bluuebunny/crossref_metadata_2025 huggingface dataset:
The Shell Gravel Deposits, and the Infauna of the Eddystone Grounds
Authors: Smith J. E.
Published: May 2009

1. The limitations of the Conical Dredge as used in obtaining a sample for quantitative estimation of the fauna of a ground are discussed, and are found to be related to

(a)The great distance over which the instrument must be hauled, with consequent inability to detect patchiness of fauna.

(b)The inability of the dredge to capture members of the epifauna.

2. The nature of the shell gravel, its position relative to the Eddystone reef, and the various factors conditioning the degree of coarseness of the deposit and the segregation of its elements are considered. The main points of note are,

(a) There are three well-defined areas, within which the gravels have their own particular characteristics.

(1) TheInner Shell Gravelarea and theMiddle Gravelarea, composed of material of inorganic and organic origin, the former being gneissic in character, and the latter being formed of the remains of animals which normally live on this particular type of deposit.

(2) TheOuter Shell Gravelarea, a mixture of matter of local and of outside origin. The area is more extensive on the western than on the eastern side of the reef.

(b) Segregation of particles according to size occurs, and is illustrated by the movement of the valves of a number of species of molluscs. Wave action and the action of gravity are considered to be the chief factors in inducing movement of particles, which movement occurs in directions radiating from the reef outwards.

3. The epifauna of the rocky bottom is referred to briefly.

4. The infauna of the shell gravel has been examined quantitatively and qualitatively, and the range of the various species over the ground noted.

5. The nature of the shell-gravel community and its relation to some of the important environmental factors, are discussed.

6. Mortality among the lamellibranchs, and the depredations of the gastropodNatica alderiare considered; figures relating to the numbers of lamellibranchs killed byN. alderiare given.
A Quantitative Study of the Fauna of the Sandy Beach at Port Erin
Authors: Pirrie Marjorie E. , Bruce J. R. , Moore H. B.
Published: May 2009

A survey of the sandy beach at Port Erin, Isle of Man, was made in. September, 1931. Observations were made, at a number of stations, involving simultaneous records of the macro-fauna and its density, and certain physical and chemical factors of the sand and interstitial water, as well as tidal level on the beach. The results enable certain general conclusions to be drawn as to the causes of the observed distribution of species, and of the differences between the faunas of this and some Scottish beaches. Plans are given, indicating tidal contours, salinity, and grade composition, in situ on the beach, together with frequency diagrams for five dominant species.
Some New Eye-Colour Changes in Gammarus cheureuxi Sexton
Authors: Sexton E. W. , Clark A. R. , Spooner G. M.
Published: May 2009

In a previous paper (9) attention was drawn to the occurrence of five different “Mutant Stocks” of ‘Red-eye’ deviations from the normal black eye. Various differences in the characteristics of these stocks were indicated. For instance, Stock I Red-eye is a stable Bright Red behaving as a simple mendelian recessive, whilst in Stock V all kinds of shades of eye-colour occur with various sorts of changes during life.
Aspects Of The Biology of the Deep-Sea CrabGeryon TrispinosusFrom the Porcupine Seabight
Authors: Attrill M. J. , Hartnoll R. G. , Rice A. L.
Published: May 2009

A study was made ofGeryon trispinosus(Herbst) from the Porcupine Seabight in the north-east Atlantic, based on detailed examination of 687 specimens, and carapace length data for a further 2000. Evidence indicates that males become sexually mature at 30–35 mm carapace length, and females between 12 and 15 mm. There is probably a terminal anecdysis, in males at 55–65 mm and in females at 45–50 mm. The chelae show limited heterochely and marked right-handedness in both sexes. Relative growth in chelae and abdomen followed expected patterns, except that the right chelae of males decreased in relative size at the puberty moult. Seasonal reproduction is indicated: laying in September/October, hatching the following May, and settlement from the plankton in August/September.
Deep Demersal Fish Assemblage Structure in the Porcupine Seabight (Eastern North Atlantic): Slope Sampling By Three Different Trawls Compared
Authors: Merrett N. R. , Gordon J. D. M. , Stehmann M. , Haedrich R. L.
Published: May 2009

The demersal ichthyofauna of the continental slope of the Porcupine Seabight, eastern North Atlantic, was studied from 144 samples taken by three different types of otter trawl. At least 118 species from 43 families were represented among some 54,000 specimens collected from 247 to 2172m soundings. Collectively, the catches were dominated in species richness by the Macrouridae, Alepocephalidae and Squalidae and in abundance by the Synaphobranchidae, Macrouridae and Moridae. Separately, relative abundance of species was more similar between the two larger trawls, setting their catches apart from the smaller net. Gear selectivity evidently accounted for this variation, which was examined by an index we developed and call species fidelity. This accounts for patterns of continuous faunal change with increased soundings concomitant with variance in species adult size and mobility. In pursuance of a more accurate representation of relative biomass and abun-dance than achieved hitherto, the best estimate, within the limitations imposed by the sampling gears and regime, was derived from a combination of the mean values per 200m stratum of the two large trawls with the addition of those of the eel, Synaphobranchus kaupi, from the small gear. Tentative comparisons between these results and those from elsewhere suggest that the Porcupine Seabight is generally lower in biomass and similar or lower in abundance. It was concluded that an accurate indication of ichthyofaunal structure with increased soundings can only be achieved through a detailed knowledge of the size structure of each species over its entire sounding range synthesized from a multi-trawl investigation via analyses of species fidelity.
Seasonal And Spatial Variation of Epilithic Micro Algal Distribution and Abundance and its Ingestion By Patella Vulgata on A Moderately Exposed Rocky Shore
Authors: Hill A. S. , Hawkins S. J.
Published: May 2009

Microbial films represent the site at which grazers exert their influence upon the recruitment of settling macroalgae and animals. The overall purpose of this study of seasonal and spatial variation in abundance and composition of epilithic microbial films was to relate such patterns to macrobenthic community dynamics within the Fucus-bar- nacle mosaic characteristic of moderately exposed rocky shores on the Isle of Man. Additionally selective grazing in Patella vulgata was examined by comparing dietary and epilithic microalgal assemblages and how this varied seasonally and spatially within the mosaic. Chlorophyll analysis was used as an index of microalgal standing crop while SEM allowed in situ estimation of microalgal abundance.
Development, Growth, and Survival of Lepeophtheirus Salmonis (Copepoda: Caligidae) Under Laboratory Conditions
Authors: Johnson S. C. , Albright L. J.
Published: May 2009

Development, growth, and survival data derived from laboratory experiments are provided for Lepeophtheirus salmonis, a common ectoparasite of wild and sea-farmed salmonids. The mean development time of eggs was 419·1 hours (17·5 days) at 5°C, 207·1 hours (8·6 days) at 10°C, and 130·8 hours (5·5 days) at 15°C. Development from the first nauplius to the infectious copepodid stage took 222·3 hours (9·3 days) at 5°C, 87·4 hours (3·6 days) at 10°C, and 44·8 (1·9 days) hours at 15°C. Development from the egg to the adult male took 40 days, and from the egg to the adult female 52 days at 10°C. No egg development occurred at 10‰ salinity. At 15‰ eggs developed but failed to produce active nauplii. At higher salinities (20–3‰) active nauplii were produced, but copepodids were only obtained at 30‰. Copepodids survived for less than 1 day in waters with a salinity of 10‰ or less. At higher salinities (15–30‰) and temperatures of 5,10, and 15°C average survival times ranged between 2 and 8 days.
Trophic Sources and Pathways to the Developing Gametes of Pecten Maximus (Bivalvia: Pectinidae)
Authors: Pennec Marcel Le , Beninger Peter Gerard , Dorange Germaine , Paulet Yves Marie
Published: May 2009

Ultrastructural, histological and histochemical studies were performed on the gonad of adult Pecten maximus at various intervals during the reproductive cycle in St Brieuc Bay, France, in order to understand better the sources and transfers of energy to developing gametes in scallops. In addition to the well-known pathways of energy acquisition through feeding and transfer of somatic reserves, a number of novel pathways were demonstrated. These were grouped into two categories: atretic recycling and intestinal loop transfer. Evidence is presented for the recovery of lytic material (resulting from gamete atresia) in the gonad acini, gonoducts, and integument; and the direct transfer of metabolites from the gonad intestinal loop to the developing gametes via vesicular cell-haemocyte couples, which appear to follow fibrous pathways within the loose connective tissue extending from the base of the intestinal epithelium to the acini. A schematic diagram summarizes the sources and transfer mechanisms of the energy exchanges involving the developing gametes in Pecten maximus.
Image Analysis of Faecal Material Grazed Upon by Three Species Of Copepods: Evidence For Coprorhexy, Coprophagy and Coprochaly
Authors: Noji Thomas T. , Estep Kenneth W. , Macintyre Ferren , Norrbin Fredrika
Published: May 2009

Experiments involving three species of copepods(Acartia clausi Giesbrecht 1889, Pseudocalanus elongatus Boeck 1872 and Calanusfinmarchicus Gunnerus 1765) incubated with freshly produced copepod faecal material were conducted and analyzed using automatic image analysis. For two species (A. clausi and C. finmarchicus) the bulk of faecal material was not ingested but was fragmented. This process, coprorhexy, was accompanied by a shift toward smaller particles in the particle size-spectrum. Increases in total volume of the faecal particles after incubation with these copepods led us to propose a process which we refer to as 'coprochaly', derived from the Greek xot/Vaoio,(a loosening, as of bandages). Coprochaly was promoted by manipulation of the faecal material by the copepods. For the third species (P.elongatus) coprorhexy and coprochaly were coupled with coprophagy (ingestion of faecal material). Calculations indicated that the combined effect of coprorhexy and coprochaly reduced sinking velocities of the faecal particles by up to 50%. These processes increase pelagic residency time of particles, increase substrate area for aerobic microbes and presumably enhance remineralization of particulate organic matter.
Some Abnormal Fishes Received at the Plymouth Laboratory
Authors: Ford E.
Published: May 2009

Theobject of this short paper is to describe a number of fishes exhibiting interesting abnormalities. It will be seen from the list given below that several of the specimens to be described were sent to the Laboratory on the personal initiative of gentlemen to whom I express my thanks. I am also greatly indebted to Dr. H. A. Harris and the staff of the X-ray Department of the Institute of Anatomy, University College, London, for the beautiful radiograms they supplied.
The Absorption of Fats and Lipoids in the Plaice (P. platessaL.)
Authors: Dawes Ben
Published: May 2009

1. Fat occurs in all three types of cell composing the gastric epithelium at the end of a period of fasting extending over 6 or 7 days, but is completely absent from the mucosa of all post-pyloric regions of the alimentary tract at such a time.

2. There is a marked increase in the fat content of the superficial epithelium of the stomach after 30 hours and 50 hours of gastric digestion, the stomach being thus shown to be an effective organ of fat absorption.

3. Considerable quantities of fat are present in the duodenal and intestinal epithelia after fat-containing meals have been digested. The rectum is capable of some slight absorption, although its capacity in this respect is very much smaller than that of the duodenum or intestine.

4. It is suggested that there is a transference of the function of fat absorption from the stomach to the post-pyloric intestine when the frequency with which meals are taken is increased.

5. Globules of true fat are not typically observed in the areolar tissue layer of the alimentary tract, although lipoid granules may occur in abundance. It is suggested that resynthesis of the cleavage products of fats does not occur in this layer.

6. Data are presented bearing upon the rate of digestion ofMytilus edulisand Nereid worm.
The Cœlenterate Plankton of the Northumbrian Coast during the Year 1925
Authors: Watson Henry G.
Published: May 2009

This is a report of the Cœlenterate plankton taken during the cruises of the Evadne in 1925, and investigated at the request of Professor A. D. Peacock. I am indebted to Miss Ann R. Sanderson, B.Sc., for considerable help in the identification of specimens.
Further Investigation upon the Water Movements in the English Channel. Drift-Bottle Experiments in the Summers of 1927, 1928 and 1929, with Critical Notes on Drift-Bottle Experiments in General.
Authors: Carruthers J. N.
Published: May 2009

In July–August of three different years common surface-floating bottles were set adrift at International Station E2 (49° 27' N.—4° 42' W.). With them, various types of drag-fitted bottles were also put out. The journeys accomplished are discussed, and the striking differences as between year and year in the case of the common surface floaters, and as between the different types in the same year, are commented upon in the light of the prevailing winds. An inter-relationship of great simplicity is deduced between wind speed and the rate of travel of simple surface floating bottles up-Channel and across the North Sea from the results of experiments carried out in four different summers.
A Preliminary Comparison of the Neon Lamp and Potentiometer Methods of Submarine Photo-Electric Photometry
Authors: Atkins W. R. G. , Poole H. H.
Published: May 2009

1. J. H. J. Poole’s neon lamp method (1928) of integrating the photo-electric current is serviceable for work at sea down to moderate depths, which further experience may extend considerably. It is specially valuable for determining the light just above the water, and at such depths down to 5 m., at which the variability of the light renders the potentiometer method (1925) very difficult or quite impossible in rough water. For greater depths, down to 70 m. (bottom in the English Channel around our normal range) we have so far been able to use the latter only.

2. The loss due to the shadow of the ship, obtained by subtracting the illumination just above water from that on the deck-house roof, was found to vary from an extreme case of 52 per cent, and a normal loss of 30 per cent, with an overcast sky, down to 11 per cent with a clear sun at 31° altitude.

3. The loss of light due to its entering the water was found to vary from 7·5 to 16·5 per cent, mean 13·1 per cent.

4. It is desirable that the illumination just above and just below the water surface should be determined by the neon lamp method as a routine.
Studies on Ligia oceanica. I. A. Habitat and Effect of Change of Environment on Respiration. B. Observations on Moulting and Breeding
Authors: Nicholls Aubrey G.
Published: May 2009

1. Ligia is a nocturnal animal inhabiting crevices in rocks above high-tide level. It is omnivorous though Fucus spp. form the main article of diet.

2. Immersion experiments were carried out in which the animals were subjected to a gradual transition from salt to fresh water. None survived this treatment for more than one month. It was noticed that the reduction in salinity was accompanied by an increase in the rate of beat of the pleopods.

3. Animals were subjected to sudden and gradual changes in temperature. One specimen survived a change from water at 15° C. to water at 30° C. for 28 minutes, but was dead after 78 minutes; a second, changed from water at 15° C. to water at 35° C, was to all appearances dead after 8 minutes, but recovered after being replaced in water at the original temperature.
Studies onLigia oceanica. Part II. The Processes of Feeding, Digestion and Absorption, with a Description of the Structure of the Foregut
Authors: Nicholls Aubrey G.
Published: May 2009

1. Ligia is an omnivore, though normally feeding on Fucus. Portions of food are cut off by the mandibles and passed into the œsophagus. Its feeding period is limited.

2. The foregut is provided with a number of ampullæ and lamellæ which are furnished with spines and bristles and are so arranged as to form a filter for the separation of the liquid portion of the food from the solid particles.

3. A second filter is found in the floor of the foregut protecting the entrance to the hepato-pancreas.

4. A ventral valve is present preventing the entry into the hepato-pancreas of solid food from the intestine.

5. The hepato-pancreas consists of three pairs of tubules provided with a muscular network for producing contractions. The epithelium possesses discrete cells.
A Study of the Respiration and of the Function of Hæmoglobin inPlanorbis corneusandArenicola marina
Authors: Borden Mabel A.
Published: May 2009

A study of the respiration and of the function of hæmoglobin inPlanorbis corneusandArenicola marinahas been undertaken.

The oxygen consumption of Planorbis is of the order of 0·026 c.c. per gm. per hour, measured at 15° C.

The blood volume is approximately 0·581 c.c. per gm.

The combined oxygen of the blood is 0·013 c.c. per c.c. of blood, the total oxygen being 0·014 c.c. per c.c. The total oxygen capacity of the blood per gm. of snail is estimated to be 0·0081 c.c.

The oxygen supplied by the blood is calculated to last 18 minutes and is found by experiment to last 25 minutes.

The snail does not immediately oxidise its hæmoglobin after subjection to anaerobiosis. Oxidation begins after 10 minutes and is complete within 20 minutes.
Hydroid Pigments. I. General discussion and pigments of the Sertulariidæ
Authors: Payne Nellie M.
Published: May 2009

1. The yellow colours of the hydroids include at least two groups, the carotinoids found in the Antennulariidæ and Haliciidæ and the flavone-like pigments that occur in the Sertulariidæ. From the literature a third group, the uradines, may be added.

2. The flavone pigments and their relatives are all water soluble and are thus distinguished from the carotinoids which are not water soluble, but may be dissolved in the usual fat solvents.

3. In the Sertulariidæ studied, a graded series of chromatophore groups and pigments was found which ranged from the colourless speciesSertularia argenteaEllis and Solander, through the yellow ofSertularella gayiLamaroux andS. polyzoniasLinnæus, to the orange-brown ofThuiaria articulataPallas. The brown ofSertularia pumilais probably also a flavone derivative.

4. The flavones and related pigments occur extensively in the plant kingdom. It is probable that the flavone-like pigments found in the Sertulariidæ are of plant origin.
Clione limacina in Plymouth Waters
Authors: Lebour Marie V.
Published: May 2009

The pteropod Clione limacina (Phipps), now regarded as one of the tectibranchs, occurs at times in the neighbourhood of Plymouth. In 1930, however, it was extraordinarily abundant, especially in the summer, and was breeding freely. Although not specially recorded it has been seen singly or in small numbers in almost any month of the year, and for some years the eggs and larvæ (not recognised at the time as belonging to Clione) have been seen in summer. So far it is known from the British coasts in the North Sea and the west and extreme south-west of England. Its distribution, as known up to 1908, is given fully for the area of International Fisheries Investigations by Paulsen (1910). There it is shown that it is an Arctic-boreal species, spreading southwards nearly to the Bay of Biscay, which is about its southerly limit. It is known to occur in the northern and mid North Sea, but not in the southern North Sea, and at that time was only recorded from the Channel in the extreme west. It is also common in the Atlantic. Paulsen was led to infer that Clione limacina did not enter the North Sea from the Channel, but its prevalence sometimes at Plymouth shows that it can come a long way up the Channel and, as few samples are taken to the east and in the southern North Sea, this view should be carefully reconsidered.
The Larval Stages of Trivia europea
Authors: Lebour Marie V.
Published: May 2009

In 1926 Pelseneer discovered the eggs of Trivia europea on the French coast. These he found were laid in capsules embedded in the compound ascidian Polyclinum luteum, the molluse biting a hole and laying its eggs in a vase-like capsule completely enveloped in the ascidian except for the wide lip of the vase which projects freely and can be easily seen with the naked eye (Pelseneer, 1926, Figs. 11–12). He also hatched some larvae from these eggs which were very interesting, as they possessed an accessory shell somewhat similar in shape to the Echinospira of Lamellaria perspicua. He did not obtain the eggs directly from the Trivia and was not able to keep the larvæ alive more than a few days. In his paper he expresses the hope that some worker will confirm his observations experimentally. This I am now able to do, having procured the eggs actually laid by the Trivia, hatched them out and kept them alive for more than a week, afterwards collecting the larvæ from the plankton from stages which exactly corresponded with those from the egg up to late stages which metamorphosed into young Trivia, and young stages of Trivia feeding on compound ascidians which corresponded with the metamorphosed forms.

Trivia europea is common at Plymouth between tide-marks and in a few fathoms of water; occasionally further out in deeper water. Records are available from the shore to the region beyond the Eddystone.
A New Type of Luminescence in Fishes, III. The Gland in Cœlorhynchus cœlorhynchus Risso
Authors: Hickling C. F.
Published: May 2009

The luminiferous organ of the Macrurid fish Cœlorhynchus cœlorhynchus Risso is described in this paper. It consists of a gland, flattened dorsoventrally, placed in the body-wall, just in front of the pelvic fins. The secretory epithelium is thrown into a series of tubules, projecting downwards from the roof of the gland into a system of collecting spaces: the latter are confluent, posteriorly, with a duct which leads backwards, between the pelvic fins, to the anus. Blind pouches, which run upwards for a short distance beside the rectum, arise from the duct at its external opening at the anus.
Growth and Maintenance in the Plaice (P. platessa, L.) Part II
Authors: Dawes Ben
Published: May 2009

In a previous paper (Journ. Mar. Biol. Assoc., Vol. XVII, No. 1, Sept., 1930) I described in detail a series of experiments on Growth and Maintenance in the Plaice which were carried out during 1928 and 1929 at Cawsand, near Plymouth, and at Lympstone, near Exmouth. The purpose of the present paper is to present and discuss data collected at the above places during 1930 in continuing the experiments. The conditions under which the last experiments were carried out were identical with those of 1929, i.e. refined with reference to those of 1928. Several additions were made, however, to the series of 1929. Two fish of each sex were supplied with maximum rations while living under the conditions maintained during 1928 and were segregated in a box, which had the original ½″ mesh wire-netting windows but which was divided up into compartments. This experiment was arranged in order that we might ascertain the possibility of food leakage due to tidal action during the course of the earliest experiments, but it also enables us to compare the results obtained under slightly different conditions of water circulation, which is important in view of the fact that the windows of the modified boxes were of necessity minimal in area.
Biogeography of Isistius brasiliensis in the north-eastern Atlantic, inferred from crater wounds on swordfish (Xiphias gladius)
Authors: Muñoz-Chápuli R. , Salgado J. C. Rey , Serna J. M. De La
Published: May 2009

A hypothesis about the biogeography of Isistius brasiliensis in the north-eastern Atlantic is formulated through the study of frequency, size and geographic distribution of crater wounds, produced by this shark on swordfish (Xiphias gladius) and other large pelagic vertebrates. The results suggest that the bulk of the population of adult I. brasiliensis is found between 11° N and 16° N. Probably there are nursery areas in more southern latitudes. Large individuals would be frequent northwards of 16° N parallel.
Ultrastructure of the hepatopancreas of the Pacific white shrimp, Penaeus vannamei (Crustacea: Decapoda)
Authors: Caceci Thomas , Neck Kay F. , Lewis Donal D H. , Sis Raymond F.
Published: May 2009

Fourteen specimens of the hepatopancreas of the Pacific white shrimp, Penaeus vannamei, were prepared for examination with the transmission and scanning electron microscopes and with the light microscope. The histology and ultrastructure of this organ is similar to that seen in other Decapoda. At the ultrastructural level, it was observed that B-cells rupture at approximately the level of gap junctions located on the lateral plasma membranes of the cells, and discharge the contents of their large vacuoles into the intercellular space. This efflux of enzymatic material may be the mechanism by which cells are released from the wall of the tubule at the proximal end: the rupture and collapse of a B-cell may be analagous to the removal of the keystone which supports an arch. Deprived of support, and lacking structural adaptations for cohesion (there are no desmosomes or interdigitations in the epithelium) and with the intercellular material digested, the remaining intact cells collapse into the lumen of the tubule. The lysis of individual cells of all types - R-, F-, and B-cells - may contribute to the tubules’ total complement of digestive enzymes.
The larval development of Pholoe minuta (Polychaeta: Sigalionidae) in Galway Bay, Ireland
Authors: Heffernan P. , Keegan B. F.
Published: May 2009

Natural spawning of laboratory-held populations of Pholoe minuta occurred in synchrony with wild populations in Galway Bay. Larval development is described up to an age of 14 days using light and scanning electron microscopy. A pelagic planktotrophic larval phase (4-segment metatrochophores) was observed. Settled 3- and 4-chaetiger stages are described from meiofaunal benthic samples from the study area. A 3-week larval phase is indicated and the current findings are discussed in the light of existing literature on larval development in Pholoe minuta.
Spawning of Herring in Milford Haven
Authors: Clarke D. R. , King P. E.
Published: May 2009

Information regarding spawning grounds of the Atlantic herring Clupea harengus Linnaeus has been based mainly on the collection of spawning fish, newly hatched larvae, or the presence of eggs within the stomachs of predators (Postuma, Saville & Wood, 1977). This type of evidence indicates general areas of spawning, rather than accurately delineating the spawning grounds. Though samples of spawn have been obtained from several localities in the North-East Atlantic (Ewart, 1884; Runnström, 1941; Fridriksson & Timmerman, 1951; Bolster & Bridger, 1957; Parrish et al. 1959; Hemmings, 1965; Bowers, 1969; Anthony, Sauskan & Sigaer, 1970), few quantitative studies of individual grounds have been made. In consequence, little is known of the factors influencing the selection of grounds by Atlantic herring, the shape of these grounds and egg distribution within spawning areas.
Seasonal Catches, Size and Meristic Data for Sprat, Sprattus Sprattus, in the Severn Estuary
Authors: Potter I. C. , Claridge P. N.
Published: May 2009

While the sprat, Sprattus sprattus (L.), may live for up to a total of six years, at the end of which time the total length can exceed 150 mm, the fishery in British waters is based primarily on the second, third and fourth year classes (Robertson, 1936, 1938; De Silva, 1973). Historically, the sprat was a major contributor to the fishery of the Bristol Channel and Severn Estuary (Matthews, 1933; Lloyd, 1942). Although this fishery has declined during recent decades, the sprat has remained an important component of the teleost fauna of the region. This point is illustrated by the observation that S. sprattus was by far the most abundant of all teleosts in plankton samples taken throughout the Bristol Channel between the spring and autumn of 1974 (Russell, 1980). While length–frequency data were provided by Russell (1980) for these recently spawned sprat and there is comparable information for those sprat which form the basis of the commercial fishery in the Bristol Channel (Lloyd, 1942), no such data are available for those members of the population which are known sometimes to enter the Severn Estuary in considerable numbers (Lloyd, 1941).
Annual Macrofauna Production in A Hard-Bottom Reef Community
Authors: George C. L. , Warwick R. M.
Published: May 2009

This paper is the third and last in a series employing cohort growth-analysis techniques to describe the secondary production of the major component species in the macrobenthic communities of the Bristol Channel. Previous studies were made in soft-bottom areas of aVenuscommunity (Warwick, George & Davies, 1978) and anAbracommunity (Warwick & George, 1980). The hard-bottom areas of the Channel support what might classically be denned as aModioluscommunity(sensuThorson 1957; see Warwick & Davies, 1977), but within these communitiesModiolusitself is inconspicuous because of its small size. This community is found in its purest form on the rock-floors of the central region of the Channel, but gravel accumulates in areas of slower current seaward of this region and may often have admixtures of finer sediment accommodating a mixed-bottom subgroup of theModioluscommunity, containing additional species more typical of soft bottoms. The intention of this study was to examine a site representative of the community in its purest form. Quantitative grab sampling in the rock-floor areas was naturally impossible, but fortunately areas exist in which extensive reefs of the tubewormSabellaria spinulosaLeuckart are found, and the structure of these reefs is sufficiently brittle that quantitative grab samples can be collected. Such sites have a more diverse fauna than the open rock areas, the interstices of the reef providing a refuge for a large number of smaller species.
On The Fine Structure of Lateral-Line Canal Organs of the Herring (Clupea Harengus)
Authors: Jørgensen J. Mørup
Published: May 2009

The lateral-line system of water-living lower vertebrates is provided with mechanoreceptors enabling the animals to detect water displacements, either caused by moving objects such as prey, predators or neighbours in a school or by deformations of pressure waves from the swimming animal caused by other objects. Cyclostomes, some fish and water–living amphibians have their lateral-line organs situated superficially in the epidermis as free neuromasts, while most fish besides these neuromasts possess a canal system in the dermis. Ordinarily the lateral line canal system consists of a few canals on the sides of the head and a trunk canal. In herring, however, the canal system is confined to the head and opercule. It forms a very richly branched system with numerous pores which connect the canal fluid with the surrounding sea water.
Feeding By Oyster Larvae: The Functional Response, Energy Budget and A Comparison With Mussel Larvae
Authors: Crisp D. J. , Yule A. B. , White K. N.
Published: May 2009

Whereas there is a wealth of literature on the feeding of herbivorous holo-plankton, notably copepods, feeding by herbivorous larvae of benthic animals has been somewhat neglected. This paper considers the functional feeding response of veliger larvae of Ostrea edulis L., Crassostrea gigas (Thunberg) and Mytilus edulis L. fed on several micro-algal species. It also provides some data on the influence of temperature on feeding, and assesses the energy needs of the larvae in relation to their potential ingestion rate and to the availability in the sea of micro-organisms on which they feed.
The Genus Echinoderes (Kinorhyncha: Cyclorhagida) From The English Channel
Authors: Higgins Robert P.
Published: May 2009

The English Channel was the site of the discovery of the phylum Kinorhyncha in 1841 by the French zoologist Felix Dujardin. Although initially reported from St Malo, Rennes, and Paris by Dujardin (1851), St Vaast la Hougue, France was the site from which the first species, Echinoderes dujardinii Claparede, 1863 was described 12 years later. Since then, E. dujardinii has been reported from many localities in northern Europe as well as from the Mediterranean, the Black Sea, and the Canary Islands (cf. Higgins, 1983). Reports of this species from various North Pacific Ocean localities are either incorrect or higher questionable (Higgins, 1983).
Comparative Notes on Postlarvae and Pelagic Juveniles of the Rocklings Gaidropsaurus Mediterraneus, Rhinonemus Cimbrius, Ciliata Mustela and C. Septentrionalis
Authors: Demir Neclā , Southward A. J. , Dando P. R.
Published: May 2009

Five species of rockling: Gaidropsaurus vulgaris (Cloquet), G. mediterraneus (L.), Rhinonemus (Enchelyopus) cimbrius (L.), Ciliata mustela (L.) and C. septentrionalis (Collett), are commonly recorded from British waters. With the exception of G. mediterraneus, which has not been recorded from the North Sea, the other four species occur all round the British coasts. Two additional species have recently been added to the list of British fishes, Antonogadus macrophthalmus (Günther), a southern boreal species and Onogadus argentatus (Reinhardt), a northern boreal species (Wheeler, 1969; Russell, 1976). The identity of adult A. macrophthalmus is, however, still in confusion. It is not clearly known if it is a different species from A. megalokynodon Kolombotovic (a species which occurs in the Mediterranean and adjacent Atlantic waters), since both of them are considered as synonyms of G. biscayensis (Collett) (Bini, 1970; Tortonese, 1970; Svetovidov, 1973). Cohen & Russo (1979) have since relegated Onogadus and Antonogadus to synonyms of Gaidropsaurus, though the exact number of species is uncertain.
Seasonal changes in the phytoplankton as indicated by chlorophyll estimations
Authors: Atkins W. R. G. , Parke Mary
Published: May 2009

The pigments of pure cultures of algae, of known number per volume, have been extracted with aqueous acetone after separation by filtration. The extracts were compared in a Kober colorimeter with standard solutions of a preparation of bought chlorophyll. The number required to give 1 mg. of chlorophyll was thus determined.

The algae studied included: Chlorophyceae, two species ofChlamydomonasand oneChlorellanot yet described; Chrysophyceae,Dicrateria inornataParke; Bacillariophyceae,Coscinodiscus centralisEhr.,Thalassiosira gravidaCleve andNitzschia closterium(Ehr.) W.Sm. formaminutissima; Cryptophyceae,Hemiselmis rufescensParke; Dinophyceae,Gymnodiniumsp. The numbers per milligram of chlorophyll varied from 74 × 103forCoscinodiscusto over 3200 × 106forHemiselmis rufescens. Of the nine cultures, six were between 50 and 750 × 106. The volume of the cell is the decisive factor in the milligram count.
The identification of British species of the genus Ensis Schumacher (Lamellibranchiata)
Authors: Holme N. A.
Published: May 2009

The diagnostic characters of the British species of Ensis are described. The shell remains the primary means of identification, but additional characters in the soft parts are necessary for certain recognition. The three forms of Ensis described are considered to be valid species.
A statistical study of variability in catch obtained by short repeated trawls taken over an inshore ground
Authors: Barnes H. , Bagenal T. B.
Published: May 2009

The variability in catch of a series of hauls with a V.D. trawl taken under, as far as possible, controlled working conditions has been determined.

For analysis the species were divided into ‘round’ fish and ‘flat’ fish together with Nephrops; for both groups the coefficient of variation varied from 40 to 85 %. Taking 75 % as a representative value, the 2σ fiducial limits are 30–300 % for a single species from a single haul of half an hour duration.

It has been found that the standard deviation is roughly proportional to the mean, and that the variance is greater than the mean and increases with the mean. This suggests aggregation of the population.

The species are considered over the whole sampling period (4 weeks). Except for haddocks and dogfish the ‘round’ fish constituted a constant population. Changes were found in the other groups and their origin is discussed.
The status of the common seal (Phoca vitulinaL.) on the East Anglian coast
Authors: Sergeant D. E.
Published: May 2009

A study has been made of the food, population, and some aspects of the ecology of the common seal (Phoca vitulinaL.) along the East Anglian coast.

Examination of stomach contents of 194 seals killed in the Wash in 1947 confirms earlier evidence that the species here feeds largely on whelks (Buccinum undatum). The food is estimated by weight as 92 % molluscs, 4 % fish and 4 % Crustacea. Young seals for 2–3 months after weaning feed almost exclusively on shrimps (Crangon vulgaris).

Data derived from six stomachs, together with verbal reports, suggest that seals on the open coast feed more exclusively on fish, chiefly pleuronectids. This agrees with the findings of other workers in Holland and Washington State, U.S.A., that fish are the primary food animals. It is therefore suggested that in the Wash, where suitable breeding sands are common, the seals have become adapted to feeding on a ‘second-class’ food in the absence of dense stocks of fish.
Observations in the sea on the reaction to ultra-violet light of certain sound scatterers
Authors: Craig R. E. , Baxter I. G.
Published: May 2009

Two experiments on the reaction to ultra-violet light of certain sound scatterers in the area are described.

The source was a 125 W. ultra-violet lamp.

The scatterers were detected using a Kelvin and Hughes recording echo-sounder, type 22.

The traces on both occasions were of the confused type caused by a number of different organisms, apparently lying between 20 and 60 m. and 8 and 30 m. respectively.

The responses of the different organisms to the ultra-violet light as shown by the components of the traces are described and their speeds of reaction calculated.

The types of organisms causing the traces are suggested.
Vitamin A and carotenoids in certain invertebrates. I. Marine Crustacea
Authors: Fisher L. R. , Kon S. K. , Thompson S. Y.
Published: May 2009

Planktonic, benthic and littoral Crustacea were collected from localities around the British coast, from Norwegian and Faeroese waters and from the Antarctic, and their content of preformed vitamin A and carotenoid pigments was measured.

Methods are described for the preservation of specimens, the extraction and separation of vitamin A and carotenoids and the measurement of vitamin A by chemical, physical and biological tests, and of carotenoids by physical tests.

Free-swimming euphausiids were found to contain, in addition to large quantities of astaxanthin, high concentrations of preformed vitamin A, but no β-carotene.
A note on the breeding season, sex ratio and embryonic development of the dogfish Scyliorhinus canicula (L.)
Authors: Harris John E.
Published: May 2009

Records of nearly 2000 dogfish collected from the Ilfracombe region suggest that the spawning season of this fish starts in November and continues at least until July. This area probably represents a spawning ground into which the females migrate during the spawning season; the males follow them much later in April and May.

Figures are given to show the time taken at different temperatures for the embryo to develop to a series of definite morphological stages; these suggest that the temperature characteristic of the development (µ = 20,000) is substantially the same as for several teleost species.
Factorial Analysis in the Ecology of Rocky Subtidal Areas Near Brest (West Brittany, France)
Authors: Castric A. , Chasse C.
Published: May 2009

In order to investigate the characteristic species and the relative importance of selected environmental conditions of rocky bottom communities in coastal waters and to estimate their richness, 27 sites in the Brest area were surveyed by diving. The abundances of underwater species, from a check-list of 115, were plotted as number of individuals or colonies in m2 or in percentage cover of the rock, against the environmental conditions (depth, bedrock slope, substrate type and sediment nature of the nearest soft bottom). Raw data were converted to biovolume expressed as mm3 m–2 and expressed as log 10 (x + 1).

Various correspondence analyses were applied to these data: the first included bedrock slope (lit/dark surfaces) and takes into account the four biological formations according to the depth. It shows zonation with depth and decreasing light as factor 1, hydrodynamic conditions (waves or current) as factor 2, mixing of estuarine and oceanic waters as factor 3 and turbidity as factor 4. Four species assemblages emerge from these four axes, for which the main species contributing to the four axes may be considered as characteristic species. These correspond well to four broad communities described in British waters: very exposed to wave-action, semi-exposed to wave-action, exposed to strong tidal current, very sheltered sites. The second analysis, in which lit and dark surfaces are distinguished, but some very close sites are fused together, shows in detail the photophilous or sciaphilous nature of the species. Values of hydrodynamic conditions and percentage of surface light plotted on the 'stations-points' of the graphs allow drawing of a factorial network which may be used as hydrodynamic and illumination scales.
Foraging Activity of Limpets in Normal and Abnormal Tidal Regimes
Authors: Little Colin , Partridge Julian C. , Teagle Linda
Published: May 2009

Activity of Patella vulgata was monitored in the asymmetrical tidal regime of an Irish sealough, Lough Hyne, and also outside the lough in a normal tidal regime. An automated method was used, allowing continuous records to be made over two weeks. Most activity occurred at night while the limpets were emersed. Rainfall depressed activity. There was little activity during daytime emersion, contrary to the results of previous studies in which low-shore limpets foraged diurnally as well as nocturnally. Timing of activity in relation to tidal coverage was similar inside the lough and outside.

Activity of high-shore limpets within the lough was greater at spring tides than at neaps, but that of low-shore limpets was greater at neaps. Outside the lough, both high-shore and low-shore limpets showed greater activity at spring tides. Reasons for the differences are discussed.

Using Maximum Entropy Spectral Analysis, three periodicities underlying limpet activity were indicated. These were at h, 124 h and 8–2 h. When limpet activity was simulated by adding three sine waves of appropriate periodicity, rhythms very similar to those recorded from the shore were produced.
Biological and Physical Factors Controlling the Spatial Distribution of the Intertidal AlgaGelidium Pristoidesin the Eastern Cape, South Africa
Authors: Carter A. R. , Anderson R. J.
Published: May 2009

Gelidium pristoidesdominates the lower and mid-eulittoral zones of rocky shores in the eastern Cape, South Africa. A disproportionately high percentage of the plants is attached to barnacle and limpet shells, or restricted to rock crevices. Our experiments at Port Alfred indicate that this distribution is caused by grazing by the limpetPatella oculusand/or strength of attachment of the plants to the different substrata. Exclusion of limpets caused an approximately four-fold increase in the cover of G.pristoideson rock, and an increase from almost 0 to 80% cover on sterilised (dead) limpet shells. Measurements showedG. pristoidesto be more than 50% more strongly attached to barnacle and limpet shells than to rock. The distribution ofG. pristoideson the various substrata is largely determined by limpet grazing and possibly the different strengths of attachment to the different substrata. The upper distribution limit ofG. pristoidesis set by physical effects of emersion and was largely unaffected by limpet exclusion. Competition with other algae is important in setting the lower limit: in the sublittoral fringe, although limpet exclusion enhanced recruitment, juveniles were later displaced by articulated corallines, and adult transplants senesced because of encrusting coralline epiphytes.
The Hypobranchial Gland in Morula Granulata (Gastropoda: Prosobranchia)
Authors: Srilakshmi G.
Published: May 2009

The hypobranchial gland ofMorula gramilata (Duclos) has been morphologically and histochemically characterized. The marginal zones of the gland have mucocytes and eosinophil cells while the median region has in addition ciliated cells and gland cells. Neurosensory cells are also present. Two types of mucous cells have been identified. Type I secrete a diastase-resistant, neutral mucopolysaccharide, while type II secrete PAS unreactive, strongly acidic and highly sulphated mucins. Exposure to low temperatures, ultraviolet rays and irritants resulted in the production of a purple dye.
Sexually Dimorphic Free-Swimming Behaviour in the Amphipod Crustacean Ampelisca Abdita
Authors: Borowsky B. , Aitken P.
Published: May 2009

This paper describes a novel sexually dimorphic pattern of behaviour in the tube-building amphiplodAmpelisca abdita (Mills). Mature males and females enter the water column at night. However, while males enter the water column every night, females enter it only when they moult. Since female amphipods only mate shortly after they moult, it is hypothesized that this sexually dimorphic pattern of free-swimming behaviour is an adaptation that permits males and receptive females to locale each other during the brief period when copulation can occur, while reducing the time that females are exposed to pelagic predators.
The Influence of Photoperiodicity on Hatching ofSepia Officinalis
Authors: Paulij W. P. , Herman P. M. J. , Roozen M. E. F. , Denuce J. M.
Published: May 2009

The influence of photoperiodicity on hatching ofSepia officinaliswas investigated under different experimental light-dark (LD) conditions. The results are viewed in relation to some relevant properties of the perivitelline fluid (PVF) and the egg capsule during embryonic development. In embryos ofS. officinalisthe transition from light to dark ap-pears to act as a 'Zeitgeber' or synchronizer. The embryos consistently hatched during periods of darkness, even when the duration of the dark period was short (1–4 h) and replaced part of the natural light period. The hatching rhythm was independent of the embryonic stage at which the experimentwas started. Embryos that developed under a given LD rhythm did not hatch at that rhythm if it was changed or eliminated. In the absence of an external LD rhythm the time to hatching increased. Lack of pigmentation in the egg envelope appeared to reduce the time to hatching. If embryos were exposed to a single dark period of 1–4 h significantly more hatched during darkness while a dark-pulse of ten minutes resulted in no hatching. At the end of embryonic development the egg capsule ofS. officinalisbecomes thinner due to the expanding PVF. Absence ofthe envelope did not affect embryonic development but dramatically increased mortality and prema hire hatching (96%). Spectrophotometrical investigations indicated that light between 200 and 900 nm is absorbed similarly by the envelope and by female ink. The function of pigmentation in the envelopes remains obscure.