bluuebunny/crossref_metadata_2025 huggingface dataset:
Methylotrophic and autotrophic bacteria isolated from lucinid and thyasirid bivalves containing symbiotic bacteria in their gills
Authors: Wood Ann P. , Kelly Don P.
Published: May 2009

Bacteria have been isolated into pure culture from the gills ofLucinoma borealis, Myrtea spinifera, Thyasira flexuosaandT. sarsicollected from several British and Scandinavian coastal sediments. It is proposed that these bacteria are symbiotic with the animals. The bacteria were either autotrophs, obtaining energy from oxidation of inorganic sulphur compounds, or methylotrophs using methanol or methylamine as the source of carbon and energy. The latter could also oxidize thiosulphate to tetrathionate and precipitate elemental sulphur. The pure cultures have been characterised in some detail, showing that (1) their DNA base composition falls in the range 47–58% guanine + cytosine; (2) although all grow well at the natural environment temperatures of 8–15°C, their optima lie between 30 and 35°C; (3) all produce copious amounts of extracellular slime when grown at low temperatures; (4) the autotrophic isolate is facultatively heterotrophic, containing a repressible ribulose bisphosphate carboxylase, and excreting up to 30% of its carbon dioxide fixation into the culture medium; (5) the methylotrophs include some containing high activities of hexulose phosphate synthase for assimilation of formaldehyde by the ribulose monophosphate cycle; others may have novel assimilatory metabolism. The possibility is discussed that environmental factors may determine whether a methylotroph-animal or autotroph-animal symbiosis is established rather than the symbiont type being an invariable species-specific character.
Seasonal and year-to-year changes in the phytoplankton from the Plymouth area, 1963–1986
Authors: Maddock Linda , Harbour D. S. , Boalch G. T.
Published: May 2009

Samples of phytoplankton from nets towed in the surface waters off Plymouth over a period of 24 years were subjected to a correspondence analysis. There was a high species diversity throughout the year, and a strong seasonal cycle. A total of 104 species was divided into eight groups showing different seasonal and year-to-year occurrence. Over the 24 years the seasonal pattern of species changed in a fairly systematic way and there were two periods (1968–70 and 1983–85) when the changes were most marked. These patterns could be related to changes in the weather patterns, and were similar to those found by other workers in other groups of organisms and in other areas.
Report on the Tunicata of Plymouth
Authors: Garstang Walter
Published: May 2009

The southern shores of the English Channel have long been famous for the wealth of their Tunicate fauna, having furnished material in abundance for the classical researches of Milne-Edwards, Giard, and Lacaze-Duthiers. The Channel Islands also have been repeatedly visited by English zoologists, and have amply supplied those among them who have been in search of Tunicate treasures. Probably the peculiar tidal conditions of this part of the Channel are especially favourable to a rich development of littoral forms; but, as the work of Montagu, Couch, Clark, Alder, Gosse, Cocks, Bate, and Norman sufficiently testifies, the Devon and Cornish coasts of England can lay claim to an almost equally luxuriant shore fauna, the rocky bays and long sheltered estuaries being especially wealthy in this respect. During my residence at Plymouth I found that the Tunicata were among the best represented groups of the fauna, and, as I devoted considerable attention to the search for rare or new, as well as for well-known forms, I trust that a classified report upon the local representatives of the group will not be without its usefulness to other investigators.
The Turbellaria of Plymouth Sound and the Neighbourhood
Authors: Gamble F. W.
Published: May 2009

I propose in this paper to furnish a list of the marine Turbellaria of Plymouth Sound and the neighbourhood, including all species that have hitherto been recorded from this locality. That such an attempt is in some respects premature I am only too well aware, but I have written it for the convenience of those who are working at, or are interested in, the fauna of Plymouth, and it may serve as a starting-point in our knowledge of the Turbellaria of the Sound. The synonymy and descriptions of the species are given by v. Graff, Lang, Jensen, and recently, together with figures of the new species and the literature, by myself.
North Sea Investigations
Authors: Holt Ernest W. L.
Published: May 2009

I have again so many acknowledgments to make for help received that it would be invidious to select names, whilst to enumerate all would unduly trespass on the space allotted to me.

The work, as before, has been carried on at the Marine Fisheries Society's Laboratory at Cleethorpes.
Researches on the Coloration of the Skins of Flat Fishes
Authors: Cunningham J. T.
Published: May 2009

In the year 1890 I tried an experiment upon young flounders, with the object of discovering what would be the effect upon the lower sides of the fish if these sides were continually exposed to daylight. Under ordinary conditions the upper side of the fish is dark-coloured, the lower side white; and the upper side is exposed to light, while the lower side being usually in contact with the ground, and always turned away from the sky, is protected from the light. A connection between the difference of the two sides in relation to light and in coloration naturally suggests itself. If the difference in coloration is due to the difference in the exposure of the sides to light, when the lower side of the fish is kept exposed to the light it ought to become coloured.
Nerve Elements of the Embryonic Lobster
Authors: Allen Edgar J.
Published: May 2009

After repeated trials with dilute solutions of methylene blue upon larvæ and embryos of a number of the smaller decapod Crustacea, a favourable object for the study of the nervous system was at last found in the embryo of the common lobster. The embryos of this animal are specially advantageous on account of their large size, which enables them to be readily manipulated without much damage being done to their tissues, and also on account of the large size of the individual nerve elements.
Energetics of leaping in dolphins and other aquatic animals
Authors: Blake R. W.
Published: May 2009

The energetics of leaping (porpoising) in aquatic animals is investigated employing two simple hydromechanical models. The first compares the energy required for swimming at different depths below the surface with that for leaping, the second is employed to calculate maximum cruising speeds in fish and cetaceans for the cases of laminar and turbulent boundary layer flow. Leaping is energetically less efficient than swimming close to the surface up to a certain speed (crossover speed) after which it is more efficient. It is shown that dolphins ought to be capable of reaching the required crossover speeds even if subject to a turbulent boundary layer. This is not so for the larger cetaceans that have been observed to porpoise (e.g. killer whales,Orcinus orca).However, crossover speeds for leaping are well within their scope for the case of a boundary layer that is half laminar and half turbulent. Crossover speeds in pelagic animals that do not undulate a substantial proportion of their body in swimming (e.g. baleen whales and penguins) are relatively high. The crossover speeds of the baleen whales are about four times their observed cruising speeds. It is suggested that these animals swim at speeds at which their filtration apparatus (baleen) operates most efficiently. Pelagic fish do not porpoise and reasons are suggested for this.
The digestive tract ofOctopus vulgaris:the anatomy, physiology and pharmacology of the upper tract
Authors: Andrews P. L. R. , Tansey E. M.
Published: May 2009

This paper reports a preliminary investigation into physiological and pharmacological aspects of the motor activity of the digestive tract ofOctopus vulgaris,with reference tothe relevant anatomy. The results suggest that the octopus gut shows many similarities to somevertebrate guts in terms of functional morphology and motor control. Pharmacological experiments suggest that acetylcholine, noradrenaline and 5HT may act as neurotransmitters and probablyregulate the digestive activity by antagonistic actions, reminiscent of the classical divisions of the vertebrate autonomic nervous system. Histochemical evidence is presented that some ofthese substances are located in the nerves and ganglia of the digestive tract.
Isidascus bassindaleigen.nov., sp.nov. (Ascothoracida: Crustacea) from north-east Atlantic with a note on the origin of barnacles
Authors: Moyse John
Published: May 2009

A new ascothoracid,Isidascus bassindaleigen.nov., sp.nov., has been discovered in the north-east Atlantic Ocean at a depth of over 2000 m. It forms permanent galls on the branches ofAcanella arbuscula, a gorgonian of the Family Isidae (Octocorallia, Coelenterata). The new genus is related toGorgonolaureus, species of which form galls on paramuriceid gorgonians. The gall of the present form unlike that ofGorgonolaureusincorporates a cup of host calcite. Twenty-three adult female specimens and one male were examined in this study. The adult parasite is characterized by elevated humps in a median dorsal position on each of thoracomeres 2,3 and 4. A further feature is a tapering filamentary appendage arising near the base of first thoracopod. The parasite apparently feeds on its host's coenosarc. The likely function of the first and second antennae and each of the three pairs of stylet-form mouth parts is suggested. A case is made for interpretting the species as a protandrous sequential hermaphrodite. Whilst still immature, protanders apparently seek out and settle alongside an adult female. Later, following growth and sexual maturation they again become mobile and after copulation with the nearby female depart to prepare for sex change on a separate branch of the host.
The effects of copper on the behaviour, respiration, filtration and ventilation activity ofMytilus edulis
Authors: Manley Andrew R.
Published: May 2009

The behaviour and physiological responses of Mytilus edulis L. to increased concentrations of copperare dependent on the absolute copper concentration present and not the rate of increase of concentration. The sequence of behavioural responses isolating the animal from heightened sea-water copper concentration is similar to that observed in response to lowered salinities. The effects of copper onthe oxygen consumption of intact and ‘propped open’ and animals whose posterior adductor muscles havebeen severed suggest that only measurements of animals in the latter state give a true reflexion of the effects of copper on the oxygen consumption of the tissues of Mytilus. The effects of increased sea-water copper concentrations on the filtration and ventilation activity of mussels are assessed, but consideration of the data in terms of Dejour's equation of gaseous exchangesuggest that indirect measurement of ventilation activity gives rise to differing results. The adaptive advantage of theresponse of Mytilus to heightened sea-water copper concentrations is considered.
Body temperature of the salmon shark, Lamna ditropis
Authors: Smith R. L. , Rhodes D.
Published: May 2009

The salmon shark, Lamna ditropis Hubbs and Follett, is a streamlined, pelagic predator capable of rapid swimming locomotion, very similar to its close relative, the Atlantic porbeagle, Lamna nasus (Bonnaterre). The porbeagle is warm-bodied, maintaining deep body temperatures 7–11 °C above those of the surface water from which they are captured (Carey & Teal, 1969a). Presumably, Lamna ditropis is also warm-bodied. Opportunities to measure temperatures of salmon sharks occurred on 2, 4 and 5 September 1979, when one of us (D.R.) hooked and landed three salmon sharks while hand-trolling for salmon. The sharks were all caught near Cape Edgecumbe, about 60 km from Sitka, Alaska (57° 6´N, 135° 55´ W) at a depth of 12–40 m.
The effect of oscillating temperatures on the metal ion metabolism of Mytilus edulis
Authors: Watkins Barbara , Simkiss K.
Published: May 2009

The effect of increasing the temperature of Mytilus edulis by 10 °C is to increase the rate of 65Zn uptake. If the temperature is oscillated through this range there is a further enhancement of metal uptake. The effect is associated with a decrease in cytosol metal and an increase in granular fractions. These unexpected results are interpreted in terms of cellular metal-ligand homeostasis.
Larval settlement and metamorphosis of two gregarious sabellariid polychaetes:Sabellaria alveolatacompared withPhragmatopoma californica
Authors: Pawlik Joseph R.
Published: May 2009

Two sabellariid polychaetes,Sabellaria alveolatafrom European waters andPhragmatopoma californicafrom the west coast of North America, are known from previous work to have larvae that settle and metamorphose preferentially on the cemented sand tubes of conspecific adults. The naturally occurring inducers of larval metamorphosis were recently isolated and identified forP. californica.In the present study, larval behaviour ofS. alveolataandP. californicawas compared in reciprocal laboratory settlement assays. For both species, metamorphosis occurred to a greater extent on conspecific tube sand than on control sand or on heterospecific tube sand. Extraction of the tube sand ofS. alveolatawith organic solvents diminished its capacity to induce metamorphosis pi conspecific larvae, but this capacity was not transferred to the extracts, as was the case forP. californica. The substance responsible for the enhanced metamorphosis ofS. alveolataon conspecific tube sand remains unknown. The free fatty acid (FFA) inducers of larval metamorphosis ofP. californicaeither inhibited, or had no effect on, metamorphosis ofS. alveolata. Both species responded abnormally upon exposure to unnaturally high concentrations of certain (particularly polyenoic) FFAs. Abnormal larval responses ofS. alveolata, however, did not incorporate behavioural components of normal metamorphosis, as were observed forP. californica. FFAs were isolated from the natural tube sand ofS. alveolataat less than one-tenth the concentration found in the natural tube sand ofP. californica. The differences between the two species provide further evidence that a very specific mechanism is responsible for the perception of FFAs by the larvae ofP. californica.
The benthic environment of the North Sea (56° to 61°N)
Authors: Basford D. , Eleftheriou A.
Published: May 2009

In an attempt to describe the physical and chemical characteristics of the sediments as an environment for the invertebrate benthos, a total of 273 stations covering the sector from 56° N to 61° N in the North Sea was sampled. The sediment samples which were collected by grab and corer were analysed for particle size (as well as silt-clay content and sorting), organic carbon, plant pigments and trace metals (Cd, Pb, Zn, Ni, Co, Cu). On a smaller scale a few stations were sampled for redox potential, pH and pesticides.

Taking into account the geological history and the on-going hydrographic processes, explanations for the formation of the sedimentary provinces in the North Sea were provided. The sediments were predominantly fine to medium sand, but there was a depth-related gradient with the finer grades, organic carbon and, to a lesser extent, plant pigment being found in the deeper sedimentation basins of the Fladen Grounds and Norwegian Trench.

Trace metals and pesticide contaminants associated with the finer organic and inorganic fractions were higher in the sediments of the above deeper areas as well as in the vicinity of estuaries. It could be concluded that despite the enhanced concentrations of Cd, Ni, Pb and Co, at the east of Shetland, which were due to a geochemical anomaly, there was no evidence of any important or large-scale contamination of the North Sea as a whole.
Some Observations Upon the Distribution of Strontium in Four Species of Ophiuroids – Ophiocomina Nigra (Abildgaard), Ophiura Albida (Forbes), Ophiothrix Suensoni (Lütken) and Ophioderma Cinereum (Müller and Troschel)
Authors: Pagett Richard M.
Published: May 2009

Strontium was shown to occur in marine organisms in the early part of the nineteenth century (Moretti, 1813; Vogel, 1914). However, since early detection methods have relied upon chemical separation, accurate quantitative determination of small amounts of strontium, has presented many difficulties due to the chemical similarity of strontium and calcium. During the last 30 years a number of relatively sensitive methods have been developed (Smales, 1951; Thompson & Chow, 1955; Bowen, 1956; Hummel & Smales, 1956; Odum, 1957b; Sugawara & Kawasaki, 1958; Culkin & Cox, 1966; Riley & Segar, 1970; Gibbs & Bryan, 1972). Towards the beginning of this period, Vinogradov (1953) made an extensive review of the chemical data on the marine biota. Due to the limitations mentioned above there was relatively little information available on the occurrence of strontium.
Some Anatomical and Physiological Differences in Chorda Filum from Coastal Waters of Finland and Great Britain
Authors: Russell G.
Published: May 2009

A comparative study of Chorda filum populations from the British Isles (S 34‰) and the Baltic coast of Finland (S 6‰) has revealed differences in response by live adult thalli to treatment for 2 h with sea water of different salinities. Water uptake and loss by thalli differed significantly in salinities of х o‚ х 1/6, х ⅓ and х 1 ( = 34‰). British material showed severe cell disruption in freshwater whereas Finnish material did not. Killed thalli also behaved differently, British material showing little response to salinity treatment but Finnish plants continuing to react much as live tissues.

Anatomical differences between populations were also observed, cortical cells in Finnish plants being significantly smaller than their British counterparts. Diaphragms traversing lumens of British material were simple, entire structures, but those in Finnish plants were deeply dissected and complex in organization.

It is postulated that Baltic Chorda may have undergone a process of evolutionary divergence in response to its changed saline environment.

INTRODUCTION

Chorda filum (L.) Stackh. is one of several species of north Atlantic Phaeophyceae to be found in the inner Baltic Sea and Gulf of Bothnia; its geographical limit being associated with sea water salinity of approximately 4‰, (Waern, 1952; Hällfors et al. 1981). This species has been studied by Norton & South (1969) and South (1966) who traced the development of gametophytes and early sporophytes in culture media of different salinites. Although their cultures had been established from British material only, they felt able to argue from their results that the Baltic population did not constitute ‘… a different physiological strain specially adapted to the extreme environmental conditions prevailing there’.
The Influence of an Electric Light on the Capture of Deep-Sea Animals by a Midwater Trawl
Authors: Clarke Malcolm R. , Pascoe P. L.
Published: May 2009

For centuries man has used lights to attract and concentrate fishes near the sea surface to aid their capture by nets or hooks (Ben-Yami, 1982). Underwater lights lowered into shallow seas are now regularly used to lure fish into set nets, large nets suspended beneath ships or into the vicinity of powerful pumps (Sidelnicov, 1981; Andreev, 1962; Nikonorov, 1969). Usually lights of more than 1 kw are used and such power requires a surface generator and strong insulated cable from the surface to the light. Although we know from these applications that some fish species are attracted by lights, the use of lights on trawls has not been developed for commercial exploitation or for research sampling. Perhaps such development has been discouraged by the safety problem and technical difficulties of providing electrical power on deck and handling heavily insulated conducting cable between the trawl and the generator. Lights have been used on commercial trawls with television in experiments to study fish reaction to trawls but such experiments were not concerned with finding the effect that lights might have on the quantity of fish caught and catches have not been analysed (A. Maclntyre, personal communication).
A Numerical Taxonomic Study ofFucus Distichus(Phaeophyta)
Authors: Rice E. L. , Chapman A. R. O.
Published: May 2009

The genusFucusL. is widely distributed through the cool temperate waters of the north Atlantic and north Pacific oceans. The very large number of sub-generic taxa (> 100) previously recognized was reduced by Powell (1963) to only 6 species. In his revision, Powell recognizedF. distichusL. emend. Powell as the most variable of these. He classified the intra-specific variation in this species into 4 sub-species:F. distichus distichus, F. distichus anceps(Harv. et Ward ex. Carruthers) Powell,F. distichus evanescens(C.Ag) Powell andF. distichus edentatus(Pyl.) Powell. Because of reports that intermediate forms existed in Iceland (Jonsson, 1903) and the Faeröes (Börgesen, 1902), Powell (1957a,b) decided to use sub-specific status rather than specific designation for these 4 taxa. However, within North America the 4 sub-species ofF. distichuswere often assigned specific rank (e.g. Taylor, 1957).
The Buoyancy and Vertical Distribution of Eggs of Sprat (Sprattus Sprattus) and Pilchard (Sardina Pilchardus)
Authors: Coombs S. H. , Fosh C. A. , Keen M. A.
Published: May 2009

Observations on the density of pelagic marine fish eggs have indicated that they are near neutral buoyancy for most of development and have a tendency to become denser towards hatching (see Russell, 1976). However, most of this information has been based on limited laboratory observations on the relative buoyancy of eggs; only a few experiments have given more precise estimates of the absolute density of eggs based on the salinity of water in which they are neutrally buoyant (e.g. Franz, 1910; Sundnes, Leivestad & Iversen, 1965). Recently, a new technique (Coombs, 1981), based on the use of a stable column of continuously graded sea-water concentration has allowed more precise and routine measurements of the density of fish eggs throughout development.
The Redfield Ratio and Phytoplankton Growth Rate
Authors: Tett P. , Droop M. R. , Heaney S. I.
Published: May 2009

Goldman, McCarthy & Peavey (1979b) argued that growth rates of phyto-plankton in apparently oligotrophic ocean waters may near maximal. Their hypothesis was succinctly restated by Goldman (1980): ‘…the chemical composition of phytoplankton is extremely variable under exacting laboratory conditions of nutrient limitation and approaches the ‘Redfield’ proportions (C:N:P of 106:16:1) when neither nitrogen nor phosphorus is limiting so that near maximal growth rates are attained. In marine surface waters the chemical composition of particular matter often is in the Redfield proportions, thus implying that natural phytoplankton growth rates may be close to maximal.’ We argue on theoretical, experimental and observational grounds that this implication may not necessarily be correct.
Reducing Activity and the Formation of Base in the Shore Crab,Carcinus Maenas
Authors: Digby Peter S. B.
Published: May 2009

Crustacean cuticle consists essentially of chitin impregnated and coated with protein which is tanned with quinone (Dennell, 1947a). The outer surface is most heavily tanned, and the cuticle is further strengthened by calcification. The various theories as to the mechanism of calcification in crustacean and other biological material have been reviewed briefly by Digby (1967). Most appear unsatisfactory for various reasons, and evidence was outlined that calcification might arise from the formation of base by processes which are essentially electrochemical in origin. The quinone-tanned protein of the cuticle is electrically semiconducting and supports electrode action in suitable gradients of potential (Digby, 1965), and small potential differences may arise by diffusion or by active processes. Thus the deposition of calcareous salts might arise partly at least by action comparable to that which takes place at a metallic cathode. In support of this, the position of the initial calcareous deposits inCarcinus maenas(L.) was found to change with the gradient of sea-water salinity in the manner expected if some control were exercised by diffusion potentials, acting across a thin semiconducting layer to generate small changes of pH (Digby, 1968).
The Nest Structure of the Corkwing Wrasse, Crenilabrus Melops (Labridae: Teleostei)
Authors: Potts Geoffrey W.
Published: May 2009

There are five common species of wrasse (Labridae) in British coastal waters, two of which are hermaphrodite, (Labrus bergylta Ascanius and Labrus mixtus L.) and three are gonochorists with discrete sexes (Ctenolabrus rupestris) (L.), Centrolabrus exolelus (L.) and (Crenilabrus melops (L)) (Dipper & Pullin, 1979; Dipper, 1981). L. bergylta (Sjolander, Larson & Engstrom, 1972; Potts, personal observation) and L. mixtus (Wilson, 1958; Potts, 1984) lay their eggs in shallow depressions excavated in coarse paniculate substrates often closely associated with sublittoral reefs. Ctenolabrus rupestris, the smallest of the species is most usually associated with sublittoral crevices, and is the only one to produce pelagic eggs despite showing territorial aggression in the spawning season, a behaviour mostly confined to species with demersal eggs. Little is known about Centrolabrus exoletus, but from the striking sexual dichromism at maturity and its association with rocky reefs it may be supposed that it exhibits some form of parental care for the demersal eggs (Potts, 1984). Crenilabrus melops shows parental care of its eggs which are laid in large and complex algal nests, a feature which is common to all this genus (Fiedler, 1964; Quignard, 1966; Potts, 1984). The corkwing wrasse is one of the commonest coastal species which at maturity show sexual dimorphism and dichromism, a feature which led to taxonomic confusion among earlier workers and which is discussed by Potts (1974).
The Right Hon. Thomas Henry Huxley
Authors: Lankester E. Ray
Published: May 2009

The Journal of our Association cannot be allowed to appear without a few words in memory of our first President, the great naturalist and leader of Science, whom we all mourn.

Huxley's studies in marine biology, and his position as a Government official, as well as his keen, practical common-sense, made his selection as a member of two Government Commissions on Fisheries (in 1863 and again in 1883) very appropriate. He did valuable work on those Commissions, and in 1881 was appointed, by Sir William Harcourt, to be Inspector of Salmon Fisheries. In 1883 he took an active part in the work of the International Fisheries Exhibition, and emphasized in an address given there, the fact that, whilst civilized man had brought all the resources of science to bear on the “harvest of the land,” little or nothing had been done in the same spirit for the “harvest of the sea.”
Faunistic Notes
Authors: Allen E. J.
Published: May 2009

The following notes on the collecting work carried out during the period from January to June, 1895, follow the lines of Mr. Garstang's notes for 1892 and 1893. In putting the observations on record, I should like to thank the various workers at the Laboratory during the period covered, for the help which they have given. My own part of the work has consisted chiefly in keeping the record, and in endeavouring to give a certain amount of continuity to the whole. At the same time the final responsibility for the names adopted must be my own.
Additional Observations on the Nerve-Elements of the Embryonic Lobster
Authors: Allen E. J.
Published: May 2009

In Vol. III., No. 3, p. 208, of this Journal, a summary was given of certain observations made in the Plymouth Laboratory on the nerveelements of the embryonic lobster. A more detailed description of these elements, with figures, appeared in the Quarterly Journal of Microscopical Science, vol. 36, 1894. The observations have since been extended, and the following summary of the additional results may not be without interest.
On the Effect of the severe Winter of 1928–1929 on the Oyster Drills (with a record of five years' observations on sea-temperature on the oyster-beds) of the Blackwater Estuary.
Authors: Orton J. H. , Mabel Lewis H.
Published: May 2009

During the year 1928 the writer was engaged in a study of the bionomics of the oyster drills on the oyster beds in the region of the River Blackwater, Essex. At this time the presence of a foreign species was detected (1) and definite records were made of the relative abundance of the three following drills or tingles:—Murex erinaceus (=Ocinebra), Purpura lapillus (=Nucella), and Urosalpinx cinerea. It so happened that the winter of 1928–29 was unusually cold; the temperature of the water over the oyster beds was unusually low in January and February, 1929, ranging about the freezing-point of fresh water (see Table II and Fig. 1). The oyster-cultivators in this locality had many years previously stated that during severe winters many marine animals, such as the oyster drills or tingles and the burr Echinus miliaris, are killed in such great numbers as sometimes to exterminate the species. The observations made by the writer in 1928 offered an opportunity to test these statements, and of estimating the effect of the extreme cold in early 1929 on the animals mentioned above.
The Muds of the Clyde Sea Area. III. Chemical and Physical Conditions; Rate and Nature of Sedimentation; and Fauna
Authors: Moore Hilary B.
Published: May 2009

A Preliminary survey of the area with regard to the distribution of the total nitrogen and phosphate content of the muds was described in a previous paper (Moore, 5). A number of stations were worked, and these were further examined for nature and distribution of particles, water content, and density, and as a result of this survey certain stations were chosen as suitable for more extensive work. At the same time it became evident that the layers in which the greatest and most important changes were taking place were those within a few centimetres of the surface, and these were therefore studied most intensively.
Rays and Skates of Devon and Cornwall. Methods of Rapid Identification on the Fishmarket
Authors: Steven G. A.
Published: May 2009

In carrying out detailed investigations into the life-histories and distribution of the Rays and Skates around the extreme south-west of England, large numbers of commercial landings have had to be examined. On account of their size and cost, regular and adequate samples of Rays and Skates cannot be delivered at the laboratory, as is possible with such a small and inexpensive fish as the Herring, for example. It therefore has been essential to learn rapidly to distinguish the different species as they lie exposed for sale on the fishmarkets. This has been necessary not only to promote rapidity of work, but also to obviate all unnecessary handling of the fish, too much interference with which is apt greatly to annoy fishermen, salesmen, and buyers alike.
The Vertical Distribution of Marine Macroplankton. X. Notes on the Behaviour of Sagitta in the Plymouth Area
Authors: Russell F. S.
Published: May 2009

1. The diurnal behaviour of Sagitta of different sizes is shown as a result of collections made with the 2-metre stramin ring-trawl throughout 24 hours on July 15th–16th, 1924, and on June 3rd–4th, 1926.

2. The younger stages ofSagitta elegansappear to withstand higher intensities of light in the daytime than do the older stages, and they migrate first to the surface at dusk, as do those ofSagitta setosa. The older stages leave the surface first at dawn.

3. Diagrams are given showing the curves of equal intensities of light beneath the sea surface throughout 24 hours as calculated from air intensities obtained in June, with a reflection loss of 15%; (a) assuming a coefficient of absorption of 0·200 at all depths, and (b) assuming a coefficient of absorption of 0·100 at all depths.

4. It appears, from a comparison of the behaviour ofSagitta eleganswith the calculated light conditions beneath the surface, that the older Sagitta at any rate are more sensitive to light in the early morning after the darkness of the night and can become adapted to light of higher intensities later in the day.

5. Previously published observations on the behaviour of Sagitta sp. on June 17th–18th–19th, 1925, show quite a different type of behaviour from the above, possibly due to more transparent water, the Sagitta only appearing abundantly above 30 metres in the dark. They had again migrated to below 30 m. before there was any appreciable light.
The Validity of Single Vertical Hauls of the International Net in the Study of the Distribution of the Plankton
Authors: Gardiner A. C.
Published: May 2009

In both the series of hauls made for the purpose of estimating the reliability of a single haul of the International Vertical Net, the possibility that the variation in the size of catch of successive hauls is due to errors of the methodique has been examined.

Errors due to variations in the speed of hauling, and to the effect of light and darkness on the catch of the net can be ruled out.

The enumeration error, even where the enumerated total rests on a single count, is insufficient to account for the major part of the variations found, and, having regard to the fact that such totals were derived from two, and sometimes more, separate “counts” from each sample, there is good reason to believe that the main cause of variation in the size of catch is to be sought elsewhere, the most likely being the lack of uniformity in the distribution of the organisms themselves.
The Deterioration of Fabrics Exposed on a Roof after Treatment with Fishing-net Preservatives
Authors: Atkins W. R. G.
Published: May 2009

(1) Cotton and linen fabrics were exposed horizontally on the Laboratory roof at Plymouth for two years. During this time the fabrics lost from one to two-thirds of their initial tensile strengths in both warp and weft.

(2) The application of copper oleate, mixed copper soaps, also of the latter with resin or tar as binding agents, had no effect or a slight effect only in lessening deterioration; such weakening must therefore be due to weathering, chiefly the action of light, since these substances have been shown to be useful antiseptics on nets immersed in salt or fresh water.

(3) No deleterious action may be expected when nets treated with these substances are exposed to light, since the treated fabrics were no weaker than the untreated; but where Cuprinol had been used, there appears to have been some weakening, though the antiseptic properties of Cuprinol are excellent.
Note on Some Abnormalities of Labial Palps and Foot of Mytilus edulis
Authors: Atkins D.
Published: May 2009

In view of Pelseneer's work on “Les Variations et leur Hérédité chez les Mollusques,” it seems worth while to record briefly certain observed abnormalities of the labial palps and the foot of Mytilus edulis. Among some thousands of specimens examined, however, such conditions were rare, and it is probable that at least some of them arose through injury.
Note on the Regeneration of the Gill of Mytilus edulis
Authors: Atkins D.
Published: May 2009

Experiments have shown that the gill of Mytilus is capable of regeneration, and that this may occur in less than eight months. It may be confined to the formation of a food grove at the cut edge of the gill, without appreciable regeneration in length of the gill filaments. Regeneration of a food groove appears always to occur at the cut edge, if the ends of the descending and ascending filaments are able to touch and so to fuse. On the other hand, regeneration of gill filaments does not seem to occur invariably, and when it does the rate is slow, at least under experimental conditions and in mussels of a length of about 7·0 to 8·0 cm., such as were used for the experiments: it is possible that regeneration would occur more surely and rapidly in young mussels, but owing to the thinness of the shell they would be more difficult to wedge open without fracturing. Coulthard (6, p. 136), however, says that “The rate of growth is independent of size in the mussel, being apparently influenced only by the environment.” Perhaps the lack of an abundant food supply under the conditions of the experiments should be taken into consideration, though it is well known that in general the amount of food available to an animal has little influence on regeneration (9, p. 27). The salinity of the water in general circulation is about 36–37°/oo, that is, higher than normal sea-water, which is about 35°/oo, and would be considerably higher than the optimum salinity for growth (see Flattely and Walton, 7, p. 81). This may also possibly have a retarding effect on the initiation of regeneration and the rate.
Notes on the Ciliate Boveria stevensi Issel from Galeomma turtoni Sowerby at Plymouth
Authors: Mackinnon D. L. , Ray H. N.
Published: May 2009

The little bivalve mollusc Galeomma turtoni is not very common of the coast of South Devon; but two specimens were brought in while we were working at the Marine Biological Laboratory last August, and when we examined them we found that the branchiæ and mantle cavity were aswarm with a small colourless ciliate.
The Relation of the Plankton to some Chemical and Physical Factors in the Clyde Sea Area
Authors: Marshall S. M. , Orr A. P.
Published: May 2009

1. Simultaneous observations are recorded of some biological, physical, and chemical changes in the Clyde Sea Area in 1924, 1925, and 1926.

2. A close relation between diatom increases and changes in pH value, dissolved oxygen saturation and dissolved phosphate has been found.

3. It appears that the more numerous diatom increases in Loch Strivan as compared with the open sea are due to the more frequent mixing.

4. Confirmation of the fact that diatom increases begin at the surface and gradually spread into deeper water has been obtained.

5. The occurrence of Peridinians is apparently related to high temperature and low salinity.

6. The amount of sunshine in the early part of the year does not exert any apparent influence on the date of the spring diatom increase in the Clyde Sea Area.

7. The regeneration of phosphate in the deep water of Loch Strivan has been described.
Fragmentation in the Genus Autolytus and in other Syllids
Authors: Allen E. J.
Published: May 2009

In a former paper (Allen, Phil. Trans. Roy. Soc. B., Vol. 211, p. 131, 1921) it was shown that the Syllid Procerastea Halleziana Malaquin, addition to the ordinary mode of sexual reproduction which occurs in this group, reproduced asexually by a process of fragmentation, followed by the regeneration by each fragment of a new head and series of anterior segments and of a new pygidium and posterior segments. The fragments usually consisted of sections of two, three, or four segments each, in the region of the body behind the seventh setigerous segment. It was further shown that this breaking up of Procerastea, which could be produced artificially at any time by treating the worms with sea-water of low salinity, made by adding distilled water to natural sea-water, took place according to a definite law. The first section consisted normally of the head and setigerous segments 1 to 7, then followed three sections of two segments each (Segments 8 and 9; 10 and 11; 12 and 13), then three sections of three segments (14–16; 17–19; 20–22), followed by four or five sections of four segments each, and then a number of sections of three segments.
A Revision of the Genus “Portunus” (A. Milne-Edwards, Bell, etc.)
Authors: Palmer Richard
Published: May 2009

1. The characters of the species of “Portunus” are redescribed in detail and comparatively.

2. On the basis of the characters studied an attempt is made to determine the relationships of the constituent species, both within the genus and with allied genera, P. corrugatus and P. arcuatus, being regarded as the more primitive forms.

3. P. marmoreus and P. holsatus are separated by a large number of characters.

4. The status of various foreign, fossil and doubtful species is discussed.

5. An account is given of the present state of knowledge regarding the distribution of the species.

6. The synonymy of the generic name is considered at length.
On the Mode of Feeding of the Hermit-crab, Eupagurus Bernhardus, and some other Decapoda
Authors: Orton J. H.
Published: May 2009

The hermit-crab, Eupagurus Bernhardus, is common in the oyster beds in the upper part of the Fal Estuary, and experiments indicate, while observations and experiments on the mode of feeding virtually prove, that these hermit-crabs do not harm healthy small oysters one inch or more in length, and the larger oysters, but that spat less than one inch may occasionally be damaged or eaten by hermit-crabs picking with their claws indiscriminately at growths on shells and stones.

E. Bernhardus obtains food largely by its small claw and third maxillipedes, and may at certain periods of the year feed mainly on microorganisms, and at others on macroscopic, but mainly tiny living organisms which have been disturbed and captured in the deposits on the sea-bottom. Food can be obtained by the use of the third maxillipedes alone.
Observations on the Fal Estuary Oyster Beds during 1926, including a study in Over-fishing
Authors: Orton J. H.
Published: May 2009

During the summer and autumn of 1926 frequent visits were made to the oyster beds in the upper Fal Estuary, and in view of the continued decline in the yield of oysters from these grounds, the opportunity was taken to record any facts which, besides being of value in the study of the bionomics of the oyster, might also be helpful in determining those steps most likely to lead towards an improvement of the general state of the fishery. A special investigation of the spawning in relation to tides and temperature was made, and will be compared in a separate publication with similar work carried out at about the same time on the River Blackwater beds in Essex.
A Note on the Physiology of Sex and Sex-determination
Authors: Orton J. H.
Published: May 2009

In a previous paper in this Journal (Vol. XIV, p. 967) a theory of the control of sex in the oyster by rhythmical changes in the general metabolism has been outlined and discussed briefly with the information at present available. As the connexion between metabolism and sex has long been regarded as important, and by some, e.g. Geoffrey Smith (1913), as all-important, this relation may be considered briefly with regard to modern views on the physiology of sex.
Rays and Skates of Devon and Cornwall. II. A Study of the Fishery; with Notes on the Occurrence, Migrations and Habits of the Species
Authors: Steven G. A.
Published: May 2009

1. Until the beginning of the present century there was little demand in this country for Rays and Skates. This fishery is now of major importance both nationally and within the Devon and Cornwall area.

2. Of the eleven species of Raia present in the western area of the Channel, R. clavata makes the greatest numerical contribution (37%) to the total landings in Devon and Cornwall. The composition of the catches obtained by different methods of fishing varies greatly.

3. R. clavata is the most widely distributed species in the Channel area at all depths and on all kinds of sea bottom.

4. In a series of trawl hauls off the west coast of Ireland R. clavata was most numerous in the catches down to about 100 fm. From that depth down to about 170 fm. (the greatest depth fished) R. fullonica was most numerous.

5. Unispecific and even unisexual shoals of at least three species of Raia—R. clavata, R. brachyura, R. fullonica—occur.

6. When more than one species of Raia is present within the same area at the same time, the members of the different species have been found not to mix indiscriminately.

7. R. clavata appears to hatch out in shallow water close inshore and gradually move seawards into deeper water as it grows.

8. Adult R. clavata show definite migratory movements, though the full extent of their wanderings is not yet known. There is an inshore migration in early spring of adult fish to a small part of the coast near Plymouth. The first fish to appear are females, males appearing later.

9. There is evidence of somewhat similar migratory movements by R. brachyura.

10. R. clavata—and possibly also R. brachyura and R. batis—at times may feed almost entirely on Herrings.

11. Large R. batis feed to no inconsiderable extent on other species of Eaia.

12. In foraging for their food Rays and Skates depend upon some sense other than sight.

13. There has been in recent years a steady decline in the landings of Rays and Skates from the English Channel—probably due to depletion of the available stock of fish.
The Bacterial Flora of the Slime and Intestinal Contents of the Haddock (Gadus aeglefinus)
Authors: Stewart Mary Macfarlane
Published: May 2009

Thesurface of most fish is covered with a coating of slime which increases in amount after death when the fish is held at room temperature or stowed in ice. The slime has been examined by Dr. Ingvaldsen of the Prince Rupert Station who has found that 3 c.c. of this material contain 33.348 mg. of nitrogen of which 11.9 per cent is amino-nitrogen. It is poor in carbohydrates, but along with the mineral salts contained in seawater it appears to provide an excellent medium for bacterial growth. In the fresh fish, the slime is clear, of mucous consistency, and shows comparatively few organisms in stained films, but in fish which are not quite fresh the slime appears to be increased in amount, is opaque and increased in consistency. With increasing age the slime becomes yellowish and evil-smelling, and stained films show an enormous increase of bacteria. In the early stages of the work attempts were made to correlate the number of organisms in the slime with the age of the fish by making bacterial counts, but owing to the irregular distribution of the slime over the surface of the fish and the difficulty of making homogeneous suspensions the results were not very satisfactory, although gross changes-were readily detected.
The Feeding Habits of the Galatheidea
Authors: Nicol Edith A. T.
Published: May 2009

The Galatheidea are divided into two families, the Galatheidæ and the Porcellanidæ, which differ from each other in their feeding habits as well as their structure.

Galathea dispersa has been taken as typical of the Galatheidæ. An examination of the gut contents shows that the food in the stomach consists of finely divided particles mixed with sand and detritus. In addition larger pieces of animal and vegetable matter are occasionally found. Observations of the animals in captivity show that they feed by two methods; either large pieces of food are seized by the chelæ and maxillipeds and passed to the mandibles or, as is more usual, the third maxillipeds are used to collect finely divided material from the substratum.The setæ on the terminal segments of the maxillipeds form a dense tuft which sweeps over the substratum, loosening and collecting small particles. The terminal tufts are cleaned out by the setse of the second maxillipeds, and the food passed to the mouth.