bluuebunny/crossref_metadata_2025_split huggingface dataset:
Osmoregulation in some palaemonid prawns
Authors: Kesava Panikkar N. 
Published: May 2009

1. The brackish-water prawnPalaemonetes variansand the marine prawnsLeander serratusandL. squillaare hypotonic in normal sea water, the blood of these species showing osmotic pressures equivalent to 2·3, 2·8 and 2·6 % NaCl respectively, in an external medium of 3·5 % NaCl.2.Palaemonetes variansis isotonic in water of about 2·0 % NaCl and the species is practically homoiosmotic, the difference in its osmotic pressure over a range of 5·0 % NaCl in the external medium being only 0·8–1·0 %. The species has a very wide range of tolerance from water that is nearly fresh to concentrated sea water equivalent to 5·2 % NaCl.3.Leander serratusis much less homoiosmotic thanPalaemonetes, and has a limited tolerance to dilution and concentration of the environment. Homoiosmoticity is maintained up to a dilution of 2·5 % in the external medium when isotonicity is reached; but in lower dilutions there is a steady decline in osmotic pressure and the regulatory mechanism evidently breaks down.4. The osmotic behaviour ofLeander squillais very similar to that ofL. serratus, but the homoiosmotic behaviour is more marked and it has greater tolerance to dilution of the environment.5. WhenLeanderandPalaemonetesare transferred to very dilute sea water, the internal osmotic pressure falls gradually for about 14–24 hr., varying according to the size of the individual. After the lowest value has been registered there is a slight rise, and a steady state is thereafter maintained.6. Studies on the changes of weight of prawns when transferred to diluted media indicate that the integument (gills) is permeable to water and that, at least inLeander serratus, the amount of water entering is mainly responsible for the dilution of the blood. There is a similar fall in weight when prawns are transferred to concentrated media, due to loss of water.
The relationship between cirral activity and oxygen uptake inBalanus balanoides
Authors: Newell R. C. , Northcroft H. R. 
Published: May 2009

The rate of cirral beat ofBalanus balanoidesis related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.Balanus balanoidesexhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.
The American whelk tingle, Urosalpinx cinerea (Say), on British oyster beds
Authors: Cole H. A. 
Published: May 2009

The American whelk tingle, Urosalpinx cinerea (Say), a gastropod enemy of oysters, has been introduced to Britain with American oysters and is now established in the rivers Blackwater, Colne, Crouch and Roach in Essex and on the Kentish Flats off Whitstable. Evidence available concerning the migratory powers of Urosalpinx is conflicting, but it is probable that migration is of local significance only in the spread of this pest. To infest new areas tingles or their spawn must be transported by human or other agency, for Urosalpinx has no free-swimming larval stage, the eggs being deposited in capsules from which fully formed young tingles emerge.Females of Urosalpinx grow more quickly than males and reach a larger size. In males the annual increase in shell height never exceeds 0·2 cm. after the first 3 years, and is generally rather less. In females an annual increment of 0·2 cm., or slightly more, is general up to the age of about 7 years, after which it gradually falls. Males and females of the same age differ in height by about 0·25 cm. Growth marks are frequently to be seen on the shell and are of value in assessing growth rates. In both sexes a maximum age of 13–14 years may be reached. Urosalpinx reaches a much greater average size in Britain than in its natural habitat on the Atlantic coast of the U.S.A.Females may deposit some spawn during the first 2 years of life, but the amount is insignificant in relation to the production of older tingles. Spawning begins when the water temperature in its seasonal rise reaches 12° C. Adult females may deposit an average of 25 egg capsules at a single laying, but it is possible that further capsules are deposited later in the season. The bulk of the spawn is deposited in May and June on British beds, but a few freshly laid capsules may sometimes be found in August and September. The average period of incubation is about eight weeks. Young tingles usually begin to emerge early in July. The average number of young emerging from each capsule is 11–74. Urosalpinx appears to be more prolific on British oyster beds than in America.
The distribution of Arachnactis albida M. Sars in the Celtic Sea
Authors: Corbin P. G. , Panikkar N. Kesava 
Published: May 2009

The distribution of Arachnactis albida in the Celtic Sea in 1937–9 is described. The species appears, to have a definite centre of distribution in the neighbourhood of lat. 50° N., long. 10° W. The larvae have been taken as far south as lat. 48°, and eastwards up to the mouth of the English Channel, but they are absent from the tongue of low salinity water continuous with the St George's and Bristol Channels. Their distribution in the remaining area can be correlated with the cyclonic circulation.The larvae obtained from the Celtic Sea are specifically identical with those found off the west coast of Ireland and with the typical A. albida of the Faroe-Hebrides region.
Further Observations on Fish Growth in a Fertilized Sea Loch (Loch Craiglin)
Authors: Gross F. 
Published: May 2009

Flounders grew much more slowly in 1944 than during the previous 2 years. From October 1943 to October 1944 their mean size increased from 7·9 cm., 6·8 g., to 12·7 cm., 23·6 g., an increment which was if anything smaller than under normal conditions. The reason for the reduction in growth rate is attributed to the increasingly unfavourable hydrographic conditions resulting from the prolonged closure of the dam, in particular to the high H2S concentration, the high pH and the low oxygen concentration of the water.In the autumn of 1944 the sluice gate of the dam was opened for several months. In 1945/46 the growth of stock III flounders was very rapid. They reached a mean size of 32·3 cm., 409 g., in March 1946 and 36·8 cm., 580 g., in March/April 1947. Native flounders reached a mean size of 30·6 cm., 353 g., in 2 years.
The Thixotropy and Dilatancy of a Marine Soil
Authors: Chapman Garth 
Published: May 2009

Modifications are described to the penetrometer originally designed by Chapman & Newell (1947) for the measurement of the resistance to penetration of marine soils.An account is given of qualitative and quantitative tests made during the study of the thixotropy and dilatancy of the muddy sand of theArenicolaregion of the shore at Whitstable. The results of tests made with the dilatancy viscometer originally used by Freundlich & Röder are shown not to be in clear agreement with the observed behaviour of the soil.
A preliminary report on the Plymouth marine and Brackish-Water Rotifera
Authors: Hollowday E. D. 
Published: May 2009

Six species of rotifer, including one oceanic species and representing four genera, are recorded for the first time from Plymouth. Remarks are made on various interesting features of their anatomy, details are given of their times of occurrence at Plymouth, with notes on their location and known distribution in other parts of the British Isles, and in foreign waters.Attention is called to the apparent poverty of the Plymouth marine and brackish-water Rotifera as compared with that of Liverpool, investigated at length by Galliford. It is stressed that no exact conclusions as to the reason for this can be made until after a more exhaustive survey, as some likely habitats adjacent to the Sound were not investigated. Attention is also called to the caution which must be exercised in terming rotifers marine, as most of those collected in coastal waters appear at present to be confined to areas where a considerable amount of fresh water is discharged into the sea. At least two species, one of which occurs in the Sound in May, are known to be truly oceanic, having been found in mid-Atlantic.It is suggested that ‘brackish’ and ‘estuarine’ are the terms most applicable to the majority of coastal rotifers in the present state of our knowledge.
Population-dispersion inTellina Tenuisda Costa
Authors: Holme N. A. 
Published: May 2009

A population of the lamellibranchTellina tenuisin the Exe estuary is shown to be uniformly distributed, indicating a significant degree of ‘over-dispersion’.By plotting the position of each shell in squares ofm.2area it is shown that fewer individuals than would be expected occur less than 1 in. from their nearest neighbour, and none occurs closer than 0·6 in.When the population density was artificially increased on the shore the same characteristic spacing was found at a moderate density, but not at a rather higher density.It is suggested that spacing is correlated with the foraging activities of the inhalent siphon on the soil surface.Very dense populations have been found by Stephen in other areas, indicating that the size of the ‘territory’ does not limit density. His results show no evidence of the same phenomena as observed in the Exe.
Gregariousness during settlement in the barnacle Elminius modestus Darwin
Authors: Knight-Jones E. W. , Stevenson J. P. 
Published: May 2009

A gregarious tendency during settlement, similar to that already demonstrated in oyster larvae, was suspected in Elminius, because cyprids settled in groups during the initial stages of colonization of surfaces (crowded later arrivals showed a spacing-out tendency) and because settlement on test-plates was peculiarly sparse at stations with a muddy bottom, where barnacles were absent.Settlement was much heavier on areas of smooth glass, which already bore recently settled barnacles, than on similar adjoining areas which were bare.When barnacled microscope slides were stuck to one set of glass plates, bare slides to another and the two sets exposed side by side, settlement was consistently much heavier on the plates which bore the barnacled slides. The mean density of settlement on the bare slides and the surrounding plates was uniformly low, except for a greater density immediately adjoining the slides, probably due to sheltering alongside their edges. On the barnacled slides density of settlement was much higher and on the plates immediately alongside still more so, whilst at increasing distances from the slides it became gradually smaller but was still much heavier than on the plates with the bare slides. This suggests that the sensory basis for gregariousness can act at a distance. It may possibly be olfactory.
The Distribution of Octopus Vulgaris Lamarck in British Waters
Authors: Rees W. J. 
Published: May 2009

In Britain Octopus vulgaris occurs on the Channel coast and only very rarely on other coasts. In Brittany and the Channel Islands it frequently makes its lair at low water, but on the English side of the Channel it does not come so close inshore except in abnormal years of high sea temperatures.The discovery of Octopus larvae of various sizes, from newly hatched to 6·0 mm. (mantle length), in plankton hauls taken to the north of the Channel Islands, proves that the species has a much longer planktonic life than hitherto supposed.The water circulation in the English Channel, as indicated by drift bottles, is admirably suited to the dispersal of larvae to our shores from breeding centres on the coasts of Brittany and the Channel Islands.
The seasonal variation in the cellulose content of the common Scottish Laminariaceae and Fucaceae
Authors: Black W. A. P. 
Published: May 2009

Monthly samples of the common British Laminariaceae and Fucaceae taken during 1946 have been analysed for cellulose.The cellulose content has been found to increase with the depth of immersion of the weed.In the Laminariaceae, both in the stipe and frond it undergoes marked seasonal variation, exhibiting two maxima, March/April and September/October with a distinct minimum in June/July.In Laminaria cloustoni, in March, maxima of 5·7 (dry basis) occur in the fronds and 10·3% in the stipes with minima, in June, of 4·1 and 8·4% respectively. In Laminaria saccharina the cellulose content (dry basis) varies between 4–5% in the frond and 7–8% in the stipe and in Laminaria digitata between 3–5% in the frond and 6–8% in the stipe.
A Biological Study of Fucus Vesiculosus L. and F. Serratus L.
Authors: Knight Margery , Parke Mary 
Published: May 2009

A certain variation in level of the fucoid zone with latitude is demonstrated. The belt of Fucus vesiculosus and F. serratus lies lower on the Devon coast than on either the Manx or the Argyll coast.The conditions for the optimum germination of fertilized eggs are dissimilar to those for maximum rate of frond-extension.Normal growth-rates have been established for both species for the first 3 years of life. In F. vesiculosus the average rate of elongation per week is 0·48 cm. on the Devon coast, 0·45 cm. on the Manx coast and 0·68 cm. on the Argyll coast. In F. serratus the average rate of elongation per week is 0·49 cm. on the Devon coast, 0·68 cm. on the Manx coast and 0·85 cm. on the Argyll coast. The rate of growth is shown to vary with the conditions of the environment. Shelter from rough water tends to enhance growth-rate, and there is an indication that greater stature is achieved by the plants from the Argyll station than from either of the other stations.
On the Rearing and Breeding of Gammarus in Laboratory Conditions
Authors: Sexton E. W. 
Published: May 2009

The following paper has been prepared in the hope that it will be of assistance to anyone desirous of carrying out experiments on Heredity with Gammarus chevreuxi. This Amphipod has been the subject of study at the Plymouth Laboratory since 1912, and the following notes are chiefly concerned with rearing and breeding it under Laboratory conditions.Details of the work will be found in the papers mentioned in the bibliography on page 54.
The Post-Larval Development of Loimia medusa Sav
Authors: Wilson Douglas P. 
Published: May 2009

1. The larva of a Terebellid which is very common in plankton from the Plymouth district during spring has been reared and proved to be the young of Loimia medusa Sav. This larva is characterised by its very large gelatinous tube.2. The development of the external structures is described from a stage in which the first tentacle was just appearing to a juvenile stage in which all the main characters of the adult had been assumed.3. The building of the first sandy tube on the bottom is described.4. The development of the bristles and uncini are dealt with in some detail and a comparison made with the corresponding development in Nicolea zostericola. Evidence of the suppression of a pair of larval bristle-bundles in Loimia is indicated.5. Previous records of Loimia larvse are discussed.6. McIntosh's separation of our British Loimia to a new species, L. montagui, is shown to be probably unjustified.
Seasonal Variations in the Phosphate and Silicate Content of Sea Water during 1926 and 1927 in Relation to the Phytoplankton Crop
Authors: Atkins W. R. G. 
Published: May 2009

1. A comparison of the strength of the wind, Beaufort Scale, and of its direction during the periods when the vernal diatom outburst caused phosphate depletion of the surface water, has failed to indicate that there is any connection between either strength or direction and the date of the outburst. The spring sunshine still appears to be the important factor at El.2. The sequence of the years studied as regards the main spring diatom outburst deduced from phosphate depletion at Station El is as follows: 1924, early March; 1926, late March to early April; 1925, early April; 1923, early May.
Chemical Constituents of Biological Importance in the English Channel. Part III. June-December, 1932. Phosphate, Silicate, Nitrate, Hydrogen Ion Concentration, with a Comparison with Wind Records
Authors: Cooper L. H. N. 
Published: May 2009

In August, 1932, marked stratification of the water in the English Channel led to an unusual distribution of minor chemical constituents. Two thermoclines were present, between which high silicate values were found, indicating rapid re-solution of silica as found in former summers; pH was also very high at 15 metres.In or about December in four years, nitrite in inshore waters has been found much in excess of that present in the open Channel.The “mean cube Beaufort number” is suggested as a useful practical measure of sea disturbance. Three out of four midwinter plankton outbursts, inferred from a fall in the phosphate content of the water, have followed periods of sunny weather with little wind.
The Food Consumed by Shags and Cormorants around the Shores of Cornwall (England)
Authors: Steven G. A. 
Published: May 2009

1. 188 Shags and 27 Cormorants, which had been feeding around the shores of Cornwall and whose stomachs contained identifiable food organisms, have been examined.2. The Shags were found to have been feeding principally upon Sand Eels (Ammodytes spp.), and other non-marketable fishes.3. The proportion of flatfishes and other economic species which had been devoured by the Shags was negligible.
The Magnesium and other Inorganic Constituents of some Marine Invertebrates
Authors: McCance R. A. , Shipp H. L. 
Published: May 2009

The sodium, potassium, calcium, magnesium and iron of a number of marine invertebrates have been determined and some of the findings are very briefly discussed.The common winkleLittorina littoreacontains 330–510 mg. of magnesium per 100 g. of live weight. All the organs appear to contain these high concentrations. Boiled specimens of whelks contained about 160 mg. of magnesium per 100 g.We should like to thank the Director and Staff of the Laboratory of the Marine Biological Association for their assistance. R. A. McC. has held a part-time grant and H. L. S. a full time grant from the Medical Research Council during this work.
Abnormal Eyes in WildGammarus zaddachiSexton
Authors: Bassindale R. 
Published: May 2009

Of 198 specimens ofGammarus zaddachicollected in the Estuaries of the Rivers Earn and Tay four individuals had abnormal eyes. This is the first record of abnormal eyes in wild specimens of a Gammarus species, although Laboratory strains ofG. chevreuxihave developed them.The investigation described in this paper was carried out as part of the programme of the Water Pollution Research Board of the Department of Scientific and Industrial Research, and is published by permission of the Department. My thanks are due to Dr. E. J. Allen and to Mrs. E. W. Sexton for their assistance in preparing the paper.
Observations on the Reactions of Marine Plankton to Light
Authors: Spooner G. M. 
Published: May 2009

1. The most noticeable response of marine plankton to light, under laboratory conditions, is the formation of groups on the lighted (or opposite) side of the vessel containing them.2. Specimens from such groups were tested under different conditions of illumination, and in all cases they moved in thedirectionof the light quite irrespective of accompanying changes ofintensityin the surroundings.3. Groups form around the line of direction of the light, or the resultant direction when the light is scattered or falling from more directions than one, this being the direct result of individuals moving along the mean path of incidence of the light.4. The behaviour of individuals was examined more closely to distinguish between the two possible ways in which the directed movement could have been brought about, viz. (i) reactions to bilateral inequalities of illumination (here called “true topotaxis”), and (ii) reactions to changes in total illumination of light-receptors (a type of “phobotaxis”). For a number of species it was clearly a case of “true topotaxis,” and very probably for at least the majority of the rest.5. In two very different cases, namely,Acartia clausiandPoecilochaetus serpens, there was no orientation of the body, but nevertheless efficient orientation of the path of movement. It is believed that this is the first occasion on which such behaviour has been described.6. The observations described point to the fact that movement in the direction of incidence of the light, however this may be affected, is general among a wide range of the smaller, free-living, bilaterally symmetrical, marine animals, and would tend to dominate other possible response to light. This behaviour on the part of individuals provides a substantial basis for attempted explanations of the correlations, that have been demonstrated by ecological workers, between the vertical distribution of populations and light-intensity.
Relationships between the sex and degree of maturity of marine crustaceans and their lipid compositions
Authors: Morris R. J. 
Published: May 2009

The results of decapod lipid analyses have shown that females and gravid females generally contain high levels of monounsaturated acids and that the eggs of some of these decapods are composed mainly of phospholipid and triglyceride. These are probably present mainly as energy reserves. The percentages of saturated fatty acids are not found to vary with either maturity or sex, whereas the composition of the polyunsaturated acids are affected by both sex and maturity differences. Females are generally much lower in their content of polyunsaturated acids than juveniles and males, the males showing a greater requirement for 20:5 acid compared to the females.For the euphausiids there is a slightly different picture, the monounsaturated acids appear as the stable fraction and forEuphausia krohniithe juveniles are similar to the females in their content of the polyunsaturated acids.Neomysis integeris quite unlike the oceanic crustaceans showing a very specific difference in fatty acid composition between the males and females, the juveniles being rather intermediate in composition.
The meiofauna of a flatfish nursery ground
Authors: McIntyre A. D. , Murison D. J. 
Published: May 2009

The meiofauna was studied over a 10-year period on a flatfish nursery ground between the high-water mark and a depth of 10 m below low-water springs.The sediment was well sorted sand, with median diameter from 210 to 279 μ in the intertidal area and 160 to 208 μ in the subtidal. It was composed of medium rounded quartz, with the calcium carbonate content mainly 0·25 to 2·20% by weight. Porosity was 33·39% and the coefficient of permeability ranged from 1·66 to 2·33 × 10–2 cm per sec, indicating good drainage. The sand was usually over 90% water-saturated, and seldom less than 60%. The annual average concentration of particulate organic carbonwas 205 μg/g sand in the intertidal, and 684 μg/g at 5 m depth. Corresponding values for chlorophyll a were 0·75 and 4·50 μg/g.