bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution, Abundance and Size Composition of Mullet Populations in the Severn Estuary and Bristol Channel
Authors: Claridge P. N. , Potter I. C.
Published: May 2009

The following three species of grey mullet (Mugilidae) are recorded by Wheeler (1978) for the waters of north-western Europe: thick-lipped mullet, Chelon labrosus (Risso, 1826); thin-lipped mullet, Liza ramada (Risso, 1826) and golden mullet, Liza aurata (Risso, 1810). Liza ramada was obtained in relatively large numbers during the course of extensive sampling of the material collected on the intake screens of power stations in the Bristol Channel and Severn Estuary (for details of other studies see e.g. Claridge & Gardner, 1977, 1978; Titmus, Claridge & Potter, 1978; Abou-Seedo & Potter, 1979; Claridge & Potter, 1983, 1984). Since there is apparently no detailed information on the biology of the thin-lipped mullet in the estuaries of north-western Europe based on regular frequent collections, the power station material was used to provide data on seasonal and annual abundance, size composition, growth and lip depth of this species in the Severn Estuary and Bristol Channel. Comparisons have been made between these data and those obtained for C. labrosus from the same environments and more particularly from outside the area at Pembroke where much larger collections of this latter species were taken.
A Structural Analysis of the Spermatophore of Runcina Ferruginea Kress (Opisthobranchia: Cephalaspidea)
Authors: Kress Annetrudi
Published: May 2009

A spermatophore is defined as a capsule of albuminous matter containing a number of sperm. Among opisthobranchs the families Retusidae, Philinoglossidae, Bullidae, Atydae and Runcinidae are all said to possess a copulatory apparatus which stores sperm and also forms spermatophores (Ghiselin, 1966). Relatively little information exists concerning the structure of the copulatory apparatus or the spermatophore in these groups and practically nothing is known about the copulatory behaviour of the animals and the fate of the spermatophore (Perrier & Fischer, 1914; Ghiselin, 1963, 1966; Thompson, 1976;Beeman, 1977). This paper will focus on the structure of the spermatophore of the cephalaspid Runcina (Kress, 1977). The formation of sperm occurs in the hermaphroditic glands, in a more central position than that of the eggs. These autosperm leave via the common genital aperture which is located laterally to the gills. They travel by means of strong ciliary action, through a seminal groove to the male copulatory apparatus on the right of the mouth. The sperm then moves through the penis and the prostate into a storage sac, the seminal vesicle. For copulation, these sperm are packed into a spermatophore which should presumably be introduced into the common genital aperture but which may be found attached to the mantle or foot, even to animals not yet sexually mature. We have taken this opportunity to study the spermatophore which otherwise might not be easily detected.
Recent Investigations into the Distribution of Regular Echinoids in the North Sea
Authors: Cranmer G. J.
Published: May 2009

A major contribution to our understanding of the distribution and taxonomy of echinoids in British waters was made by Mortensen (1927, 1928–1951). Many earlier qualitative investigations (e.g. Süssbach & Breckner, 1911; Brattström, 1941) which dealt only with limited areas, were combined in Mortensen (1928–1951) to produce an overall assessment of the North Sea echinoid fauna.

In his discussion paper Ursin (1960) synthesized findings from his 20 year grab sample survey with the work of others to produce a valuable quantitative analysis of the echinoids of the central North Sea (54–5 8° N).

In recent years (1977–1983) participation on demersal fish surveys in the North Sea has enabled the distribution and population structure of the macroepibenthic component of the water column to be recorded (Dyeret al.1982, 1983; Cranmer, Fry & Dyer, 1984).

Although this present study has added no new echinoid species to the fauna it has given a detailed picture of echinoid distribution in the area.
Chemistry of Calcified Portions of Nautilus Pompilius
Authors: Crick R. E. , Burkart B. , Chamberlain J. A. , Mann K. O.
Published: May 2009

The Sr, Mg, and Ca chemistry and mineralogy of the shell, beaks, and inorganic compounds of the renal appendages of Nautilus pompilius Linné 1758 reveal a complex physiochemical system of biomineralization. The chemistry of the shell and septal aragonite is similar, and establish that N. pompilius discriminates against the concentration of Sr and Mg in sea water by 78% and more than 99% respectively. Beaks consist of high-Mg calcite (4.4% MgCO3). Renal appendages contain either aggregates of crystals (uroliths) of Mg-oxalate dihydrate with nuclei of hydroxyapatite or disassociated particles of hydroxyapatite or both. There is no evidence that uroliths or hydroxyapatite particles serve as temporary reservoirs of Ca during calcification of septa.
Tube Formation in Pomatoceros triqueter L
Authors: Faouzi H.
Published: May 2009

As a serpulid, Pomatoceros triqueter L. realises to the highest degree the adaptation to a sedentary life. The calcareous tube in which this annelid lives is characterised by a keel running along its upper surface. It is rather misleading to say that this tube is triangular in section. Figure 2 shows a newly formed calcareous rod; it is spur-shaped; the two rami of the spur might approach each other so nearly as to simulate an almost complete tube. The substratum in this species not only serves as a support, but completes the tube. This is in accordance with the fact that the tubes of Pomatoceros never extend freely off the support as happens with tubes of other serpulids–Protula, for instance. The aim of this paper is to record some observations on the way an adult Pomatoceros endeavours to build a new calcareous tube if it is artificially removed from its old one. I undertook this observation as original work at Roscoff, where a complete literature was not available. I discovered later that Harms, in the course of his research on regeneration in Hydroides pectinata, arrived at identical results. My paper cannot therefore pretend to more than a confirmation of previous results.
The Larvæ of the Plymouth Galatheidæ. II. Galathea squamifera and Galathea intermedia
Authors: Lebour Marie V.
Published: May 2009

In a previous paper (Lebour, 1930) the general characters of the larvæ of Galathea were described and the various stages of Galathea strigosa and Galathea dispersa identified. The present paper deals with the larvæ of Galathea squamifera and Galathea intermedia which have also been followed through their life histories. This completes the larvæ of the Galatheidæ from Plymouth with the exception of Galathea nexa, the larvæ of which have not been seen. As is noted in the previous paper this Galathea is regarded as a separate species from G. dispersa.
The Lower Limits of Perception of Electrical Currents by Fish
Authors: Regnart H. C.
Published: May 2009

In recent years attention has been given to the influence of electrical currents as fish deflectors or screens, and experiments have been made to determine the magnitude of the currents which are sufficient to paralyse or act as deterrents to fish which may enter the electrical field, but in such strong fields the perception of the mechanism by which fish respond to electric currents is masked by the paralysis produced. It seemed possible that experiments with very weak currents might give fuller information concerning the mechanism by which fish respond to electrical stimulus than those made in strong fields. There is also the possibility that weak electric currents may occur in nature to which fish respond, but before exploring that field of phenomena it is necessary to observe the behaviour of fish under the influence of very weak fields. McMillan found that the field (volts per inch) required to paralyse young salmon varied with the resistivity of the water; thus when the latter was 10,000 ohms per inch cube the paralysing voltage was about 1·5, so that a current density of ampere per square inch was sufficient to cause paralysis, whereas when the resistivity was twelve ohms per inch cube the current required was ·03 ampere. In the former case the conductivity of the fish was greater than that of the water, in the latter case less.
On Abnormal Conditions of the Gills inMytilus edulis. Part II. Structural Abnormalities, with a Note on the Method of Division of the Mantle Cavity in Normal Individuals
Authors: Atkins D.
Published: May 2009

In the examination of a total of about twenty-four thousand mussels from various localities in Devon and Cornwall—estuaries of the Fal, Hamoaze, Yealm, Teign and Camel, and the Promenade Pier, Plymouth— it has been observed that those from various parts of the Fal Estuary included a high percentage of specimens with the gills in an abnormal condition, whereas such abnormalities were rare or absent in other localities.
An Amœba from the Intestine of an Ascidian at Plymouth
Authors: Mackinnon D. L. , Ray H. N.
Published: May 2009

While working at Plymouth in December, 1928, and in August, 1930, we noticed amœbæ in the intestine of Phallusia mamillata (Cuvier) which had been dredged in the Sound. The ten animals examined were all infected. The only previous record we can find of an amœba in such a situation is a short account given by Huxley (1920) of a small form occurring in large quantities in the stomach of Clavellina lepadiformis at Naples. The amœbæ we have seen are not like those from Clavellina and they seem to merit some description.
The Adsorption of Ions from Sea-Water by Sand
Authors: Stowell F. P.
Published: May 2009

1. The ions present in sea-water are normally adsorbed by sand.

2. Percolation of sea-water through sand causes a slight abnormality in the concentrations of calcium and magnesium ions, due to the fact that sand is not an inert adsorbing agent, but is capable of discharging calcium ions into the water in exchange for magnesium and sodium.

3. The extent of adsorption and exchange is insufficient to cause hydrolysis and alteration in pH if the bulk of the sea-water is large.
Notes on the Biology of some Lamellibranchs in the Clyde Area
Authors: Stephen A. C.
Published: May 2009

The paper deals with four species from the Clyde Area, namely: Tellina tenuis, Tellina fabula, Abra alba, and Cardium edule.

T. Tenuis.

1. The growth at one station below L.W.M. in Kames Bay is considered. This is slower than in any other part of its vertical range.

2. Heavy spat-falls were recorded in 1926 and in 1930, but, in both cases, the spat grew slowly and died off quickly at the stations below L.W.M.

3. The general rate of growth for the species from its upper to its lower limit of distribution in Kames Bay is tabulated.
Observations on the Fauna and Constituents of an Estuarine Mud in a Polluted Area
Authors: Fraser James H.
Published: May 2009

1. An ecological survey of the fauna of Dingle Beach, Mersey Estuary, has been made.

2. A detailed analysis of the constituents of the mud, sand and gravel is given.

3. A quantitative analysis of the Molluscan fauna from a series of stations has been made.

4. Type of ground and fauna at different tidal levels are correlated.Mya arenaria is only found in abundance where there are stones. Macoma balthica is abundant wherever there is thick mud.

5. Dingle Beach is a type of Macoma community but differing markedly from the typical community described by Petersen as “d”.

6. The importance of sewage in producing silt and the part played by sewage in the food chain are discussed.
The Larval Stages of Simnia patula
Authors: Lebour Marie V.
Published: May 2009

Simnia patula (Pennant)=0vula is common feeding on Ahyoniwm digitatum and on Eunicella verrucosa, trawled in Plymouth waters. Mr. E. A. Todd records in the 1904 Plymouth Fauna List (Plymouth Marine Invertebrate Fauna, Journal of the Marine Biological Association, VII, 1904), which is quoted in the new fauna list (1931, Marine Biological Association), that “spawn probably belonging to this species has been found in April, June-July.” This spawn is also well known to other members of the staff of the Laboratory and it is often found with the Simnia itself. It is now quite certain that it is the spawn of this mollusc, for it has been deposited in a plunger-jar on the glass and on Alcyonium (Jan. 19/20, 1932), and hatched out Feb. 21/22, 1932; it has been hatched out in the Laboratory, the larvae distinguished in the plankton and reared until the crawling stage in a plunger-jar; and young stages which bridge the gulf from larva to adult have also been found. The adults will live for months in a plunger-jar feeding voraciously on Alcyonium. The life-history is described here for the first time. It is very interesting because it is quite unlike that of Trivia euro-pea recently described (Lebour, 1931b), although the two are placed in the same family. Trivia bites holes in compound ascidians and lays its eggs in vase-shaped capsules embedded up to the neck in the ascidian, and these hatch out into larvae having accessory shells rather like those of Lamellaria but with distinct differences. Simnia lays its eggs in a single layer of capsules, spreading over the Alcyonium for an inch or more in an irregular roundish mass (Text-figure 1).
The Eggs and Early Larvæ of Two Commensal Gastropods, Stilifer stylifer and Odostomia eulimoides
Authors: Lebour Marie V.
Published: May 2009

Stilifer stylifer (Turton) has been recorded from Plymouth many years ago living on Psammechinus miliaris (=Echinus) and Echinus esculentus; also from several other British localities (see Jeffreys, 1867, IV, p. 196). Jeffreys describes the spawn and larvæ hatched from it, but apparently these have never been figured. It had not been rediscovered at Plymouth until 1931 when in August Mr. A. D. Hobson found several specimens of Psammechinus miliaris from deep water beyond the Eddystone with these small commensal molluscs on them. In the first lot of about a dozen Psammechinus, three were covered; with the spawn of Stilifer, one having one mollusc and two having two. In a second lot taken a few days afterwards, five were covered with spawn, one having one mollusc, two having two, and two having three. These were placed in a plunger-jar, but unfortunately most of the Stilifer left the Psammechinus and were presumably eaten by them as pieces of their shells were found. They probably did not like their surroundings. Some of the spawn was removed from the Psammechinus and placed in a fresh plunger-jar with some Nitzschia where some of the larvæ hatched out. A Psammechinus was introduced in the hope that the larvæ might settle down, but they all died after living only a few days.
The Determination of Nitrate in the Sea by Means of Reduced Strychnine
Authors: Cooper L. H. N.
Published: May 2009

The recent criticism of Thompson and Johnson (7) of the method of determining nitrate in the sea by means of reduced strychnine is held to be unsound.

Preparation of the reagent given due care and pure materials has offered little difficulty.

A possible method for the preparation of nitrate-free sulphuric acid is outlined.

The effect of iodate in concentrations likely to be met in the sea is negligible.

Interference by organic material has been avoided by first centrifuging all samples obtained during periods of plankton activity.

The relative intensity of colour given by nitrate and by nitrite nitrogen is discussed.
Nitrate in Sea-water and its Estimation by means of Diphenylbenzidine
Authors: Atkins W. R. G.
Published: May 2009

1. The diphenylbenzidine reaction of Letts and Rea has been examined and is recommended for use in sea-water; 2·5 ml. of sea-water is mixed with 6·0 ml. of the purest strong sulphuric acid and then allowed to cool. Subsequently 1·5 ml. of a sulphuric acid solution of diphenylbenzidine is added, the concentration being 20 mg. per 100 ml. of acid. The colour should be compared, after 20-24 hours, with a standard solution made up by adding a definite quantity of nitrate to the sea-water. A blank correction should be used. Diphenylbenzidine used must be recrystallised from boiling toluene.

2. If the sulphuric acid used is found to give a blue colour with diphenylbeniddine, this may be removed, if not too intense, by warming the acid for a few minutes. With a more intense blue the nitric acid-present may be eliminated by previous cautious treatment with hydrogen sulphide. Phosphoric acid may be used instead of sulphuric acid with fresh water, but not with sea-water.
The Development of Nereis pelagica Linnæus
Authors: Wilson Douglas P.
Published: May 2009

Larvæ of Nereis pelagica Linnæus were reared from the egg, and the young worms, which developed from them, to the age of one year.

The larvæ from an early stage possessed three chætigerous segments. At first after hatching they swam strongly by means of a prototroch, an akrotroch and three paratrochs, but as the cilia gradually disappeared they crawled more and more, finally abandoning swimming altogether.

The head developed a pair of tentacles anteriorly and a pair of palps ventrally. A pair of tentacular cirri arose posterior to the prototroch and a little later a second pair ventral to them.

The first pair of parapodia lost their bristles, and a lobe which had grown out between the noto- and neuropodial chæta-sacs became a third and posterior pair of tentacular cirri. Much later a fourth pair developed ventral to them.

About the time when the larvæ ceased to swim (18.days old) a fourth pair of larval parapodia (third adult pair) appeared, to be followed by a fifth, sixth, etc. At sixty-five days old worms had about twentyone pairs of parapodia, at one year they had sixty and were then about 1-5 cm. long.

During larval development a constant succession of bristles was seen. In the earliest stages the bristles were mainly homogomph spinigers with long appendices; later these fell out and were replaced by homogomph and heterogomph falcigers with shorter appendices. Later still these were replaced by bristles of the adult type.

It is pointed out that these larvæ differed from those which Herpin reared in that they hatched earlier and instead of crawling as soon as liberated they swam for several days by means of their ciliated girdles.
A Note onBalanophyllia regia, the only Eupsammiid Coral in the British Fauna
Authors: Yonge C. M.
Published: May 2009

TheEupsammiidé are one of the most interesting families of the Madjeporaria. They have an exceptionally wide range of distribution, being found alike in temperate and tropical seas. In the latter they were probably originally confined to deep water, where the majority of them still occur, but they have extended their vertical range (Yonge, 1930) and various species are now found on many of the coral reefs in the Indo-Pacific region. ThusDendrophyllia rameaoccurs in moderately deep water in the Mediterranean and has also been found in the English Channel off RoscofE (Lacaze-Duthiers, 1897), while other species of this genus are common near the surface on many of the Pacific coral reefs, the bright orange-coloured polyps ofDendrophyllia mannibeing, for example, very conspicuous on the fringing reefs at Kaneohe Bay on the Island of Oahu, Hawaii (Edmondson, 1929; Yonge, 1930).
Specific Differences in the Gonadial Spicules of Echinus esculentus (Linnæus) and Psammechinus miliaris (Gmelin)
Authors: Rawlinson Ruth
Published: May 2009

The observations here recorded were made as a result of a suggestion by Professor Orton. While examining material of Psammechinus miliaris he noted the presence of C-shaped spicules in the gonad. He kindly passed the material on to me, suggesting that an examination of other common Echinoids might prove interesting.
Salinity Interchange between Salt Water in Sand and Overflowing Fresh Water at Low Tide. II
Authors: Reid D. M.
Published: May 2009

Thefollowing is a continuation of the work described in a previous paper (Reid, 1930). The intention was to amplify that work by the investigation of the conditions of salinity interchange on sandy shores of less ideal type. It was considered likely that various factors might affect the condition of the water held by the sand. For instance, the rate of flow of the fresh water and its depth; irregularity in the slope of the beach; the depth of the sand and the nature of the floor on which it rests. The rate of flow of the water is not a simple factor however. It is correlated with the slope of the beach in that faster streams are usually on steeper beaches. The effect of this dual factor will be discussed later.
Mechanisms Of Resistance to Polychlorinated Biphenyls (PCB) in Two Species of Marine Diatoms
Authors: Cohen Melissa K. , West Anne S. , Cosper Elizabeth M. , Wurster Charles F.
Published: May 2009

Clones of Ditylum brightwellii and Thalassiosira nordenskioldii were isolated from New York coastal waters, and PCB-resistance in D. brightwellii was induced in the laboratory by exposure to increasing concentrations of PCB. Resistance could not be similarly induced in T. nordenskioldii, but was serendipitously discovered in unexposed cultures that had undergone sexual reproduction.

Cells of the resistant strain were substantially larger than those of the sensitive strain in both species. Larger vacuole space seemed to account for this in D. brightwellii, but in T. nordenskioldii larger cells contained more carbon. Experiments with14C-PCB tracer indicated that PCB accumulation was less in resistant strains of both species. Neutral lipid content per cell, as determined using the fluorophore Nile Red, was similar for resistant and sensitive strains of both species. Sub-cellular examination of lipid droplets in D. brightwellii suggested that the PCB-resistant strain may be sequestering this lipophilic toxicant in a location removed from physiological activity. In T. nordenskioldii a decreased ratio of neutral lipidxarbon may reduce intracellular accumulation of PCB. These diatom species have developed PCB resistance in the highly PCB-polluted Hudson River estuary and, since they are the preferred food of dominant copepods, they may offer less PCB per unit ration to zooplankton grazers.
The Ampelisca Diadema Group of Species (Amphipoda: Gammaridea) in British and Irish Waters
Authors: Myers A. A. , McGrath D.
Published: May 2009

The characters widely used for identifying members of the Ampelisca diadema group of species (A. diadema, A. spinipes, A. tenuicornis and A. armoricana) are reassessed. Highly variable characters are discarded in favour of more stable ones. Both sexes of all four species known from the north-east Atlantic are figured and diagnoses and a key to the species are provided.
The Institute Of Oceanographic Sciences Biology Programme In The Porcupine Seabight: Background And General Introduction
Authors: Rice A. L. , Billett D. S. M. , Thurston M. H. , Lampitt R. S.
Published: May 2009

An intensive investigation of the benthic biology of the Porcupine Seabight, to the south-west of Ireland, was carried out by biologists from the Institute of Oceanographic Sciences Deacon Laboratory (IOSDL) between 1977 and 1986. More than 400 benthic samples were obtained during the study using towed gears and corersover the depth range 200 to 4500 m. Transect and time-lapse photography was used extensively. This paper summarises the techniques employed and provides an analysis of the depth and seasonal coverage. In addition a review is provided of available data on the physical, chemical and geological characteristics of the Porcupine Seabight area, including information collected during the IOSDL study. Finally, existing publications based on the study are listed.
Deep Demersal Fish Assemblage Structure in the Porcupine Seabight (Eastern North Atlantic): Results of Single Warp Trawling at Lower Slope to Abyssal Soundings
Authors: Merrett N. R. , Haedrich R. L. , Gordon J. D. M. , Stehmann M.
Published: May 2009

The dynamics of clearance, segregation and elimination of a marine bacterium, Moraxella sp., by the shore crab, Carcinus maenas (L.) has been studied utilizing fluorescent and radiolabelling techniques. In addition to the gills, the hepatopancreas was a major site of bacterial accumulation with sequestration occurring within haemocyte clumps and groups of stationary cells in this organ. The heart, excretory organ and subcuticular tissues also incorporated bacteria, but to a lesser extent. By the first day post-injection, many of the segregated micro-organisms had been removed from the organs. This latter process was not due to the exodus of laden haemocytes or of intact cell clumps from the host but seemed to result from lytic action by the host blood cells. Little material arising from such bacterial/haemocytic interaction was, however, immediately excreted, and much was relocated in the general body tissues as well as the gill nephrocytes.
Population Biology of Liocarcinus Depurator (Brachyura: Portunidae) In Mussel Raft Culture AreasIn The Ría De Arousa (Galicia, Nw Spain)
Authors: Fernández L. , González-Gurriarán E. , Freire J.
Published: May 2009

The population biology of the crab Liocarcinus depurator was studied for one year in the mussel raft culture areas of the Ria de Arousa. The density and biomass of this species is much higher in the raft areas, especially in the outer part of the ria, than in the central channel area. Maximum abundance occurred during the winter months (up to 8-80 g wet weight m and 0-44 individuals m.

Maturity size in females was set at 28-30 mm carapace width, (based on ovigerous females) and is attained in the first year of life. The ovigerous females were most abundant in January (approximately 70% of the mature females), but another less important maximum value was observed in May, attributable to a second spawning. Modifications in the sex ratio from 1:1 affected individuals larger than the maturity size during the season when there was a greater number of ovigerous females present. Data on sex ratio and breeding cycle indicate that ovigerous females move towards the raft areas located in the outer part of the ria. Trawl recruitment took place in the stations located in the outer Ria, and mainly in August-September, although it continued to a lesser extent in autumn.

The Von Bertalanffy growth function was fitted to both sexes in the two outer stations. Growth rate was higher in males than in females, while variability between stations was less important. However the growth rate and reproductive output of L. depurator in the Ria de Arousa was higher than in populations from other geographical areas, possibly because of the availability of food from the rafts and or the oceanographic conditions in the ria.
The Occurrence of Ophelia Bicornis (Polychaeta) in and Near the Estuary of the River Exe, Devon
Authors: Harris Tegwyn
Published: May 2009

The occurrence of a population of Ophelia bicornis has been recorded at a site which may be the most northerly for the species, and the only one within the United Kingdom. The irregular and patchy distribution of the population is described and reviewed in relation to other recorded occurrences of the polychaete.
The Determination of Specific Characters for the Identification of Certain Ascidians
Authors: Lindsay Sheila Taylor , Thompson Harold
Published: May 2009

In the course of a study involving the routine identification of Tunicata the need became apparent of an attempt being made to define more clearly than has been done the diagnostic characters of certain species. The examination of a widely-collected material demonstrates the fact that in certain species considerable variations in structure accompany changes of habitat (depth, latitude, temperature, type of substratum, etc.), while other species vary but slightly.
On the Hypothesis of Mitogenetic Radiation
Authors: Choucroun Nine
Published: May 2009

1. The observed “action at a distance” undoubtedly exists.

2. This action cannot be ascribed to a radiation, nor more generally to an action “through the wall” of the receptacles.

3. This action must then be exercised “across the surface” of the wall of the receptacles by a mechanism which remains to be explained. This seems, however, to be of great interest in view of the apparently very small mass of the substance concerned in the action.

4. The action of something material is rendered probable from the fact that the eggs develop very abnormally in sea-water previously exposed to the active culture.

5. Although these experiments have only been carried out upon sea-urchin eggs, their conclusions may be valid in the case of the very numerous experiments concerning mitogenetic radiation.
Some New Eye-Colour Changes in Gammarus cheureuxi Sexton. Part I
Authors: Sexton E. W. , Clark A. R. , Spooner G. M.
Published: May 2009

1. In a large number of experiments with Gammarus chevreuxi when the animals were kept under similar conditions at temperatures ranging from 20° to 28° C., twenty instances occurred in which red-eyed mutations appeared independently and simultaneously. The most important of these (Mutant Stock V) is described in detail in this paper.

2. The Red eyes which have arisen in this Stock V and in the four previous Stocks, I to IV, have proved to be all genetically distinct from one another.

3. There are at leadt two different classes of “red-eye,” the one simple, the other with intermediate stages. Mutant Stock V, here described, represents the second type. Differences in the method of origin of the two classes have been pointed out.

4. The inheritance of the red-eyedness of the second class—namely, that in which intermediate stages and various colour changes occur—is of a complicated kind. For an interpretation in terms of Mendelian genes, even if allowance is made for an extent of variation in members of one particular genotype, clearly several of them are involved. Further, there must be considerable interplay of one kind or another among the different genes.

5. Although so many different colour shades have appeared in Mutant Stock V, all can be interpreted in terms of varying concentrations of two pigments—the black and the red. Dilute black pigment with little or no red gives a purple eye.
The Effect of Light of Different Intensities, Reduced Selectively and Non-selectively, upon the Rate of Growth of Nitzschia closterium
Authors: Stanbury F. A.
Published: May 2009

The effect of light upon plant growth is a problem which has attracted many workers since the discovery of Priestly, in 1771, that a plant could purify fixed air, carbon dioxide, which was followed by the supplementary work of Ingen-Housz and Senebier, who showed that the phenomenon was associated with the nourishment of the plant, and took place only in sunlight and through the agency of the green portions of the plant.
The Larval Stages of Nassarius reticulatus and Nassarius incrassatus
Authors: Lebour Marie V.
Published: May 2009

The two species of Nassarius (usually known as Nassa), N. reticulatus and N. incrassatus, are both common at Plymouth. N. reticulatus, the larger species, occurs from low water usually to a depth of a few fathoms, more rarely from the waters outside the Breakwater, N. incrassatus occurring between tide-marks and extending into deeper water, even to 46 fathoms.
Apparatus for the Photo-Electric Measurement of Submarine Illumination assembled for the U.S.A. Research Ship Atlantis
Authors: Gall D. C. , Atkins W. R. G.
Published: May 2009

Shelford and Gail (1922) first used photo-electric cells for submarine photometry in the Puget Sound. Poole (1925) produced an apparatus which was suitable for use on small ships in the open sea. This apparatus was used near Plymouth by Poole and Atkins (1926, 1928, 1929) with various minor alterations in design which rendered it more reliable and less subject to errors due to electrical leakage. The object of these researches was to study illumination in relation to photosynthesis, but Russell perceived their bearing on his own work on the phototropic movements of the zooplankton. When considering the research programme of the Atlantis, Dr. George L. Clarke decided that it would be of value to carry out photo-electric measurements of submarine illuminations in connection with his work on vertical distribution of the plankton. A request was accordingly made by Dr. H. B. Bigelow, Director of the Wood's Hole Oceanographic Institute, that such an apparatus should be assembled under our direction. The apparatus here described has been constructed closely upon the lines of H. H. Poole's original apparatus as modified in 1928. Special attention, however, has been given to the elimination of electrical leakage. Furthermore, J. H. J. Poole (1928) devised an apparatus in which rate of flash of a neon lamp was used to measure light. This rate of flash method is one of integration and not an instantaneous measurement as is that of H. H. Poole. The value of the neon lamp method lies in the fact that light under the water is extremely variable near the surface owing to the motion of the waves. This method of measuring under-water illumination was used in Lough Bray, Co. Dublin, by J. H. J. and H. H. Poole (1930), and has since been used at sea by Poole and Atkins (1931). It seemed advisable to include a neon lamp photometer in the outfit so that errors in determining the loss of light on entering the water might be minimised.
Algal-induced dislodgement as a cause of bivalve mortality on some Scottish beaches
Authors: Ansell A. D. , Robb L. , Powell H. T.
Published: May 2009

During July 1984, large numbers of the sandy beach bivalve Donax vittatus (da Costa) were found either stranded in the intertidal, or washing to and fro in the surf on beaches at Dornoch, on the east coast of Scotland. The affected bivalves all carried large growths of several species of algae. The normal burrowing and recovery responses of the bivalves were unable to overcome the increased drag resulting from these epizoic algal colonies so that wave action caused dislodgement from the sand and eventually, stranding and death from dehydration. The resulting mortality affected mainly older individuals in the population; younger individuals had very small or no attached algae and were not dislodged.

The algal growths were complex and showed three stages in their development: primary settlements formed generally short tufts or mats attached to the posterior tip of die shell; secondary ‘dominant’ species were also attached to die shell but formed larger growths; tertiary species were attached as epiphytes to the primary and secondary growths. At least eight species of algae were involved. Juvenile mussels (Mytilus edulis L.) were also present in many cases attached to the weed, adding further to die drag.

During 1985, at Dornoch, secondary and tertiary algal species developed progressively from overwintering primary settlements, but the size of die algal colonies which developed was generally smaller dian in 1984 and diere was apparently little dislodgement and mortality.

Donax vittatus populations on other beaches in die Moray Firdi, and on most other Scottish beaches examined, had fewer individuals with attached algae, and diose affected carried only relatively small colonies which did not prevent normal burrowing. Complex algal colonies, showing even greater species diversity than those of Dornoch were, however, found on D. vittatus on beaches in South Harris, Outer Hebrides, during September 1984.
A portable light-trap for collecting marine crustaceans
Authors: Holmes J. M. C. , O'Connor J. P.
Published: May 2009

A portable light-trap was designed and constructed to assist in Museum taxonomic studies on Crustacea. The trap was constructed throughout of transparent Perspex. The light-source was a chemoluminescent ampoule marketed under the name Cyalume® Lightstick. The present trap offers several advantages. It is inexpensive to construct, sturdy, readily portable, easy to operate, and safe to use. Field trials in Lough Hyne (Ine), Co. Cork, south west Ireland, have proved the apparatus to be most successful in attracting a wide variety of crustaceans.
Alkaline phosphatase activity in the western English Channel
Authors: Davies Anthony G. , Smith M. Ann
Published: May 2009

The spatial and vertical distributions of alkaline phosphatase activity (APA) in the western English Channel in July 1987 were determined using 2 μM 3-O-methylfluorescein phosphate as substrate. The response of APA to increases in substrate concentration followed Michaelis-Menten kinetics but differences in Ks values between stations suggested a species dependency of the half-saturation constant. Phosphate inhibition of APA was, however, similar at 3 locations. The chlorophyll specific APA (SAPA) in surface waters ranged from 0.004 to 0.57 nMPO43- μg chla-1 min-1 and was inversely exponentially related to the chlorophyll a concentration reflecting the fact that phytoplankton populations are largest where inorganic nutrient availability is greatest and synthesis of the enzyme is not derepressed. SAPA values were found to be low in the bloom of Gyrodinium aureolum in the Ushant front and in the sub-surface chlorophyll maximum in the stratified region. Vertical distributions of SAPA are discussed in terms of the hydrographic characteristics of the water column and an attempt has been made to distinguish between APA associated with phytoplankton and with bacteria.
Evidence for selective mortality inChlamys varia(L.) transplant experiments
Authors: Gosling E. M. , Burnell G. M.
Published: May 2009

Two hundredChlamys varia(L.) from Roskeeda Bay (W. Ireland) and Lough Hyne (S. Ireland) were collected and labelled in December 1979. One hundred individuals from the L. Hyne sample were then transferred to Roskeeda; similarly, 100 Roskeeda scallops were transferred to L. Hyne. At each site 100 indigenous scallops were held as controls.

After a period of approximately 1 year, survivors at each site were scored at 13 enzyme/protein loci using starch gel electrophoresis. Significant genetic differences were observed at thePgmandLaploci between native L. Hyne and native Roskeeda scallops. These differences persisted between surviving Roskeeda scallops (92% of the original sample) transferred to L. Hyne. However, after one year L. Hyne scallops transferred to Roskeeda (61% of original sample) did not differ significantly from indigenous Roskeeda scallops. Possible reasons for the observed selective mortality at this site are discussed.
The effect of silt on the parental behaviour of the sea stickleback,Spinachia spinachia
Authors: Potts G. W. , Keenleyside M. H. A. , Edwards J. M.
Published: May 2009

The sea stickleback,Spinachia spinachia, lives in shallow coastal and estuarine waters where the male builds a nest and undergoes a protracted period of parental care. The accumulation of silt in the nest has been suggested as one of the environmental factors that regulate nest-directed activities during the parental phase. Experiments have quantified the behaviour of the male fish before and after the application of silt to the nest and shown that some behaviours are affected. The fanning activity, attendance at the nest and other nest-directed activities were examined and it was found that nest inspection and nest pushing increased significantly following the application of silt. Fanning activity, a major part of the parental behaviour of the sticklebacks, was unaffected by the experimental treatment and seems to be unresponsive to environmental changes. The results are discussed in relation to the functional significance of parental behaviour, and compared with a closely related species.
Age composition, growth, movements, meristics and parasites of the whiting, Merlangius merlangus, in the Severn Estuary and Bristol Channel
Authors: Potter I. C. , Gardner D. C. , Claridge P. N.
Published: May 2009

Samples collected from power station intake screens between 1972 and 1977 have been used to study aspects of the biology of the whiting in the Severn Estuary and Bristol Channel. 0+ whiting generally started appearing in the inner estuary in July, at which time their standard length was at least 38 mm. Their numbers peaked in October and subsequently declined particularly rapidly during the wet winter of 1976/7 when salinities were frequently below 10‰. The size of 0+ whiting in the late autumn and early winter was generally less in the shallows of the Inner Severn Estuary than in neighbouring deeper waters and in the Inner Bristol Channel. Growth rates of 0 + whiting fell within the range of those recorded for the North Sea, but below those generally found in inshore waters and sea lochs on the west coast of Scotland. Following their immigration into inshore waters in the Bristol Channel and Inner Severn Estuary, young whiting became infected with the copepod parasites Lernaeocera branchialis and Clavella adunca and the metacercariae of the heterophyid digenean Cryptocotyle lingua. Prevalence of infection was less in 0+ than older fish and infection by L. branchialis caused a significant decline in condition. As whiting became larger, the main site of attachment of Clavella adunca changed gradually from the wall of the branchial chamber to the primary rakers of the first gill arch. Vertebral counts suggest that the whiting which enter the Inner Bristol Channel and Severn Estuary are not representatives of the populations found in the Irish Sea.
Lamippidae (Copepoda: Siphonostomatoida) parasitic in Alcyonium
Authors: Stock Jan H.
Published: May 2009

Two species of Lamippidae parasitic in Alcyonium digitatum (Octocorallia) are recorded from Wales and the French Channel coast: Enalcyonium forbesi and E. rubicundum. Both are redescribed. Animals recorded as ‘E. rubicundum’ from Banyuls (Mediterranean) proved to belong to an undescribed species, E. confusum n.sp. The family Lamippidae is divided into two subfamilies: Lamippinae and Linaresiinae.
The Life Cycle ofGymnophallus Rebecqui(Digenea: Gymnophallidae) and the Response Of The BivalveAbra Tenuisto Its Metacercariae
Authors: Campbell D.
Published: May 2009

In the course of a study by Gibbs (1984) of the reproductive biology and the population dynamics of the bivalveAbra tenuis(Montagu) collected from the Fleet, a brackish water lagoon in Dorset, and from the Plym Estuary, Plymouth, a number of species of apparently pathogenic larval digeneans was found. These could not be satisfactorily identified from their larval characters alone, and following collaboration with Professor J. Llewellyn (personal communication) it was decided that they should be made the subject of a further study.
Age Validation Studies on the Spines of the Spurdog (Squalus Acanthias) Using Tetracycline
Authors: Tucker Richard
Published: May 2009

Elasmobranchs, unlike teleosts, do not possess otoliths or scales suitable for age determination. Various skeletal structures of elasmobranchs have been used in an attempt to find a reliable ageing technique. These include the centra of Raja fusca (Ishiyama, 1951). R. eglanteria (Daiber, 1960), R. erinacea (Richards, Merriman & Calhoun, 1963) and Cetorhinus maximus (Parker & Stott, 1965). Yokota (1951, 1952) has described annual growth increments on the claspers of various elasmobranch species. Stevens (1975) made vertebral ring counts in the blue shark, Prionace glauca L. More recently Jones & Geen (1977a,b), using X-ray spectrometric analysis, have examined the vertebral circuli of dogfish found in British Columbia waters. Methods of age determination, using the spines of the spurdog (Squalus acanthias L.) have been described by Kaganovskaia (1933, 1937), Bonham et al. (1949) and Aasen (1961). All these authors assumed that the more or less regular series of dark bands or ‘rings’, extending from a white pigment-free base of the enamel to near the tip, were annual. Holden & Meadows (1962), on the basis of the internal and external features of the spines, concluded that the dark bands did represent annual growth increments. In particular, they argued that the dark bands were laid down during the winter when growth would be slowest, whereas the faster growth in the summer was represented by the light bands. Holden & Meadows (1962) identified several conditions, e.g. birth, double, false and spawning rings – that made interpretation of the ring structure and subsequent age determination difficult.
The Stomach Contents of A Risso's Dolphin (Grampus Griseus) Stranded at Thurlestone, South Devon
Authors: Clarke Malcolm R. , Pascoe P. L.
Published: May 2009

Risso's dolphin (Grampus griseus) (Cuvier, 1812) is not common off the coast of Devon although strandings are occasionally reported. Norman & Fraser (1948) noted that 45 had been stranded on the British coast over a period of 33 years and that these were concentrated in the south-west. While it is regularly stated that this animal eats squids exclusively the prey species have not been identified. In view of the variety of squids available to an oceanic mammal and the information its food can give on both the migration of the dolphin and the ecology of the cephalopods in its diet the stranding of a Risso's dolphin at Thurlestone Rock on 12 May 1983 provided an unusual and welcome opportunity to examine the animal and its food.
Assimilation Aand Regeneration of Nutrients off the West Coast of Brittany
Authors: Morin P. , Le Corre P. , Le Févre J.
Published: May 2009

A high degree of variation in hydrographic conditions is found in the so-called Iroise Sea, within less than 100 km of the west coast of Brittany. Tidal current maximal velocity, especially, ranges there from about 0·5 knot to more than 8 knots (locally, near the island of Ushant), i.e. practically as wide a range as found over the whole of north-west European shelf seas. Pelagic ecosystems accordingly exhibit a high degree of variety, related not only to classical inshore-offshore gradients, but also to the extent of vertical mixing or stratification. Areas where different physical and biological conditions prevail are generally separated by rather clearcut boundaries. The better-known of these is the Ushant thermal front, which runs in summer across the whole entrance to the English Channel, but also extends into the Iroise. In addition, freshwater runoff results in thermohaline stratification, or at least in the existence of thermohaline vertical gradients, in the two major bays of the west coast of Brittany. The relevant area is limited seawards by a thermohaline front, the Iroise inner front (Grail & Le Fèvre, 1967; Le Fèvre & Grall, 1970), beyond which are found the well-mixed waters inshore of the Ushant front. Fig. 1 sums up these hydrographic patterns in the area taken here into consideration.
Observation on the life history and functional morphology ofCerithiopsis tubercularis(Montagu) andTriphora perversa(L.)
Authors: Fretter Vera
Published: May 2009

Cerithiopsis tubercularisandTriphora perversafeed on siliceous sponges: a long proboscis is thrust through an osculum of the sponge, or into breaks in the surface, to reach the softer parts. These are loosened by jaws, entangled in saliva and swept into the buccal cavity by the radula.

The formation of a long introvert, which must be withdrawn through the narrow space in the nerve ring and narrow enough to go through an osculum, has brought about (i) a lengthening of the mid-oesophagus inCerithiopsis, with a narrowing of its diameter, and a spreading of the oesophageal glands along its length, (ii) inTriphora, a reduction of the ventral glandular part of the mid-oesophagus, its stripping from the food channel and a displacement of the salivary ducts so that they open into the glandular part of the oesophagus. InTriphorathere is a dorsal gland of unknown function on the posterior oesophagus.

The stomach in both species is a simple ciliated sac: the oesophagus opens anteriorly and ventrally, and the intestine originates above this opening; there are two ducts from the digestive gland.

The pallial region of the male and female genital duct is open; and there is no penis. It is suggested that the open condition of the duct and the absence of a penis in the mesogastropods is correlated with a long, narrow mantle cavity which contains a relatively large ctenidium.