bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Influencing Shell Shape in the Mussel Mytilus Edulis
Authors: Seed R.
Published: May 2009

An attempt is made to explain the great variations in gross shell morphology noted in field populations of Mytilus edulis.

In any one mussel population, variation in shell form can be attributed to differences in age, old mussels having proportionately heavier shells where width often exceeds shell height. This is invariably accompanied by down-turned, divergent umbones and varying degrees of incurvature of the ventral shell margin.

Variations in the age structure of mussel populations from different habitats can also account for local variability in shell morphology. Localities where the life expectancy of mussels is increased due to absence of predators (especially in the upper shore) reveal a high incidence of old ‘ungulate’ individuals, whereas populations in which the mussel turnover is more rapid show a preponderance of relatively young mussels.

Shell morphology is greatly influenced by growth rate and density. These probably exert their effect through physical compression which is maximum in localities of fast growth and high density and least in areas of slow growth and low density. High compression leads to an elongate form whereas low compression results in higher, more triangular shaped shells. Growth rates and densities, even within the same habitat, are, however, exceedingly variable.

Since all environmental conditions vary in both time and space, wide variation in shell morphology is to be expected, even in animals from the same locality.

Transplantation experiments indicate that variation in shell morphology is essentially phenotypic, older animals being more likely to exhibit a form which is characteristic of their particular habitat. Smaller mussels from widely different habitats show remarkable similarity in shell morphology.
Occurrence of Eggs of Bass Dicentrarchus Labra X on the Southern Coasts of Ireland
Authors: Kennedy Michael , Fitzmaurice Patrick
Published: May 2009

During April-June, 1967, tow-netting for bass eggs was carried out at four places on the Irish coast. Small numbers of bass eggs were obtained at two of these places, namely the Splaugh Rock, near Greenore Point, Co. Wexford and Youghal Harbour, Co. Cork. They were taken near the surface, in water of the salinity range 30–34.5%, and of surface temperature range 10.5–13.2°C.

The Irish material was larger than described by Bertolini (1933) from the Mediterranean, but smaller than described by Jackman (1954), who hatched eggs spawned in the Plymouth Laboratory Aquarium and described the larvae.

Introduction

Bass have spawned in the aquarium at Naples, and their eggs have been found in plankton in the Mediterranean (Raffaele, 1888; Bertolini, 1933). Bass have also spawned in the aquarium at Plymouth, and their eggs and the resulting young stages have been described by Jackman (1954).

Hitherto, however, the eggs of bass do not appear to have been found on the coasts of Britain or Ireland. The only young stages recorded were 14 post-larvae from 4 to 7.5 mm long, taken in the Eddystone area in the years 1925, 1926, 1931 and 1933, with dates of capture between 17 March and 4 June (Russell, 1935).

As part of a programme of research on the biology of bass in Irish waters, tow-netting was carried out in 1967 at the Splaugh Rock off the Wexford coast; at Dungarvan, Co. Waterford; at Youghal, Co. Cork; and at Baltimore, Co. Cork (Fig. 1). The Splaugh, Dungarvan and Youghal are places where bass ‘shoal’; that is, frequently gather in shoals to attack sand-eels, herring fry or sprats at the surface.
Spirorbis Species (Polychaeta: Serpulidae) From the Isles of Scilly, Including Descriptions of two New Species
Authors: Harris Tegwyn
Published: May 2009

Introduction

During the last fortnight in September of 1965, 1966 and 1967 littoral species of Spirorbis were collected by the author and, during the early part of April 1966, sublittoral species were collected by the British Museum (Natural History) and University of London Sub-Aqua Expedition. Ten species, including one new to the British Isles and two new to science, were found to be present. Details of their occurrence, together with the descriptions of the new species, are contained in this report. Representative series of the material collected are deposited in the British Museum (Natural History). In this account, specimens collected by the author are indicated by (T.H.) and those collected by the Sub-Aqua Expedition by (S-Aq. Ex.).
Mitotic Index in Selected Red AlgaeIn SituI. Preliminary Survey
Authors: Austin Alan P. , Pringle John D.
Published: May 2009

A review of the literature indicated a lack of quantitative data on cell division in macroscopic algae in the laboratory and particularlyin situ.By means of SCUBA techniques selected red algae were collected from theirin situlocation on a 24 h basis through the seasons of the year. The varied oceanographic and meteoro-logical conditions on the southern tip of Vancouver Island provided shore habitats of adequate contrast.Rhodomela larixwas found to be a suitable test species for quantitative work, and differentials in mitotic activity in the growing parts of this plant were explored. Using squash techniques a method of quantitative estimation of mitotic activity employing a point-counting method was developed. It was found necessary to define the limits of mitotic phases inR. larixto facilitate quantitative analysis which was carried out over 24 h periods both in July and in February. Mitotic activity inR. larixshowed a well-marked periodicity, although only the July data are statistically significant. The distribution of mitotic activity throughout the day was similar both in July and in February despite the dissimilarity of photo-period, temperature and tidal factors, which suggests the presence of a circadian rhythm. This preliminary work is being continued by furtherin situinvestigations correlated with laboratory cultures under controlled environmental conditions.
A New Type of Muscle Cell from the Subumbrella of Obelia
Authors: Chapman David M.
Published: May 2009

The subumbrella of the hydrozoan medusa Obelia consists of three layers of cells. The innermost layer is the endodermal lamella whose broad polygonal cells are in close contact with the middle layer of polygonal myocytes which have striated myofibrils running in two layers at right angles to one another in the same cell. These myofibrils extend beyond the myocytes as plasma membrane-enclosed prongs to make contact with the prongs of neighbouring cells in such a way that whole mounts give the impression that the slender myofibrils are continuous over the subumbrella. Cross-layered myocytes can be seen to be another means of decreasing the surface area of the subumbrella, a condition necessary for medusoid locomotion. Helically banded radial myofibrils are found in the outer layer.
Aspects of Osmotic and Ionic Regulation inCorophium Volutator(Pallas)
Authors: McLusky Donald S.
Published: May 2009

Experiments have been made to elucidate the problem of hyperosmotic regulation in the mud-dwelling euryhaline amphipod,Corophium volutator.The animal produced urine hypo-osmotic to the blood when acclimatized to low salinities, and isosmotic urine at salinities above 20%. The restricted permeable areas of the cuticle have been localized by silver staining. Over a range of salinities from 1 to 35 %C. volutatorwas found to maintain Na+, K-−, Ca2+, Cl-−, more concentrated than the medium, and Mg2~less concentrated. The importance of these mechanisms in assisting hyperosmotic regulation is discussed.
Check-List of British Marine Algae–Second Revision
Authors: Parke Mary , Dixon Peter S.
Published: May 2009

The Preliminary Check-list of British Marine Algae (Parke, 1953), with three subsequent lists of additions and corrections (Parke, 1956, 1957, 1959), was superseded by the Revised Check-list of British Marine Algae (Parke & Dixon, 1964). Since the publication of the latter, changes, both taxonomic and systematic, have been sufficiently numerous to warrant the present list incorporating additions, corrections and emendations.

The authors take full responsibility for all the changes from the 1964 Check-list. The responsibility for the preparation of the lists of species for each Class in the 1964 Check-list was as follows: (1) Cyanophyceae, H. T. Powell; (2) Rhodophyceae, P. S. Dixon; (3) Cryptophyceae, M. Parke; (4) Dinophyceae, D. Ballantine & M. Parke; (5) Haptophyceae, M. Parke; (6) Chrysophyceae, M. Parke; (7) Craspedophyceae, M. Parke; (8) Xanthophyceae, M. Parke; (9) Phaeophyceae, H. Bladder, G. Russell, P. S. Dixon & M. Parke; (10) Prasinophyceae, M. Parke; (11) Chlorophyceae, E. M. Burrows, P. S. Dixon & M. Parke.

The sequences of classes is as in the 1964 Check-list and there have been no changes in the geographical limits used therein (the coasts of Britain and Ireland or in adjacent waters, i.e. the sea area bounded by 47° N. and 63° N., 11° E. and 30° W.). Three classes (Bacillariophyceae, Rhaphidophyceae, Euglenophyceae) are still not represented and the authors would be grateful for records of marine species of these in order to facilitate their inclusion at some time in the future.

The compilers welcome any comments on the Revised Check-list (1964) or the present list.
Laboratory Survival of Alloteuthis Subulata (Cephalopoda: Loliginidae) from the Plymouth Area
Authors: Lipiński Marek R.
Published: May 2009

INTRODUCTION

Wild-caught squids have seldom survived for very long in laboratory aquaria. Tardent (1962) maintained Loligo vulgaris Lamarck, 1789 for a maximum of 60 days. Choe & Oshima (1963), Choe (1966) and LaRoe (1971) reared squids of the genus Sepioteuthis from eggs to adult size. Between 1975 and 1982 several successful attempts to maintain Loliginidae (e.g. Matsumoto, 1976; Hanlon, Hixon & Hulet, 1978, 1983; Yang et al. 1980, 1983) and Ommastrephidae (Flores et al. 1976; Flores, Igarashi & Mikami, 1977; O'Dor, Durward & Balch, 1977) were made. But to date only ten squid species have been maintained for more than forty days (review: Yang et al. 1980; Boletzky & Hanlon, 1983). Loligo opalescens Berry, 1911 holds the record for longevity in captivity at 233 days from egg to adult (Yang et al., 1983).
Abundance, Life History and Ligulosis in the Gobies (Teleostei) of the Inner Severn Estuary
Authors: Claridge P. N. , Hardisty M. W. , Potter I. C. , Williams C. V.
Published: May 2009

Eight species of the Gobiidae were recorded in weekly samples taken between July 1972 and June 1977 from the intake screens of Oldbury Power Station in the inner Severn Estuary.Buenia jeffreysii, Aphia minuta, Gobius paganellusandGobius nigeroccurred infrequently andCrystallogobius lineariswas only common in the late spring and summer of 1975 and 1976.Pomatoschistus microps, which peaked in numbers in the winter, increased in abundance each year between 1972 and 1977. The most numerous gobies were those belonging to thePomatoschistus minutuscomplex which were separated intoP. minutusandP. lozanoionly between June 1974 and July 1975. Seasonal trends in the abundance of these two species were similar, with elevated numbers occurring between July and September 1974 and in January 1975. Gonadosomatic indices and other data indicate that the decline in numbers after the latter month represented an emigration to spawning areas further down the estuary or in the Bristol Channel. AlthoughP. minutusattained a larger body size thanP. lozanoi, both these species andP. micropstypically had a one year life cycle with only a small number of individuals surviving for a further few months. The fecundity of P.lozanoi, which ranged from 410–2453 (mean 1270), was lower than that reported forP. minutusin this and other studies. Analysis of stomach contents showed that the diet of both species was similar, consisting predominantly of gammarids and mysids. While both species were infected withLigula intestinalis, the incidence of infection and the parasite index was greater inP. lozanoithan inP. minutus.
Stokes, Euler and Lagrange Aspects of Residual Tidal Transports in the English Channel and the Southern Bight of the North Sea
Authors: Pingree R. D. , Maddock Linda
Published: May 2009

INTRODUCTION

The dust cart on the Isles of Scilly did not end its service at the local tip, over the cliffs at Deep Point on the eastern side of St Mary's on 14 October 1983. Instead it floated off and continued in service as a Lagrangian drifter, indicating the residual transport of water around the islands. As a hazard to shipping its position was given out as a navigation warning and it was allegedly sighted on the western side of Scilly. The interesting oceanographic question is whether the dust cart was (or would have had it not sunk) circumnavigating the islands in a clockwise or anticlockwise sense. Accordingly this experiment has been repeated using satellite tracked Argos drifting buoys, drogued with parachutes (~ 10 m diameter), and set at depths of about 15 m. The releases showed that the residual transport was clockwise around the islands. In one instance a drogue circumnavigated the islands in about 12 h (i.e. ~ one tidal period) at an average speed of about 100 cm s−1 (Fig. 1).
Tidal Friction and the Diurnal Tides on the North-West European Shelf
Authors: Pingree R. D. , Griffiths D. K.
Published: May 2009

A numerical model is used to derive the diurnal tides on the N.W. European Shelf. The quadratic friction term was linearized using both tidal and wind driven currents. The semidiurnal tidal currents essentially provide the friction for the diurnal tides except in a few relatively small regions (semidiurnal current amphidromes) and the Skagerrak where the wind driven currents dominate. Accurate M2 tidal currents are required for the diurnal bottom stress tensor and the M2 tidal current amplitudes are considered accurate to about 95%. Some discrepancies between model energy M2 dissipation rates and some observed estimates reported for the English Channel and Celtic Sea regions were noted.
Intracellular Barite Crystals in Two Xenophyophores, Aschemonella Ramuliformis and Galatheammina Sp. (Protozoa: Rhizopoda) With Comments on the Taxonomy of A. Ramuliformis
Authors: Gooday A. J. , Nott J. A.
Published: May 2009

Biological precipitation of barite (barium sulphate) is highly unusual (Bowen, 1966, p. 129). This mineral forms statoliths in certain ciliates (Hubert et al. 1975), but the only animals in which it is known to occur in significant quantities are xenophyophores, a group of giant deep-sea protozoans placed in a separate class within the Rhizopoda (Levine et al. 1980). The importance of these previously obscure organisms at abyssal, and bathyal depths in the oceans has lately become increasingly appreciated, mainly through the work of Tendal (1972, 1973, 1975a, b, 1980a, b; Tendal & Lewis, 1978).
The Oogenic Cycle of Nereis Diversicolor Under Natural Conditions
Authors: Mettam C. , Santhanam V. , Havard M. S. C.
Published: May 2009

Until recently, the most detailed and widely quoted account of the life cycle and reproductive biology of Nereis diversicolor O. F. Müller was that of Dales (1950; 1951) for a population in the Thames Estuary followed for a single season. The study combined a periodic analysis of the population structure with assessment of reproductive maturity, by gamete analysis of individual worms, and a record of larval recruitment. The conclusions reached were that worms grew to maturity in one year, spawning in February, but that some survived up to a maximum life span of 18 months.
On Postlarvae and Pelagic Juveniles of Rocklings Gaidropsaurus Mediterraneus and G. Biscayensis
Authors: Demir Neclå
Published: May 2009

Little is known about the life history of the species of Gaidropsaurus Rafinesque, 1810. Two species of this genus, G. mediterraneus (Linnaeus, 1758) and G. biscayensis (Collett, 1890) = Antonogadus megalokynodon Kolombotovic, 1894 occur in the Sea of Marmara. The egg, larvae and pelagic juveniles of G. biscayensis have never been described. Egg, prelarval and early postlarval stages attributed to G. mediterraneus have been described and illustrated by many workers, but there has been confusion in their identifications.

Three species of Gaidropsaurus, G. mediterraneus, G. biscayensis and G. vulgaris (Cloquet, 1824) are recorded from the Mediterranean. Raffaele (1888) made artificial fertilizations of eggs of Naples specimens that he identified as Motella tricirrata Nilsson, 1832 = G. vulgaris. Holt (1899) found some eggs which are similar to those described and figured by Raffaele in the plankton off Marseille, but he considered it impossible to distinguish whether the larvae which hatched out from those eggs were Motella tricirrata i.e. G. vulgaris or Motella mediterranea Lütken, 1882 i.e. G. mediterraneus. Ehrenbaum (1905–9) who re-examined the various records of eggs and larval stages of Gaidropsaurus believes that those figured by RafFaele (1888) and Holt (1899) as well as the larvae referred to Phycis Artedi, 1792 and a pleuronectid by Emery (1886) and Marion (1894) respectively probably belong to Onos (Gaidropsaurus) mediterraneus. Aboussouan (1964) who worked on ichthyoplankton of the Gulf of Marseille also attributed some eggs and larvae to G. mediterraneus and figured one of those postlarvae which is 2·65 mm in standard length.

The eggs and prelarval stage of G. mediterraneus have more precisely been described and illustrated by Soviet investigators (Vodyanitskii & Kazanova, 1954; Duka, 1958; Dekhnik, 1973)> from the Black Sea.
The Distribution of Mercury in British Estuarine Sediments and Its Availability to Deposit-Feeding Bivalves
Authors: Langston W. J.
Published: May 2009

The recognition that non-essential metals, such as mercury, cadmium and lead, could, upon entering aquatic environments, produce harmful effects to man, directly or through food chains, has resulted in studies directed towards the identification of potentially hazardous levels.
Taxonomic Studies on British and Irish Amphipoda. Re-Establishment of Leucothoe Procera
Authors: Myers A. A. , McGrath D.
Published: May 2009

In his recent monograph on British Marine Amphipoda, Lincoln (1979) reported that three species of Leucothoe Leach had been recorded from the British Isles previous to his work and added a fourth species, L. richiardii Lessona. This fourth species he added after examining material collected in 1935, from the Eddystone grounds, by G. I. Crawford. The species had previously been recorded from the same area (Marine Biological Association, 1957) as ‘Leucothoe sp. nov. (allied to L. richiardii Lessona)’.

We have recently had the opportunity to examine more material of the above species from Ireland, together with Crawford's original material kindly loaned to us by Dr Lincoln. Females of this species closely resemble L. richiardii, and only the presence of males in the Irish material (unavailable to Dr Lincoln prior to the publication of his monograph), which differ significantly from those of L. richiardii, alerted us to the distinctness of this species.

Bate (1857) described a new species of Leucothoe from Banff, Scotland under the name L. procera Bate. His three line description however, is insufficiently precise to determine to which species he was referring. Later (Bate, 1862) he redescribed and figured the species under the name L. furina Savigny, and his description and figures agree well with present material except in the shape of epimeron 3 (quadrate) and the telson which is terminally narrow. Bate & Westwood (1862) again figure and describe the species under the name L. furina and re-emphasize the peculiar telson. The epimera are figured as rounded lobes. Unfortunately, Bate's type material is no longer extant, but there seems little doubt, when one considers the perfect agreement in the structure of the male gnathopod 2 between Bate's figured material and present material, that the two are conspecific.
Growth, Training and Swimming Ability of Young Trout(Salmo GairdneriR.) Maintained Under Different Salinity Conditions
Authors: Nahhas R. , Jones N. V. , Goldspink G.
Published: May 2009

The growing interest in farming rainbow trout in the sea (MacLeod, 1977) or in brackish water (Tatum, 1973, 1976) is economically important because it involves the use of readily available sites and resources, and provides solutions to problems related to fresh water scarcity or its increased salinity (Al-Hamed, 1971; Al-Daham & Bhatti, 1977) in certain parts of the world.
Changes in the Ormer Populations of Guernsey and Jersey
Authors: Forster G. R. , Potts G. W. , Swinfen R.
Published: May 2009

The ormer, Haliotis tuberculata L. is a greatly prized species in the Channel Isles. Since the original survey of the ormer population of Guernsey and the subsequent tagging experiments (Forster, 1962, 1967), periodical short visits to the island have been made to investigate the stocks of ormers, especially in areas fished by divers; in 1968 and 1974 visits were also made to Jersey. These surveys were all made at the request of the local Sea Fisheries Committee. In this paper we seek to bring together those aspects of the results which are of scientific interest and to discuss the role of various factors which may have affected the ormer populations particularly that of changes in temperature over the last hundred years. The reproductive biology of this species has recently been reported on by Hayashi (1980).
The Harpacticoid Copepod Fauna of the River Ythan and Its Estuary, Aberdeenshire, Scotland
Authors: Hockin David C.
Published: May 2009

Harpacticoid copepods (Crustacea) comprise an important taxon of the sedimentdwelling meiofauna, generally being numerically inferior to only the Nematoda (Hulings & Gray, 1971). This paper reports those species comprising the fauna of the sediments of the River Ythan estuary, particularly the intertidal sediments, and describes some of the properties of the meiobenthic copepod community structure.
Devaleraea, A New Genus of the Palmariaceae (Rhodophyta) in the North Atlantic and North Pacific
Authors: Guiry Michael D.
Published: May 2009

INTRODUCTION

The family Palmariaceae Guiry (Palmariales: Rhodophyta) at present includes the generaPalmariaStackhouse (the holotype genus: see Guiry, 1974, p. 523),HalosacdonKiitzing,LeptosarcaA. & E. S. Gepp andNeohalosacdocolaxI. K. Lee & Kurogi.HalosacdonandLeptosarcawere included in the original description of the family (Guiry, 1974) andNeohalosacdocolaxwas recently described by Lee & Kurogi (1978) for a small parasite onHalosacdon minjaiiI. K. Lee from the Aleutian Islands. The structure and reproduction ofNeohalosacdocolaxmake it quite clear that its affinities lie with the Palmariaceae (Lee & Kurogi, 1978). The Palmariaceae of the island of Hokkaido (northern Japan) have been the subject of a recent study (Lee, 1978) and the details of structure and reproduction given for the northwestern Pacific species ofPalmariaandHalosacdonconfirm that the unusual structure and mode of reproduction described by Guiry (1974, 1975, 1978) for Atlantic and northeastern Pacific representatives of these genera are also found in the northwestern Pacific representatives (see also Lee, 1977a).
The Distribution of Sterols and Stanols in the TunicateCiona Intestinalis
Authors: Morris R. J. , Mccartney M. J. , Bone Q.
Published: May 2009

INTRODUCTION

Until recently saturated sterols – stands – were not thought to play an active biochemical or physiological role in organisms. They were generally considered to be diagenetic products of the microbiological reduction of the common natural product Δ5sterols and as such have been reported in sediments (e.g. Gaskell & Eglinton, 1975).

Prior to the regular use of capillary gas liquid chromatographic (GLC) and gas chromatographic-mass spectrometric (GC-MS) techniques the majority of sterol analyses had been performed on packed column GLC. It is now well known that in the analysis of some of the complex mixtures of sterols which commonly occur in the marine environment, the use of packed column GLC techniques alone is an inadequate procedure (e.g. Ballantine; Roberts & Morris, 1976; Ballantineet al.1977). Certainly complete resolution of the sterol-stanol pairs cannot normally be achieved on packed columns and identification of the components within each peak has to be made by multiple mass spectral scans across each peak (Ballantineet al.1976). With the advent of techniques with better resolving powers, significant amounts of natural product stands have been found in a wide spectrum of phyla including molluscs, sponges coelenterates, echinoderms, annelids and tunicates (Morris & Culkin, 1977 and references therein; Ballantineet al.1976; Ballantine, Lavis & Morris, 1979, 1981; Voogt, 1976; Ballantineet al.1977; Ballantineet al.1978; Guptaet al.1979). In some instances the stanols have been found to account for over 50% of the animals component sterols.

As the sterol profile of marine invertebrates becomes better understood it is clear that stanolsareimportant biochemical constituents of many of these organisms; but little is known of their significance in any biochemical or physiological role.
New Records of Bathyporeia (Amphipoda) From West Scotland
Authors: Barclay I. M. T.
Published: May 2009

Two species of the amphipod Bathyporeia Lindström, B. nana Toulmond and B. sarsi Watkin, have been collected from sand beaches in the Firth of Clyde, both of which appear to be new records for the Clyde Sea area. This may be the first definite record of B. sarsi from the west coast of Britain. In addition, B. nana has been collected from a beach near Oban, Argyll.
Corymbellus aureusgen. et sp.nov., a new colonial member of the Haptophyceae
Authors: Green J. C.
Published: May 2009

A new member of the Haptophyceae,Corymbellus aureusgen. et sp.nov. is described. The cells of this species are aggregated into motile colonies which are more or less spherical at first, but which become annuloid as their size increases.

Individual cells are large and rather irregular in overall morphology with two heteroor homodynamic flagella and a short non-coiling haptonema arising from an anterior apical groove or furrow. Two types of oval body-scale are present; the larger, with upturned rim and a short central spine, are generally distributed, whilst the smaller, lacking such ornamentation, are confined to the apical groove.
The fine structure of the yolk nucleus in oocytes of Antedon bifida (Pennant) (Echinodermata: Crinoidea)
Authors: Holland Nicholas D.
Published: May 2009

The yolk nucleus of Antedon bifida is a large, intensely basophilic structure located in the cytoplasm of small to medium-sized oocytes. Electron microscopy reveals that this yolk nucleus is a conglomeration of hundreds of dense clumps. Each clump, which is a micrometer or two in diameter, consists of finely fibrogranular material in which are embedded ribosome-like particles. Also present in the oocyte cytoplasm are perinuclear dense granules, which may well be the precursors of the clumps making up the yolk nucleus. The yolk nucleus does not appear to participate directly in the elaboration of the yolk granules.
The occurrence of Mytilicola intestinalis Steuer, an intestinal copepod parasite of Mytilus, in the south-west of England
Authors: Davey J. T. , Gee J. M.
Published: May 2009

The occurrence of Mytilicola intestinalis in populations of mussels in south-west England is recorded and compared with previous data. Since 1955 there have been two main changes in the distribution of Mytilicola: (a) it has invaded all the major estuarine mussel populations on the Bristol Channel coast, and (b) many previously uninfested open-coast populations all round the peninsula are now lightly infested. It is suggested that differences in infestation levels between estuarine and open-coast populations of mussels are due primarily to differences in the degree of exposure to wave action although factors such as size, population density and location of the hosts also influence infestation. The chance of the establishment of breeding pairs of Mytilicola depends on the parasite population size and its distribution through the host population
New pelagic amphipods (Crustacea: Amphipoda) collected on the SOND Cruise
Authors: Thurston Michael H.
Published: May 2009

Two new gammaridean amphipods, Crybelocephalus birsteini sp.nov. and Halicoides discoveryi sp.nov., and a new subspecies of hyperiid amphipod, Scina wagleri atlantis subsp.nov. are described from oceanic plankton samples taken off Fuertaventura, Canary Islands.
Comparison of the acoustic and biological sampling of the sonic scattering layers: R.R.S. ‘Discovery’ SOND Cruise, 1965
Authors: McCartney B. S.
Published: May 2009

The acoustic measurements made during the SOND cruise are presented in the form of vertical profiles of relative scattering coefficient at day and night and its time dependence over sunrise and sunset for the four echo-sounders used. These profiles are compared with the scattering which is calculated would be returned from the vertical distributions of biological samples reported by other workers, but particularly from the distribution ofswimbladder fish analysed by Badcock. The similarities between the calculated and measured profiles support the assumption that swimbladder fish dominate the scattering due to their high target strengths, particularly at frequencies up to and including 36 kHz. By correlating fish sizes, daytime depth, migration behaviour and acoustic scattering several of the layers may be tentatively attributed to particular species. A calibrated echo-sounder in the frequency range up to 36 kHz is size selective, but can nevertheless be useful for looking at broad distributional features. However, because the numerically more abundant small planktonic animals are inadequately represented by the sounder the records are little more than a guide to net sampling programmes.
The distribution of collagen bundles and an epicardial coronary vasculature in the plaice (Pleuronectes platessa L.) heart ventricle at different ages
Authors: Santer Robert M.
Published: May 2009

The ventricle of the heart of the plaice (Pleuronectes platessa L.) was examined in histological sections stained with Aniline blue. The ventricles from hearts from two age groups (from 3–5 years and 9–16 years as judged from otolith examination) of plaice were studied in histological section. In younger fish (3–5 years) epicardial collagen bundles form a thin (< 24–0 μm) layer and only the superficial trabeculae are partially invested with collagen bundles, those deeper trabeculae not having collagen bundles associated with them. In older fish epicardial connective tissue had increased greatly (> 120.0 μm) in thickness and endocardial collagen is much more abundant, and was observed throughout all ventricular trabeculae. Secondly, in the hearts of older fish only, an extensive epicardial vascular system was observed, as revealed by arterial and venous profiles. This vascular system was confined to the epicardium and did not penetrate the myocardium to form a vascular bed, nor was it derived from extracardiac vessels.
Check-list of British marine algae-third revision
Authors: Parke Mary , Dixon Peter S.
Published: May 2009

The Preliminary Check-list of British Marine Algae (Parke, 1953), with three subsequent lists of additions and corrections (Parke, 1956,1957,1959), was superseded by the Revised Check-list of British Marine Algae (Parke & Dixon, 1964) and the Check-list of British Marine Algae - Second Revision (Parke & Dixon, 1968). Since the publication of the 1968 list, changes, both taxonomic and systematic, have been sufficiently numerous to warrant the present list incorporating further additions, corrections and emendations.
The permeability of the asteroid podial wall to water and potassium ions
Authors: Binyon J.
Published: May 2009

Direct measurement of water loss from isolated podia ofLuidia ciliarisunder the influence of known levels of hydrostatic pressure has yielded a revised value for the permeability of this structure to water, namely 37.4 x 10-8cm3/cm2.s.cm H2O pressure. The total fluid loss from a 50 g starfish will therefore be of the order of 0.75 ml/h. The mechanism for the replenishment of this fluid is discussed in the light of the traditional role of the madreporite. It would seem that adequate influx of fluid through this structure has not been observed, neither could it be responsible for ‘topping up’ in the case of arms severed from the parent body which still continue to move for considerable periods.
Reproduction of Dodecaceria caulleryi (Polychaeta: Cirratulidae)
Authors: Gibson P. H. , Clark R. B.
Published: May 2009

INTRODUCTION

Dodecaceria caulleryi breeds asexually by fragmentation and regeneration (schizogenesis), and sexually as an epitoke. Fragmentation is initiated in September-November in worms generally more than 40 segments long with the autotomy of the anterior 11–34 segments. Some 14–18 isolated segments are then autotomized in succession from the front of the remainder of the worm, leaving a residual 7–19 posterior segments. The anterior, individual segmental, and posterior fragments produced in this way all begin regenerating; anterior regeneration of the posterior fragment is limited to 14 or fewer segments but posterior regeneration and growth of all fragments is unlimited though slow. When the segmental fragment has regenerated about 7 new anterior and posterior segments, these may be autotomized as secondary individuals and the original segment regenerates again. The anterior regenerate is more commonly shed than the posterior regenerate and not all segmental individuals engage in secondary fragmentation.
Structure and preliminary biochemical characterization of the bioluminescent system of Ommastrephes pteropus (Steenstrup) (Mollusca: Cephalopoda)
Authors: Girsch Stephen J. , Herring Peter J. , McCapra Frank
Published: May 2009

INTRODUCTION

The ommastrephid squids are large active animals occurring in most of the world's oceans. Luminous organs or bioluminescence have been observed only in members of the subfamily Sthenoteuthinae, containing the genera Ornithoteuthis, Symplectoteuthis (= Eucleoteuthis), Hyaloteuthis, Ommastrephes and Dosidicus. The light organs of Ommastrephes pteropus are small sub-spherical bodies randomly distributed over the ventral surface of the mantle, head, arms and tentacles (Roper, 1963) and are aggregated dorsally to form a large luminous patch (Clarke, 1965). Relatively little is known about the organs, capabilities and biochemistry of luminescence in cephalopods (Harvey, 1952; Herring, in Press), and the size of the light organ and availability of O. pteropus provide an unusual opportunity for such studies. Although among the molluscs the luminescent systems of the gastropod Latia and the bivalve Pholas have been partially characterized (Shimomura & Johnson, 1968; Henry, Isambert & Michelson, 1970, 1973) the only cephalopod system which has been investigated to date is that of the enoploteuthid Watasenia scintillans (Goto et al., 1974; Inoue et al., 1975). This investigation examines the anatomy and biochemistry of the dorsal light organ of O. pteropus, which differs markedly in these respects from the brachial organs of Watasenia.
Annual growth patterns in the inner shell layer of Mytilus edulis L.
Authors: Lutz R. A.
Published: May 2009

INTRODUCTION

Molluscan age determination has long been the subject of both biological and paleonto-logical research (Mossop, 1922 a, b; Haskin, 1954; Merrill, Posgay & Nichy, 1965; Andrews, 1972). Several workers have listed difficulties associated with traditional methods of determining the age of an organism based upon surface shell morphology (Pannella & MacClintock, 1968; Farrow, 1971, 1972; Berry, 1971). Others, such as Craig & Hallum (1963) have attempted, with moderate success, to circumvent these problems statistically by using size-frequency relationships, but such methods are of little value in age analysis of isolated individuals. The principal difficulty encountered in shell surface analyses arises from an inability to distinguish spawning and disturbance lines from annual marks. Problems associated with this separation have been reduced over the past decade by the discovery of daily and tidal periodicity structures within the shells of numerous Recent and fossil species of pelecypods (Barker, 1964,1970; Pannella & MacClintock, 1968; Clark, 1968; House & Farrow, 1968; Farrow, 1971, 1972). The biological and paleontological significance of such growth increments have been discussed at length by Pannella & MacClintock (1968), Barker (1970), and Clark (1974). When present in continuous sequences, these periodicity structures facilitate an accurate age determination of individual specimens.
The effect of china clay on the fish of St Austell and Mevagissey Bays
Authors: Wilson K. W. , Connor P.M.
Published: May 2009

INTRODUCTION

During the production of china clay, a waste of fine quartz, sand kaolin and mica flakes in suspension is produced. Until recently, only a small proportion of this fine material was retained and settled in lagoons and consequently most of the effluent was discharged. Waste produced in the St Austell area was carried by the Par and White Rivers into Mevagissey Bay (see Fig. 1). In 1968 the china clay industry considered a proposal to combine all its wastes arising in the area and to discharge them into the sea via the White River or if necessary further out to sea by a pipeline. The precise location of the pipeline was not denned at that time but, irrespective of position, deterioration of conditions in St Austell and Mevagissey Bays seemed inevitable.
A check-list of marine algae of eastern Canada - first revision
Authors: South G. Robin
Published: May 2009

Since the appearance of the first documentation of marine algae from within the political boundaries of eastern Canada (South & Cardinal, 1970), a sufficiently large volume of new information has become available to warrant the revision presented here. Taxonomic and systematic changes, together with further additions, corrections and emendations are incorporated as far as possible. A total of 346 species, subspecies and varieties are listed, comprising 131 Rhodophyta, 127 Phaeophyta and 88 Chlorophyta. The treatment is largely restricted to macroscopic forms. Inclusion of microscopic species of Chlorophyta and representatives of other marine Phyla is planned for the future.
The influence of physical stability on spring, summer and autumn phytoplankton blooms in the Celtic Sea
Authors: Pingree R. D. , Holligan P. M. , Mardell G. T. , Head R. N.
Published: May 2009

The Celtic Sea extends from the south of Ireland and the St Georges Channel across the continental shelf, with the Bristol and English Channels as its eastern limits (Fig. 1) (Cooper, 1967). Although various investigations of the physical oceanography (Matthews, 1914; Cooper, 1967) and zooplankton (Russell, 1934, a, b, 1936; Corbin, 1947; and more recently Southward, 1962; Bary, 1963) of this area have been carried out, there is little or no information on seasonal changes in levels of chlorophyll ‘a’ and inorganic nutrients, and on the importance of tidal mixing in determining these distributions. Since the speeds of the tidal streams range from weak (∼ 0.5 knot) in the northern part of the Celtic Sea to strong (∼ 3 knots) around the Scilly Isles and Ushant (Fig. 2), the vertical stability of the water column as well as the duration of the seasonal thermocline (Pingree, 1975) are likely to be important factors in determining spatial and temporal variations of phytoplankton production. In this paper the influence of water-column stability on phytoplankton distributions (in spring, summer and autumn) in the Celtic Sea is described, using data for temperature, salinity, chlorophyll ‘a’ and inorganic nutrients obtained during seven cruises in 1975. An account of the red tide conditions that occurred in late July to the north-west of Ushant has already been published (Pingree, Pugh, HoUigan & Forster, 1975).
A benthic grab designed for easy operation and durability
Authors: Hunter B. , Simpson A. E.
Published: May 2009

This work is the outcome of an undertaking by the Mechanical Engineering Department to repair and if possible to improve a grab used by the Marine Laboratory. The grab was a type which has a good record of effective sampling on coarse hard sediment as reported by Smith & McIntyre (1954) and fully confirmed by our own experience. Its success in these difficult sediments is believed to be due to the initial penetration provided by the spring-propelled jaws and to adequate weight opposing the upward forces as the lifting cable closes them. Because of wear in the cocking mechanism the machine in question had become dangerous to operate and a number of parts had fractured. Improvements to the cocking/triggering mechanism were successful but it was felt that the repaired striking motion would remain prone to further failure by fatigue and wear. A fair degree of mechanical insight was necessary for effective operation and it was considered fairly laborious to use continuously, so the basic problem was reviewed from an engineering design standpoint with attention to the ergonomic and mechanical problems of achieving a quick turnaround in a small boat such as the laboratory's 10 m coble, and to ensuring durability.
A diver-controlled plankton net
Authors: Potts G. W.
Published: May 2009

Many types of plankton net have evolved for various sampling needs, but in the main they are designed for sampling in mid-water, or over fine particulate substrates where they can operate within a sledge frame. The conventional plankton nets are mostly towed behind a boat and can only be used in areas where there are no obstacles to impede their course. Many nets are described in the literature and the reviews by Tranter et al. (1966) and the UNESCO monograph on zoological sampling methods (Tranter, 1968) give further details. Nets for taking benthic plankton are generally mounted on a sledge frame and either towed behind a boat (Russell, 1928; Wickstead, 1953), towed in shallow water by persons wading and pulling the net behind them (Colman & Segrove, 1955) or pushed by SCUBA divers (Fager et al. 1966). However, all these methods still leave the need to sample rocky areas and irregular substrates where conventional methods are not possible. Such areas are often extremely rich in planktonic organisms which appear to accumulate within the shelter offered by gulleys and depressions in the bottom topography (personal observation). Often species associated with inshore algal belts are poorly represented in conventional offshore plankton samples (Russell, 1973), and it may be that such species spend much of their larval existence close in shore or in association with shallow water reefs. The present paper describes a diver-controlled plankton net which has been designed to sample rocky areas. By having direct diver control this plankton net can be used to sample other areas where conventional methods are not appropriate.
Check-list of British marine Choanoflagellida - second revision
Authors: Parke Mary , Leadbeater B. S. C.
Published: May 2009

As two pigmented taxa attributed to the class Chrysophyceae had been discovered (Lackey, 1939; Scagel & Stein, 1961) with apparently similar organization to the Choanoflagellida this group of protista was included in the Revised Check-list of British Marine Algae (Parke & Dixon, 1964) following Bourrelly (1957). The group was placed in the class Craspedophyceae erected by Chadefaud (1960) and a first revision of the genus and species list was included in the Check-list of British Marine Algae - Second Revision (Parke & Dixon, 1968).
The first occurrence of Sargassum muticum (Yendo) Fensholt in the Plymouth area
Authors: Boalch G. T. , Potts G. W.
Published: May 2009

On 11 August 1976 an observant yachtsman noted an unfamiliar alga between Misery Point and Warren Point at the mouth of the River Yealm. Suspecting that it might be ‘Japweed’ he collected a piece and took it to Mr B. W. P. Sparrow of the International Marine Coatings Laboratory who contacted the Marine Biological Association, where Dr Boalch confirmed that it was a part of a fertile plant of Sargassum muticum, the first to be recorded from the Plymouth area (see Fig. 1).
A study of the effects of copper applied continuously and discontinuously to specimens of Mytilus edulis (L.) exposed to steady and fluctuating salinity levels
Authors: Davenport John
Published: May 2009

The study reported here stems from experiments performed upon cirripedes and bivalve molluscs exposed to fluctuating sea water concentrations. It is obvious that these two groups of benthic organisms are capable of shutting themselves off to a greater or lesser degree from the external environment by opercular or shell valve closure, thus avoiding the osmotic stresses associated with exposure to lowered salinity levels. With the development by Davenport, Gruffydd & Beaumont (1975) of an apparatus to deliver fluctuating salinity regimes to experimental animals in a repeatable, routine manner, it has become possible to establish the sea-water concentrations at which such mechanisms operate.
The feeding and consequent role of Eulalia viridis (O. F. Müller) (Polychaeta) in intertidal communities
Authors: Emson R. H.
Published: May 2009

The intertidal phyllodocid polychaete Eulalia viridis (O. F. Müller) is widely regarded as a predator as stated, for example, by Newell (1970). This assertion is based on statements made by several authors, e.g. Moore & Kitching (1939), Glynne-Williams & Hobart (1952), Connell (1961), and Kensler (1964, 1967), who have reported E. viridis foraging over rocky substrates at low tide in daylight and in some cases have observed the insertion of the proboscis between the opercular plates of a barnacle and the subsequent ingestion of the soft tissues. The capture of a large chironomid by E. viridis has been recorded by Connell (1961). This was considered sufficient evidence for stating that E. viridis is a predator attacking living barnacles and other intertidal animals. Moore & Kitching (1939) further suggested that E. viridis might be as important a predator on barnacles as Thais lapillus (L). On the other hand Michel (1970) regarded E. viridis as a scavenger feeding on dead and decaying animals. There is evident disagreement about the feeding habits of E. viridis and consequently of its role in the population ecology of the community of which it forms a part. Examination of its feeding behaviour has been undertaken to clarify the situation.
Effects of a starch diet on the lipid chemistry ofNeomysis integer(Leach)
Authors: Morris R. J. , Armitage M. E. , Raymont J. E. G. , Ferguson C. F. , Raymont J. K. B.
Published: May 2009

Preliminary feeding experiments (Morris, Ferguson & Raymont, 1973) showed thatNeomysis integerwas capable of incorporating dietary labelled [1-14C]fatty acids (16:04 18:1,18:2,18:3) into its lipid. Radioactivity was observed in all the major fatty acids ofNeomysis, including the polyunsaturated fatty acids.Neomysiscould also convert dietary14C-labelled starch into lipid, producing a range of fatty acids, including long-chain polyunsaturated acids, incorporated in both triglycerides and phospholipids. During these metabolic conversions, the mysid was observed to incorporate more radioactive14C into the phospholipid fraction with increase in the experimental feeding period.
Mauthner neurons in elasmobranchs
Authors: Bone Quentin
Published: May 2009

In most fish groups, a large pair of Mauthner neurons provides a distinctive and conspicuous pathway linking the motoneurons of the cord to nerve VIII input. Physiological studies have been almost entirely on the apparatus in teleosts (review by Diamond, 1971), but its morphology is essentially similar in other groups, and it seems likely that wherever found in gnathostomes, its function is the same: to mediate a startle response involving a single rapid tail flip. It is therefore, as Whiting (1957) has emphasized, an important part of the reflex system in those lower chordates in which the myotomal musculature is used in locomotion. Not surprisingly, where locomotion is carried out in a different way (as for example in adult anura), the Mauthner neurons of the larva degenerate and disappear, as they do in a variety of teleosts where a tail flip startle response is inappropriate in the adult.