionally two, cells stain faintly and have a fine granular appearance in electron micrographs. The central region of each gland contains the main drainage duct together with feeder canals from the vesicular storage areas. The actively secreting region of each cell is peripheral and typified by abundant rough endoplasmic reticulum and Golgi apparatus. There are nerves adjacent to the glands and their contents are probably discharged in response to a food stimulus. The structure and possible function of the glands are discussed in relation to those of other species The secretions could act as a lubricant and as a binding agent to aid in the ingestion of particulate food. There is no evidence for any direct digestive function.
The Macrobenthic Infauna of the Offshore Northern North Sea
Authors: Eleftheriou A. , Basford D.J.
Published: May 2009

Between 1980 and 1985 ninety-seven stations were sampled by Smith-Mclntyre grab from the offshore northern section of the North Sea. Four hundred and nine infaunal species were identified from the 76 selected macrofaunal stations. The number of species per station varied from 25 to 80 with a maximum abundance of 9,600 individuals m−2. The biomass ranged from 0.13 to 18.86 g dry weight m−2. At most stations, however, biomass varied between 1 and 4 g dry weight m−2. Diversity and abundance were highest in the 120–140 m zone, characterised by fine sand containing variable amounts of silt. The highest biomasses were recorded in two areas; firstly where stronger currents predominate and the sediments are coarser (east of Shetland and west of the Norwegian Trough), and secondly in the fine sandy deposits of the centrally located area. In the silty sediments (Fladen Ground and smaller depressions) there was a predominantly subsurface deposit-feeding community, whereas in the coarser area east of the Shetlands carnivores predominated. Over the remaining area surface deposit feeders were dominant.