bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations on the rate of production of external ridges on the shell of Pecten maximus in the laboratory
Authors: Gruffydd LL. D.
Published: May 2009

Laboratory observations on the formation of concentric growth ridges on the shell of small Pecten maximus revealed that their rate of production was related to the size of the shell and to the growth increment in a given period. These factors are related, naturally, and the larger the shell, the greater is the growth increment and the number of ridges produced in a given time. Also, in shells of a similar size the higher the growth rate, the larger is the width of each ridge and the greater is the number of ridges produced. Faster growth is achieved therefore by increasing the width and number of ridges. The rate of ridge production at 10 °C was less than half that at 14·5 °C in conditions which were otherwise identical.
Avoidance byBalanus balanoidescyprids of settlement on conspecific adults
Authors: Moyse J. , Hui E.
Published: May 2009

The tendency under field conditions for settlingBalanus balanoideslarvae to space out from conspecific adults but not from adults of other species is reaffirmed. Explanations are advanced for the opposite conclusions reached recently by other workers. The general avoidance byB. balanoideslarvae of settling on top of older barnacles is examined. It is suggested that there must be a strong inhibiting influence, so far unexplained.
Changes in weight of the liver and the relationship to reproduction in the hagfish Myxine glutinosa (Cyclostomata)
Authors: Patzner Robert A. , Adam Hans
Published: May 2009

The hepatosomatic indices (HSI) of eight groups of Myxine glutinosa with different gonadal conditions are calculated and compared with each other. Female animals with eggs longer than 10 mm differ statistically significant in their HSI from all other groups. The production of a vitellogenetic protein in the liver of Myxine is concluded.
Year-to-year changes in the salinity of the eastern English Channel, 1948–1973: a budget
Authors: Taylor A. H. , Reid P. C. , Marsh T. J. , Jonas T. D. , Stephens J. A.
Published: May 2009

A model has been used to assess the relative importance of the various factors contributing to changes in the salinity of the eastern English Channel between 1948 and 1973. As part of the data input to the model, monthly means (1948–73) of total runoff into the eastern English Channel and monthly estimates of evaporation and precipitation for the same area (1961–73) were calculated. The results of this study have shown that river runoff is an important factor contributing to the variability of salinity in the eastern English Channel; rainfall over and evaporation from the Channel may also be important at certain times. The model can predict satisfactorily more than 80% of the variation of salinity from local data inputs. While Atlantic water movements and salinities may contribute to variability at the entrance to the English Channel, variations of flow through the Channel, caused by local wind forcing or originating further out in the Atlantic, have little effect on the fluctuations of salinity in the eastern English Channel. Furthermore, fluctuations in the salinity of the North Atlantic do not correspond to those observed at the entrance to the English Channel. River runoff and mixing due to the wind and tides appear to be the main factors responsible for the seasonal changes of salinity in the eastern English Channel.
Deep-water Pycnogonida of the INCAL, BIOGAS, GEOMANCHE and SAFARI cruises
Authors: Stock Jan H.
Published: May 2009

Ten species of deep-water Pycnogonida are recorded, mainly from the north-eastern Atlantic Basin. Of particular interest are Ascorhynchus abyssi Sars (new to the British Isles), Colossendeis arcuata A. Milne Edwards (northernmost record in European waters), C. bicinc0ta Schimkewitsch (third Atlantic record, depth range increased), C. macerrima Wilson (new records from the English Channel), Nymphon laterospinum Stock (new to the Indian Ocean), Pallenopsis (Bathypallenopsis) oscitans (Hoek) (new to the English Channel and bathymetrical range extension), P. (B.) tritonis Hoek (extension of depth range), P. (B.) tydemani caraibica Stock (second European record, now found at the entrance of the English Channel), and Anoplodactylus arnaudae Stock (range extended to the Rockall Trench).
Re-investigation of Polyoeca dichotoma and Acanthoeca spectabilis (Acanthoecidae: Choanoflagellida)
Authors: Hara Shigemitsu , Takahashif Eiji
Published: May 2009

Light and electron microscopical reinvestigation of Polyoeca dichotoma Kent revealed that Acanthoecopsis spiculifera Norris, the type species of the genus, is a synonym for Polyoeca dichotoma. Since this step invalidates the use of the name Acanthoecopsis, a new genus Acanthocorbis was established for the three species formerly included in Acanthoecopsis.

The three dimensional arrangement of costal strips forming the loricae of Polyoeca dichotoma and Acanthoeca spectabilis Ellis were examined by scanning electron microscopy. The arrangement of costal strips were similar in both species. The longitudinal costal strips and those forming the spines were arranged outside the supplementary costae and those of the transverse bonds.
The distribution of Decapoda (Crustacea) in the open ocean and near-bottom over an adjacent slope in the northern North-east Atlantic Ocean during autumn 1979
Authors: Hargreaves P. M.
Published: May 2009

The vertical distribution of Decapoda (Crustacea) at deep-water stations in the Rockall Trough and the Porcupine Seabight is discussed and compared to the near-bottom distribution of Decapoda on the continental slope of the Seabight. The vertical distribution of some species is unaffected by the shallowing of the sea floor in the slope area. Other species are found in much higher concentrations near-bottom over the slope than at similar depths at the adjacent deep-water stations and at least one species extends its lower vertical range. It is suggested that the increased food availability near-bottom may be the principal factor influencing aggregation.
Trapped diurnal waves on Porcupine and Rockall Banks
Authors: Pingree R. D. , Griffiths D. K.
Published: May 2009

A numerical model is used to demonstrate wave trapping of the diurnal tides on Porcupine Bank and Rockall Bank. These waves have wave lengths of about 300 km and travel along the sloping topography with shallow water on their right. On the slopes of Porcupine Bank the shorter period K1 wave has a longer wavelength than the O1 wave and so here the trapped diurnal spring-neap signal propagates in a direction which is opposite to the phase velocity.
A new genus and species of marine leech from British Coastal waters
Authors: Llewellyn L. C. , Jones-Knight E. W.
Published: May 2009

Brumptiana lineatan.gen. et sp., from oro-nasal region ofRaja, has a subcylindrical body, 2 pairs of eyes, 13 or 14 annuli per mid-body somite, 12 pairs of small pulsatile vesicles, 5 postcaecal fenestrae, 5 or 6 pairs of testes, a large muscular atrium with accessory glands, a thick-walled vagina and no receptaculum, conducting tissue or spermatheca.
Reproduction, growth and feeding of the dragonet, Callionymus lyra (Teleostei: Callionymidae), in Galway Bay, Ireland
Authors: King Pauline A. , Fives Julie M. , McGrath David
Published: May 2009

A Galway Bay population of the dragonet Callionymus lyra (L.) was investigated between March 1978 and November 1979. Monthly collections were made on board commercial fishing vessels. A total of 3302 fish was examined. The male to female sex ratio in the catch was 1·14:1 and it departed significantly from a 1:1 ratio. Males grew significantly faster than females, when measured by length and by weight, and attained a greater maximum length, but females had a longer life span. Females were significantly heavier than males for any body length. The spawning season was protracted, lasting from January to August and peaking during February-April. Callionymus lyra is a carnivore, feeding mainly on polychaetes and crustaceans, but molluscs and echinoderms were also eaten in abundance. A yearly cycle in feeding intensity was observed, showing reduced feeding during the colder months. The feeding index expressed as gut weight / body weight was significantly higher for females.
Circalittoral suprabenthic coarse sand community from the western English Channel
Authors: Dauvin Jean-Claude , Iglesias Angeles , Lorgere Jean-Claude
Published: May 2009

A first quantitative description of the suprabenthic fauna in a coarse sand community from the western English Channel is provided. One hundred and twenty species of Crustacea were collected in 22 suprabenthic sledge hauls collected throughout the year (1988–1989). Mysids and Amphipods dominated the fauna, among them Anchialina agilis (Sars), Gastrosaccus spp., Apherusa spp., Eusirus longipes Boeck, and Stenothoe marina (Bate) were the dominant species. Although most dominant species showed a vertically decreasing gradient of density from the lower net to the upper level of the sledge, the most abundant species, Apherusa spp., showed similar density at all four levels. The mean density at the four levels of the sledge did not differ significantly with the distance above the sediment. Species performed nocturnal vertical migrations: the densities of mysids were higher during the day than at night; conversely, the densities of amphipods and decapods were higher at night than during the day. The density and species richness showed high seasonal variation, from low values at the end of autumn and winter to high values in summer and the beginning of autumn. The results are compared with the available data on suprabenthic communities from the North Atlantic; this highlights (1) the lack of concentration of suprabenthic fauna towards the sediment on coarse sand, and (2) the highest abundance of the suprabenthic fauna from muddy substrata.
Use of photography and image analysis for In situ monitoring of growth rates of intertidal fucoid algae
Authors: Haddad A. M. G. , Ormond R.F.G.
Published: May 2009

A combination of photography and subsequent image analysis of the photographs has been used to measure maximum length, perimeter length and total area of fronds of tagged Fucus serratus L. as part of a study of the growth of this species on the Yorkshire coast. Maximum mean growth rate of 0·26 cm d-1 was observed during June–July. Minimum mean growth rate of 0·01 cm d-1 was observed during October-March. The method is relatively quick and convenient, and has the advantage that in addition to apical growth of the longest and/or other branches, lateral growth and total growth in surface area can all be recorded, while loss of tissue can also be determined. A further advantage is that a photographic record is obtained of the history of each individual plant.
A cleaning association between the oceanic crabPlanes minutusand the loggerhead sea turtleCaretta caretta
Authors: Davenport John
Published: May 2009

Columbus crabs,Planes minutus(L.) (Crustacea: Brachyura) are often found on the postero-ventral surfaces of sea turtles, particularly the loggerheadCaretta caretta(L.) (Testudines: Cheloniidae). There has been a general acceptance of a hypothesis that the crabs feed upon turtle faeces. However, evidence is presented here to demonstrate thatPlaneshas a ‘cleaning’ role, feeding on other epibionts (e.g.barnacle cyprids, parasitic amphipods) during daylight hours. At night it is likely that the crabs feed on neustonic animals (e.g.euphausids). The species is also cannibalistic.
The Microplankton of Plymouth Sound from the Region beyond the Breakwater
Authors: Lebour Marie V.
Published: May 2009

Throughout a complete year from September, 1915, to September, 1916, sea-water samples were taken regularly two or three times a week from beyond the Breakwater in the region of the Knap buoy, 2½ miles from Plymouth shore, from the surface and at 5 and 7 fathoms, The object was to supplement the existing records from the tow nets as it is well known that a very large amount of material is lost even from the finest nets, as Lohmann has shown exhaustively (1908). So far the only plankton records from this region have been from the tow nets, and a glance at the tables given at the end of this paper will show directly, if compared with those by Gough (1903–7) and Bygrave (1911), also Cleve (1899 and 1900), the great difference in numbers of the smaller forms, or their entire absence from the tow nettings. Again, no actual numerical records have been given from this region. At the same time as the water samples were taken, tow nettings, coarse, medium and very fine, were also secured, and these were regularly examined for comparison.
The Peridiniales of Plymouth Sound from the Region beyond the Breakwater
Authors: Lebour Marie V.
Published: May 2009

The following list includes all the Peridiniales identified in the plankton throughout the year from September, 1915, to September, 1916, from the water samples, details of which will be found in another paper in the same journal (p. 133). Also from the plankton in the tow nets in the same year and a portion of the summer 1915. As is shown in the abovementioned paper, the summer is the time for nearly all the Peridiniales, June being the maximum month. After October very few are seen in the water samples, although in the tow nettings the larger and stronger forms, such as Ceratium and Peridinium, are still present.
S2 tidal simulations on the north-west European shelf
Authors: Pingree R. D. , Griffiths D.K.
Published: May 2009

A numerical model is used to derive both the S2 and M3 tides for the shelf seas around the British Isles. The M2 tide was run with the S2 tide in the presence of quadratic friction. It was found that quadratic friction marginally overdamps the S2 tide. A further approximate representation of the S2 tide was obtained from a model in which the quadratic friction term was replaced by a linear frictional coefficient in a tensor form based upon the M2 tidal currents derived from the spring-neap simulation. These simulations form the basis for interpreting the M2/S2 ratios and phase differences that occur on the north-west European shelf.
The N2 tide and semidiurnal amphidromes around the British Isles
Authors: Pingree R. D. , Griffiths D. K.
Published: May 2009

A numerical model is used to derive the N2 tide around the British Isles. The model can derive any semidiurnal astronomical constituent in about 5 tidal cycles to > 90% accuracy. This simulation demonstrates the importance of quadratic friction and frequency in determining the relative positions of the N2, M2 and S2 amphidromes.
The opening response of mussels (Mytilus edulis) exposed to rising sea-water concentrations
Authors: Davenport John
Published: May 2009

When exposed to water of low salinity specimens of Mytilus edulis L. keep their shell valves tightly closed; they do not gape periodically to test the external medium. Exchange of salts and water between the mantle cavity and the environment is thus minimized. Rising salinities are registered by diffusion of salts to the tentaculate portion of the inhalent siphon and not to any other portion of the mantle edge or to any more deeply located structures.
A demographic study of the life cycle of Tisbe furcata (Baird, 1837) (Copepoda: Harpacticoida)
Authors: Bergmans Marc
Published: May 2009

The life-cycle of the harpacticoid copepod Tisbe furcata (Baird, 1837) at 18 C was studied quantitatively. Stage durations were determined by two different methods, using synchronous cohorts. Combined nauplius stages last for 80·4 h; the successive copepodite stages take 23·0, 23·2, 28·0 (♀) to 23·2 (♂), 33·4 (♀) to 24·2 (♂) and 48·8 (♀) to 34·7 (♂) h, respectively. Females develop more slowly but more synchronously than males. Age-specific survival and fertility rates were used to calculate the stable stage distribution in an exponentially growing population. From life-table data the following demographic parameters were computed: intrinsic rate of natural increase rm = 0·233 day−1; net reproductive rate Ro = 94; minimum generation time Tmin = 14·9 days; parameters related to ‘generation time’: T = 19·5 days, = 16·4 days, Tc = 25·4 days.
The comparative morphology of hepatic photophores in decapod Crustacea
Authors: Herring Peter J.
Published: May 2009

The hepatic photophores of species ofSergestes(organs of Pesta) contain fluorescent paracrystalline platelets which are the sources of the luminescence. The cells containing these crystals are contiguous with cells filled with lipid droplets which act as a diffuse reflector. The optical properties of the organ as a whole derive from the different arrangement of the various regions in the mosaic of individual tubules. The hepatic photophores ofParapandalus, ThalassocarisandChlorotocoideshave a similar anatomical position but differ considerably in structure. They do not contain paracrystalline material and they have a diffuse reflector, probably not composed of lipid, which is separated from the tubules that make up the photocytes. The organs inThalassocarisandChlorotocoidesare very similar in structure. Luminescence in the photophores of all four genera is probably intracellular.
Development and growth in laboratory-maintained and field populations ofParathemisto gaudichaudi(Hyperiidea: Amphipoda)
Authors: Sheader Martin
Published: May 2009

Parathemisto gaudichaudiwas collected off the south coast of Northumberland during 1970–2, and the moulting and growth of laboratory-maintained individuals observed. The moulting behaviour is similar to that described for other amphipods, but individuals remain attached to medusae during moulting. The minimum body size at maturity, the time from hatching to maturity and the length of the intermoult period are shown to be temperature dependent. The analysis of growth-factor data resolves growth into a rapid juvenile phase and a slower adult phase. The development of secondary sex characters is related to developmental stages of the gonads.
On the Occurrence of a Northern Hydroid Halatractus (Corymorpha) nanus (Alder) at Plymouth
Authors: München E. Stechow
Published: May 2009

On looking over some hydroid material, for which I have to thank the Biological Station at Plymouth, I found upon an alga that was thickly covered with Eudendrium album, Nutting, between the stalks of the Eudendrium a single specimen of the rare Halatractus (Corymorpha) nanus (Alder), which has until now been considered an Arctic species. The specimen is of special interest owing to the fact that this form has only been exceptionally met with in subarctic waters, and has only been recorded in England as a special rarity from the colder coast of Northumberland [Hincks, 1868; Allman, 1872; Pennington, 1885]. As far as can be gathered, it has only been found once even there. Its discovery now at Plymouth, on the warm southern coast washed by the Gulf Stream, is therefore the more surprising. In the comprehensive list of the Marine Fauna of Plymouth in this Journal (N.S., Vol. VII, pp. 155–298, 1904) the species is not included.
List of Nemerteans collected in the Neighbourhood of Plymouth from May–September, 1910
Authors: Wynhoff Gerarda
Published: May 2009

The following list is one of the results of my work during a stay of nearly four months at the Plymouth Laboratory of the Marine Biological Association. I desire to express my thanks to the Director and the Staff of the Laboratory for the interest they took in my work and for their kind assistance.
On a Method of Rearing Larvae of Polyzoa
Authors: Darmstadt M. Hasper
Published: May 2009

Colonies of Bowerbankia pustulosa, collected in July and August, 1911, in and near Plymouth Sound, contained a great many ovicells and produced numerous larvae, when kept in a flat glass trough and put under circulation during the night. The small yellowish larvae have a decidedly positive phototropism. They gather on the surface of the water on that side which is turned towards the light, from which position they sink to the bottom of the glass. Their movements slacken gradually in the course of a few hours, and at last are limited to revolving in a small circle until they fasten on the sides of the glass. Here they complete their metamorphosis, and in a few days the primary polypides are expanding their ciliated tentacles. The result was better when the just-hatched larvae were brought into a jar sterilised by hot water and filled with so-called outside water, i.e. water from beyond the Breakwater. This jar was fitted with a glass stand carrying a number of cover-glasses. When the larvae settled on these, it was easy to make total preparations of them without detaching them.
Reproductive Failure in Populations of the Dog-Whelk, Nucella Lapillus, Caused by Imposex Induced by Tributyltin from Antifouling Paints
Authors: Gibbs P. E. , Bryan G. W.
Published: May 2009

The development of male characters, notably a penis and a vas deferens, on the female (the phenomenon of ‘imposex’) of the dog-whelk, Nucella lapillus, is described. Three stages are recognized: an ‘early’ stage involving the formation of a vas deferens and a small penis, an ‘intermediate’ stage characterized by the enlargement of the female penis to a size approaching that of the male and a ‘late’ stage during which the female opening (vulva) is occluded by overgrowth of vas deferens tissue. This blockage of the pallial oviduct prevents the release of egg capsules and renders the female sterile. The extent and cause of such reproductive failure is evident from the high incidence of females containing aborted capsules in declining populations close to sources of tributyltin (TBT) contamination. These same populations comprise fewer females than expected and it would appear that the accumulation of aborted capsules within the pallial oviduct eventually causes the premature death of the female.
Sarcotaces sp., a Parasitic Copepod Infection in two Deep-Sea Fishes, Lepidion Eques and Coelorhynchus Occa
Authors: Bullock A. M. , Phillips S. E. , Gordon J. D. M. , Roberts R. J.
Published: May 2009

This paper describes the incidence and pathology of a copepod parasite (Sarcotaces sp.) in two species of deep-sea bottom-living fish. The fish Lepidion eques (Moridae) and Coelorynchus occa (Macrouridae) are common on the continental slope to the west of the British Isles at depths from about 400 to 1300 m and 700 and 2000 m respectively.

In both species the parasite was located beneath the skin. In L. eques it was found primarily on the head, whereas in C. occa it was present on the mid to lower flank, often close to the anal vent. Excision of the parasite from the host tissue showed it to consist of a pyriform sac filled with inky black fluid. Detailed histological investigations revealed the parasite wall to be a highly complex structure. Within the gut fluid shown to be of haematogenous origin, numerous copepod nauplii were often observed.
Crustacea in the Diet of Eledone Cirrhosa (Mollusca: Cephalopoda) determined by Serological Methods
Authors: Boyle P. R. , Grisley M. S. , Robertson G.
Published: May 2009

Serological methods for prey identification have been applied to the gut contents of a field sample of 100 Eledone cirrhosa from the Moray Firth and 7 from the Sound of Jura. Protein extracts from the crop were electrophoresed (Laurell rockets) into antisera raised against potential crustacean prey species, Cancer pagurus, Carcinus maenas, Crangon crangon, Liocarcinus spp. and Nephrops norvegicus. The strengths of the resulting reactions were evaluated on the basis of peak height, staining density and the number of homocentric peaks of immune precipitates. Sixty-two of the 100 Moray Firth animals gave a positive reaction to one or more of the antisera and the most critical assessment of the results ranked the incidence of the prey as Liocarcinus (15) > Nephrops (10) > Cancer (8) > Crangon (2) > Carcinus (0), a total of 35 reactions from 28 animals. Absence of a reaction in the 38 animals from which appreciable sample volumes were also obtained indicates that alternative prey had been consumed. Of the 7 Sound of Jura animals, 4 gave a positive reaction to Nephrops alone. A total of only 24 animals gave any indication of diet by visual recognition of remains. The value and difficulties of the methodology are discussed.
Gill Symbionts in Thyasirids and Other Bivalve Molluscs
Authors: Southward Eve C.
Published: May 2009

Prokaryote organisms have been found in the gills of six species of Thyasiridae, collected in the north-east Atlantic region, from depths of 15 to 1250 m. The fine structure of the gill epithelia and the symbiotic Gram-negative bacteria is described. The bacteria occur extracellularly, between a thin cuticle and the apical membrane of the host cell. This differs from the intracellular position of bacterial symbionts in two lucinid species, Lucinoma borealis and Myrtea spinifera, and many other bivalves already known to harbour symbionts in their gills. Four species of Thyasiridae and Diplodonta rotundata, a member of the closely related family Ungulinidae, were found to lack gill symbionts.
Early Ontogeny of the Septibranch BivalveCardiomya Pectinata(Carpenter, 1865)
Authors: Gustafson Richard G. , Foighil Diarmaid Ó. , Reid Robert G. B.
Published: May 2009

A minor spawning event by laboratory-held specimens of the septibranch bivalveCardiomyapectinatayielded approximately 40 developing embryos. Their early ontogeny was observed from the early gastrula stage of development until the developing shell had completely enclosed the embryos and had attained 90% of the prodissoconch size observed on juvenile shells. Available evidence indicates that this species undergoes a non-planktotrophic, direct pre-juvenile development. Support for this view includes the enclosure of the developing embryo in a negatively buoyant, adhesive capsule until an advanced stage of development; poorly developed velar ciliation and lack of prodissoconch II formation. Although incomplete, this, the first study on septibranch pre-juvenile development, reveals thatC. pectinataembryos form an external calcified shell in a manner homologous to the lamellibranch bivalves, and develop a velum modified for yolk storage, while lacking the epithelial test or pericalymma characteristic of protobranch bivalves. These data indicate that cuspidariid septibranchs are phylogenetically closer to the lamellibranchs than to the protobranch bivalves.
Heredity in Plants, Animals, and Man
Authors: Allen E. J.
Published: May 2009

Of the many branches of biological enquiry which have occupied the attention of naturalists during the last twenty years the one which has perhaps yielded the most striking results, from a theoretical point of view, has been the study of heredity in plants and animals—the study of the laws according to which the characters of parents are transmitted to their descendants.
Light and life on RRS ‘Discovery’
Authors: Herring Peter J. , Partridge Julian C.
Published: May 2009

Research ships are much more numerous on the high seas in the 1990s than they were in the 1950s. At that time the United Kingdom was fortunate in that it had a purpose-built research vessel, RRS 'Discovery II' (see inside back cover), the successor to Scott's 'Discovery' (which was itself granted the title Royal Research Ship in 1923, see inside front cover). 'Discovery II's prime objectives had originally been oceanographic research in the Antarctic relevant to the whaling industry, to which end she had completed six two-year Antarctic commissions. In the 1950s she was being operated by the National Institute of Oceanography and was working extensively in the North Atlantic, covering the gamut of marine physics, chemistry, biology and geology, including participation in the research programme of the International Geophysical Year. However, by 1959 she was 30 years old, and both scientific space and stability had become limiting. Increasingly stringent Ministry of Trade requirements were also making successive refits less and less cost-effective. In April of that year the first brief outline for a replacement vessel was prepared, and six months later discussions between naval architects and the National Oceanographic Council (represented by Dr H.F.P. Herdman) produced an outline draft specification for the new ship. Further discussions with the Admiralty finally resulted, in June 1961, in an order being placed for a new vessel, at an estimated cost of £800K (Deacon, 1967).

The new ship, the RRS 'Discovery', was launched in July 1962 and commissioned on 17 December, 10 m shorter than her originally conceived length but at a contained final cost of £802K.
Demersal ichthyofaunal distribution in the abyssal eastern North Atlantic, With special reference to Coryphaenoides (Nematonurus) armatus(Macrouridae)
Authors: Merrett N. R.
Published: May 2009

Three latitudinally separated assemblages (49°–41°N, 38°–30°N, 22°–20°N in 11°–25°W) of abyssal demersal fishes in the eastern North Atlantic have been identified from combined data from 13 new and 12 previously reported trawl samples. The northerly assemblage remained unaltered by the new data, but the intermediate one could be sub-divided into shallow (4370–4475 m) and deep (4835–5440 m) elements. This sub-division revealed that bathymetry was acting with latitude to influence previous results. The new, southerly, assemblage was found below surface waters enriched by upwelling along the continental margin. The composition of dominant species identified each assemblage. The biological characteristics of these species were largely consistent with the former hypothesis linking them to the influence of the overlying production regime. The contrast between this preliminary evidence for structured demersal fish assemblages in the abyss with its lack on the slope and rise was discussed in the terms of the respective patterns of trophic input.
Adaptations of tapeta in the eyes of mesopelagic decapod shrimps to match the oceanic irradiance distribution
Authors: Shelton P. M. J. , Gaten E. , Herring P. J.
Published: May 2009

Eyeshine brightness was measured in a number of species of oplophorid shrimps and one sergestid. Eyeshine varies in a systematic way across the eye. Forward and downward looking parts of the eye often have the brightest eyeshine. In many cases eyeshine is graded in the horizontal and vertical axes. Eyeshine brightness can be explained in terms of underlying tapetal morphology. These features of the decapod eye can be rationalised in terms of the normal irradiance distribution in the sea and the need for certain parts of the eye to have enhanced sensitivity. Contrary to the expected results, when six species of oplophorid were compared there was a clear trend of decreasing brightness with depth at whichthey occurred. In a number of species the tapetum is incomplete with distinct holes. Such holes occur in the dorsal region of two species of oplophorid. In one deep-water species the central tapetum is lacking. This feature, and the observed decrease in eyeshine with depth, may be adaptations to reduce the signal that eyeshine provides to potential predators.
A note on the elongated eye of the octopus Vitreledonella richardi
Authors: Land Michael F.
Published: May 2009

The elongated eye of Vitreledonella richardi is described from two specimens caught at 200 m in the North Atlantic. It is shown that the cylindrical shape, with the lens placed centrally, results in a reduced field of view in the horizontal plane. It is argued that the unusual shape is an adaptation which minimises the silhouette of the eye as seen from below, and is part of the animal's camouflage strategy.

Introduction

The majority of fish and cephalopods have two hemispherical eyes, each of which has a field covering roughly the 180° on one side of the animal (Walls, 1942; Packard, 1972). The commonest exceptions to this rule are animals with so-called ‘telescopic’ eyes, found in many species of deepsea fish (e.g. Benthalbella, Argyropelecus, Opisthoproctus, Scopelarchus, see Marshall, 1954; Locket, 1977) and some cephalopods (Amphitretus, see Chun, 1915; Histioteuthis sp., see Young, 1975a). These eyes are tubular, with the lens at the open end of the tube, and a retina with a reduced field of view at the other. The eyes usually point upwards, and it is generally agreed that their shape is determined by the need to concentrate sensitivity and resolution into the rather narrow field above the animal where the residual daylight is still adequate for visual detection. It is 200 times darker in the downward direction (Denton, 1990), and so there must be some depth at which upward vision works, but downward vision does not. These are not the only kind of tubular eyes, however. In some cephalopods, but not to my knowledge in any fish, there are eyes of tubular appearance but with the lens not at the end, but in the centre of the tube (Figure 1).
Single and multiple visual pigments in deep-sea fishes
Authors: Partridge J. C. , Archer S. N. , Vanoostrum J.
Published: May 2009

The visual pigments in the retinal rods of 17 species of deep-sea fish were examined by microspectrophotometry or visual pigment extract spectrophotometry. In 15 species single visual pigments were found with peak sensitivities between 470 and 490 nm, typical of deep-sea fishes. However, in one species,Stylephorons cordatus, two visual pigments were found with λ values at 470 and 481 nm. In another species,Scopelarchus analis, three visual pigments were found with mean λ values of 444, 479 and 505 nm. The short-wave pigment of this species was found both in main and accessory retinae. It was present both in single rods and in outer segments which had the most long-wave sensitive pigment in their distal parts. It is argued that these two-pigment rods are in the process of changing their visual pigment from a ‘juvenile’ VP505 pigment to an ‘adult’ VP444 pigment. The VP479 was found only as a single pigment in rods in the accessory retina.
Mixed light imaging system for recording bioluminescence behaviours
Authors: Widder Edith A.
Published: May 2009

Video recordings of bioluminescence have depended on the use of image-intensified systems, which generally suffer from poor resolution and image persistence. These characteristics, coupled with the restriction that any illumination must be dimmer than the bioluminescence, have complicated efforts to record behaviours associated with bioluminescent displays. The Mixed Light Imaging System (Mlis), described here, uses (1) an intensified video camera, (2) an infra-red (IR) sensitive video camera (3) a dichroic beam splitter, (4) strobed IR illumination and (5) a video mixer to record stop-action images of organisms superimposed on intensified images of their bioluminescence. With the MLIS, behaviours associated with bioluminescent emissions, including rapid escape responses, were recorded from the mesopelagic copepods Euaugaptilus magnus and Gaussia princeps.
Bioluminescence of the oceanic apogonid fishesHowella brodieiandFlorenciella lugubris
Authors: Herring Peter J.
Published: May 2009

The pyloric caeca and posterior intestine ofHowella brodieiare bioluminescent, and are associated with internal reflective tissues. The bioluminescence is not bacterial in origin. Unlike that of several shallow water apogonids, it does not depend uponVargulaluciferin.Florenciella lugubrishas bioluminescent oesophageal diverticula and is able to eject a pulse of luminescent material from beneath the operculum.

The luminescence of the two species is compared with that of other perciform fishes.

Introduction

The perciform family Apogonidae (cardinal fishes) contains several bioluminescent coastal species in the Indopacific generaSiphamia, Rhabdamia, Archamia, andApogon. Their oceanic relatives are less well known and their systematic position is still a matter of some conjecture.Howellahas been assigned to the Apogonidae but has also been included in the Moronidae (Tortonese, 1986), and, more recently, in the Percichthyidae (Post & Quéro, 1991). Some authors have followed Mead & De Falla (1965) in assigning the oceanic apogonid-like fishes to the family Cheilodipteridae(e.g.Fedoryako, 1976), in recognition of the fact that they ‘are so different from their coastal relatives that comparison is pointless’ (Mead & De Falla, 1965).

Bioluminescence has not been described in detail in any of the oceanic species. Mayer (1974) reported that one of the pyloric caeca inEpigonus macropswas separated from the others and associated with reflective structures. This strongly suggested that it was bioluminescent, based on comparisons with known luminescent shallow water perciforms, such as species ofPempherisandParapriacanthus.Mead & De Falla (1965) described a ventral reflective strip inRosenblattia robustawhich, by analogy with similar appearances in luminous neritic species, they considered a possible indication of bioluminescence.
On the locomotion of ascidian tadpole larvae
Authors: Bone Q.
Published: May 2009

This paper describes the locomotor movements of the tadpole larvae of the ascidians Ciona and Dcndrodoa and the associated electrical activity of the caudal muscle cells. Although very different in size and trunk shape, both larvae show essentially the same two movement patterns; symmetrical swimming and asymmetrical tail flicks. Swimming movements at tailbeat frequencies up to 40 Hz and forward speeds up to 10 L s (in the Reynold's number range 5·25) involve large lateral movements of the tail, and large yaw of the trunk. Tail oscillations are produced by muscle cells arranged in three segmented rows along the tail, coupled by gap junctions. Swimming is driven by axons innervating anterior ventral muscle cells. The second type of movement, single or multiple tail flicks, is driven by axons innervating dorsal muscle cells, all of which are innervated along the length of the tail. The middle row of muscle cells is not innervated. This small scale oscillatory swimming system is compared with those of chordates and larvacean tunicates, and it is concluded that both of these are very different from that of the ascidian tadpole.
The effects of salinity and low temperature on eggs of the Icelandic capelin Mallotus villosus
Authors: Davenport John
Published: May 2009

The embryos of Icelandic capelin (which spawn subtidally) tolerate as low temperatures, and are as euryhaline, as those of Balsfjord capelin which spawn intertidally. The median lethal lower temperature for Icelandic capelin eggs exposed for 6 h to low temperatures in frozen seawater films (34‰) is -6.3°C. The median lethal high salinity (6 h exposure) is 88.3‰. Eggs were reared and hatched successfully in all salinities from 1.5 to 34‰. When exposed to high salinities capelin eggs shrink in a matter of seconds (shrinkage being manifested in depressions of the chorion), but resume a normal shape in a few minutes as salts diffuse into the perivitelline fluid. Evidence is presented to show that mortality in frozen seawater films is due to osmotic dehydration, rather than to a final invasion by ice crystals. A model of freezing avoidance in capelin eggs is described.
On the pelagic occurrence and dispersal of the benthic amphipod Corophium volutator
Authors: Essink Karel , Kleef Hans L. , Visser Wim
Published: May 2009

Field data on the pelagic occurrence of Corophium volutator were obtained in 1981–82 in the Dollard (Ems estuary). The pelagic population density averaged over a tidal half cycle was in the range 0–15 m-3. The pelagic population represents about 0.06% of the benthic population. On most sampling days pelagic occurrence resulted in a net flood surplus transport.
Aspects of the life history of a tide pool population of Amphipholis squamata (Ophiuroidea) from South Devon
Authors: Emson R. H. , Whitfield P. J.
Published: May 2009

A tide pool population of the brittle-star Amphipholis squamata in South Devon was monitored from July 1986 to July 1987 with respect to a number of population dynamical attributes. The population had a simple life history. Most individuals recruited into the population in the period June-September, were reproductively active in the following summer and died when 13-17 months old. The population differed from others studied in temperate latitudes in pattern of recruitment, survival and in duration of reproductive activity. We speculate that these differences are a consequence of tide-pool conditions.
The life history and reproductive biology ofOdostomia eulimoides(Gastropoda: Opisthobranchia) on the south coast of Ireland
Authors: McFadden Y. M. T. , Myers A. A.
Published: May 2009

Populations ofOdostomia eulimoidesHartley were sampled from mussel beds on an exposed rocky shore at Preghane Point on the south coast of Ireland from April 1984 to October 1985 and from sublittoral farmed mussels at Bantry Bay on the south west coast of Ireland from March to October 1986.

At Preghane PointO. eulimoideshad a area-annual life cycle with summer-autumn recruitment. Peak recruitment occurred from May to July in 1984 and from July to September in 1985. This aphasic recruitment was explained by the lower mean adult shell height recorded from April to June 1985 than in these same months in 1984.
The effect of feeding levels on the fecundity of plaice (Pleuronectes platessa)
Authors: Horwood J. W. , Walker M. Greer , Witthames P.
Published: May 2009

Previous field studies have recorded yearly variations in fecundity of 40–60% in similar sized plaice, and an experiment was conducted to investigate whether these changes could be generated, in the laboratory, by feeding plaice different levels of ration. One group of plaice was fed at a rate of about 2–2.3% of wet body weight per day, and a second group was fed initially 0.5% and later 1.8% per day. The experiment lasted for a period of 406 days.

Of those fed on the lower ration, 39% produced no granular oocytes, whereas all fish on the higher ration produced granular oocytes. A comparison between the two groups, of those which did produce granular oocytes, found that the better-fed fish had 59% more granular oocytes, but the differences were less pronounced for the smaller, mature fish. Numbers of resting oocytes are also recorded.

The results suggest that food level can significantly affect fecundity, and also revealed a new mechanism for regulation of fecundity in the plaice. The lack of granular oocytes was not due to atresia, but to an early decision not to proceed with gonad development; whether this is of practical significance for the population of plaice in the wild is not yet established.
New species of Terschellingia (Nematoda: Linhomoeidae) from the Tamar estuary, England and the Maldive Islands
Authors: Austen M. C.
Published: May 2009

A new species of free-living marine nematode, Terschellingia gourbaultae sp. nov., from the Tamar estuary, south-west England, is described and illustrated. This species has also been recorded from Brittany, France. T. daviger, sensu Gerlach (1963) nec Wieser (1956) is a junior homonym and is re-named T. maldivensis sp. nov. Five Terschellingia species including the new species are distinguished by their lack of a distinctly offset, rounded oesophageal bulb; a table and figures are given to aid identification of these species.
On the structure of the inshore fish community of England and Wales
Authors: Henderson P. A.
Published: May 2009

Records of fish captures on power station intake screens were used to analyse the structure of the English and Welsh inshore fish community. The study was undertaken as part of a programme to predict fish captures at future power station sites. It was found that 118 of the 122 fish species known to live inshore were recorded from the screens of 12 coastal power stations. The maximum number of species at one site was about 80, achieved at fully marine localities along the English Channel coast. This number declined with increasing latitude and decreasing salinity.

Fish subdivide their use of the inshore habitat both spatially and temporally and the proportion of species complement within the major subdivisions of the habitat was remarkably similar at all sites. On average, 28 species were present simultaneously and these would include 4 pelagic, 8 demersal and 16 benthic species.
Shell morphology of larval and post-larval mytilids from the north-western Atlantic
Authors: Fuller S. Cynthia , Lutz Richard A.
Published: May 2009

Comparison of early shell morphological features of six mytilids from the north-western Atlantic revealed differences useful for species identification and classification. Brachidontes exustus, lschadium recurvum, Geukensia demissa, Amygdalum papyrium, Mytilus edulis, and Modiolus modiolus larvae and post-larvae were cultured in the laboratory. Scanning electron micrographs of the shell and hinge during early ontogenetic stages showed that all species had a long provinculum with taxodont dentition. In addition, provinculum length and number of teeth increased during the larval period in the six species. The small, numerous provincular teeth of Mytilus edulis and the bold, comparatively few provincular teeth of Amygdalum papyrium clearly differentiated these two species. Most species had a low umbo, round posterior margin, and more pointed anterior margin, although Amygdalum papyrium was distinguished by a high, prominent umbo. Distinction of Geukensia demissa and lschadium recurvum larval shells was difficult due to similarity in their shapes and hinge dentition. However, discriminant analysis using larval shell length, shell height, provinculum length, and number of teeth aided in classification of these and other sympatric species.
Cadmium and the phosphate granules in Littorina littorea
Authors: Nott J. A. , Langston W. J.
Published: May 2009

Previous studies with the marine gastropod Littorina littorea have shown that cadmium is concentrated in the digestive gland and that cytosolic metallothionein-like proteins sequester a large proportion of the accumulated burden. In the current investigation, an electron microscope cryo-preparation method and X-ray microanalysis have revealed that some cadmium, in association with sulphur, is localised in the region of the limiting membrane of the mineralised granules which detoxify certain metals as an insoluble phosphate salt. It appears, therefore, that there could be interaction between the sulphur and phosphate systems for binding metals within the basophil cells of the digestive epithelium.
The Lobster Fishing of one Boat in Plymouth District, from May 1st to September 29th, 1890
Authors: W. L. C.
Published: May 2009

The data for this paper were again supplied by Mr. Roach, and have all been reduced to tabular form. I shall here state only the general results.

The total number of lobsters taken was 1753. Of these 1226 were males and 527 females, i. e. 699 more males than females.
The Head Kidney of Teleostean Fishes
Authors: Calderwood W. L.
Published: May 2009

Until the year 1881, when Balfour wrote on the subject, the pronephros was generally believed to be a functional kidney, not only in the larval condition, but also in those adult forms described as possessing the organ.

Balfour, in his more detailed paper, published later, states that in the fishes examined—pike, eel, smelt, and angler—although the pronephros had all the appearance, externally, of a true functional kidney, no uriniferous tubules were present, and that a minute examination only disclosed a degenerate trabecular tissue which he describes as lymphatic.

The angler (Lophius), it may be observed, is generally considered to possess only a head kidney. This organ Balfour found to be in a perfectly functional condition, but he declines to believe that it is a persistent head kidney, and argues from the highly modified structure of the fish that the organ in question is in reality the mesonephros. shifted forward from its normal position. He also maintains that in adult Ganoids the head kidney has no longer a renal function. His general conclusion, therefore, is, that since the pronephros was only supposed to persist in Ganoids and Teloosteans, it must be now considered as non-existent except in the embryonic or larval conditions.