bluuebunny/crossref_metadata_2025 huggingface dataset:
Fine-Structural Observations on some Marine Choanoflagellates from the Coast of Norway
Authors: Leadbeater B. S. C.
Published: May 2009

The external morphology of eight species of Choanoflagellates representing eight genera have been investigated with an electron microscope. These include one new species (Acanthoecopsis apoda). Sections have been obtained of Monosiga ovata, a species without a lorica. All the other species possess loricas with very regular and precise distinguishing features when seen in shadowcast whole mounts. The position of the group is discussed in a preliminary way in the light of fine structure.
Behavioural Rhythms in Littoral Prawns
Authors: Rodriguez G. , Naylor† E.
Published: May 2009

Palaemon elegansRathke on South Wales coasts, unlikeP. serratus(Pennant), does not migrate offshore in winter but stays in intertidal pools throughout the year. Both species occur in rock pools in summer, withP. elegansextending farthest up the shore and often occurring in pools above M.H.W.N. Each shows a spontaneous but short-lived tidal rhythm of locomotor activity in constant laboratory conditions, the rhythm persisting longer in isolated prawns than in groups of animals recorded together. Peak activity occurred on the ‘expected’ ebb, and light/dark changes, including those associated with tidal rise and fall, appear to be important in synchronizing the rhythm. The tidal rhythm ofPalaemon elegansabove M.H.W.N. quickly rephases to a semi-diurnal dusk/dark rhythm during the period of neap tides, the rhythm again becoming tidal when spring tides return. The possible significance of ebb activity is discussed.
Gobiid Fishes of the Caspian GenusKnipowitschiaFrom the Adriatic Sea
Authors: Miller P. J.
Published: May 2009

The diagnostic features of the Ponto-Caspian gobiid genusKnipowitschiaIljin, 1927 and related European genera are summarized with reference to the cephalic lateral-line system. The AdriaticGobius panizzaeVerga, 1841 is now shown to belong toKnipowitschia, and a second species,K. caucasica(Kawrajsky, in Berg, 1916), widespread in the Ponto-Caspian region, is recorded from the northern Adriatic (Gulf of Venice). The occurrence of these species in the Adriatic Sea is explained by Quaternary changes in union between the Mediterranean and Black Sea, withK. panizzaederived from Black SeaKnipowitschiastock emigrating via a temporary Riss/Würm interglacial confluence, and theK. caucasicaof very recent origin through the existing postglacial connexion. A redescription ofK. panizzae, based on syntypes and more recent material, is provided in an Appendix.
Cordylophora Morphogenesis: Precocious Sporosac Development in Non-Sessile Colonies
Authors: Lesh Georgia E.
Published: May 2009

Precocious development of sexual reproductive structures (sporosacs) in Cordylophora (Pallas, Allman) occurs when colonies are grown in the absence of a suitable substratum. Neither varying the nature of the substratum provided nor diverse surgical manipulations will induce this morphogenetic modification. Sessile colonies will also initiate sporosac development if ubstrate availability is limited experimentally.
The Effect of diet on the Component Fatty-Acid Composition of Artemia Salina
Authors: Hinchcliffe P. R. , Riley J. P.
Published: May 2009

Artemia salina has been reared on unialgal diets of Phaeodactylum tricornutum, Monochrysis lutheri, Platymonas tetrahele and Chlamydomonas sp. In most instances the component fatty-acid distribution of the Artemia bore little resemblance to that of its food. Thus, oleic and stearic acids are relatively enriched in the shrimps, whereas hexadecatetraenoic acid is much depleted. It is suggested that the metabolic requirements of the shrimps is of at least equal importance to the composition of their food in determining the component fatty-acid distribution of their lipids.
A Preliminary Survey of the Benthic Macrofauna and Sediments in Lochs Etive and Creran, Sea-Lochs Along the West Coast of Scotland
Authors: Gage John
Published: May 2009

The hydrographic conditions in the two sea-lochs is briefly described where relevant to the survey of the benthos. Seasonal changes in temperature and salinity in Loch Etive appear to follow roughly the local coastal pattern but usually with a lag in timing that is considered to be because of the restricting effect of the twin sills. Replenishment of deep-basin water by ventilation over the sills is spasmodic and controlled by surface stratification; the latter being due primarily to freshwater runoff. This situation contrasts with Loch Creran which has only a small catchment and where the seasonal hydrography closely follows the pattern outside. Other possible reasons for the differences observed between the two lochs are discussed.

The bottom fauna of both lochs was sampled semi-quantitatively with an anchor dredge at 22 stations in Loch Etive and 8 in Loch Creran at depths from 7–117 m. A detailed list of the fully marine fauna present is given. The species occurrences in the single-haul samples are compared objectively using a coefficient of similarity of the presence/absence records. An attempt is made to relate the groupings shown up to the classical ‘bottom community’ concept, to the feeding-type categories of the bottom animals and to analysis of particle size of sediment samples taken at the same stations. A correlation to sediment type was apparent. This is considered to owe as much to local hydrographic conditions which the sediment reflect as to the sediment itself.
The vertical distributions and diurnal migrations of calanoid copepods collected on the SOND Cruise, 1965 I. The total population and general discussion
Authors: Roe H. S. J.
Published: May 2009

On the SOND Cruise of R.R.S. 'Discovery' in 1965 a day and a night series of horizontal hauls were made with a modified Indian Ocean Standard Net (N113 H) fitted with a catch dividing bucket (C.D.B.). The hauls were of 1 h duration, made at approximately 50 m depth intervals from 960 to 40 m, at a position off Fuerteventura in the Canary Islands. This paper is one of a series by various authors on the vertical distributions of the animal groups sampled (Angel, 1969; Clarke, 1969 a; Baker, 1970; Badcock, 1970; Foxton, 1970a, b). Details of the cruise and of the hydrology of the area are given by Currie, Boden & Kampa (1969), and Foxton (1969) gave details of the sampling methods.
Horizontal and Vertical Distribution of the Interstitial Harpacticoid Copepods of a Sandy Beach by Roger
Authors: Harris P.
Published: May 2009

In a previous paper (Harris, 1972) the meiofauna of an exposed sand beach at Whitsand Bay, Cornwall, was described in relation to the physical environment. During this study special emphasis was placed on the harpacticoid copepods, of which 13 species were recorded on the beach. In the present paper the horizontal and vertical zonation of the copepod species on the beach is described. An account of seasonal changes in the copepod population will be given in a subsequent paper.
Frond Structure and Growth in Laminaria Hyperborea
Authors: Larkum A. W. D.
Published: May 2009

On rocky shores of the British Isles and neighbouring regions of the North Atlantic coastline, the sporophyte of Laminaria hyperborea (Gunn) Foslie is the dominant member of most sublittoral algal communities. The bathymetric distribution, like the geographical distribution, is extensive; L. hyperborea is often dominant from extreme low water level of spring tides (E.L.W.S.) to depths of up to 32 m. The great changes in environment encountered by this species over this wide range of distribution would suggest a highly adaptable organism. Changes in size, rate of growth and growth pattern have indeed been recorded between plants at different latitudes and different depths. Plants from northerly waters generally are much larger with longer stipes and have a greater frond area (Kain, 1962; Bellamy & Whittick, 1968; Greenhager, 1958), although Kain (1963, 1967) points out that this is often due to greater longevity of individuals rather than greater growth rates. Increasing depth affects the density of distribution; the typical L. hyperborea forest becomes more sparse until an open community, called 'the park' when first recorded by Kitching in 1941, replaces the forest at about 15 m. The plants in the open community are smaller than those in the forest and have shorter stipes (Kain, 1962, 1966, and observations described in this communication). However, despite these changes in growth,, almost no morphological variation had been recorded prior to the present investigation. More recently there has been a report of a form L. hyperborea f. cucullata (Svendsen & Kain) from deep water and waters not subject to water movement with thin enlarged fronds and short stipes (Svendsen & Kain, 1971; Kain, 1971).
Osmoregulation inthe Jaera AlbifronsGroup of Species [Isopoda, Asellota]
Authors: Jones M. B.
Published: May 2009

Thejaera albifronsLeach group of species is a common component of estuarine faunas in Britain, where each species may occur in considerable numbers. Some members of the group also occur in less variable, marine localities in Britain and elsewhere, indicating that each species is capable of survival in a wide range of salinity combinations and that the group as a whole is euryhaline (see, for example, Naylor & Haahtela, 1966; Jones & Naylor, 1971). Naylor & Haahtela (1966) showed that the four species ofjaerawhich occur in Britain occupy preferred areas on an estuarine shore such thatjaera ischiosetosaForsman is common on stones in areas affected by freshwater seepage,jaera albifronsLeach occurs on stones either in pools or in parts of the shore where water is retained (aroundM.t.l.),jaera praehirsutaForsman occurs onFucus serratus(L.), andjaera forsmaniBocquet can be found under stones aroundL.w.s.t.-l.w.n.t.where there is little retention of water. A later investigation by Jones & Naylor (1971) has shown that these habitat preferences persist throughout a 2-year period, and that each of thejaeraspecies is capable of successful reproduction and development in a characteristic pattern of fluctuation in salinity, temperature and exposure to air
Photoreceptive Function of an Epithelial Receptor in Nassarius Reticulatus [Gastropoda, Prosobranchia]
Authors: Mary Crisp
Published: May 2009

Many animals have a diffuse extra-ocular sensitivity to light. Limited areas of particular dermal photosensitivity have been localized in, for example, Mya siphon (Light, 1930) and the tail of ammocoetes (Steven, 1951) but identification of the receptors is difficult. Even when candidate receptors are known, owing to their small size and the limitations of light microscopy, they have been imperfectly characterized (e.g. Light, 1930) and their identification questioned (Steven, 1963).
On the Ecology of an Adult Digenetic Trematode Proctoeces Subtenuis From a Lamellibranch Host Scrobicularia Plana
Authors: White I. C.
Published: May 2009

Typically, adult digenetic trematodes are found as parasites of vertebrates, but Freeman & Llewellyn (1958) described sexually mature, unencysted digeneans from the kidney region of the mud-dwelling lamellibranch Scrobicularia plana (da Costa) collected from Chalkwell, near Southend-on-Sea, in the Thames estuary. The trematodes were identified as belonging to the genus Proctoeces (Odhner, 1911) and of the family Fellodistomatidae, subfamily Haplocladinae (Odhner, 1911). Freeman and Llewellyn considered that the features exhibited by the specimens were consistent with the description for Proctoeces subtenuis (Linton, 1907) Hanson, 1950, a species which had been recorded up until that date only as a parasite of the hind gut of marine teleosts belonging to the families Labridae and Sparidae from the Red Sea, New Zealand and the eastern seaboard of America.
Salinity Tolerances Of Some Common Prosobranchs
Authors: Arnold D. C.
Published: May 2009

The abundance of gastropods characteristic of rocky shores throughout the world (Southward, 1958) has encouraged investigation of their ecology and behaviour in several areas, although studies under laboratory conditions seem to have been restricted largely to the common European species Littorina littorea and Patella vulgata. Most investigations of littorinid behaviour have concentrated upon their response to light and gravity (see Newell, 1958, for a critique of earlier work), as the most important factors, after exposure, to influence life upon the shore. Variations in salinity are also significant, however, and ecological observations make it clear that littorinids are able to withstand a considerable range of salinity (Moore, 1958; Fretter & Graham, 1962; Newell, 1964; Green, 1968). But ecological studies alone do not necessarily reveal whether this capacity is to resist an adverse environment by a period of inactivity or, more particularly, to retain activity within a wide salinity range; nor do they show how far the potentialities of particular populations are related to the conditions under which they actually live. Examination of this aspect has been undertaken with L.littorea on the Atlantic coast of Canada (Gowanloch & Hayes, 1927) and with L.knysnaensis Philippi and other prosobranchs in False Bay, South Africa (Broekhuysen, 1940). However, these studies were restricted to determination of limiting salinities, without consideration of the extent to which activity occurred within the range of tolerance of the species concerned. Investigation of salinity tolerances in L.littorea is also of some general interest since, as pointed out by Newell (1958), the behaviour pattern of this species is probably fairly typical of the more mobile intertidal invertebrates.
Second Occurrence of Stygiomedusa Fabulosa [Scyphozoa]
Authors: Cornelius P. F. S.
Published: May 2009

The second recorded specimen of Stygiomedusafabulosa Russell was taken in June 1971 from 1200–1400 m in the Bay of Biscay, near the area in which the first was caught. The similarity of the two specimens of S.fabulosa suggests that Stygiomedusa stauchi Repelin, described from a single specimen taken near the Congo estuary, is a distinct species.
Function of Theswimbladder-Inner Ear-Lateral Line System of Herring in the Young Stages
Authors: Blaxter J. H. S. , Denton E. J.
Published: May 2009

INTRODUCTION

The preceding paper (Allen, Blaxter & Denton, 1976) describes the development of the swimbladder-inner ear-lateral line system of the herring.

In the larval stage of herring the pro-otic bullae start to develop at a body length of about 18 mm. Between 18 and 30 mm the bullae become filled with gas. At 26 mm the lateral recess membrane starts to develop, becoming silvered at about 42 mm. The lateral line develops between 19 and 45 mm. The swimbladder silvers and contains gas from about 38 mm. The adult system is complete at 50–60 mm body length, some four months after hatching.

This paper concerns the system in its intermediate stages of development. It examines the problems of how the bullae are filled with gas and how the gas spaces are maintained. It gives evidence on the possible roles of the gas-filled spaces as hydrostatic pressure receptors and as aids to buoyancy and discusses the limitations of the system before it can gain or lose gas to a gas-filled swimbladder.
2-Aminoethylphosphonic Acid inMonochrysis
Authors: Baldwin M. W. , Braven J.
Published: May 2009

Introduction

The first naturally occurring compound to be identified containing a carbon-phosphorus bond was 2-aminoethyphosphonic acid
Studies on The Biology of The Entocommensal RhynchocoelanMalacobdella Grossa
Authors: Gibson Ray
Published: May 2009

Introduction

Despite the amount of literature published concerning the entocommensal rhynchocoelan,Malacobdella grossa(O. F. Müller), few references have been made about its ecology and life-history, and these for the most part consist of little more than isolated observations. The ecological knowledge available is composed almost exclusively of details pertaining to geographic distribution, hosts from which the worm has been recorded, and reports of the infection incidences found. Apart from suggestions by von Kennel (1878) and Gering (1911) that a relationship exists between host size and both worm incidence and size, the only detailed analysis of the host-commensal associations is that of Gibson (1967), who established a statistical correlation between host size and both incidence of infection and nemertean length, recorded the disposition frequency of the worm within its host, and examined both the occurrence of multiple infections and theMalacobdellapopulation size composition.

Von Kennel (1878) further suggested that host-commensal size relationships would depand on the age (i.e. size) at which infection by the pelagic larvae occurred, and Ropes (1963) speculated on the role played by surface currents upon larval distribution.
Studies on the Growth of Phaeodactylum Tricornutum IV. Comparison of Different Isolates
Authors: Hayward J.
Published: May 2009

Introduction

The diatom Phaeodactylum tricornutum Bohlin has been used in numerous experiments on the physiology and biochemistry of diatoms since the publication of the first paper involving this organism by Allen & Nelson (1910). The taxonomic position of the organism has been dealt with by Lewin (1958), who also lists the papers which she considers to have involved the use of P. tricornutum. The present study reports the results obtained from a comparison of different isolates of this organism.
Vitamin B12and Marine Ecology. IV. The Kinetics of Uptake, Growth and Inhibition inMonochrysis Lutheri
Authors: Droop M. R.
Published: May 2009

57Co-labelled vitamin B12was used to study the kinetics of vitamin B12limitation inMonochrysis lutheriin continuous and exponentially growing batch cultures and in washed cell suspensions.

Specific growth rate in the chemostats was found not to depend directly on medium substrate concentration but on the concentration within the cells (cell quota), obeying a hyperbolic equation of the form
Distribution and Seasonal Population Changes of Campecopea Hirsuta [Isopoda: Flabellifera]
Authors: Harvey Clare E.
Published: May 2009

Campecopea hirsuta (Montagu) occurs in rock crevices, and among barnacles and the lichen Lichina in south-west Britain. It is particularly abundant on shores ex-posed to wave action, occurring most commonly at about M.T.L. and below on shallow slopes, and from M.T.L. to H.W.N. on steep slopes. Young Campecopea of about 1–5 mm long are released in late summer. Females attain a maximum length of 35 mm and males 4–0 mm, each having a life span of no more than 1½ years.
Some Observations on the Biology and the Ecology of a Venus Striatula Population in the Bay of Douarnenez, Brittany
Authors: Guillou J. , Sauriau P. G.
Published: May 2009

INTRODUCTION

Venus striatula (da Costa) (= Venus gallina L.) occurs in high densities in shallow water on a bottom of clean fine sand in the Bay of Douarnenez. The environmental conditions are characterized by an obvious sediment instability due to a high exposure to westerly swells (Guillou & Le Moal, 1978). This species is preferentially distributed in the fine sands (Petersen, 1913; Thorson, 1957), but is relatively tolerant towards certain ecological factors and so is sometimes found in very muddy sediments. It also shows an extended latitudinal range, since it is recorded from the Lofoten Islands to the Canaries, in the Mediterranean and the Black Sea (Tebble, 1966).
Mitotic E- and Secretory F-Cells in the Hepatopancreas of the Shrimp Penaeus Semisulcatus (Crustacea: Decapoda)
Authors: Al-Mohanna S. Y. , Nott J. A. , Lane D. J. W.
Published: May 2009

INTRODUCTION

It is apparent, in a review on the decapod hepatopancreas (Gibson & Barker, 1979) that there is some consensus of opinion that the epithelium consists of E-, R-, F- and B-cells and M-cells (Al-Mohanna, Nott & Lane, 1985). Also, it is agreed that the gland produces enzymes and absorbs, digests and stores nutrients and excretes waste material. However, the apportionment of these functions to the different cells and the descriptions of the cytological processes involved are variously explained. Thus, the activity of proteases and amylases has been demonstrated in the secretion produced by the gland but the source of these enzymes is attributed to different cells and various modes of secretion are proposed. Also, no secretion granules of the zymogen type have been seen.

There are probably two main reasons for the inconsistent interpretation of the activities of the cells. First, the different stages of the feeding and moult cycles are not taken into account and both these affect the cytology of the gland. Second, some of the functions have been deduced from observations of the fine structure without any experimental treatments to demonstrate more directly the processes involved. In the present work all the animals are taken at the same moult stage and observations are made throughout the feeding cycle. Also, aspects of the function are studied with markers which are administered in the diet and injected into the blood. The activities of hydrolytic enzymes associated with the different epithelial cells have been studied but these will be the subject of a separate publication dealing with the cytochemistry of the digestive processes.
Vascular and Pericardiac Pressures inAscidiella Aspersa(Urochordata: Ascidiacea)
Authors: Jones H. D.
Published: May 2009

INTRODUCTION

The heart of tunicates is of physiological interest for several reasons: it is a simple peristaltic tube; it lacks valves; and the direction of the contractions changes periodically thus reversing the direction of blood flow. The phylogenetic importance of tunicates, being invertebrate chordates, also make physiological details of interest.
Calorific Values and Elemental Analysis of Eleven Species of Oceanic Squids (Mollusca:Cephalopoda)
Authors: Clarke A. , Clarke M. R. , Holmes Lesley J. , Waters T. D.
Published: May 2009

INTRODUCTION

Cephalopods may be divided into five types according to their buoyancy. Members of several families such as the Octopodidae, Loliginidae and Ommastrephidae are negatively buoyant and must swim to stay in midwater and are therefore highly muscular animals. Others have mechanisms to make them neutrally buoyant so they can remain suspended in midwater without effort. Nautilus, Spirula and cuttlefishes have low pressure gas-filled chambers and their flesh is muscular and non-buoyant (Denton & Gilpin-Brown, 1973). Squids of one family, the Gonatidae, have a low density oil in their livers to give buoyancy but most of their body is muscular. Some oceanic octopods have very watery tissues in which lighter chloride ions replace sulphate ions (Denton & Shaw, 1961). In 12 of the 26 teuthoid families the buoyancy is provided by low-density ammonia-rich solution in their body and head tissues or in an expanded coelomic cavity (Clarke, Denton & Gilpin-Brown, 1979). These ammoniacal squids are extremely abundant in the oceans of the world and form a large part of the diet of birds, cetaceans, seals and fish (Clarke, 1977). When their biomass is estimated from their utilization by predators it is important to know their properties as food and, in particular, their calorific values. As pointed out by Croxall & Prince in a review of the calorific values of cephalopods (1982), all the known values are of muscular, negatively buoyant species because they are of value as food for humans but no measurements have been made on the ammoniacal or oily species which are probably as important, or even more important, in the economy of the ocean (Clarke, 1983).
The Reproductive Cycles of Monodonta Lineata and Gibbula Umbilicalis on the Coast of Mid-Wales
Authors: Garwood P. R. , Kendall M. A.
Published: May 2009

At Aberaeron, Dyfed, mid-Wales, the two trochid species, Monodonta lineata and Gibbula umbilicalis breed during the summer months. M. lineata showed a discrete spawning period in late July in both 1980 and 1983, whilst G. umbilicalis spawned in August in both years, though with gamete release prolonged into September in 1980. In both species gonad development begins in April/May, and by June the characteristic bimodal oocyte diameter distribution of mature females has been established. Vitellogenesis and the development of a jelly coat around the oocyte begin when the oocytes have a diameter of 70–80 μm, with mature oocytes reaching 140–180 μm in diameter, excluding the jelly coat.
Faunas Associated with Longitudinal Furrows and Sand Ribbons in a Tide-Swept Area in the English Channel
Authors: Holme N. A. , Wilson J. B.
Published: May 2009

INTRODUCTION

In the central regions of the English Channel surface tidal streams are strong, often exceeding 160 cm s−1 at peak springs, with maximum values of over 250 cm s−1 off the headlands of Portland Bill and Cap de la Hague (Sager & Sammler, 1975). Correspondingly high values for bottom stress (Pingree & Griffiths, 1979) result in a scoured sea-bed covered with a minimum of sediment, the underlying bedrock being exposed in places. Study of current-generated bedforms in relation to the prevailing tidal currents has indicated the presence of a bed-load parting zone across the Channel from the Isle of Wight to Cap de la Hague (Stride, 1963; Johnson et al. 1982).
Duration and Timing of Spermatogenesis in a Stock of the Mussel Mytilus Californianus
Authors: Kelley R. Norman , Smith-Ashwood Michael J. , Ellis Derek V.
Published: May 2009

Determining the duration and timing of spermatogenesis in Mytilus californianus Conrad became key questions in our study of carcinogen-mutagen indices in the marine environment. We had postulated that the murine sperm deformation assay of Bruce, Furrer & Wyrobek (1974) should have marine analogues, and we assayed a number of marine invertebrates sampled near potentially carcinogenic waste flows, and by γ-ray dose-response experiments. Our field results demonstrated some deformation but only at a very low level (less than 5 % in Mytilus edulis L.). Development of a γ-ray doseresponse (90–900 rads) procedure for M. californianus by radium needle inserted through a drilled hole closed with a plastic plug, and subsequent biopsy of gonadal tissue at measured distances from the site of irradiation, did not show deformations from a pilot test in June 1979. If a viable dose-response procedure was to be developed it was necessary to establish seasonal reproductive timing so that specimens could be collected or cultured to maximize spermatogenesis and hence response potential, and also to establish the duration of spermatogenesis so that response measures via a gonadal tissue extraction could be appropriately timed.
Meiobenthos of a Sublittoral Sandbank in the Southern Bight of the North Sea
Authors: Willems K. A. , Vincx M. , Claeys D. , Vanosmael C. , Heip C.
Published: May 2009

The background and aims of this study are outlined in the introductory section of the preceding paper (Vanosmael et al. 1982).
Benthos of a Sublittoral Sandbank in the Southern Bight of the North Sea: General Considerations
Authors: Willems K. A. , Vanosmael C. , Claeys D. , Vincx M. , Heip C.
Published: May 2009

In two previous papers (Vanosmael et al. 1982; Willems et al. 1982) the macrofauna and meiofauna of a sublittoral sandbank in the Belgian coastal waters of the North Sea were described. This sandbank, the Kwinte Bank, is one of a series of parallel linear banks, the Flemish Banks, which are 15–25 km long and 3–6 km wide and rise about 25 m above the surrounding sea-floor. They are stressed, high-energy environments, subject to extreme physical disturbance by the very strong tidal currents which run parallel to the long axis of the sandbank and which put the whole upper layer of the sediment in a state of suspension at times.
Mean Heat and Salt Budgets for the Eastern English Channel and Southern Bight of the North Sea
Authors: Maddock Linda , Pingree R. D.
Published: May 2009

In an earlier study Pingree, Pennycuick & Battin (1975) used a diffusion model to study the monthly temperature distribution and heat exchange in the English Channel. This showed that the diffusion would have to be adjusted according to the tidal ellipses for an improvement in the predicted temperature distributions, and that advection was probably an important factor at certain times of year. An attempt to use the same model for prediction of the salinity distributions was unsuccessful due partly to lack of information on run-off, precipitation and evaporation. The present study is an attempt to provide an overall monthly mean heat and salt budget for the eastern English Channel and Southern Bight of the North Sea which could serve as a preliminary to a two-dimensional mixing/advection model in which the horizontal eddy diffusion is represented as a tensor based on the tidal ellipse properties (Hunter, 1975).
The Blood Cells ofCiona Intestinalis: An Electron Probe X-Ray Microanalytical Study
Authors: Rowley A. F.
Published: May 2009

As long ago as 1911, Henze first showed that the ascidian,Phallusia mammillatahas the ability to accumulate vanadium from the surrounding sea water into its tissues. Since this report, many other workers have demonstrated vanadium as well as other metals such as iron (Koval'kii, Rezaeva & Kol'tsov, 1962; Milanesi & Burighel, 1978; Macara, McLeod & Kustin, 1979a), manganese (Noddack & Noddack, 1939) and niobium (Carlisle, 1958) in various tunicate species.
The Effect of Hydrostatic Pressure Cycles on the Activity of Young Plaice Pleuronectes Platessa
Authors: Gibson R. N.
Published: May 2009

The responses of marine animals to changes in hydrostatic pressure have been widely studied (see reviews by Knight-Jones & Morgan, 1966; Fliigel, 1972; Nay lor & Atkinson, 1972). Most of these studies, however, have been concerned with invertebrates, particularly Crustacea, and few deal with fish (Gordon, 1970). Blaxter's (1978) review of baroreception summarizes recent work in this field and points out that a limitation of many experiments has been the use of sudden, rather than gradual, pressure changes. The limitation is especially true with respect to fish. This paper describes the results of experiments in which young plaice (Pleuronectes platessa L.) were subjected to hydrostatic pressure cycles of varying amplitude and frequency in order to describe the response to such pressure cycles, to determine the threshold of the response and to relate the response to the fish's behaviour in the sea.
Contents of Vanadium and Sulphur in the Blood Cells ofAscidia Mentula and Ascidiella Aspersa
Authors: Bell M. V. , Pirie B. J. S. , McPhail D. B. , Goodman B. A. , Falk-Petersen I.-B. , Sargent J. R.
Published: May 2009

Henze (1911) was the first to discover large amounts of vanadium and sulphuric acid in the blood of certain species of tunicates. Webb (1939) established that both the sulphuric acid and the vanadium were present in blood in the same cell type, termed a vanadocyte. Since then much further work (reviewed by Goodbody, 1974) has been done on these highly unusual cells. Some species of tunicates accumulate other metals, including iron, titanium, niobium and tantalum (Carlisle, 1968) but the role(s) of these metals and indeed of vanadium itself remains unclear. The vanadium is present in vanadocytes in a reduced cationic form largely as vanadium(III) (Carlson, 1975; Tulliuset al.1980) which is complexed with a chromagen of as yet undefined structure and with sulphate as the counter anion (Bieliget al.1966). The blood ofAscidia nigrais not capable of reversible oxygen binding (Macara, McLeod & Kustin, 1979), and there has been speculation that the reduced vanadium is involved in the synthesis of the tunic material (see Goodbody, 1974). The tunic of ascidians also contains cells rich in vanadium and sulphuric acid and roles for them in anti-fouling and anti-predation have been considered (Stoecker, 1980a, b).
Direct Observation of Sex Change in the Patellacean Limpet Lottia Gigantea
Authors: Wright William G. , Lindberg David R.
Published: May 2009

Protandric hermaphroditism, the sequential change from male to female, has been reported in several superfamilies of prosobranch gastropods including the Fissurellacea, Patellacea, Calyptraeacea, and Eulimacea (Webber, 1977). It is most common in members of the Calyptraeacea and the Patellacea. In the Calyptraeacea changes in sex are readily followed by observing copulative structures (Coe, 1944). Because patellacean limpets are predominantly broadcast spawners with external fertilization, external characters that can be used to determine the sex of individuals are rare. Hence, previous to this report the occurrence of protandry in most patellacean limpets has been based primarily on sexual dimorphism in size; the smaller size classes being made up of male individuals and the larger size classes of female individuals (Willcox, 1898; Orton, 1920, 1928; Orton, Southward & Dodd, 1956; Dodd, 1956; Branch, 1974). However, given this type of data it is often difficult to assess whether the observed sexual dimorphism is indicative of protandry or merely a result of differential growth and/or survival. The presence of simultaneous hermaphrodites in the intermediate size classes, as evidence of protandry is of limited value because simultaneous hermaphrodites occur sporadically in patellaceans that do not show a sexual dimorphism in size (Dodd, 1956; Branch, 1974). The only unambiguous way of proving the existance of protandry in patellacean limpets is the direct monitoring of gonadal changes in individuals through time. We report here the first direct observations of protandric hermaphroditism in a patellacean limpet.

Lottia gigantea Sowerby, 1834 is a large (100 + mm), territorial, intertidal limpet that ranges from northern California to central Baja California, Mexico (Stimson, 1970).
The Reproductive Biology ofOphiacantha Bidentata(Echinodermata: Ophiuroidea) From The Rockall Trough
Authors: Tyler P. A. , Gage J. D.
Published: May 2009

INTRODUCTION

Ophiacantha bidentata(Retzius) is a widespread arctic-boreal ophiuroid with a circumpolar distribution in the shallow waters of the Arctic seas and penetrating into the deep sea of the.North Atlantic and North Pacific (Mortensen, 1927, 1933a; D'yakonov, 1954). Early observations of this species were confined to defining zoogeo-graphical and taxonomic criteria including the separation of deep water specimens as the varietyfraterna(Farran, 1912; Grieg, 1921; Mortensen, 1933a). Mortensen (1910) and Thorson (1936, pp. 18–26) noted the large eggs (o.8 mm diameter) in specimens from Greenland and Thorson (1936) proposed that this species had ‘big eggs rich in yolk, shed directly into the sea. Much reduced larval stage or direct development’. This evidence is supported by observations ofO. bidentatafrom the White and Barents Seas (Semenova, Mileikovsky & Nesis, 1964; Kaufman, 1974)..
Taxonomic Studies on British and Irish Amphipoda. the Genus Gammaropsis
Authors: Myers A. A. , Mcgrath D.
Published: May 2009

INTRODUCTION

Lincoln (1979) stated that ‘four species (of Gammaropsis Liljeborg) are reported from the British Isles, Gammaropsis maculata (Johnston), G. palmata (Stebbing & Robertson), G. nitida (Stimpson) and G. sophiae (Boeck)’. In fact, six species of Gammaropsis have been reported from the British Isles in the literature, the records of G. lobatus (Chevreux) (Spooner, i960) and G. melanops (Sars) (Jones, 1948) having apparently been overlooked by Lincoln (1979). Spooner's (1960) material is apparently no longer extant, but the material attributed to G. melanops by Jones (1948) has been re-examined by us and found to be referable to G. lobata. Recent collections of G. lobata from the west coast of Ireland confirm a rather wide distribution of this species in the southwest of these islands.

Five species of Gammaropsis are therefore now known from these islands, and G. melanops can, at least for the present, be deleted from the British and Irish list of species.

Lincoln (1979) was unable to examine any British material of G. sophiae, everything labelled as such, in the material examined by him (including the Norman collection at the B.M.N.H.)* being referable to G. nitida. He therefore figured the species from West African material. G. sophiae is quite widespread along the southwest coast of Ireland and since it differs somewhat from the material described by Lincoln (1979) it is figured herein from the Celtic Sea.

Krapp-Schickel & Myers (1979) reviewed the Mediterranean species of Gammaropsis and segregated the species into two groups, group ‘A’ species characterized by the possession of a toothed urosome, toothed coxa 1 and long acute epistome, and group ‘B ‘ species characterized by having a smooth urosome, smooth coxa 1 and short epistome.
The Role of the outer Conducting Epithelium in the Behaviour of Salp Oozooids
Authors: Bone Q.
Published: May 2009

INTRODUCTION

Both the inner and outer epithelia of salps propagate action potentials (Mackie & Bone, 1977). Skin pulses in the outer epithelium underlying the test (OSPs) evoked by mechanical or electrical stimulation of the epithelium ‘enter’ the brain and may alter the regular rhythmic locomotor activity (Mackie & Bone, 1977; Andersonet al.1979). The route of'entry’ has not been determined, but has been assumed to be via the axons of the scattered mechanoreceptor sensory cells lying in the outer epithelium. The OSP system would thus operate to extend the sensory field of such cells, as in the appendicularianOikopleura(Bone & Mackie, 1975; Bone & Ryan, 1979) where two sensory cells are coupled to a conducting epithelium.

Salps alternate generations between the solitary asexual oozooid, and the aggregated sexual blastozooids (budded from the stolon of the oozooid). The linked blastozooids form chains, along which OSPs pass to regulate the locomotor behaviour of individual zooids in the chain. The zooids are not linked by gap junctions, and OSPs pass along the chain in a complex.manner, involving alternating epithelioneural and neuroepithelial synapses (Bone, Anderson & Pulsford, 1980; Anderson & Bone, 1980). The OSP system of the oozooid generation is less well understood, although it is known that OSPs in the outer epithelium of the oozooid propagate into the stolon, where they have been studied by Anderson (1979). This paper shows that oozooids possess a similar system of neuroepithelial synapses to that of blastozooids, and that these ‘ drive’ OSPs in the same way as occurs during the regenerative transmission of OSPs along the blastozooid chain.
An Analysis of Factors Determining Seasonal Variation in the Byssal Attachment Strength of Mytilus Edulis
Authors: Price H. A.
Published: May 2009

INTRODUCTION

The common mussel Mytilus edulis L. is one of the most successful shore molluscs. It is widely distributed in the northern hemisphere and is abundant not only in the most sheltered bays and loughs but also in conditions of extreme exposure (Lewis, 1964; Seed, 1976). Attachment to the substratum is by means of the proteinaceous byssus complex, the strength of which has been shown to vary seasonally (Price, 1980b). This variation could be a response to seasonal fluctuations in wave action, as suggested by Pieters et al. (1978), or may result from the seasonality of other environmental variables. Some of these, e.g. salinity and sea temperature, have been shown to influence byssus production (Glaus, 1968; Van Winkle, 1970; Allen et al. 1976), Phytoplankton density, spawning and the reduced ‘scope for growth’ during winter months (Bayne & Widdows, 1978) may also play a role in determining byssus strength.

In the present study, the relationships between byssal attachment strength and environmental and other variables are examined in a population of mussels on the South Wales coast.
Growth of the Queen Scallop Chlamys Opercularis in Suspended Cages in the Firth of Clyde
Authors: Richardson C. A. , Taylor A. C. , Venn T. J.
Published: May 2009

INTRODUCTION

Estimations of the growth of bivalves have traditionally been determined from measurements of animals collected on a regular basis from natural populations. Generally size frequency distributions have been analysed or growth rates estimated from measurements of the distances separating the annual rings (Hughes, 1970; Seed & Brown, 1978; Taylor & Venn, 1978). While both methods provide valuable information on shell growth, a more direct approach is to investigate experimentally the growth of individual animals held in cages and to follow the seasonal changes in the dimensions of their shells.

The queen scallop Chlamys opercularis (L.) is found in large numbers in areas around Great Cumbrae Island in the Firth of Clyde where they form the basis for a small local fishery. In 1979 the British Steel Corporation started operating a deep-water terminal at Hunterston unloading and loading iron ore and coal. It was envisaged that accidental spillage of material during transfer from the vessels to the shore might affect the queen scallop populations in the area.
Speed Sensing in a Harbour Seal
Authors: Renouf Deane , Gaborko Linda
Published: May 2009

Many pinnipeds travel long distances between breeding and feeding grounds in some cases showing remarkable homing abilities (James & Dykes, 1978). Very little is known about the methods they use to plot their course but if they were aware of their rate of movement, this ability could conceivably assist them. The following procedure which was undertaken with a captive male harbour seal (Phoca vitulina Linnaeus) demonstrated that the animal was able to determine his swimming speed.

The seal was first trained to swim at any speed through ten hoops 48 cm in diameter submerged at equal intervals around the periphery of an 8 m oval tank filled with sea water to a depth of 1.2 m. Each trial consisted of one circuit of the tank, and always began at the same hoop. A screen preventing the seal from going through this start hoop was removed to indicate the onset of each trial. The seal was then trained to swim the 17 m course maintaining a speed of 6 km/h. The experimenter observed from a bridge suspended over the tank, and measured the animal's speed by listening to a series of tones. These tones were audible only to the experimenter and were timed such that if the seal were swimming at 6 km/h, he would reach each hoop at the same moment the experimenter heard the tone. A buzzer was sounded whenever the animal swam at less than the required speed, and a whistle was blown if he were moving too quickly.
Two Species of Algal Symbiont in Naturally Occurrin G Populations of Convoluta Roscoffensis
Authors: Mcfarlane A. E.
Published: May 2009

Convoluta roscoffensis (Graff) has long been known for its symbiosis with a green flagellate definitively described from French stock as Platymonas convolutae by Parke and Manton (Parke & Manton, 1967). Provasoli subsequently discovered a species of Prasinocladus in a culture isolated from C. roscoffensis, but concluded that it was a surface contaminant of the animal (Provasoli, Yamasu & Manton, 1968).

Populations of C. roscoffensis from Aberthaw, South Wales (Mettam, 1979), and eighteen sites on Guernsey have been studied. In most patches of the Aberthaw colony, and in two of the Guernsey sites, two algal symbionts have been found. One of the Guernsey, and one of the Aberthaw symbionts appear identical to Platymonas convolutae.

They can be distinguished at the ultrastructural level by the presence of canaliculi which penetrate the pyrenoid, and are lined with the double-layered plastid envelope. In both cases the second flagellate shows the nucleus-pyrenoid complex typical of the genus Prasinocladus, where the nucleus penetrates the pyrenoid, and a pair of thylakoid membranes separate the pyrenoid from the starch shell (Parke & Manton, 1965). Neither symbiont has been identified specifically.

It is also possible to distinguish the two symbionts in the living animals, since the cup-shaped pyrenoid of the Prasinocladus type is easily distinguished from the spherical condition in Platymonas using the light microscope. A mixed population of symbionts has never been found in an individual worm. For each patch of animals in a colony it was possible to establish the percentage of animals containing each symbiont. This ratio varies from patch to patch in the colony, but has remained remarkably constant within each patch over the six months it has been studied. The Prasinocladus type always predominates at Aberthaw, the Platymonas type being absent in places.
The microanatomy ofHymenomonas lacunasp.nov. (Haptophyceae)
Authors: Pienaar Richard N.
Published: May 2009

A new species ofHymenomonasStein,Hymenomonas lacunasp.nov. from San Juan Island, Washington, U.S.A. is described using light and electron microscope techniques. The cells normally occur in non-motile clumps growing on the sides of the culture vessel. Each cell has a body covering composed of a single layer of coccoliths of unusual construction and several layers of circular unmineralized rimless scales. Occasional small elliptical scales are sometimes found.

The general cytology of the cells is discussed with special attention paid to the unusual pyrenoid and the role of the Golgi body in scale and coccolith production.

The relationship of this species toH. roseolaStein is discussed.
Effects of temperature and salinity on growth and uptake of 65Zn and 137Cs for six marine algae
Authors: Styron C. E. , Hagan T. M. , Campbell D. R. , Harvin J. , Whittenburg N. K. , Baughman G. A. , Bransford M. E. , Saunders W. H. , Williams D. C. , Woodle C. , Dixon N. K. , McNeill C. R.
Published: May 2009

Population growth and concentration factors for 65Zn and 137Cs have been measured for Achnanthes brevipes Agardh, Carteria sp. Diesing, Chlamydomonas sp. Ehrenberg, Dunaliella salina Teod., Nannochloris atotnus Butcher, and Phaeodactylum tricornutum Lewin subjected to factorial combinations of eight temperatures (6–40 °C) and ten salinities (3.5–44.0 p.p.t.). Regression coefficients were calculated for polynomial models describing response surfaces for growth and radionuclide concentration. Salinity was more important than temperature in describing population growth for Carteria, Dunaliella, Nannochloris and Phaeodactylum. No independent variable was consistently of primary importance in describing 137Cs concentration factors, while temperature accounted for more variation in 65Zn concentration factors than salinity or population growth in all algae except Dunaliella. Concentration factors for 65Zn were uniformly higher than 137Cs concentration factors.
Pavlova calceolata (Haptophyceae), a new species from the Tamar Estuary, Cornwall, England
Authors: Van Der Veer J.
Published: May 2009

A new flagellate alga is described which has the flagellar apparatus characteristic of the genus Pavlova, but not the external particles on the cell body. The minute particles on the long flagellum contain acid polysaccharide. Paramylon and polyphosphate occur as vacuolar inclusions. A peroxide resistant layer is present in the superficial cisterna. The opposite membranes of the superficial cisterna differ considerably in structure. A diagnosis is given and taxonomic relationships are discussed.