bluuebunny/crossref_metadata_2025 huggingface dataset:
Gill Morphometry of the Mudskipper,Boleophthalmus Boddarti
Authors: Hughes G. M. , Kadhomiy-Al N. K.
Published: May 2009

Measurements of gill dimensions in relation to body weight have been carried out in a mudskipper,Boleophthalmus boddarti. The data was analysed with respect to body weight using logarithmic transformations (logY= loga + blogW). The slope(b)of the log/log regression lines for the gill area, total filament length, average number of secondary lamellae/mm, bilateral area of an average secondary lamella, and total gill area/g were 1·0496, 0·427, -0·229, 0·851 and 00496 respectively.

These results indicate variations in growth patterns for the different dimensions of the gills. The analysis shows that the increase in gill surface area with the body size is mainly due to an increase in the area of individual secondary lamellae and, to a lesser extent, an increase in filament length and total number of lamellae.

The average weight-specific area for 14 specimens measured (3·6–35·4 g) was 108–15 mm2/g. This value is consistent with results obtained with some other intertidal species.

Marked differences were found in the thickness of the water/blood barrier, which is thinner around the marginal channels. Morphometric diffusing capacity taking this heterogeneity into account was estimated as 0·0208 ml O2min1mmHg−1kg−1.

INTRODUCTION

Morphological studies on the gills of many fish have shown adaptations of the basic structure which can be related to the particular mode of life. Among these adaptations, air-breathing species show many remarkable structural modifications (Munshi, 1976), which extend to the gills forming air sacs in species such asHeteropneustes fossilis(Hughes & Munshi, 1979). Fish which inhabit the intertidal zone, like other seashore animals, are subjected to periodic exposure to air, which may produce problems of water loss and reduction in support for the gills, with consequent collapse and restriction of gas exchange surfaces.
Influence of 70 Watt Electric Lights on the Capture of Fish By Otter Trawl Off Plymouth
Authors: Clarke M. R. , Pascoe P. L. , Maddock L.
Published: May 2009

The effect of two 70 W underwater electric lamps on the catch rate of a commercial bottom otter trawl was determined by comparative trials both at night and in daylight. It was found that, although the overall numbers and weights of fish caught did not differ, most of the species which were caught in large enough numbers for a judgement to be made showed a reaction to light. Three species, Trachurus trachurus, Merlangius merlangus and Trisopterus minutus were attracted and four species, Eutriglagurnardus, Micromesistius poutassou, Merluccius merluccius and Limanda limanda were scared off by light.

The possible use of lights to further the development of selective commercial bottom trawling by attracting or scaring particular species is discussed.
Zooplankton Fauna of Killary Harbour: the Seasonal Cycle of Abundance
Authors: Ryan T. H. , Rodhouse P. G. , Roden C. M. , Hensey M. P.
Published: May 2009

Killary Harbour is a fjord-like inlet on the west coast of Ireland and is an important site for suspended culture of mussels. As part of a study of the production ecology of the inlet, the zooplankton fauna was sampled quantitatively at two week intervals, between February 1981 and January 1982 using nets with mesh apertures of 90 and 335μm. The dominant holozooplankton species of Killary Harbour are typical of inshore or neritic waters but there are also representatives of estuarine and oceanic faunas. Inflow of water into the bay below the surface layer of low salinity apparently maintains conditions suitable for neritic species and accounts for similarities between the zooplankton faunas inside and outside the bay. Large populations of estuarine species presumably do not develop because of the variability of freshwater discharge. During September 1981 there was evidence of an intrusion of oceanic water into the bay.
On the use of ammonium for buoyancy in squids
Authors: Clarke M. R. , Denton E. J. , Gilpin-Brown J. B.
Published: May 2009

Squids (teuthoids) fall into two distinct groups according to their density in sea water. Squids of one group are considerably denser than sea water and must swim to stop sinking; squids in the other group are nearly neutrally buoyant. Analyses show that in almost all the neutrally buoyant squids large amounts of ammonium are present. This ammonium is not uniformly distributed throughout the body but is mostly confined to special tissues where its concentration can approach half molar. The locations of such tissues differ according to the species and developmental stage of the squid. It is clear that the ammonium-rich solution are almost isosmotic with sea water but of lower density and they are present in sufficient volume to provide the main buoyancy mechanism of these squids. A variety of evidence is given which suggests that squids in no less than 12 of the 26 families achieve near-neutral buoyancy in this way and that 14 families contain squids appreciably denser than sea water [at least one family contains both types of squid]. Some of the ammonium-rich squids are extremely abundant in the oceans.
The influence of heavy infestations of Polydora ciliata on the flesh content of Mytilus edulis
Authors: Kent R. M. L.
Published: May 2009

The dry weight condition index and water content of two groups of mussels, one with heavy infestations and the other with mild infestations of Polydora ciliata, were determined over a period of 15 consecutive months. The results were seasonally variable, but for most months the heavily infested mussels had a condition index significantly lower, and a water content significantly higher, than the mildly infested mussels. This suggests that heavy infestations of P. ciliata are associated with reduced flesh content in mussels.

Further analyses of the body components of the two groups of mussels, showed that the mantle tissue of heavily infested mussels was reduced much more than the nonmantle tissue. Since the mantle is the main repository of gametes, this suggests that heavy infestations of P. ciliata might lower the fecundity of mussels.
A laboratory study of predation by the dog-whelk Nucella lapillus on the barnacles Elminius modestus and Balanus balanoides
Authors: Barnett B. E.
Published: May 2009

Predation of the barnacles Balanus balanoides and Elminius modestus by the common dog-whelk, Nucella lapillus was studied in the laboratory. Greater numbers of B. balanoides were taken as prey unless the whelks had been previously subjected to an extensive period of starvation.

Selective predation is discussed in the light of similar studies on Nucella and related predatory species. The effects of prey selection on the competitive interactions of the prey species are also considered.

The method of predatory attack involves either a drilling or a prizing technique. The latter is used predominantly when Nucella attacks E. modestus, whereas drilling is employed to a far greater extent when attacking B. balanoides. Attacks using the drilling technique are usually made at the occludent margins of the opercular valves.
The reproductive biology of Corophium volutator and C. arenarium (Crustacea: Amphipoda)
Authors: Fish J. D. , Mills A.
Published: May 2009

The life-cycles of Corophium volutator (Pallas) and C. arenarium Crawford in the Dovey Estuary are based on two generations per year. Reproduction is well established by April and although the overwintering generation dies during the summer, reproduction continues until October as a result of the breeding of summer-generation animals. The mean brood size of C. volutator is greater than that of C. arenarium and both species show high levels of egg loss from the brood pouch. Hatching and moulting of the embryonic cuticle take place simultaneously and the initial rupture of the egg membranes is made by spines on the cuticle of the telson of the future free-living animal. These spines persist throughout post-embryonic life.

Adult females of both species show a semi-lunar breeding rhythmicity and, associated with this, adult males show a rhythmic pattern of crawling behaviour. As the tide ebbs during the rising spring tide period, adult males emerge from the sediment and crawl across the mud surface in search of burrows occupied by adult females. It is concluded that copulation takes place in the burrow and not in the water column.
Some new records of anthozoa from British waters
Authors: Manuel R. L.
Published: May 2009

During the course of collecting trips made in 1976–8 two anthozoans, the actiniarianAiptasiogeton comatus(Andres), and the octocoralCornularia cornucopiae(Pallas) were found in Portland Harbour. Neither species has been previously recorded in British waters. A third species,Isozoanthus sulcatus(Gosse), was collected on the shores of the Gower Peninsula, South Wales. Since this species was last recorded in British waters in 1861 and its true taxonomic status is uncertain it is described here.
On the structure and behaviour ofFritillaria(Tunicata: Larvacea)
Authors: Bone Q. , Gorski G. , Pulsford A. L.
Published: May 2009

INTRODUCTION

Rather little is known of the behaviour of larvaceans, although they are of great importance in the sea as one of the few groups able to exploit the nanoplankton. Of the two larvacean groups, oikopleurids have received most attention: the behaviour ofOikopleura dioicahas been studied in detail by Gait (1972, Ph.D. Thesis, University of Washington, Seattle), and some notes on the electrical correlates of behaviour have been given by Gait & Mackie (1971) and by Bone & Mackie (1975) forO. dioicaandO. labradoriensis. Much less is known of fritillariid larvaceans and, apart from the brief notes on behaviour by Fol (1872) and by Lohmann (1899) in the course of their classical histological investigations, which were extended by Salensky (1904) and Martini (1909), the only recent investigation of living fritillariids is that of Fenaux (1961) who described the remarkable mode of action of the pyloric cilia.
Some notes on the biology of the snake blenny, Lumpenus lampretaeformis on the west coast of Scotland
Authors: Gordon J. D. M. , Duncan J. A. R.
Published: May 2009

Large catches of the snake blenny, Lumpenus lampretaeformis, have been made in the inshore waters of the west coast of Scotland. Analysis of these catches confirm the view that this species shows marked seasonal variations in abundance. The species lives for up to 9 years and has a rapid growth rate in the first 2 years. It feeds mainly on meiobenthic organisms, of which polychaetes, harpacticoid copepods, ostracods and nematodes are the most important. The reason for the seasonal variation in catch rate is discussed and it is speculated that it may result from the fossorial habit of the adults and the parental care of the eggs.
Cold resistance in the eggs of the capelin Mallotus villosus
Authors: Davenport John , Vahl Ola , Lönning Sunniva
Published: May 2009

Eggs of the capelin, Mallotus villosus, are laid superficially on sandy beaches where they may be exposed to temperatures below –5 °C during tidal emersion. The eggs do not freeze until the temperature of their surroundings falls to a mean of –11.9 °C for eggs at the late blastula stage and –10.6 °C for eggs about to hatch, even though films of sea water covering the eggs are frozen. Newly hatched capelin larvae freeze at a mean temperature of –2.5 °C when the sea water surrounding them freezes, and are probably supercooled at temperatures below this before hatching. Evidence is presented which demonstrates that capelin eggs survive low temperatures by supercooling, and that they can do so in the presence of external ice crystals because the chorion prevents ice penetration and hence seeding of the eggs' internal fluids. The chorion of Mallows is shown to possess an extra secondary layer, like that of the related smelts. The primary function of this outer layer appears to be be concerned with adhesion to sand grains but it seems likely that it also prevents or delays ice penetration.
Distribution of paralytic shellfish poison among Pyrrhophyta
Authors: Schmidt Robert J. , Loeblich Alfred R.
Published: May 2009

Using the mouse bioassay for paralytic shellfish poison (PSP), the distribution of toxicity among 23 dinoflagellate species was studied. Special consideration was given to red-tide-forming species and to those species previously implicated as causative organisms in paralytic shellfish poisoning. Among those investigated were ten marine species of the genusGonyaulax, previously known to contain three toxic species. The presence of PSP was detected only inGonyaulaxspecies of the sectionCatenella. The amount of toxin varied in different species, ranging from 0.05 to 24 pg/cell. The amount of toxin per cell also varied with the phase of growth (exponential or stationary) in the New England red-tide species, G.tamarensisvar.excavataBraarud.
On the hypothesis of a relationship between dinoflaggelate blooms and the ‘Amoco-Cadiz’ Oil spill
Authors: Févre J. Le
Published: May 2009

Dinoflagellate blooms occurred repeatedly along the coasts of France in 1978, and the question was raised, both in newspapers and in the report of the Inquiry Committee of the French Senate on the ‘Amoco-Cadiz’ disaster, of a possible relationship between these occurrences and the oil spilled from the tanker. This hypothesis does not, however, appear to be supported by the data regarding bloom occurrences. These are listed in Table 2, compiled from various sources. Those which concern Brittany and nearby areas, as well as the extent of coast fouled by the ‘Amoco-Cadiz’ oil, are shown in Fig. 2. It is clear from this map that some of the ‘red tide’ occurrences were quite remote from the site of the wreck at Portsall; those outside the area shown in Fig. 2 (e.g. Seine Estuary) were, of course, even more so.
Occurrence of nematode parasites in Calocaris macandreae (Crustacea: Decapoda) from an Irish Sea population
Authors: Perez-Calderon J. A.
Published: May 2009

INTRODUCTION

A number of nematodes are known to develop in decapod crustaceans. These parasite nematodes are present in the coelom of the host either free or surrounded by different types of host cells. All belong to the order Ascaridida or Spirurida and most of them develop only to the third larval stage in the decapod host; further development takes place in a predator of the crustacean which is generally a teleost or elasmobranch (Berland, 1961; Ouspenskaia, 1960; Petter, 1970; Poinar & Kuris, 1975;Uspenskaja, 1953; Yamaguti, 1961). The life-cycle in most cases is not fully understood. Ouspenskaia (1960) and Uspenskaja (1953, 1963) deduced the life-cycle for Ascarophis morrhuae van Beneden and A. filiformis Poljanski in the Barents Sea by relating the larvae found in decapod crustaceans through affinity of characters to the adults present in cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus L.). Similarly, the life-cycle of the spirurid Proleptus obtusus was described by Lloyd (1928); the larvae occur in a decapod crustacean, usually the hermit crab Pagurus bernhardus L. and in some cases the shore crab Carcinus maenas L. and the adults are found in the lesser spotted dogfish (Scyliorhinus canicula L.). A more complex life-cycle has been proposed for some anisakids such as Anisakis, Contracaecum and Hysterothylacium (Berland, 1961; Norris & Overstreet, 1976; Wootten, 1978) in which more than one intermediate host is required.
On the genus Holophryxus (Isopoda: Epicaridea), with description of the male and redescription of the female of Holophryxus acanthephyrae
Authors: Jones M. B. , Smaldon G.
Published: May 2009

INTRODUCTION

Adults of the isopod genus Holophryxus (Dajidae) occur as ectoparasites on natant decapod crustaceans, but little is known of the ecology and life-history of most species. Species of Holophryxus are thought to have a typical dajid life cycle involving an intermediate host (copepod), a definitive host (prawn) and three larval stages (epicaridium, microniscus, cryptoniscus), and the one species for which details are available fits this pattern (Coyle & Mueller, 1981). The final host is infected by the cryptoniscus, a stage superficially resembling a cirolanid isopod, and the first cryptoniscus to settle loses its isopod-like appearance and develops through a juvenile stage into a rather inflated, highly modified female (Coyle & Mueller, 1981). Any subsequent settler becomes a male, retains the small cryptoniscus body form and lives within the marsupium of the female.
Size data and stomach contents of common dolphins, Delphinus delphis, near Plymouth
Authors: Pascoe P. L.
Published: May 2009

INTRODUCTION

The laboratory at Plymouth was notified of the capture of five dolphins in a commercial trawl on 9 December 1982, three of the specimens were living and therefore immediately released. The remaining two were brought to the laboratory, identified as Delphinus delphis Linnaeus, 1758, their size and sex were recorded and the stomachs removed for examination of their contents. The exact location of capture was not recorded, but is known to be within 40 miles of Plymouth.

Reports of strandings of D. delphis collected by the British Museum (Natural History), (Harmer, 1914–27; Fraser, 1934, 1946, 1953, 1974) and more recent recorded sightings (Evans, 1980) show that the common dolphin is clearly not rare in British waters. Although the species has been recorded off all British coasts, sightings and strandings are concentrated off the south and south-west coasts of Britain and Ireland. The variation in their numbers and distribution both during this century and on a seasonal basis each year has been accounted for mainly by the fluctuation and movement of their food supply (Evans, 1980; Sheldrick, 1976).
The taxonomy of some little-known Sipuncula from the north-east Atlantic region including new records
Authors: Gibbs P. E.
Published: May 2009

INTRODUCTION

Early investigations of the deep-sea fauna of the north-east Atlantic region resulted in many new Sipuncula species being described, notably by such workers as Koren & Danielssen (1877), Théel (1905), Sluiter (1900, 1912) and Southern (1913). Many of these species were erected from single, or few, specimens and some are still known only from the original records.

This paper examines the status of certain species, mostly the seemingly-rare golfingiids described by Sluiter and Southern (see Table 1), the types of which were deposited in the collections of the Irish National Museum, Dublin (INMD) and the Musée Océanographique, Monaco-Ville (MOMV), and presents some new observations and records. The names of taxa follow the classification of Cutler & Gibbs (1985); Nephasoma Pergament and Apionsoma Sluiter, formerly considered as subgenera of Golfingia Lankester, are now elevated to generic rank.
Growth of juvenile Haliotis tuberculata (Mollusca: Gastropoda) in their natural environment
Authors: Clavier Jacques , Richard Olivier
Published: May 2009

INTRODUCTION

The ormer (Haliotis tuberculata L.) occurs in some abundance off the north coast of Brittany and the Channel Islands. On the French coast, exploitation of this species is not legally authorised except in the intertidal zone and the sublittoral stocks have for some years aroused the interest of local fishermen. Studies have therefore been initiated to investigate the exploitation potential of this new resource, and different aspects of the biology and ecology of the ormer have been examined so as to make use of models of population dynamics. Thus, a study of growth merits particular attention.
On reproductive strategies in adjacent lagoonal and intertidal-marine populations of the gastropodHydrobia ulvae
Authors: Barnes R. S. K.
Published: May 2009

The coastal prosobranchHydrobia ulvaeis known to occur in a wide range of marine and brackish habitats and to display great variation in its breeding and life-history characteristics. Several hypotheses have been advanced to account for the latter, including that the variation is environmentally induced and that the species can be divided into ecotypes. Comparison of two adjacent populations in Norfolk, U.K., one from the marine intertidal zone and the other from a non-tidal, landlocked, brackish coastal lagoon, however, disclosed that although shell form differed markedly (including a mean height ratio of 1:1.2), there was no difference in such otherwise variable features as numbers of eggs per capsule, size at hatching and larval type. In both, each capsule contained an average of 21-22 eggs, which hatched at a shell length of 152-154 μn to liberate relatyyively long-lived, free-swimming veligers. The two populations were also interfertile. In no respect had the isolated lagoonal population diverged away from the parent marine one towards the contrasting reproductive strategies characterizing the specifically lagoonal species ofHydrobiathat occur nearby. The ‘displacement’ of shell size observed in the lagoon in the absence of sympatric hydrobiids is considered to cast further doubt on competitive character displacement in this genus.
Ultrastructural and histochemical studies of the digestive system of Pholoe minuta (Polychaeta: Sigalionidae)
Authors: Heffernan Peter
Published: May 2009

This work reports on the fine structure and histochemistry of several regions of the alimentary canal in Pholoe minuta (Fabricius, 1780). Particular emphasis is placed on the elaborate secretory cells (tryptophan-containing secretion) associated with the pharyngeal jaws. Mucus gland cells were located and described for the oesophagus (acid mucins), pharynx papillae (sulphated acid mucins), pharynx luminal lining (mixed acid mucins) and the intestine (mixed acid mucins). Enzymic gland cells (zymogen-like secretory granules) were identified in the luminal lining of the pharynx and in the intestine. Lysosome-containing cells (presumably absorptive) were described in the intestine. Glycogen reserves were observed along the coelomic peritoneum and a seasonal pattern for their deposition and utilization is briefly discussed.
Development of the gut and segmentation of newly settled stages ofRidgeia(Vestimentifera): implications for relationship between Vestimentifera and Pogonophora
Authors: Southward Eve C.
Published: May 2009

Young vestimentiferans, ranging from 0.15 to 10 mm in length, were examined by light and electron microscopy (SEM and TEM). The newly settled stages have a functional gut and traces of larval ciliation, which suggests that they may have developed from a planktonic trochophore stage. The larval mouth becomes an elongated siphon and the ciliated gut persists for some time after the development of the bacterial symbiosis in the trophosome. The segmentation of the body in the earliest stages is similar to that in postlarval Pogonophora, and it is concluded that Vestimentifera and Pogonophora are closely related.
Salinity preference of twenty species of Vaucheria (Tribophyceae)
Authors: Christensen T.
Published: May 2009

Twenty species, one of them represented by two ecologically different isolates, were grown at salinities from 0 to 60‰ at intervals of 5‰ or less. Growth was measured spectrophotometrically on a pigment extract, and formation of sexual organs was recorded. For each species the results are presented in a diagram, and compared with the salinity preference suggested by information in the literature and by the author's observations in nature.
The Foraminifera of the Exe Estuary
Authors: Worth R. H.
Published: May 2009

Samples of sand were taken, either from the shore immediately above low water of spring tides, or from the bottom in a few inches of water.

With one exception no samples were dredged. The localities were few: Polesands; the north or estuarine shore of the Warren west of Salthouse Lake; the banks of the Salthouse Lake; a low-water stream on the Warren; near Lympstone; and (the dredged sample) within Exmouth Docks.
The Alcyonaria, Antipatharia, and Madreporaria collected by the “Huxley“ from the North Side of the Bay of Biscay in August, 1906
Authors: Hickson Sydney J.
Published: May 2009

The principal feature of interest in these collections is the presence of a single fine specimen of Corallium maderense. Only one other specimen of this species has hitherto been obtained, and no specimen of the family has hitherto been recorded from the Bay of Biscay
Hymedesmia Canadensis (Porifera: Poecilosclerida), a New Species Among New Geographical Records from the Bay of Fundy, New Brunswick, Canada
Authors: Ginn B.K. , Logan A. , Thomas M.L.H. , Van Soest R.W.M.
Published: May 2009

Sixteen sponge species were recorded from Little Letite Passage, an area of highvelocity tidal currents located in the Bay of Fundy near Deer Island, New Brunswick, Canada. Of these 16 species, four species (Myxilla fimbriata, Hymeniacidon heliophila, Hemigellius sp. aff. flagellifer, and Crella rosea) have not previously been recorded from the Bay of Fundy. One new species, Hymedesmia canadensis, is described, based on the presence of a second peculiar chelate microsclere added to the spicule armament.
Biological Cycle of Podocoryna Exigua (Cnidaria: Hydrozoa) from a Sandy Bottom of the Ligurian Sea
Authors: Cerrano Carlo , Bavestrello Giorgio , Puce Stefania , Sarà Michele
Published: May 2009

The genus Podocoryna is characterized by species living on shells usually inhabited by hermit crabs; but the mutual benefits of this association are not well understood.

This study, besides describing the biological cycle of the hydroid Podocoryna exigua, brings new information on the relationship between hydroid and the hermit crab Diogenes pugilator, especially concerning their trophic strategies.

The hydroid shows a seasonal cycle with a minimum density during summer and an increase during autumn and winter, reaching the highest value in spring. The production of medusae is almost constant during all seasons. The dwelling behaviour of the hermit crab affects a particular sedimentivorous strategy of the polyps while a clepto-commensalistic strategy is adopted by the hermit crab towards the hydroid. Laboratory experiments show that the presence/absence of the hermit crab in the shell and also the seawater temperature strongly influence the number of spines, particularly structures developing from polyps. In addition, free-living polyps in the sediments may represent a strategy to colonize free shells.
Karyotypic Differences Between Two Species ofPomatoceros, P. TriqueterandP. Lamarckii(Polychaeta: Serpulidae)
Authors: Dixon D.R. , Pascoe P.L. , Dixon L.R.J.
Published: May 2009

Consistent with most other closely-related polychaete species which have been analysed cytogenetically to-date,Pomatoceros triqueterandP. lamarckiishare an identical chromosome number (2n=24) and have a number of other karyotypic features in common. However, commensurate with their separate species status, their karyotypes differ at least in four chromosome positions as a result of structural chromosomal rearrangements. With a rDNA probe using the FISH technique, we have been able to demonstrate that the nucleolar organizer region (NOR) occurs at the same site on the same pair of chromosomes in the two species, which indicates that an inversion event is unlikely to have been the cause of the species variation in this particular case. Taken together, these karyotypic differences may be indicative of a chromosomal barrier to the formation of fertile offspring; an important feature for maintaining species integrity where the two forms occur sympatrically, such as in parts of south-west England.
Spatial Distribution and Biological Rhythms of Suprabenthic Mysids from the English Channel
Authors: Zouhiri Souaad , Vallet Carole , Mouny Pascal , Dauvin Jean-Claude
Published: May 2009

One hundred and ninety-eight suprabenthic hauls from the English Channel and the Seine Estuary were taken with a modified Macer-GIROQ sledge. Numerically, mysids were the dominant group amongst the peracarids collected with the sledge and 28 species were recorded. Mysid densities were higher in the oligohaline zone (>200,000 ind 100 m-3) of the Seine Estuary than at other stations in the English Channel (where the density was the highest on medium sand stations, ~5000 ind 100 m-3). Two main gradients of mysid distribution were identified: (1) a higher species richness in the western part of the Channel compared with the eastern part of the Channel; and (2) an increasing density gradient from west to east during spring and a decreasing gradient from west to east during the autumn (eastern high abundance of Haplostylus spp. during spring, and western high abundance of Schistomysis ornata and Erythrops elegans during autumn). Mysids showed important diel rhythms with maximum abundance at sunrise and sunset, and low density at night. According to their swimming activities, suprabenthic mysids were classified into three groups: upper organisms with a very strong activity, species with a strong activity and occupying the whole water column near the sea-floor, and lower species with limited swimming activity. Nevertheless, the swimming activity could be modified according to the hydrodynamics of each site. A seasonal cycle of abundance (summer recruitment for dominant species Anchialina agilis, Haplostylus lobatus, Haplostylus normani) was observed on two stations where temporal samples along the year were available.
Cirral Activity in the Whale Barnacle Cryptolepas Rhachianechi
Authors: Achituv Yair
Published: May 2009

The cirral activity of the whale barnacle Cryptolepas rhachianechi was studied in a flow tank at different flow regimes. In still water, unidirectional flow, and oscillating flow, the cirral fans of adult animals always beat in the direction of the rostrum. Adults did not respond to water current from the carinal direction by facing the cirral fan into the current; however, during copulation they could turn the cirral fan so it faces the carina. Newly settled animals responded to flow from the carinal direction and to oscillating flow by facing their cirral fans towards the oncoming current, but there is no synchronization between changes in water flow direction and the change in cirral direction. Since these barnacles are normally exposed only to unidirectional currents, with no need to respond to flow from the carinal direction or to oscillating flow, it seems likely that they have lost the ability to change the direction of their cirral beats. This loss of the ability to respond to changes in current direction is a specialization of C. rhachianechi related to its epizoic mode of life.
The Alien Chinese Mitten Crab, Eriocheir Sinensis (Crustacea: Decapoda: Brachyura), in the Thames Catchment
Authors: Clark Paul F. , Rainbow Philip S. , Robbins Roni S. , Smith Brian , Yeomans William E. , Thomas Myles , Dobson Gina
Published: May 2009

Eriocheir sinensis, the Chinese mitten crab, is a native of east Asia and predominantly lives in freshwater but migrates seawards to breed. In 1912 a specimen was collected in the River Aller, a tributary of the Weser, Germany and now this exotic species has a European distribution from Finland to the Atlantic coast of southern France. In the UK, the mitten crab has been reported from the Humber, Medway and Thames catchments. Although the population in Thames had remained low, recent evidence suggests it is increasing, which has potential environmental implications.
Route Selection in The Foraging ofPatella Vulgata(Mollusca: Gastropoda)
Authors: Chelazzi G. , Santini G. , Santina P. Della
Published: May 2009

The prosobranch limpetPatella vulgatais an intertidal grazer performing looped excursions centred on a home scar. Foraging within each excursion is mostly concentrated around the point of maximum distance from home. The orientation of the foraging excursions in a group of limpets was analysed on a vertical substrate on a sheltered shore in North Wales. The spatial relationship between different excursions of the same individual was also analysed. A total of 174 complete excursions from 47 adult limpets were obtained using the LED (light emitting diode) tracking technique. In particular, the leaving direction and the direction of the main foraging area of each excursion were computed. When considering the foraging strategy over five consecutive days, a substantially radial cropping pattern was evident at both the population and individual level, with no evident directional preference. However, when considering consecutive excursions of the same individual a concordance in leaving directions was evident in about 40% of cases. The high overlap between the outward branch of the trajectory of one night and the homing branch of the previous one suggests that the directional decision can be based on a trail-following mechanism. Moreover, our data suggest that directional decisions are taken at the beginning of each excursion when leaving home.
Reproductive Cycleso Of the Razor Clam Ensis Siliqua and the Clam Venus Striatula off Vilamoura, Southern Portugal
Authors: Gaspar M.B. , Monteiro C.C.
Published: May 2009

Annual reproductive cycles of two commercially important bivalves, the razor clam Ensis siliqua and the clam Venus striatula were investigated. Specimens of both species were sampled monthly from a site off Vilamoura, south of Portugal, between June 1992 and May 1993. Gonadal development was monitored using standard histological methods. Observed gametogenic progression was categorized by six stages: (0) inactive; (I) early active gametogenesis; (II) late active gametogenesis; (HI) ripe; (IV) partially spawned; and (V) spent. Both males and females showed a synchronism in gonadal development. The gametogenesis in the razor clam began in December and by late April the gonads were characterized morphologically by an abundance of ripe eggs and sperm. Partially spawned individuals were first encountered in May. All were spent by July. The gametogenic activity in V. striatula began in the months of October/November and continued until March. Spawning occurred between April and early August. Both species reached maturity during the first year of life.
Associations between Behavioural Ontogeny and Habitat change in Clupeoid Larvae
Authors: Higgs Dennis M. , Fuiman Lee A.
Published: May 2009

The ontogeny of evasive behaviours was examined in Atlantic menhaden (Brevoortia tyrannus, Clupeidae) and bay anchovy (Anchoa mitchilli, Engraulidae), with supplemental data for scaled sardine (Harengula jaguana, Clupeidae). Predicted relationships between ecology and behavioural ontogeny were tested using the different patterns of inshore vs offshore habitat utilization displayed by these species. In two of the species, menhaden and anchovy, the roles of vision, mechanoreception, and audition in evasive behaviours were examined ontogenetically and compared to the morphological development of these sensory systems. Anchovy early larvae were more responsive to a predatory stimulus than were menhaden; sardine early larvae were intermediate in responsiveness. By the end of the larval period most individuals tested in all three species responded. These results matched the pattern predicted by larval habitat. Ontogenetic trends in reactive distance did not match predictions based on habitat for these species but instead appeared to be more dependent upon changes in sensory morphology. In menhaden, ontogenetic changes in responsiveness were more dependent upon neuromast proliferation and cephalic lateral-line canal formation, while in anchovy these behavioural changes were more dependent upon ontogeny of the retina. Auditory stimuli were not implicated for either menhaden or anchovy in responding to the stimulus used.
Feeding Habits ofAlepocephalus Rostratus(Pisces: Alepocephalidae) in the Western Mediterranean Sea
Authors: Carrassón M. , Matallanas J.
Published: May 2009

The present study examines the feeding habits ofAlepocephalus rostratus, the only species of the family Alepocephalidae in the Mediterranean Sea and the second most important fish species, in terms of biomass, inhabiting the deep slope of the Catalan Sea. Samples were obtained at depths between 1000–2250 m. Diet was analysed for two different size-classes (immature and mature specimens) at three different bathymetric strata during two different seasons. The feeding habits ofA. rostratusincluded a narrow range of mobile macroplanktonic organisms (e.g.Pyrosoma atlanticumandChelophyes appendiculata)and some material of benthic origin.Pyrosoma atlanticumwas the preferred prey item in spring at 1000–1425 m, being very scarce in summer at the same depth as a consequence of its scarcity in the environment during this season. There were some ontogenic differences in the diet ofA. rostratusat 1425–2250 m. Adults ingested more and larger prey than juvenile specimens. The scarcity of resources below 1200–1400 m fostered a more diversified diet, as well as passive predation of sedimented material.
Thermal Conductivity of Sand and Its Effect on The Temperature of Loggerhead Sea Turtle (Caretta Caretta) Nests
Authors: Speakman J.R. , Hays G.C. , Lindblad E.
Published: May 2009

The conductivity of sand at a depth of 30–50 cm was measured at 15 sites on the beach at Captiva Island in south-west Florida which is used by nesting loggerhead turtles (Caretta caretta). The mean daily temperature of the sand was correlated with conductivity at the same depth measured the same day (r=0·611). When day to day variation was removed the correlation between nest temperature and conductivity increased to 0·694. The sand was highly variable in its grain structure. The dominant variability (80·6%) was redescribed by the first two principal components of a Principal Components Analysis (PCA). These two components were influenced mostly by percentages of large (> 1 mm) and small (< 500 μm) grains respectively. Conductivity was strongly correlated with the grain structure of the sand. The first three principal components describing sand grain structure, explained 84·1% of the variation in conductivity. Moisture content of the sand (always < 5%) was not an important factor. Sites dominated by larger grains generally had poorer conductivity and were cooler. Comparisons of eight nests to seven adjacent random sites revealed no strong evidence for directional selection in nest placement relative to sand conductivity. The variance in conductivities recorded at nests was also not significantly different from the variance at random sites.
Phenotypic Identification of three Genetically Differentiated Morphs of the Intertidal Beadlet Anemone Actinia Equina (Anthozoa: Cnidaria)
Authors: Watts Phillip C. , Thorpe John P.
Published: May 2009

The commonest column colours of Actinia equina (Anthozoa: Cnidaria) are various shades of dark red or brown. However, these colour forms conceal genetically differentiated upper (U), mid (M) and lower (L) shore morphs. It is now evident that these morphs have differing ecological requirements and probably constitute different biological species. Identification by examination of diagnostic gene loci is not practicable for most ecological purposes. The L morphs can be readily identified, but there is no known morphological character to distinguish reliably between the U and M morphs. A study of acrorhagial characters indicates that, whilst neither the type, number, colour nor size of the acrorhagi themselves were diagnostic, there is a clear difference between the U and M morphs in the size of the holotrichs (a category of nematocyst). The holotrichs were significantly smaller in the U morph than in either of the other two morphs. In the M and L morphs the holotrichs did not differ significantly in size.
Pholoe(Polychaeta: Pholoidae) from Northern Europe: A Key and Notes on the Nearshore Species
Authors: Petersen Mary E.
Published: May 2009

The scaleworm genusPholoe(formerly referred to Sigalionidae) is common and often abundant in marine benthos. In northern Europe, 1–3 species may be present in a single sample but not recognized as distinct, or one species may be reported under different names in different studies. This results in an underevaluation of diversity and precludes comparison between data sets. Four valid species ofPholoeare common in nearshore European waters, but inadequate descriptions and species misinterpretation have resulted in most of these being misidentified as the western North AtlanticP. minuta, not known to occur in European waters. The present note attempts to resolve this confusion; it is based on examination of thousands of specimens, many of them alive, from northern Europe and elsewhere. An illustrated key and notes with brief synonymies for four nearshore northern European species are provided; use of Shirlastain A for temporarily darkening protruding structures is described.Pholoe inornata(type species of the genus),P. balticaandP. assimilis(resurrected) are briefly characterized.
Impact of Winter Mortalities On Post-Larval And Juvenile Stages, In Ruditapes Philippinarum From Western Brittany
Authors: Calvez I. , Guillou J.
Published: May 2009

Introduced for aquaculture purposes, Ruditapes philippinarum has naturally recruited in several areas along the French Atlantic coast, and is subject to recurrent mortalities in late winter. The possible impact of these mortalities on both newly settled spat and juvenile R. philippinarum, was examined in a population from the Bay of Brest (western Brittany), in parallel with a survey of the main environmental parameters. From February to March 1994, 84% of the juvenile clams, between 1 and 2-y old, disappeared. No direct link could be made between these mortalities and the environmental parameters. Such winter mortalities were not observed in the newly settled spat.
The Effect of Bioturbation on Roxann®, a Remote Acoustic Seabed Discrimination System
Authors: Pinn Eunice H. , Robertson M.R.
Published: May 2009

Whilst evaluating the use of RoxAnn® for benthic biotope mapping it was noted that over certain visually similar sediments differences were observed in the acoustic signature. To assess this phenomenon a number of physical parameters were determined (mean sediment grain size, sediment sorting, sediment organic carbon content and the percentage of sand, silt and clay present in the substratum) from within a survey area in the North Minch. Investigation of the epifaunal and burrowing megainfaunal communities was also carried out using towed underwater television (TV) techniques. Generalized linear modelling showed that changes in Nephrops norvegicus burrow density could account for 94·7% of the variability in the RoxAnn® E1 signal. The model, however, appeared to be improved when both the percentage of silt present and the sorting of the sediment were also taken into account, with 984% of the variance in El being explained. Although improving the original model, the addition of these extra variables was, however, considered insignificant in terms of the variability accounted for by N. norvegicus density alone. The findings of this study are discussed in relation to possible shellfish management.
Meiofaunal Communities in a Malaysian Mangrove Forest
Authors: Somerfield P.J. , Gee J.M. , Aryuthaka C.
Published: May 2009

The free-living benthic copepods and nematodes in samples of decaying leaves and sediment, from aRhizophora apiculata-dominated mangrove forest bordering the Sungai Merbok Estuary in north-western peninsular Malaysia, were identified to putative species. Analyses of community structure of these taxa revealed that both are concentrated within the surface layers of the sediment; communities associated with decomposing leaves are distinct from those associated with the sediment surface; and variation between physically similar sites within the forest is relatively small. It is suggested that the meiofaunal communities in tropical soft sediment mangrove estuaries respond primarily to salinity and exposure gradients as in temperate non-vegetated estuaries. Copepod communities of the Merbok mangrove system appear to be much more diverse than those in estuarine and saltmarsh habitats in other climatic regions, and detailed faunal analysis suggests that there is a high degree of species endemism, particularly in genera which are only found on decaying plant material.
Studies on some new and rare Reported Marine Planktonic Ciliates (Ciliophora: Oligotrichia) from Coastal Waters in North China
Authors: Song Weibo , Bradbury Phyllis C.
Published: May 2009

Eight marine oligotrichous ciliates including one new genus, two new combinations, and five new species collected from the Yellow Sea, north-eastern China, are morphologically and biometrically investigated based on observations of living specimens and permanent preparations after protargol impregnation: Strombidium tintinnodes; Novistrombidium testaceum gen. nov., comb. nov. (formerly Strombidium testaceum); Tontonia turbinata sp. nov.; Pelagostrobilidium simile sp. nov.; Rimostrombidium orientale sp. nov.; Strombidinopsis elongata sp. nov.; Strombidinopsis elegans sp. nov., and Strombidinopsis minima comb. nov. (formerly Strobilidium minimum). Four junior synonyms are considered: Strombidium oculatum; S. obliquum; S. hadai and Strombidinopsis cheshiri. A comparison with other known members within Strombidiidae resulted in the establishment of a new genus, Novistrombidium gen. nov. It is similar to Strombidium but characterized by the conspicuously opened girdle kinety with a large gap on its ventral side, through which the ventral kinety extends.
A New Species of Poecilosclerid Sponge (Porifera) from Bathyal Methane Seeps in the Gulf Of Mexico
Authors: Maldonado Manuel , Young Craig M.
Published: May 2009

A new species of poecilosclerid sponge from methane seeps on the Louisiana Slope, Gulf of Mexico, USA is described. This thickly encrusting sponge grows around vestimentiferan tubes and has a very patchy distribution. The skeletal structure and the spicule set match those characterizing the genusEctyomyxilla. The new species,Ectyomyxilla methanophilasp. nov., is distinguished from the remaining species in the genus by the structure of its ectosomal skeleton, where small acanthostyles are never present, and by its choanosomal skeleton, which is barely reticulate and has echinated main tracts. The small size of the choanocyte chambers suggests occurrence of nutritional benefits derived from association with chemoautotrophic symbiotic bacteria. However, the presence of oscules, ostioles, aquiferous canals and choanocyte chambers indicates that this sponge also relies partly on filtration for its nutrition. This is the first record of the genusEctyomyxillain the northern hemisphere, and the first non-carnivorous demosponge known to exploit methane-rich marine environments.
Guitarra Flamenca sp. nov. (Porifera: Poecilosclerida) With a Sem Revision of the Spiny Isochelae and Placochelae in the Genus
Authors: Carballo J.L. , Uriz Ma.J.
Published: May 2009

All the currently known species of Guitarra with spiny isochelae have been reviewed by SEM: Guitarra fimbriata, Guitarra indica, Guitarra bipocillifea, Guitarra abbotti and Guitarra laplani. A new species from Namibia;Guitarra flamenca, is described, which is characterized by bipocilla-like spiny isochelae similar to those of Tetrapocillon atlanticus, placochelae in two different morphological categories and very robust megascleres. After a revision through SEM of the specimen of Guitarra fimbriata var. indica, it clearly belongs to Guitarra flamenca sp. nov. The morphological variability of the placochelae and the spiny isochelae across the Guitarra-species has been analysed and the main parameters useful to differentiate species are highlighted.