bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the ecology of a dense bed of the brittle-star Ophiothrix fragilis
Authors: Warner G. F. 
Published: May 2009

INTRODUCTIONThe occurrence of dense beds of the brittle-star Ophiothrix fragilis (Abildgaard) in certain localized areas around the British Isles has been reported by several authors (Allen, 1899; Vevers, 1952; Cabioch, 1961; Holme, 1961; Brun, 1969), with population densities varying from 340/m2 (Vevers, 1952) to 2196/m2 (Brun, 1969). These populations seem to be permanent features of the sea bed since the aggregation sampled by Allen was in the same position as that photographed by Vevers fifty years later.
The biology of Paramysis arenosa [Crustacea, Mysidacea]
Authors: Mauchline J. 
Published: May 2009

INTRODUCTIONParamysis arenosa (G. O. Sars) occurs quite commonly in sandy bays on the west coast of Scotland. It is common in Kames Bay, Millport, Brodick Bay on Arran and on Fairlie Sands in the Firth of Clyde. It has been taken in Loch Crinan, Argyll and at Ganavan Sands and Loch Nell Bay, both north of Oban, Argyll. It is common in Firemore Bay, Loch Ewe and in Gairloch and Gruinard Bay in Wester Ross.
The biology of Neomysis integer [Crustacea, Mysidacea]
Authors: Mauchline J. 
Published: May 2009

INTRODUCTIONThere are more than twenty species in the genus Neomysis Czerniavsky, of which the only British representative is N. integer (Leach). This is one of the commonest species of mysids round the coasts of Britain. It lives in estuarine, brackish-water situations and Tattersall & Tattersall (1951) have summarized its distribution. The present investiga- tion has added many records from the west coast lochs of Scotland: Lochs Striven, Riddon, Fyne, Gilp, Ranza in the Firth of Clyde; Lochs Craignish, Feochan, Etive, Creran, Shuna, Linnhe, Eil and Torridon farther north. The biology of Neomysis species is much better known than that of species in other genera:N. americana (Smith) has been studied by Cowles (1930), Whiteley (1948), Hulburt (1957) and Hopkins (1965); the biology of N. awatschensis (Brandt) has been examined by Ii (1964) and Turner & Heubach (1966), that of N. czerniawskii Derjavin and N. intermedia (Czerniavsky) by Ii (1964), that of N.japonica Nakazawa by Ishikawa & Oshima (1951) and Ii (1964), that of N. rayii (Murdoch) and N. spinosa Nakazawa by Ii (1964).
The meiofauna off the coast of Northumberland. II. Seasonal stability of the nematode population
Authors: Warwick R. M. , Buchanan J. B. 
Published: May 2009

INTRODUCTIONIn an earlier paper (Warwick & Buchanan, 1970) the structure of the nematode communities at three stations off the Northumberland coast was compared. It was shown that the offshore mud community at station ‘C’ was faunistically the most homogenous. This station has been selected for a more intensive investigation of meiofaunal production since it provides the simplest situation for study, and furthermore the type of nematode community found here is thought to be of common occurrence in similar sediments round Northern Britain.
Intertidal activity, breeding and the floating habit ofHydrobia ulvaein the Ythan estuary
Authors: Anderson A. 
Published: May 2009

INTRODUCTIONEcological studies of EiderSomateria mollisima, ShelduckTadorna tadorna, RedshankTringa totanus[Aves], and FlounderPlatichythys flesus[Osteichthys], in the estuary of the River Ythan, Aberdeenshire, have entailed investigations of their food requirements, and there is evidence to suggest thatHydrobia ulvae[Gastopoda], as a numerous food item common to all, may in some instances have influenced their breeding success and numbers in some years. In order to get an index of abundance ofHydrobia, the Ythan population has been sampled four times a year since May 1963. The full results of this sampling programme are being published separately. At the same time data on the annual cycle ofHydrobiawere collected from one area (transect number 3, Fig. 1), on the assumption that breeding onset and intensity would be the same in other parts of the estuary in any one year.
Terpenoid quinones and steroids in the nutrition ofOxyrrhis marina
Authors: Droop M. R. , Pennock J. F. 
Published: May 2009

INTRODUCTIONOxyrrhis marinaDujardin is among the few phagotrophic micro-organisms, and the only dinoflagellate with this mode of nutrition, to have been cultivated under axenic conditions. In common with most other phagotrophs studied,Oxyrrhishad to be supplied with a natural source of lipid growth factors for axenic cultivation, lemon rind or grass extracts in this instance (Droop, 1959). The eventual replacement of these natural sources by ubiquinone (Droop & Doyle, 1966) cleared the way for the development of a completely denned culture medium forOxyrrhisand the completion of the nutritional study, the water-soluble nutrients having been fully worked out previously (Droop, 1959). However, identification of this requirement immediately raises two questions. The answer to the first, whether ubiquinone is the only lipid required, appears to be in the negative, and the details of an additional, fairly specific, steroid requirement are presented in the second part of this paper. The other question concerns the specificity of the quinone requirement. Is the quinone merely a convenient source of the benzene ring – mammals require at least one aromatic compound in the diet – or does it act as a true growth factor, in which case the requirement would be unique and would have more than protozoological interest?
Observations on the keeping of adult female Pseudocalanus elongatus under laboratory conditions
Authors: Corkett C. J. , Urry D. L. 
Published: May 2009

Stocks of adult female Pseudocalanus elongatus have been kept for the past 6 years in a laboratory remote from the sea. The techniques used in maintaining these stocks are described.The most suitable temperature for keeping the copepods has been found to be 10 °C.The control of pH has not been necessary.Although an allowance of 30 ml. of sea water for each copepod is recommended, it has been found that survival is not affected by densities of up to 1 copepod/10 ml.
First Record of the American Jack Knife ClamEnsis Directuson the French Coast of the North Sea
Authors: Luczak C. , Dewarumez J.-M. , Essink K. 
Published: May 2009

Ensis directus(Bivalvia: Solenidae) was noted for the first time along the French coast of the North Sea in June 1991. High numbers of post larvae after a period of northerly winds indicate that settled larvae originated from adult populations in Belgian or Dutch coastal waters. Future dispersal ofEnsis directuscould be used as a biological tracer of coastal water movements between the Southern Bight of the North Sea and the English Channel.The American jack knife clam,Ensis directus(Conrad, 1843), synonymEnsis americanus(Binney, 1870)sensuvan Urk (1964,1972), was discovered in Europe in the German Bight for the first time in June 1979 (Von Coselet al., 1982). This species is assumed to have been transported in its larval stage by a ship containing ballast water. Considering the dimensions of the specimens, this probably happened in the first half of 1978 (Von Coselet al., 1982; Mühlenhardt-Siegelet al., 1983). Since then this species has spread rapidly in the North Sea in subtidal and intertidal areas. Dense populations were found along the German coast within a few years (Von Coselet al., 1982; Mühlenhardt-Siegelet al., 1983; Swennenet al., 1985). In 1986 Ensisdirectuswas reported from the north and east Danish coasts as far as the Belgian coast (Kerkhof & Dumoulin, 1987) (Figure 1). Since then no new records have been reported.
The Size of Diatoms IV. The cell diameters in Rhizosolenia styliformis var. oceanica
Authors: Wimpenny R. S. 
Published: May 2009

Consideration has been given to the cell diameters of twenty-four samples of Rhizosolenia styliformis var.oceanica from a wide range of latitude together with material from eleven other collections already briefly recorded in Part II of this paper.It was found that the cells of the smallest diameter occurred in high latitudesand that the average values were greater at lower latitudes.More auxospore generations were present simultaneously in higher latitudes. An interpretation of these observations is that the prevalence of smaller cell diameters and the simultaneous presence of more auxospore generations in high latitudes could be due to relatively lighter grazing by herbivorous zooplankton in these regions.Measurements of a few samples of a form of Rhizosolenia styliformis (Bright-well) which I called var. oceanica have been published earlier (Wimpenny, 1946), and auxospore formation was recorded from the Faroe-Shetland area. Since that time, owing to the kindness of the late Dr Vedel Taning, I have been able to see sixteen samples taken in the North Atlantic by the Danish research ship 'Dana' in1948. Mr J. Corlett of the Fisheries Laboratory, Lowestoft, has also been good enough to have made available to me three collections containing this variety from the Weather Ships 'Jig' and 'Item' in 1950 and two from the west ofBear Island in 1952. Finally, I have to add two samples of 33 and 50 specimens fromthe northern North Sea area made available to me many years ago by the late Miss Ogilvie and another sample from which I have been able to measure 100 specimens givenme by Dr James Fraser (E 34, 1934).
Vitamin A compounds and lipids in the blood of the Cod Gadus morhua from the Arctic, in relation to gonadal maturation
Authors: Plack P. A. , Woodhead P. M. J. 
Published: May 2009

Cod (Gadus morhua L.) from the Arcto-Norwegian stock that spawns off northern Norway were caught at various times during the course of their gonadal maturation cycle, and plasma samples were collected for the determination of vitamin A compounds and lipids.The main changes found concerned vitamin A aldehyde, which increased from a resting level of2μg/100 ml. plasma for adult females caught in September to 10 μ/100 ml. in ripe females caught in January-March approaching their spawning grounds; by contrast little change was observed in the males. In the fish of both sexes caught in September, just prior to the onset of maturation, dehydroretinal formed about 38 % of the total aldehyde, but in the plasma of ripe females the proportion was only 16 %. In both sexes there was a fairly steady decline in the levels of vitamin A esters and alcohol in the plasma during the winter. Similarly, the concentration of plasma lipids fell during the winter in the male cod, but in the adult females, during the period of ovarian maturation, the concentration of lipids increased and was maintained at about 0·5 g/100 ml. higher than in the males; in spent fish the concentration of lipids fell to the same low levels in both sexes.It was considered that the changes in vitamin A aldehyde, and also of blood lipid, in the females were directly linked with sexual maturation, these compounds being transported to the developing eggs in the ovary. On the other hand, the general decline of vitamin A esters and alcohol in both sexes, and of lipids in the males, was probably due to the obligatory winter starvation which occurs in this stock.
Determination of nitrate in sea water by cadmium-copper reduction to nitrite
Authors: Wood E. D. , Armstrong F. A. J. , Richards F. A. 
Published: May 2009

An accurate, dependable determination of 0–60 μg-at./l. of NO−3-N in sea water has been developed. The sample is treated with tetrasodium ethylenediaminetetraacetate solution and passed through a column of copperized cadmium filings. A nearly quantitative reduction of nitrate to nitrite results. Nitrite is then determined by a diazotization method. Neither sulphide nor high nitrite concentrations interferes. Approximately eight samples per hour per column can be analysed with a standard deviation of 0.12 μg-at./l. at the 20 μg-at./l. level.IntroductionAccurate determinations of nitrate ions in sea water have been difficult, especially under shipboard conditions.The colorimetric method described by Harvey (1926, 1930) and improved by Cooper (1932), Zwicker & Robinson (1944), and others uses strychnidine in concentrated sulphuric acid to produce a red colour. The reagent lacks reliable sensitivity, because it is dependent on the rates of mixing and cooling.In a method by Armstrong (1963), the absorbance of nitrosyl chloride in the UV region is measured with a spectrophotometer. While the method is good for small samples containing high concentrations of nitrate, the use of concentrated sulphuric acid and lack of sensitivity limit its use in routine analysis.A method in which nitrate is quantitatively reduced to nitrite would be advantageous, because nitrite can be readily determined by the sensitive diazotization method proposed by Griess (1879). Several such methods have been proposed. FØyn (1951), Vatova (1956), and Chow & Johnstone (1962) used zinc powder for the reduction, but the reduction is sensitive to temperature, and it is necessary to centrifuge or filter each sample.
Physiological ecology ofPatella. II. Effect of environmental acclimation on the metabolic rate
Authors: Davies P. Spencer 
Published: May 2009

The physiological basis for the previously reported differences in the rate of respiration between high-shore-level and low-level populations ofPatella vulgatain the summertime has been investigated in relation to distribution differences between this species andP. aspera.The respiration rate of bothP. asperaand low-levelP. vulgatais low in the winter but increases in the spring to a level which is maintained until the post-spawning period in the autumn. The respiration rate of high-levelP. vulgatadoes not increase in the spring but remains at the low winter level. The inter-population difference in rate of respiration therefore appears in the spring and is maintained until the autumn.The difference in rate of respiration cannot be accounted for by differences in the amount of non-respiring tissue in equal weight individuals and is phenotypic and not genotypic, as indicated by transplantation experiments. These experiments also rule out the possibility of differences in age of equal weight individuals from the two populations being responsible.Respiration rate was found to be a function of both intertidal height and of the abundance of algal food in the habitat. It is suggested that the low-level population ofP. vulgatashould be regarded as the normal form and that the low respiration rate of high-level limpets in the summer represents a form of adaptation to the stresses of their habitat. It is possible that both nutritional level and temperature acclimation are important in this, and it is speculated that inability to reduce the level of metabolism may be one factor preventing the colonization of high-shore-level habitats byP. aspera.
Cryptic polymorphism in the cirratulid polychaete,Cirriformia tentaculata
Authors: George J. David 
Published: May 2009

Investigations showed that populations ofCirriformia tentaculata(Montagu) at Plymouth, Coverack and Salcombe produce both free-swimming and demersal larvae from single egg batches. The proportion of free-swimming to demersal larvae varies from one brood to another but is constant in different cultures from a single brood. Control of the proportion in which the two behavioural types are produced appears to be genotypic and not phenotypic. The larval types could not be separated morphologically but additional evidence for the existence of polymorphism in the species was provided by the variation of esterase pattern between adults. The population that existed in Southampton water previous to the winter of 1962/63 and which produced only demersal larvae was probably genetically isolated from other populations of the worm and showed behaviour atypical of the species as a whole.IntroductionSince the publication of a note reporting behavioural differences existing between the larval stages ofCirriformia tentaculata(Montagu) from Southampton Water and from Plymouth Sound (George, 1963), continuing investigations have shed more light on the problem. Observation of the Southampton population from 1959 to 1962 showed that demersal larvae were produced throughout the breeding season, from May to September (George, 1964a), whereas Wilson (1936) found that a population from Drake's Island, Plymouth Sound, produced a free-swimming larval stage in July of 1928 and 1933. It is known that some species of polychaete produce pelagic and non-pelagic forms according to the time of year (Mesnil & Caullery, 1917; Thorson, 1946). The Plymouth population was therefore re-examined to determine whether free-swimming larvae were produced during the entire breeding season.
Experiments on the tidal rhythm ofBlennius pholis
Authors: Gibson R. N. 
Published: May 2009

The endogenous tidal rhythm of the littoral fishBlennius pholisL. was studied in the laboratory. It was found that there was no difference in the mean level of activity of fish caught on spring and neap tides. The time-interval between activity peaks (the period length) gradually increased in constant darkness. A similar, although not significant, increase was also observed in continuous illumination.There was no evidence of any diurnal component in the rhythm, but freshly caught fish subjected to alternating periods of light and darkness, equal in duration to the natural period, responded to the onset of illumination by greatly increased activity only when the light period began between activity peaks.Fish which had been kept in the laboratory for several weeks and had lost their natural rhythm still responded to light by increased activity. This increase was not as great as that shown by freshly caught fish, however, and the response decreased with time. Evidence of re-entrainment of the natural rhythm after 7 days in alternating periods of light and darkness was not found. It was shown that feeding the fish half-way through the 12 h light-period resulted in a reduction of activity after feeding. This did not occur when the fish were fed half-way through the dark period.A 4h cold shock of 10° C resulted in partial re-entrainment of rhymthic activity inB. pholis.B. pholis, which alone appears to have a persistent rhythm, differs from certain other fish examined in its strictly littoral habitat and its possible need for activity periods synchronized with the tide.
Biochemical differences betweenCalanus finmarchicusandC. helgolandicusEsterases, malate and triose-phosphate dehydrogenases, aldolase, ‘peptidases’, and Other enzymes
Authors: Manwell Clyde , Baker C. M. Ann , Ashton P. A. , Corner E. D. S. 
Published: May 2009

Three species of copepods—Calanus finmarchicus(Gunnerus),C. helgolandicus(Claus) andC. hyperboreus(Krcyer)—can be easily and consistently differentiated by starch-gel electrophoresis of a number of their enzymes. The techniques used allow the study of individual variation in natural populations of small invertebrates, some of the variation being readily equated with known genetically based protein polymorphisms in man and other species.C. finmarchicusandC. helgolandicushave 15 enzyme zones in common and differ by 24-28 zones. By the rationale of molecular biology it can be suggested that these two forms differ in two-thirds of the structural genes. The results support the morpho-logical studies by Rees (1949) and Matthews (1966b) and the chromosomal studies by Harding (1963). Hence it is clear that the‘finmarchicus-helgolandicus’problem is solved:C. finmarchicusandC. helgolandicusare distinct species. The potentials and problems of biochemical systematics are discussed with particular reference to marine biology.INTRODUCTIONElectrophoretic techniques have contributed to the solution of many taxonomic problems—for example, the monophyletic origin of ratite birds (Sibley, 1960), the discovery of a sibling species of sea-cucumber (Manwell & Baker, 1963 a; Manwell, 1966a), the status of species and populations of pheasants (Baker, 1965; Baker, Manwell, Labisky & Harper, 1966), the union of the orang-utan, chimpanzee, gorilla and man into one family, the Pongidae (Tashian, 1965), and the recognition of hybridization in lizards (Dessauer, Fox & Pough, 1962) and fishes (Manwell, Baker & Childers, 1963).
Influence of Food and Predatory Attack on Mysid Swarm Dynamics
Authors: Ritz D.A. , Osborn J.E. , Ocken A.E.J. 
Published: May 2009

Using video and image analysis techniques we analysed the response of swarms of the mysid Paramesopodopsis rufa to food and predatory attack. After food was added to the tank, mysid aggregations initially (up to 45 s) increased in volume. Subsequently volume decreased significantly until it was smaller than the initial level. After a period of ~12 h during which no food was added, the swarm expanded to near its original volume. These changes are interpreted as resulting from a need by individuals to optimize food capture and protection. The pattern of volume changes in response to food was independent of aquarium size but the magnitude of the changes was reduced in a smaller tank.Predatory attacks on mysid swarms were simulated using a model fish which ‘swam’ a single pass along the tank driven by an electric motor. Models (latex-covered real preserved fish), represented two different attack styles: ambush (seahorse Hippocampus abdominalis); and lunging (Australian salmon Arripis trutta). ‘Swimming’ speeds resembled those measured for real fish i.e. 0·5–2·0 cm s-1 for seahorse and 15 cm s-1 for salmon. Again changes in swarm volume were recorded. No obvious response by the swarm to the approaching seahorse was apparent; the aggregation simply parted to allow the fish through. No tailflips were seen among the mysids. The swarm resumed the original volume rapidly after the fish had passed. Approach of the salmon was evidently detected from further away, escape reactions were frequent and energetic, and tailflipping was common. After the fish had passed, it took longer for the original swarm volume to be restored. These results suggest that seahorse ambush techniques have evolved to minimize warning of the predator's approach. When the salmon ‘menaced’ the swarm at seahorse speeds, it appeared the mysids still reacted as though it was a ‘normal’ salmon attack so the fright response was not just a function of speed of attack.Dynamic changes in swarm volume seem to be a useful simple index of motivational state of individuals.