bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations on swimming, posture and buoyancy in the giant oceanic ostracods,Gigantocypris mulleriandMacrocypridina castanea
Authors: Davenport John
Published: May 2009

Gigantocyprisis a good swimmer, capable of moving fast enough to overtake a variety of zooplanktonic Crustacea and chaetognaths. It swims smoothly without violent accelerations and decelerations. Previous reports of unstable weak swimming in this species stem from the study of overheated animals;Gigantocyprisis stenothermal, adversely affected at temperatures above about 15°C.Gigantocyprisis nearly neutrally buoyant (sinking speed 0·2 mm s−1) and is capable of hovering for long periods with the aid of slight movements of the propulsive antennae. When swimming quicklyGigantocyprisachieves an average speed of 164 mm s−1(9·6 mm body length; 391 antennal beats min−1) at 12·5°C. It is unlikely thatGigantocyprisperforms significant diurnal vertical migrations. The heart ofGigantocyprisis large and beats atca100 beats min−1.Macrocypridinais a faster swimmer (<52·3 mm s−1(8·3 mm body length) at 12·5°C with an antennal frequency of 583 beats s−1), but each beat is accompanied by great accelerations and decelerations.Macrocypridinais dense, sinking at 40 mm s−1.Macrocypridinais eurythermal, its swimming speed increasing steadily between 11·5 and 20°C.
Differences in the swimming behaviour of the amphipod Corophium volutator from different populations
Authors: Hughes R.G. , Horsfall I. M.
Published: May 2009

The swimming behaviour of Corophium volutator from Wales and East Anglia was investigated to establish whether differences apparent from two previous studies are real or artefacts of the different techniques used. Swimming C. volutator were caught in a Welsh estuary in the summer, but only rarely in the autumn and winter, and in both daylight and darkness. In simulated tidal conditions in the laboratory C. volutator from two sites in East Anglia never swam, while those from Wales swam whenever the substratum was immersed, in daylight and darkness, mostly on the ebb tide and in winter. The unnatural swimming in winter may have been stimulated by laboratory conditions, but the East Anglian amphipods were not so affected. The tidal swimming rhythm is different to east coast C. volutator which only swim at night. This difference may be related to the time of spring tides, when most swimming occurs. In Wales high water of spring tides may occur only in daylight in summer and nocturnal swimming may not be possible. The ebb tide swimming by C. volutator in Wales contrasts with the flood and ebb swimming of east coast amphipods and may reflect differences in their habitats. The former were collected close to the sea while the latter were 15 km up a narrow estuary and may represent a sub-population of amphipods with a disposition to swim early (on the flood tide) enabling them to colonise upstream habitats.
Gametogenesis and the reproductive cycle in the deep-sea anemone Paracalliactis stephensoni (Cnidaria: Actiniaria)
Authors: Praet-Van Michel
Published: May 2009

This ultrastructural investigation of gametogenesis in a deep-sea anemone of the Bay of Biscay trawled around 2000 m depth, contributes to the knowledge of biology and strategy of reproduction of deep-sea benthos.

This sea anemone is dioecious. The sperm appears very similar to those of shallow water sea anemones of the genus, Calliactis. The ultrastructural investigation of oogenesis allows the characteristics of the stages of previtellogenesis and vitellogenesis to be defined. The latter begins with a period of lipogenesis correlated with the formation of a trophonema. Mature oocytes measure up to 180 (im in diameter. Study of spermatogenesis and oogenesis reveals that spawning occurs in April/May. In males, the main area of testicular cysts, full of sperm, reaches maximal development from March to May and, in females, the percentage of mature oocytes decreases from 33% in April to 1% in May.

Spawning may be induced by the advent in the deep-sea of the products of the spring phytoplankton bloom. This period of spawning, during the increased deposition of organic matter to the deep-sea floor, may be an advantageous strategy for early development of Paracalliactis.
Seasonal reproduction in the seastar Dytaster grandis from 4000 m in the north-east Atlantic Ocean
Authors: Tyler P. A. , Billett D. S. M. , Gage J. D.
Published: May 2009

Examination of the reproductive biology of the abyssal seastar Dytaster grandis taken at different times of the year in the NE Atlantic suggests seasonal reproduction that is related to the seasonal pulse of phytodetritus to the deep-sea floor. Although this seastar is an omnivore, the availability of this labile organic material may fuel vitellogenesis during the summer and autumn months. The egg size suggests planktotrophic larval development. Spawning occurs in the early part of each year to allow the zygote to develop into a feeding larva to coincide with the downward flux of phytodetritus. Thus the flux of detritus may constitute an environmental forcing pressure at least at two points in the life history of D. grandis.
Preliminary observations on factors affecting foraging activity in the limpet Patella vulgata
Authors: Little Colin , Morritt David , Paterson David M. , Stirling Penny , Williams Gray A.
Published: May 2009

Activity patterns of limpets were studied at two adjacent sites in an Irish sea lough, Lough Hyne, in order to relate timing of activity to physical and biological influences. Activity was suppressed during heavy rainfall, and osmotic stress from dilution appears to have led to increased mortality in transplanted limpets. Activity increased as tides progressed from neaps to springs, and for limpets low on the shore it was enhanced by wave action. It is suggested that lack of activity in calm water may reduce predation pressure from crabs, which caused high mortality in transplanted limpets. Either low relative humidity or dryness of the rock diminished activity of low-water limpets. Differences in feeding activity between low-water limpets and high-water limpets may relate to food supply, since more food was available low on the shore, and the guts of low-water limpets contained more diatoms than those of high-water individuals. Differences between the two sites are at present unexplained but may relate to differences in micro habitats.
A biochemical investigation of a Phaeocystis sp. bloom in the Irish Sea
Authors: Claustre H. , Poulet S. A. , Williams R. , Marty J. -C. , Coombs S. , Mlih F. Ben , Hapette A. M. , Jezequel-Martin V.
Published: May 2009

In early June 1988, an extensive bloom of Phaeocystis sp. (29xlO6 cells 1−1) was observed in the eastern Irish Sea along the North Wales coast. Chlorophylls, carotenoids, free amino acids, fatty acids, vitamin C, carbon and nitrogen were measured in particles from three size categories (<22 μm, 22–100 μm and 100–200 μm) at a station 13 miles off the coast line. Phaeocystis sp. formed 99% of the total particle stock below 22 μm and was characterized by (1) the presence of chlorophyll c3, (2) the dominance of fucoxanthin over 19'- acyloxyfucoxanthins, (3) the presence of C18:5 fatty acid at trace levels and (4) different proportions of amino acids compared to those measured in particles greater than 22 μm. These larger particles were dominated by diatoms, dinoflagellates and ciliates. The poor nutritional value of Phaeocystis sp. for herbivorous zooplankton was characterised by its low content of polyunsaturated fatty acids and vitamin C. Comparison between the chemical composition of Phaeocystis sp. and copepod faecal pellets showed that the copepods were feeding predominantly on other phytoplankton.
Studies on the growth of Phaeodactylum tricornutum III. The effect of iron on growth
Authors: Hayward J.
Published: May 2009

The iron nutrition of Phaeodactylum tricornutum (Bohlin) has been studied, and the limitation of growth because of iron deficiency demonstrated. Evidence is presented suggesting the ability of the organism to utilize paniculate iron and to adjust its utilization of iron in the presence of a continuing deficiency. One effect of lack of iron is a reduction in the degree of pigmentation and the ability of added iron to restore the pigmentation. Figures are presented showing the iron content per cell, and a comparison with other organisms suggests that the brackishwater P. tricornutum may be atypical when compared with coastal and oceanic members of the marine phytoplankton.
Bothriocephalus scorpii [Cestoda: Pseudophyllidea] in turbot and brill from british coastal waters
Authors: Davey J. T. , Peachey J. E.
Published: May 2009

Three hundred and thirty-one turbot and 350 brill of varying ages were examined for infection with the tapeworm Bothriocephalus scorpii (Müller, 1776).

This survey showed that: (i) turbot and brill acquired infections of B. scorpii before they were 1 year old; (ii) all the adult turbot were infected with B. scorpii, often heavily, whereas only half the adult brill were infected and then only slightly; (iii) differences in the structure of the gut mucosa could account for the strong attachment of the scoleces in turbot compared with the loose attachment in brill.
Some aspects of the development of eggs and larvae ofSabellaria alveolata(L.)
Authors: Wilson Douglas P.
Published: May 2009

The rate of growth of larvae ofSabellaria alveolata(L.) reared in the laboratory varied greatly between different rearings and between individuals of the same age in the same rearing vessel, the temperature throughout being maintained close to 15 °C. The shortest recorded time from fertilization to metamorphosis was 6 weeks, the longest nearly 8 months. Within any one rearing some larvae metamorphosed weeks or months earlier than the last to do so. The larvae were fed on phytoflagellates, especiallyIsochrysis galbana, and the variations in growth were partially due to differing quantities of food available and to the differing character of the food. The largest larvae obtained, up to 700 μ long, fed in their later stages on anOlisthodiscussp., alone or with another flagellate. The smallest larvae, only about 400 μ long, ate voraciously large quantities of the coccolithCoccolithus huxleyi. The normal length of larvae fed onIsochrysisalone was about 500 μ.
A new member of the Chrysophyceae, bearing polymorphic scales
Authors: Lucas I. A. N.
Published: May 2009

Paraphysomonas cribosa n.sp. possesses two unequal flagella, one short and smooth, the other long, bearing numerous fine hairs. The cell surface is covered with scales which are resolvable using the electron microscope. These are polymorphic, built of rods and generally having an oval periphery. Struts from this support an inner oval ring, and further struts support a central perforated area.
Some effects of salinity on the distribution and abundance of Corophium volutator in the Ythan estuary
Authors: McLusky Donald S.
Published: May 2009

A study of the effects of salinity on the distribution and abundance of the amphipod Corophium volutator (Pallas) on the estuary of the River Ythan, Aberdeenshire, indicates that 2‰ is a critical minimum salinity controlling its distribution. In areas with salinities between 2 and 5‰ C. volutator was present, but in reduced numbers. Breeding occurred only in salinities greater than 7·5‰. In areas with salinity greater than 5‰, the distribution and abundance of C. volutator were controlled by the nature of the substrate; however, in areas with suitable substrates, but where the salinity was below 5‰, the effects of salinity override the effects of the substrate. The annual life-cycle is discussed. The results of this study are compared with those of a recent experimental study.
Fenestrulina barrosoi sp. nov. (Bryozoa: Cheilostomida) With A Review of the Genus Fenestrulina on the Iberian Peninsula
Authors: Alvarez Juan A.
Published: May 2009

Since 1980 many papers dealing wholly or partly with the genus Fenestrulina have been published, mainly by Anglo-Saxon and South American authors: e.g. Gordon (1984, 1989), Hayward (1980), Hayward & Ryland (1990), Hayward & Taylor (1984), Moyano (1985). These studies have increased the number of species of the genus known around the world. However, few authors have worked on the genus Fenestrulina in European seas, probably because it was assumed that this taxon was well known in these regions.
Deep water pycnogonids of the Cape Verde Slope
Authors: Bamber Roger N. , Thurston Michael H.
Published: May 2009

The Pycnogonida are a group regularly recorded in deep-sea benthic samples, although normally in low numbers. Most analyses from such surveys record new species, and many of these remain known only from a few specimens, often only the types. However, the amount of deep sea-bed sampled is necessarily proportionately so small that it may be argued that any species taken are probably common, owing to their having been sampled at all. It is evident from the gaps in the (often world-wide) distribution of these known species and their limited occurrence that deeper water pycnogonid faunas are still at best poorly known (q.v.Child, 1982).
Uptake, tissue distribution and metabolism of 14C-labelled tributyltin (TBT) in the dog-whelk, Nucella lapillus
Authors: Bryan G. W. , Bright D. A. , Hummerstone L. G. , Burt G. R.
Published: May 2009

A study of tributyltin (TBT) uptake, tissue distribution and breakdown in dog-whelks, Nucella lapillus, was carried out using 14C-labelled tributyltin chloride. The compound was introduced into animals by exposure to sea-water, from a diet of labelled mussels and by injection. Measurements of 14C were made on tissue extracts containing total 14C, TBT+DBT and TBT. Organs examined included digestive gland, kidney, mantle, foot, viscera, gonads and blood. Absorption of dissolved TBT occurred primarily via tissues associated with the mantle: autoradiographic evidence showed that of these the ctenidium (gill) and osphradium were probably most important. Of non-reproductive tissues, mantle displayed least evidence of TBT degradation whereas kidney and digestive gland contained lower proportions of 14C as TBT (~60%) than other tissues. By virtue of its more rapid response, initially at least, the kidney had a primary role in degrading dissolved TBT that reached the blood. Dog-whelks feeding on labelled Mytilus edulis absorbed organotins very efficiently via the digestive gland, which then played a major role in TBT breakdown. However, the capacity for degradation is not sufficient to prevent, TBT concentration factors of the order of 100,000 (dry tissue/water) being attained in N. lapillus. Autoradiography revealed surprisingly high grain-counts in nerves, which may be significant in view of evidence in the literature that neurohormones are intermediaries in the chain linking TBT with imposex.
A Method For Marking Small Juvenile Gastropods
Authors: Gosselin Louis A.
Published: May 2009

Methods used to identify individual organisms consistently over time have been invaluable tools in ecological studies, enabling reliable assessments of time-dependent parameters such as growth and mortality, and an accurate determination of their variance. These methods have proved to be particularly amenable to gastropods owing to the presence of an external shell on which marks or tags can be applied with little or no adverse effects on the animal. Marking and tagging techniques have enabled the study of several ecological parameters in adult marine gastropods, including growth (Frank, 1965; Hughes, 1972; Palmer, 1983; Gosselin & Bourget, 1989), mortality (Frank, 1965; Hughes, 1972), movements (Frank, 1965; Chapman, 1986), and foraging behaviour (Menge, 1974; Hugheset al., 1992). Small organisms, however, can pose considerable problems for individual marking (Southwood, 1978). As a result, marking and tagging methods have seldom been applied to newly hatched or recently settled juvenile marine gastropods. Several methods have been developed for simultaneously labelling large numbers of invertebrate larvae (Levin, 1990), and some of these methods may be applicable to juvenile gastropods. The usefulness of these methods, however, is limited because all animals receive the same label and, consequently, individual animals cannot be recognized. To my knowledge, no method of individually marking very small juvenile marine gastropods has been documented. In fact, it is sometimes perceived that small juveniles cannot be individually marked due to their small size and sensitivity (Frank, 1965; Palmer, 1990). The object of this paper is to present a simple method of marking early juvenile gastropods, which consists of applying colour codes to the shells of individuals as small as 0·9 mm in length.
A Note On Two Rays Lacking Part of the Snout
Authors: Forster G. R.
Published: May 2009

Two unusual specimens of Raja richardsoni Garrick from the N. Biscay area lacked part of the snout, apparently because it had been bitten off.
Growth and Nutrition ofAplysia PunctataFeeding on a Variety of Marine Algae
Authors: Carefoot Thomas H.
Published: May 2009

The growth rates ofAplysia punctataCuvier feeding on eight species of marine algae were found to decrease in the order:Plocamium > Enteromorpha > Ulva > Heterosiphonia > Cryptopleura > Delesseria > Laminaria.The brown alga,Desmarestia aculeata, was not eaten. Except forEnteromorphaandDesmarestia, this was also the order found for the feeding preference of sublittoralAplysia. Enteromorphawas eaten byAplysiain preference to all the other algae studied.

No clearly defined trends in the concentrations of ash, protein, fat and carbohydrate in the seaweeds were found to account for these differences in growth rates. Absorption of total dry food matter was lowest from the algae giving the poorest growth (45 and 53%, respectively, of the total dry weight consumed forDelesseriaandLaminariadiets) and highest from the seaweeds giving moderate growth (71–75% forUlva, HeterosiphoniaandCryptopleuradiets). ForPlocamiumandEnteromorphadiets the values were 59 and 65%, respectively. Carbohydrate materials were found to constitute 42–75% of the total dry weight of food material absorbed byAplysiaon all the algal diets, and represented the major portion of each. The efficiency of conversion of absorbed food matter into tissues was highest on the algae giving the poorest over-all growth (73% forDelesseriaand 40% forLaminaria). For the other seaweed diets the efficiencies decreased in direct relation to the decrease in the value of each for growth ofAplysia(from 35% forPlocamiumto 15 % forCryptopleura).

The same amino acids were found in each food.
Iron Metabolism in Mytilus Edulis 1. Variation in Total Content and Distribution
Authors: Hobden D. J.
Published: May 2009

The iron content of fresh Mytilus edulis L. from Southampton is usually 20–40 μg/g wet weight after the animals have eliminated their gut contents. In spring some animals have much higher iron contents, sometimes in excess of 100 μg/g. The much higher values reported by some authors are probably erroneous.

Prolonged starvation in sea water of low iron content will not reduce the mean iron content of the animals below 20–25 μg/g. This represents a permanent store. Higher values are produced by a temporary store that is fairly rapidly lost on starvation.

The highest iron concentrations are usually in the digestive gland, which contains the major part of the temporary store, much of which can be regarded as particles being subjected to the digestive processes.

Only iron in the temporary store could be demonstrated by histochemical techniques.

INTRODUCTION

The trace element metabolism of Vertebrates, particularly Mammals has been reviewed by Bothwell & Finch (1962); and Vinogradov (1953) has made a comprehensive review of the elementary chemical composition of living organisms. With notable exceptions, such as the copper in haemocyanin, the trace elements discovered in many invertebrates have no known function. The reported values for many elements differ considerably, depending on the author and the techniques used. In general, despite a number of errors in the values quoted, Vinogradov's data establish at least the order of magnitude of many elements in a variety of animals. Some of these elements occur in greater amounts than would be expected if they were not of metabolic significance. One example, namely iron in Mytilus edulis L., was selected for investigation.
An Examination of Polymorphism in the Hydroid Hydractinia Echinata
Authors: Burnett Allison L. , Sindelar William , Diehl Norma
Published: May 2009

Several aspects of polymorphism in Hydractinia echinata (Fleming) have been examined. Polymorphism in Hydractinia appears to be the result of inhibition of the normal developmental sequence and not the result of direct genetic control. The inhibition is mediated by both intrinsic and extrinsic factors. The former are responsible for the formation of reproductive zooids in the colony, but this process may be accelerated by extrinsic factors (crowding, increased pCO2). It is suggested that intrinsic factors consist of an inducer or growth stimulator produced in the hypostomal region of the polyps and an inhibitor of growth and differentiation produced by dividing cells beneath the hypostome. The ratio of these two factors throughout the colony ultimately determines the polyp type which will be formed.
A Study of Detergent Pollution By Molecular Methods: Starch Gel Electrophoresis of a Variety of Enzymes and Other Proteins
Authors: Manwell Clyde , Baker C. M. Ann
Published: May 2009

Tissues from a number of marine species were treated with a variety of solutions, including 1% of the major ‘detergent’ (B.P. 1002) used in attempting to disperse the oil from the ‘Torrey Canyon’ and 1% of each of the three major constituents of B.P. 1002, two of which are non-ionic surfactants.

The extracts were submitted to vertical starch-gel electrophoresis in order to measure both the effect of the detergent in facilitating the breakdown of cellular structure (extractability), and the irreversible effect on activation or inhibition of various enzymes and other proteins.

The proteins studied include a variety of NAD- and NADP-linked dehydrogenases, esterases, blood and nerve haemoglobins, plasma proteins, egg white and yolk proteins, and r-phycoerythrin.

The results confirm the general opinion that detergents increase the extractability of proteins from cells. In particular lipoprotein systems are altered, e.g. ‘fast’ serum lipoprotein in fishes (and other vertebrates). Other effects are also observed, e.g. sole but not turbot haemoglobin is rendered relatively insoluble, probably because the detergent stabilizes haemoglobin binding to other components in the erythrocyte. Certain enzymes, e.g. some esterases and amylases, are activated—a not surprising observation. However, a few enzymes are altered in electrophoretic mobility or in activity in a way that one might not expect, e.g. bass Morone labrax lactate dehydrogenase.

The results indicate that ‘oil-spill’ detergents and their constituent surfactants are biochemically quite powerful agents. It is too early to attempt to correlate in vitro and in vivo observations but there is an indication that starch-gel electrophoresis provides a useful supplement to more conventional methods used in the studies on complex pollution problems.
The Development of the Retina and Retinomotor Responses in the Herring
Authors: Blaxter J. H. S. , Jones M. Pattie
Published: May 2009

The eye of the larval herring has only single cones in the retina. They are characteristic in ultrastructure at this stage with a striated outer segment, an ellipsoid packed with mitochondria and with a connecting cilium at the junction. Cones are gradually added at the margin of the retina as the larva grows. There are no retinomotor responses in the larval eye. It has, however, adult characteristics in the postero-ventralarea temporalis(though it is undifferentiated at this stage) with its blindly ending anterior pocket and in the falciform process closing off a trough-shaped ‘ancillary’ eye.

At metamorphosis (30–40 mm) a number of changes occur: theareadifferentiates, twin cones and the rods appear, the latter perhaps developing from cells originating in the bipolar layer and migrating to a position inside the external limiting membrane. Retinomotor pigment migration and change in length of the cone myoids also develop when the eye is subjected to changing light intensities, the threshold being 1.0–0.01 me (metre candles).

In the adult eye the fully developed retina has anarea temporalispacked with single cones giving high acuity on the main visual axis, which is in the upperfore direction. The lens presumably gives accommodation by postero-ventral movement brought about by a postero-dorsal suspensory ‘ligament’ and a ventroanterior falciform process. This process also delimits theareaand divides off the ‘ancillary’ eye from the main retina.

Over the whole range of development the cone ellipsoids grow in diameter from 2 to 12 μ and decrease in density correspondingly.
The ultrastructure of the skeleton and skeletogenic tissues of the temperate coral Caryophyllia smithii
Authors: Le Tissier Martin D'A.A.
Published: May 2009

The skeleton and calicoblastic ectoderm of the scleractinian non-zooxanthellate coral Caryophyllia smithii were investigated by light microscopy, scanning and transmission electron microscopy. Except for some costal spines, the skeleton was fasciculate. Fasciculi were made up of bundles of crystalline needles, each crystalline needle consisting of a number of linear series of small (<1 μm) rounded crystals. Fractured skeletons showed the fasciculi to be arranged into layers and that within some septa, theca and costal spines there were spaces that contained neither mineral nor organic matter. These spaces could also be found at the growing edges of septa and theca. Demineralization of the skeleton revealed an organic matrix whose configuration mirrored the architecture of the skeleton. In areas of the skeleton where deposition was occurring the overlying calicoblastic ectoderm was relatively thin with prominent intercellular spaces and secretory vesicles. In contrast, over non-depositing areas the calicoblastic ectoderm was thick and contained residual bodies, nematocysts and membrane-bound granules. The results are compared and contrasted with those from scleractinian corals that have endosymbiotic zooxanthellae.
Observations on the locomotion of post-larval and juvenile flying fish
Authors: Davenport John
Published: May 2009

Post-larval specimens ofHirundichthys affinisare capable of jumping out of water, but the pectoral and pelvic fins are not extended when in air. Penetration through the air/ water interface demands a force to overcome surface tension which is similar in magnitude to the force required for the jump itself. However, post-larvae do not produce the single propulsive tail flick which powers the jump until most of the animal has passed through the interface. The post-larva emerges at an angle close to 45°, thus maximising the horizontal distance travelled before re-entry.

Whether swimming slowly (4 body lengths s-1), or at maximum speed (36 body lengths s-1), post-larvae swim with the pectoral and pelvic fins extended. Calculations show that fast swimming post-larvae operate at Reynolds’ numbers of about 4×103, where surface roughness and projections decrease rather than increase drag.
Spawning and development of Calliostoma granulatum in the Mediterranean Sea
Authors: Ramón Montserrat
Published: May 2009

The spawning, larval development, and postlarval characteristics of Calliostoma granulatum have been described and illustrated from laboratory observations. Spawning in this species does not follow a seasonal pattern, since adult specimens caught at all times of the year released viable gametes after two or three days in tanks. Eggs had a mean diameter of 341 μm and were surrounded by a mucous sheath by which they were agglutinated into ribbons of variable length that formed amorphous clumps on the bottom of the tanks. The veliger larval stage was short (two days) and took place inside the egg membrane. Development was direct, and at 18–19°C juveniles emerged as crawling young four days after fertilization. Larval and postlarval shells were studied with the aid of a scanning electron microscope.
The role of the sensory systems of herring larvae in evading predatory fishes
Authors: Blaxter J.H.S. , Fuiman L.A.
Published: May 2009

Herring (Clupea harengus L.) larvae, ranging from 8–35 mm T.L. were subjected to predation by juvenile herring and sprats (Sprattus sprattus L.) ranging from 80–160 mm T.L. Responses to attacks and non-threatening encounters were recorded by a TV system operated with infra-red light, which was invisible to both predator and prey. Records were made in both light and dark with larvae before and after the otic bullae filled with gas, before and after lateral line canal formation, and before and after chemical ablation of the neuromasts with streptomycin.

Larvae often responded with a C-start, turning away from the stimulus source, both in dark and light. Attacks on larvae occurred only in the light. Responsiveness to attacks was very low in the smaller larvae but increased as the otic bulla filled with gas and the lateral line canal developed. Larger larvae responded more often to attacks than to non-threatening encounters with predators. Vision seems to inhibit unnecessary responses since responsiveness was lower in the light than the dark for non-threatening encounters. Response distances were generally short, only 2–4 cm, with no substantial differences associated with sensory capability.
Isolation and partial characterisation of the serum immunoglobulin of the flounder,Platichthys flesus
Authors: Glynn P.J. , Pulsford A.L.
Published: May 2009

Whole flounder serum has been fractionated by gel filtration on Ultrogel AcA22. Pooled material from the first major peak of the elution profile was further fractionated by FPLC ion-exchange chromatography and this yielded one major and three minor peaks. Under both reducing and non-reducing conditions SDS electrophoresis showed that the major peak and two of the minor ones were immunoglobulin (Ig). All three of these Ig populations were tetrameric, with estimated molecular weights of 710 kD. However, approximately 90% of the major Ig species consisted of tetramers which were covalently linked by disulphide bonds, whereas the remaining 10% was composed of dimeric molecules held together by non-covalent interactions. The heavy chains of all three Ig populations had apparent molecular weights of approximately 72 kD but the light chain composition showed considerable heterogeneity. In the major population, five polypep-tides were detected in the light chain region of the gel with apparent molecular weights covering the range 22–28 kD. However, there was no difference in the light chain composition of covalently and non-covalently linked tetramers. The two minor populations differed both from each other and from the major species in respect of their light chain compositions. No evidence was found for a monomeric serum Ig, and alkaline urea electrophoresis failed to demonstrate a J chain.
Age determination, growth rate and population structure of the horse musselModiolus modiolus
Authors: Anwar N.A. , Richardson C.A. , Seed R.
Published: May 2009

The age and growth rate ofModiolus modiolushave been studied from acetate peel replicas of polished and etched shell sections. Age estimates could be reliably obtained from the alternating patterns of light (summer) and dark (winter) growth lines present in the middle nacreous layer of the shell. Growth lines in the inner nacreous layer, however, generally converged to form blocks of nacre such that the identity of individual lines was lost, whilst in the umbones growth lines were often tightly compressed and difficult to resolve. Data obtained from analyses of the internal growth lines in the middle nacreous layer were used to construct growth curves for several subtidal populations using the von Bertalanffy growth equation. The fastest growth rate was recorded for mussels growing epifaunally on the legs of a drilling platform in the North Sea; these mussels achieved a maximum shell length of 110 mm within ten years. The oldest mussel (from Ling Bank in the northern North Sea) was 48 years old and measured 133 mm in length whilst the largest mussel (from Loch Spelve in western Scotland) was 147 mm long and 38 years old. With the exception of the relatively young population (maximum age 10 years) from the drilling platform, most of the benthic populations studied included mussels in excess of 35 years of age. It is clear, therefore, thatM. modiolusis a potentially long-lived member of the subtidal benthos.
Immunocytochemical localization of the neuropeptide S1 and serotonin in larvae of the starfishPisaster ochraceusandAsterias rubens
Authors: Moss Claire , Burke Robert D. , Thorndyke Michael C.
Published: May 2009

Studies of the larval nervous system of two species of starfish were carried out using antisera to a recently isolated native echinoderm neuropeptide, GFNSALMFamide (S1), and to serotonin. S1-like immunoreactivity was found in the larvae of the asteroidsPisaster ochraceusandAsterias rubens(Echinodermata: Asteroidea), originating in the apical region and becoming concentrated as two groups of cells in the dorsal ciliary band, the preoral transverse and adoral ciliary bands in larvae up to the early brachiolarian stage (five weeks). The pattern of serotonin immunoreactivity, although appearing earlier in the apical nerve plexus, is very similar to that of the peptide, with paired groups of immuno- reactivity apparent in the dorsal ciliary band. This evidence, together with other recent studies, indicates that this neuropeptide is present in both the larval and adult nervous system, despite the complete reformation of the system at metamorphosis. The close localization of SI with serotonin may also suggest a possible function for the peptide in larval and adult nervous systems.
Immunocytochemical investigations of muscle differentiation in the Atlantic herring (Clupea harengus: Teleostei)
Authors: Johnston I. A. , Horne Z.
Published: May 2009

The myotomes in yolk-sac larvae of the Atlantic herring (Clupea harengus: Teleostei) contain a single layer of small-diameter superficial muscle fibres surrounding an inner mass of around 280 larger-diameter muscle fibres. The fraction of muscle fibre volume occupied by mitochondria is dependent on temperature, and in larvae reared at 8°C was 41% for the superficial fibres, and 25% for the inner muscle fibres. The inner muscle fibres of larvae share some myofibrillar proteins with adult white muscle, but contain unique isoforms of myosin heavy chains, troponin T, troponin I and myosin light chain 2. A monoclonal antibody has been produced which is specific to myosin light chain 3 (MLC3). Immunocytochemical studies have shown that the expression of MLC3 is switched off in the superficial muscle fibres at the start of metamorphosis when larvae reach 28–30 mm total length (TL). Metamorphosis to the juvenile stage is complete in fish 35–40 mm TL and is also associated with the development of gill filaments and the production of presumptive slow muscle fibres which form externally to the larval superficial muscle fibres in the region of the lateral line nerve.
Tolerance to low dissolved oxygen by the tubicolous polychaete Loimia medusa
Authors: Llanso Roberto J. , Diaz Robert J.
Published: May 2009

Tolerance and behaviour to hypoxia and anoxia by the annelid Loimia medusa (Savigny) (Polychaeta: Terebellidae), a common species in estuarine habitats where summer hypoxic events often occur, were examined in the laboratory. The worm can tolerate anoxia or severe hypoxia (7% air saturation at 26°C) for 3 to 5 d. Under low dissolved oxygen (<14% air saturation) feeding stops, although tube irrigation continues and periodic protrusions from the tube are common. Most worms come out to the sediment surface, but the number of worms dead on the surface is higher in anoxia than in hypoxia. The prevalence of L. medusa in deep estuarine channels may be partially explained by its tolerance to prolonged periods of hypoxia (14 d at 14% air saturation). Our data, however, suggest that subtle changes in oxygen concentrations may be important in the control of populations of L. medusa in habitats affected by low oxygen disturbances.
Antarctic Megacalanidae (Copepoda: Calanoida) and the distribution of the family
Authors: Michel Harding B.
Published: May 2009

The global distribution of the 12 described, deep-living megacalanid species is presented in a report on collections made in the Southern Ocean during the United States Antarctic Research Program. Included are four species and one subspecies described in 1967 from samples obtained early in the program. In the material lent to the author by the Smithsonian Oceanographic Sorting Center, only six of the described species were found. Bathycalanus bradyi, common in those samples and elsewhere, is made a synonym of B. richardi. The predominant forms are, in order, B. richardi, Megacalanus princeps, and B. princeps, with Bradycalanus sarsi, B. typicus and B. gigas also present. Knowledge of their distribution and ecology is discussed.
Genetic variation, systematics and distribution of the venerid clamChamelea gallina
Authors: Backeljau Thierry , Bouchet Philippe , Gofas Serge , Bruyn Luc De
Published: May 2009

Two morphotypes of the venerid bivalveChamelea gallina(L.), viz.C. gallina s.s.andC. striatula, were electrophoretically compared at seven polymorphic enzyme loci. In three populations from the Ría Formosa (southern Portugal), both morphotypes occurred sympatrically. Analyses of genotype frequencies in these mixed populations revealed departures from Hardy-Weinberg expectations at nearly all loci. These deviations were mainly attributable to a Wahlund effect, caused by mixing the two morphotypes. Nei's mean unbiased genetic distance between the two forms wasD=1·138, while the mean genetic distances between populations within morphotypes were D=0·083 inC. gallina s.s.andD=0·229 inC. striatula. It is therefore concluded thatC. gallinaandC. striatulaare reproductively isolated (biological) species, the geographical distribution of which is outlined.
The tenacity ofElminius modestusandBalanus perforatuscyprids to bacterial films grown under different shear regimes
Authors: Neal A. L. , Yule A. B.
Published: May 2009

The tenacity of cypris larvae of the barnacles (Crustacea: Cirripedia)Balanus perforatus(Bruguiere) andElminius modestusDarwin was measured on multispecies biofilms developed under contrasting shear regimes. For both species, relatively thin, dense biofilms associated with high shear (83 s-1) afforded increased tenacity over relatively thick, less dense films associated with low shear (15 s-1). Although both species showed reduced tenacity on low-shear films compared to high-shear films,E. modestuscyprids attached as strongly to low-shear films as they did to unfilmed surfaces.Balanus perforatuscyprids, however, attached less strongly to low-shear films than to unfilmed surfaces. The results show thatB. perforatusand E.modestusmay appreciate differences in bacterial communi-ties grown under different shear conditions and highlight the potential for biofilms as one of the many cues to barnacle settlement.
The Effect of Storage Temperature on the Enumeration of Epifluorescence-Detectable Bacterial Cells in Preserved Sea-Water Samples
Authors: Turley C. M. , Hughes D. J.
Published: May 2009

Rates of decrease in epifluorescence-detectable bacteria in preserved sea-water samples changed significantly with temperature. This apparent cell loss was substantial even in preserved samples stored in a refrigerator, decreasing exponentially with time, with 56% apparent cell loss after 99 days’ storage. Storage at room temperature resulted in the greatest decrease in detectable cells, with 73% apparent cell loss after the same storage period. No significant difference was found between storage in two different containers. The apparent cell loss can be modelled in order to calculate the original cell numbers with confidence. However, models produced from one set of samples cannot be applied to the data from another.
A quantitative study of the polychaete fauna of certain fine deposits in Plymouth Sound
Authors: Gibbs P. E.
Published: May 2009

Results of quantitative surveys of the polychaete fauna of certain fine deposits within Plymouth Sound, comprising a total of forty-eight species, are presented. The juvenile stages of certain species are described and sixteen species that have not been found previously in the area are recorded.
The co-ordination of the rhythmical fin movements of dogfish
Authors: Roberts B. L.
Published: May 2009

The muscle fibres of the radial muscles of the unpaired fins of dogfish can be divided into two populations—an outer group of red muscle fibres which are smaller and fewer than the inner white muscle fibres and which differ in structure, number of nuclei and pattern of innervation. Two types of potential were detected in the two muscle systems when recordings were made with implanted electrodes during movements of the fins. The red muscle fibres were associated with small, slow junctional potentials which changed in amplitude when the activity of the system was altered.
Choniostomatid parasites on species of Erythrops [Crustacea, Mysidacea]
Authors: Mauchline J.
Published: May 2009

Parasites occurred on Erythrops serrata (G. O. Sars) and E. elegans (G. O. Sars) caught in the Clyde sea area and were identified tentatively as species of Thalassomyces, belonging to the Ellobiopsidae (Mauchline, 1968). Wim Vader of the Biological Station, Espegrend, Norway, however, on seeing the drawing of the parasite published by me pointed out that it was more probably a species of choniostomatid copepod. The parasites have now been re-examined and compared with Hansen's (1897) descriptions of these copepods.
A glucosephosphate isomerase inhibitor of seasonal occurrence in cod (Gadus morhua) and other fish
Authors: Dando P. R.
Published: May 2009

A similar inhibitor has been found in red mullet {Mullus surmuletus L.), megrim (Lepidorhombus whiff-iagonis Walbaum) and greater forkbeard (Urophycis blennoides Briinnich). The inhibitor is of a seasonal nature in these fish also and may be linked with the spawning cycle.
An investigation on sonic-scattering layers: the R.R.S. ‘Discovery’ Sond Cruise, 1965
Authors: Currie R. I. , Boden B. P. , Kampa E. M.
Published: May 2009

This is preliminary to a series of papers resulting from SOND 1965 Cruise aboard R.R.S. ‘Discovery’. The cruise was designed as an ecological study of sonic scattering layers at a certain season in a restricted volume of ocean in the region of the Canary Islands. These papers will appear periodically in this journal.
The Eastern Subtropical Gyre (North Atlantic): Flow Rings Recirculations Structure and Subduction
Authors: Pingree R.D.
Published: May 2009

Thirteen carefully prepared drogued buoy assemblies have been deployed in the eastern subtropical North Atlantic giving ~20 buoy years of Lagrangian data at a depth of 200 m. The buoy results together with hydrography have revealed the structure of the eastward flowing Azores Current (AC). The main jet had a transport of 26 Sv (near 28°W) with compensating counterflows in March 1992. Jet and counterflows were readily seen in the ADCP current structure and evident in the upper layer temperature (salinity) structure on an isopycnal surface. Buoys and hydrography showed that the adjacent westward flowing counterflows resulted in recirculation both north (anticlockwise circulation) and south (clockwise circulation) of the AC - the Subtropical Recirculations. South-south-west flow (3 cm s−1) occurred in the central region of study west of the Canary Islands. The long-term movement measured in the south or northern North Equatorial Current region was 3·5 cm s−1west-south-west. The mean south displacement per year of the buoys was 2·2° of latitude to the south and most of this displacement occurred in the first half of the year (February-August). The maximum westward displacement rate occurred six months later in October and November. The Subtropical Front/Azores Current region was identified as a zone of increased levels of kinetic energy (>100 cm2s−2) at a latitude near 34°N at the 200 m level, stretching for >2000 km, and as a marked horizontal winter sea surface temperature contrast at a latitude near 36°N. Winter mixing created an outcropping region of water with density in the range 26–4<σ0<26·6 kg m−3along the Subtropical Front near 34°N with a maximum vertical extent of 200 m.
A Towed Video Survey of Megafaunal Bioturbation in the North-Eastern Irish Sea
Authors: Hughes D.J. , Atkinson R.J.A.
Published: May 2009

In September 1993 the Irish Sea floor near the Sellafield nuclear reprocessing plant was surveyed by towed video to assess the distribution, abundance and behaviour of large burrowing invertebrates believed to be important in the transport and mixing of radionuclide-contaminated sediments. Sixteen stations were surveyed, covering a range of sediment types. Burrow openings and mounds were counted and assigned to species where possible. Particular attention was paid to the similarities and differences between the features observed and those produced by the same species in Scottish sea lochs, the source of most relevant ecological data. Several different burrowing communities were identified from bottom topography. Offshore muddy sands supported dense populations of the thalassinidean crustacean Callianassa subterranea, in burrows similar to those described from the North Sea. Coarse sediments closer inshore had C. subterranea at lower density, with the thalassinidean Upogebia deltaura and the crab Goneplax rhomboides also present. Softer muds were dominated topographically by ejecta mounds of the echiuran Maxmuelleria lankesteri and burrows of the Norway lobster Nephrops norvegicus. The thalassinideans C. subterranea, Jaxea nocturna and Calocaris macandreae were also present at low density. Surface bioturbation features in this habitat were very similar to those described from sea lochs. Population densities estimated from surface bioturbation features were always lower than counts of specimens from box-cores. The visual survey therefore gave minimum estimates of population density. Available data on rates of bioturbation by the species concerned are collated to give rough estimates of biogenic sediment transport in the habitats surveyed.
Allozymic Characterization of Scottish and Aegean Populations ofNephrops Norvegicus
Authors: Passamonti Marco , Mantovani Barbara , Scali Valerio , Froglia Carlo
Published: May 2009

One Scottish and two Aegean samples ofNephrops norvegicus(Crustacea: Decapoda) were allozymically tested using a total of 110 individuals and compared with two already characterized Adriatic populations. Three main characteristics of their genetic structure emerge: a highly homogeneous allele pattern, a strong heterozygote deficiency at some loci and a significant genotypic variance among populations, mainly caused by thePgmlocus. Population subdivision, intraunit inbreeding, bottlenecks and selective constraints are taken into account to allow for these genetic features, although none of them proved decisive. The search for straightforward characters differentiating Norway lobsters of geographically different areas proved unsuccessful, although a significant genotypic differentiation was noticed among our samples. Observed D values among the geographically distant samples indicate a very low genetic divergence, so that no clear phyletic conclusions can be traced on the sole allozyme-gene analysis.