bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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 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.
The Shell Gravel Deposits, and the Infauna of the Eddystone Grounds
Authors: Smith J. E. 
Published: May 2009

1. The limitations of the Conical Dredge as used in obtaining a sample for quantitative estimation of the fauna of a ground are discussed, and are found to be related to(a)The great distance over which the instrument must be hauled, with consequent inability to detect patchiness of fauna.(b)The inability of the dredge to capture members of the epifauna.2. The nature of the shell gravel, its position relative to the Eddystone reef, and the various factors conditioning the degree of coarseness of the deposit and the segregation of its elements are considered. The main points of note are,(a) There are three well-defined areas, within which the gravels have their own particular characteristics.(1) TheInner Shell Gravelarea and theMiddle Gravelarea, composed of material of inorganic and organic origin, the former being gneissic in character, and the latter being formed of the remains of animals which normally live on this particular type of deposit.(2) TheOuter Shell Gravelarea, a mixture of matter of local and of outside origin. The area is more extensive on the western than on the eastern side of the reef.(b) Segregation of particles according to size occurs, and is illustrated by the movement of the valves of a number of species of molluscs. Wave action and the action of gravity are considered to be the chief factors in inducing movement of particles, which movement occurs in directions radiating from the reef outwards.3. The epifauna of the rocky bottom is referred to briefly.4. The infauna of the shell gravel has been examined quantitatively and qualitatively, and the range of the various species over the ground noted.5. The nature of the shell-gravel community and its relation to some of the important environmental factors, are discussed.6. Mortality among the lamellibranchs, and the depredations of the gastropodNatica alderiare considered; figures relating to the numbers of lamellibranchs killed byN. alderiare given.
The Absorption of Fats and Lipoids in the Plaice (P. platessaL.)
Authors: Dawes Ben 
Published: May 2009

1. Fat occurs in all three types of cell composing the gastric epithelium at the end of a period of fasting extending over 6 or 7 days, but is completely absent from the mucosa of all post-pyloric regions of the alimentary tract at such a time.2. There is a marked increase in the fat content of the superficial epithelium of the stomach after 30 hours and 50 hours of gastric digestion, the stomach being thus shown to be an effective organ of fat absorption.3. Considerable quantities of fat are present in the duodenal and intestinal epithelia after fat-containing meals have been digested. The rectum is capable of some slight absorption, although its capacity in this respect is very much smaller than that of the duodenum or intestine.4. It is suggested that there is a transference of the function of fat absorption from the stomach to the post-pyloric intestine when the frequency with which meals are taken is increased.5. Globules of true fat are not typically observed in the areolar tissue layer of the alimentary tract, although lipoid granules may occur in abundance. It is suggested that resynthesis of the cleavage products of fats does not occur in this layer.6. Data are presented bearing upon the rate of digestion ofMytilus edulisand Nereid worm.
A Preliminary Comparison of the Neon Lamp and Potentiometer Methods of Submarine Photo-Electric Photometry
Authors: Atkins W. R. G. , Poole H. H. 
Published: May 2009

1. J. H. J. Poole’s neon lamp method (1928) of integrating the photo-electric current is serviceable for work at sea down to moderate depths, which further experience may extend considerably. It is specially valuable for determining the light just above the water, and at such depths down to 5 m., at which the variability of the light renders the potentiometer method (1925) very difficult or quite impossible in rough water. For greater depths, down to 70 m. (bottom in the English Channel around our normal range) we have so far been able to use the latter only.2. The loss due to the shadow of the ship, obtained by subtracting the illumination just above water from that on the deck-house roof, was found to vary from an extreme case of 52 per cent, and a normal loss of 30 per cent, with an overcast sky, down to 11 per cent with a clear sun at 31° altitude.3. The loss of light due to its entering the water was found to vary from 7·5 to 16·5 per cent, mean 13·1 per cent.4. It is desirable that the illumination just above and just below the water surface should be determined by the neon lamp method as a routine.
Studies on Ligia oceanica. I. A. Habitat and Effect of Change of Environment on Respiration. B. Observations on Moulting and Breeding
Authors: Nicholls Aubrey G. 
Published: May 2009

1. Ligia is a nocturnal animal inhabiting crevices in rocks above high-tide level. It is omnivorous though Fucus spp. form the main article of diet.2. Immersion experiments were carried out in which the animals were subjected to a gradual transition from salt to fresh water. None survived this treatment for more than one month. It was noticed that the reduction in salinity was accompanied by an increase in the rate of beat of the pleopods.3. Animals were subjected to sudden and gradual changes in temperature. One specimen survived a change from water at 15° C. to water at 30° C. for 28 minutes, but was dead after 78 minutes; a second, changed from water at 15° C. to water at 35° C, was to all appearances dead after 8 minutes, but recovered after being replaced in water at the original temperature.
Studies onLigia oceanica. Part II. The Processes of Feeding, Digestion and Absorption, with a Description of the Structure of the Foregut
Authors: Nicholls Aubrey G. 
Published: May 2009

1. Ligia is an omnivore, though normally feeding on Fucus. Portions of food are cut off by the mandibles and passed into the œsophagus. Its feeding period is limited.2. The foregut is provided with a number of ampullæ and lamellæ which are furnished with spines and bristles and are so arranged as to form a filter for the separation of the liquid portion of the food from the solid particles.3. A second filter is found in the floor of the foregut protecting the entrance to the hepato-pancreas.4. A ventral valve is present preventing the entry into the hepato-pancreas of solid food from the intestine.5. The hepato-pancreas consists of three pairs of tubules provided with a muscular network for producing contractions. The epithelium possesses discrete cells.
A Study of the Respiration and of the Function of Hæmoglobin inPlanorbis corneusandArenicola marina
Authors: Borden Mabel A. 
Published: May 2009

A study of the respiration and of the function of hæmoglobin inPlanorbis corneusandArenicola marinahas been undertaken.The oxygen consumption of Planorbis is of the order of 0·026 c.c. per gm. per hour, measured at 15° C.The blood volume is approximately 0·581 c.c. per gm.The combined oxygen of the blood is 0·013 c.c. per c.c. of blood, the total oxygen being 0·014 c.c. per c.c. The total oxygen capacity of the blood per gm. of snail is estimated to be 0·0081 c.c.The oxygen supplied by the blood is calculated to last 18 minutes and is found by experiment to last 25 minutes.The snail does not immediately oxidise its hæmoglobin after subjection to anaerobiosis. Oxidation begins after 10 minutes and is complete within 20 minutes.
Hydroid Pigments. I. General discussion and pigments of the Sertulariidæ
Authors: Payne Nellie M. 
Published: May 2009

1. The yellow colours of the hydroids include at least two groups, the carotinoids found in the Antennulariidæ and Haliciidæ and the flavone-like pigments that occur in the Sertulariidæ. From the literature a third group, the uradines, may be added.2. The flavone pigments and their relatives are all water soluble and are thus distinguished from the carotinoids which are not water soluble, but may be dissolved in the usual fat solvents.3. In the Sertulariidæ studied, a graded series of chromatophore groups and pigments was found which ranged from the colourless speciesSertularia argenteaEllis and Solander, through the yellow ofSertularella gayiLamaroux andS. polyzoniasLinnæus, to the orange-brown ofThuiaria articulataPallas. The brown ofSertularia pumilais probably also a flavone derivative.4. The flavones and related pigments occur extensively in the plant kingdom. It is probable that the flavone-like pigments found in the Sertulariidæ are of plant origin.
The Larval Stages of Trivia europea
Authors: Lebour Marie V. 
Published: May 2009

In 1926 Pelseneer discovered the eggs of Trivia europea on the French coast. These he found were laid in capsules embedded in the compound ascidian Polyclinum luteum, the molluse biting a hole and laying its eggs in a vase-like capsule completely enveloped in the ascidian except for the wide lip of the vase which projects freely and can be easily seen with the naked eye (Pelseneer, 1926, Figs. 11–12). He also hatched some larvae from these eggs which were very interesting, as they possessed an accessory shell somewhat similar in shape to the Echinospira of Lamellaria perspicua. He did not obtain the eggs directly from the Trivia and was not able to keep the larvæ alive more than a few days. In his paper he expresses the hope that some worker will confirm his observations experimentally. This I am now able to do, having procured the eggs actually laid by the Trivia, hatched them out and kept them alive for more than a week, afterwards collecting the larvæ from the plankton from stages which exactly corresponded with those from the egg up to late stages which metamorphosed into young Trivia, and young stages of Trivia feeding on compound ascidians which corresponded with the metamorphosed forms.Trivia europea is common at Plymouth between tide-marks and in a few fathoms of water; occasionally further out in deeper water. Records are available from the shore to the region beyond the Eddystone.
Seasonal changes in the phytoplankton as indicated by chlorophyll estimations
Authors: Atkins W. R. G. , Parke Mary 
Published: May 2009

The pigments of pure cultures of algae, of known number per volume, have been extracted with aqueous acetone after separation by filtration. The extracts were compared in a Kober colorimeter with standard solutions of a preparation of bought chlorophyll. The number required to give 1 mg. of chlorophyll was thus determined.The algae studied included: Chlorophyceae, two species ofChlamydomonasand oneChlorellanot yet described; Chrysophyceae,Dicrateria inornataParke; Bacillariophyceae,Coscinodiscus centralisEhr.,Thalassiosira gravidaCleve andNitzschia closterium(Ehr.) W.Sm. formaminutissima; Cryptophyceae,Hemiselmis rufescensParke; Dinophyceae,Gymnodiniumsp. The numbers per milligram of chlorophyll varied from 74 × 103forCoscinodiscusto over 3200 × 106forHemiselmis rufescens. Of the nine cultures, six were between 50 and 750 × 106. The volume of the cell is the decisive factor in the milligram count.
A statistical study of variability in catch obtained by short repeated trawls taken over an inshore ground
Authors: Barnes H. , Bagenal T. B. 
Published: May 2009

The variability in catch of a series of hauls with a V.D. trawl taken under, as far as possible, controlled working conditions has been determined.For analysis the species were divided into ‘round’ fish and ‘flat’ fish together with Nephrops; for both groups the coefficient of variation varied from 40 to 85 %. Taking 75 % as a representative value, the 2σ fiducial limits are 30–300 % for a single species from a single haul of half an hour duration.It has been found that the standard deviation is roughly proportional to the mean, and that the variance is greater than the mean and increases with the mean. This suggests aggregation of the population.The species are considered over the whole sampling period (4 weeks). Except for haddocks and dogfish the ‘round’ fish constituted a constant population. Changes were found in the other groups and their origin is discussed.
The status of the common seal (Phoca vitulinaL.) on the East Anglian coast
Authors: Sergeant D. E. 
Published: May 2009

A study has been made of the food, population, and some aspects of the ecology of the common seal (Phoca vitulinaL.) along the East Anglian coast.Examination of stomach contents of 194 seals killed in the Wash in 1947 confirms earlier evidence that the species here feeds largely on whelks (Buccinum undatum). The food is estimated by weight as 92 % molluscs, 4 % fish and 4 % Crustacea. Young seals for 2–3 months after weaning feed almost exclusively on shrimps (Crangon vulgaris).Data derived from six stomachs, together with verbal reports, suggest that seals on the open coast feed more exclusively on fish, chiefly pleuronectids. This agrees with the findings of other workers in Holland and Washington State, U.S.A., that fish are the primary food animals. It is therefore suggested that in the Wash, where suitable breeding sands are common, the seals have become adapted to feeding on a ‘second-class’ food in the absence of dense stocks of fish.
Observations in the sea on the reaction to ultra-violet light of certain sound scatterers
Authors: Craig R. E. , Baxter I. G. 
Published: May 2009

Two experiments on the reaction to ultra-violet light of certain sound scatterers in the area are described.The source was a 125 W. ultra-violet lamp.The scatterers were detected using a Kelvin and Hughes recording echo-sounder, type 22.The traces on both occasions were of the confused type caused by a number of different organisms, apparently lying between 20 and 60 m. and 8 and 30 m. respectively.The responses of the different organisms to the ultra-violet light as shown by the components of the traces are described and their speeds of reaction calculated.The types of organisms causing the traces are suggested.
Vitamin A and carotenoids in certain invertebrates. I. Marine Crustacea
Authors: Fisher L. R. , Kon S. K. , Thompson S. Y. 
Published: May 2009

Planktonic, benthic and littoral Crustacea were collected from localities around the British coast, from Norwegian and Faeroese waters and from the Antarctic, and their content of preformed vitamin A and carotenoid pigments was measured.Methods are described for the preservation of specimens, the extraction and separation of vitamin A and carotenoids and the measurement of vitamin A by chemical, physical and biological tests, and of carotenoids by physical tests.Free-swimming euphausiids were found to contain, in addition to large quantities of astaxanthin, high concentrations of preformed vitamin A, but no β-carotene.
A note on the breeding season, sex ratio and embryonic development of the dogfish Scyliorhinus canicula (L.)
Authors: Harris John E. 
Published: May 2009

Records of nearly 2000 dogfish collected from the Ilfracombe region suggest that the spawning season of this fish starts in November and continues at least until July. This area probably represents a spawning ground into which the females migrate during the spawning season; the males follow them much later in April and May.Figures are given to show the time taken at different temperatures for the embryo to develop to a series of definite morphological stages; these suggest that the temperature characteristic of the development (µ = 20,000) is substantially the same as for several teleost species.