bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the biology of the commoner gadoids in Manx waters
Authors: Nagabhushanam A. K. 
Published: May 2009

The food and feeding habits, and general biology of the commoner gadoids in Manx waters have been studied. During the pelagic phase the diet of the gadoids showed a great similarity, consisting mainly of various abundant calanoid copepods. The larger pelagic post-larvae supplemented this basic diet with the inclusion of euphausiid ‘furcilia’ larvae and (in whiting) the amphipod Hyperia. Whiting, cod and pout were often found associated with medusae: the whiting, 21–53 nun long, were taken in large numbers, and their diet was found to be modified as a result of this association.Young gadoids in a shallow sandy bay showed a great similarity in their basic diets, which typically consisted of various small, swarming mysids, amphipods and isopods. This habitat was a nursery area for many of the gadoids.The larger fishes fell into two groups: (i) those that were characteristically feeders on the infauna and large, slow-moving epifauna; such fish being provided with stout barbels, well equipped with taste-buds, e.g. cod; (ii) those that feed largely, on the smaller active epifauna and nektonic prey, and possessed no, or only rudimentary, barbels, e.g. whiting.The larger gadoids showed a concentration after spawning on a shallow, submarine shelf (the Warts Bank) to the south of the Isle of Man. Here the spent fish fed on an abundant and localized food, sand eels. The gadoids were found in this habitat from March to September, and were the object of a local fishery.There was evidence that the gadoids exercised choice of food from that potentially available from the four primary food sources in each habitat; but if their favourite food was scarce or lacking, they would take substitute food by exploiting sources otherwise normally neglected.
Studies on reflexion of light from silvery surfaces of fishes, with special reference to the bleak, Alburnus alburnus
Authors: Denton E. J. , Nicol J. A. C. 
Published: May 2009

The problem of how a fish can make itself invisible in the natural light-conditions in an aquatic environment is discussed with particular reference to the silvery surfaces of fish.In fish which we have examined, the silvery surfaces are of two types: (1) an argenteum which consists of long thin crystals of guanine whose reflecting surfaces are approximately parallel with the surface of the fish; (2) layers of guanine crystals lying either on the inner surfaces of the scales or in the subdermis—these crystals are not, in general, orientated with their reflecting surfaces parallel with the surfaces of the fish, and are much broader than those of the argenteum.Methods are described by which the orientation of the crystal planes with respect to the planes of the scales on which they lie can be determined.The orientation of the crystals of type 2 in different parts of the body is described for the horse mackerel, Trachurus trachurus (L.), and for the bleak, Alburnus alburnus (L.).For the bleak it is shown that although the planes of the crystals are often very much inclined with respect to the planes of the scales, the long axes of the crystals are always approximately parallel with the planes of scales. The inclination of the crystals, therefore, is away from the scales across their short axes.Measurements of the light transmitted by silvery scales of the bleak show that they reflect light strongly when this falls obliquely on the crystals which they contain and that they are most transparent to light which strikes the scales in a direction perpendicular to the reflecting planes of the crystals.
On some Copepoda from Plymouth, mainly associated with invertebrates, including three new species
Authors: Gooding R. U. 
Published: May 2009

The adults of three new cyclopoid copepods are described and figured, namelyMicropontius ovoides, gen. et sp.nov., occurring on spatangid echinoids;Lichomolgus leptodermatus, sp.nov., andConchyliurus cardii, sp.nov., both associated with pelecypod molluscs.Micropontiusis made the type of a new family, the Micropontiidae.Some other copepods,Asterocheres violaceus(Claus),Scottomyzon gibberum(T. & A. Scott),Pseudanthessius liber(Brady & Robertson),Bomolochus confususStock,Euryte longicaudaPhilippi var.minorT. Scott andPeniculus fistulaNordmann, are recorded for the first time from the Plymouth region; and mention is also made ofTisbe elongata(A. Scott).Points of interest in the biology, morphology, systematics and distribution of all these are discussed.
On the behaviour of barnacles III. Further observations on the influence of temperature and age on cirral activity
Authors: Southward A. J. 
Published: May 2009

The range of temperature over which the cirri were active, and the frequency of beating of the cirri at different temperatures were measured in a further five species of barnacles from a variety of habitats. In three of the species the temperature range and frequency of cirral beat were related to the geographical distribution of the species. The tropical and warm temperate species Balanus amphitrite was active at higher temperatures, and showed a greater frequency of beating than the northern species B. balanus; conversely, the latter was active to much lower temperatures than JB. amphitrite. The species with the widest geographical range, B. improvisus, showed cirral activity over the widest range of temperatures, although its behaviour at high temperatures was similar to that of the related species B. amphitrite. It is suggested that B. improvisus is a tropical species that has adapted itself to colder climates; its tolerance of a wide range of temperatures may be associated with its tolerance of low salinities.The stalked barnacle Lepas anatifera showed too restricted a temperature range for its supposed world-wide distribution, and it is suggested that the species may contain physiological races adapted to different climates. The extremely restricted range of temperatures over which the cirri of the deepsea barnacle Hexelasma hirsutum were active can be correlated with the almost uniform temperature conditions at great depths.In B. balanus age-groups can be clearly distinguished by growth rings on the shell, and the cirral frequency was found to be slower in the older specimens. Even slower cirral beating was found in some starved specimens.
The breeding and fecundity of the Long Rough Dab Hippoglossoides platessoides (Fabr.) and the associated cycle in condition
Authors: Bagenal T. B. 
Published: May 2009

Details are given of the breeding biology, including the fecundity, of the Long Rough Dab deduced from samples taken in the Clyde Sea area from October 1953 to April 1955. Where possible breeding is related to the condition of the fish; the index of condition is based on the length-weight relation.The weight of Long Rough Dabs of each sex and stage in maturity increases as a power, slightly greater than the cube, of the length. An annual cycle of fluctuations of this power is seen in the immature females, and indicates how changes in condition at different seasons affect the different size-groups. The measure of condition is taken as the expected weight of a 20 cm Long Rough Dab, and the changes in this weight are followed through the sampling period for males and for immature, maturing and spent females. All groups tend to be in best condition during November and December followed by a decline to the spawning time, in March and April, after which there is a slow recovery.
Bio-assay of nitrogen available to two species of phytoplankton in an off-shore water
Authors: Harvey H. W. 
Published: May 2009

A bio-assay of the nitrogen which was available to two phytoplankton species with their associated bacteria in an off-shore water is described.The concentrations found by assay (11·5 and 13μg N/1.) were similar to the concentration of total inorganic nitrogen compounds found by analysis (10μg N/1.).Of the organic nitrogen normally present in solution in sea water, an insignificant quantity appears to be available to the plant-bacteria community.
The determination of ammonia and total ionic inorganic nitrogen in sea water
Authors: Riley J. P. , Sinhaseni P. 
Published: May 2009

Microdiffusion using a Cavett flask has been employed instead of vacuum distillation for the separation of ammonia from sea water; diffusion is approximately 75% complete after 24 h at 70°C. The recovered ammonia is determined by a modification of the phenate-hypochlorite method.Raney nickel in the presence of ethylenediamine-tetraacetic acid has been used for the reduction of nitrate and nitrite to ammonia. The latter is separated by microdiffusion and determined colorimetrically. The method showed a coefficient of variation of 2·5% on a sample of sea water containingNo interference was encountered from a variety of organic nitrogen compounds.
Observations during embryonic development in the genusDoto(Gastropoda, Opisthobranchia)
Authors: Kress Annetrudi 
Published: May 2009

While working on taxonomic problems in the family Dotoidae and comparing the Mediterranean and Atlantic species (Schmekel & Kress, in the Press), it became apparent that very little embryological information was available for this group, other than that published by Alder & Hancock (1845–55), Pelseneer (1911), Miller (1958, Ph.D. Thesis, University of Liverpool) and Thompson (1967).In the course of studies on the changes in egg-capsule volume in different nudibranch species (Kress, 1971, 1972) a fresh attempt has been made to obtain some comparative data on egg and capsule sizes and on the course and rate of embryonic development in the three species ofDotomost commonly found in the Plymouth area, namelyD. coronata(Gmelin, 1791),D. pinnatifida(Montagu, 1804) andD. fragilis(Forbes, 1838).
The relationship of the zoogeographic distributions of the planktonic ostracods in the North-east Atlantic to the water masses
Authors: Fasham M. J. R. , Angel M. V. 
Published: May 2009

The quantitative zoogeography of pelagic zooplankton is a subject very much in its infancy. This is due to a number of causes; firstly, the taxonomy of a large number of animal groups has not been finalized and new species are still being regularly discovered. Secondly, many samples, especially from the earlier expeditions, were obtained from broad depth ranges and without accurate depth measurements or the use of opening-closing nets. This latter problem has been overcome by modern sampling devices (e.g. Baker, Clarke & Harris, 1973).Underlying the thinking of a lot of previous workers has been the hypothesis that the water masses of the various oceans (usually delineated by means of temperature-salinity relationships (Sverdrup, Johnson & Fleming, 1942)) support a distinct fauna. This point of view has been summarized by Johnson & Brinton (1963), Banse (1964) and Beklemishev (1966, 1971). Examples of studies in which the relationship of species distributions to water masses have been studied are Pickford (1946; the cephalopodVampyroteuthis infernalis), David (1958,1963; chaetognaths), Bieri (1959; Pacific chaetognaths), Brinton (1962; Pacific euphausiids), McGowan (i960; the wormPoebius meseres) and Haffner (1952; the fish genusChauliodus). In the last case it was suggested that the oxygen content of the water was also an important factor.
Experiments with the behaviour of the bivalves Montacuta substriata and M. ferruginosa, ‘commensals’ with spatangoids
Authors: Gage John 
Published: May 2009

The behaviour involved in the maintenance of the ‘commensal’ associations of Montacuta substriata and M. ferruginosa with spatangoids was investigated experimentally.Both species are highly mobile when isolated from the ‘host’, and this activity was recorded through their mucous trails on glass plates, and photographically with a repetitive electronic flash system. Their responses were analysed mainly in a trough apparatus with a slow flow of water. The behaviour was resolved into responses to factors normally present in their environment. These included both gravity and water currents and a chemical influence from the ‘host’ spatangoid. M. substriata showed a marked negative geotaxis, while M. ferruginosa showed a similar response but of opposite sign. Pedal activity was stimulated as a kinesis to an unknown chemical ‘attractant’ from the urchin. The bivalves showed no specificity in this response since it was shown by both species to any of the spatangoids tested, regardless of the urchin species from which they were taken.
Preliminary studies on haemoglobin and other proteins of the Pogonophora
Authors: Manwell Clyde , Southward E. C. , Southward A. J. 
Published: May 2009

Starch gel electrophoresis of extracts ofSiboglinum atlanticumshowed that all five individuals tested have two acidic haemoglobin components and a strong α-naphthyl acetate esterase. There was individual variation in the position of the esterase. Low levels of amylase activity were found in the extracts but no trace of dehydrogenases for such important substrates as glucose-6-phosphate, lactate, malate, and glutamate could be revealed by standard histochemical methods as applied to zone electrophoresis. The high level of haemoglobin and the protein peculiarities of the Pogonophora are discussed in relation to experiments on respiration. It is concluded thatSiboglinumhaemoglobin functions at very low oxygen partial pressures and that the high level of haemoglobin dissolved in the blood plasma of pogonophores does not reflect a high level of oxygen consumption or activity. The meagre biochemical data at present available on the Pogonophora do not favour relationship of this phylum to the echinodtrm-chordate line any more than to the annelids or other invertebrate phyla.INTRODUCTIONLargely as a result of studies by A. V. Ivanov, the phylum Pogonophora has become recognized by zoologists in the past decade (reviewed by Hyman, 1959, esp. pp. 208–27; Ivanov, 1963; E. C. Southward, 1963). Pogonophores are small, extremely vermiform animals, living in tubes partly im-bedded in mud or muddy sand; while in some areas they are sufficiently abundant to dominate the benthic fauna, their occurrence at great depths has made living pogonophores very difficult to obtain.Two especially interesting problems associated with this newly recognized phylum are:(a)Pogonophora are the only group of free-living Metazoa without a gut at any stage in their development, and thus, the method of feeding and type of metabolism has been the subject of considerable speculation;(b)Pogonophora possess a few characteristics—e.g. a ventral heart and dorsal nerve cord—suggestive of the echinoderm-chordate line of evolution.
The hydroid and the medusaBougainvillia principis, and a review of the British species ofBougainvillia
Authors: Edwards C. 
Published: May 2009

The hitherto unknown hydroid of the anthomedusaBougainvillia principishas been found in the Firth of Clyde, and medusae from it have been reared. The hydroid and the stages of development of the medusa are described and figured. The medusa is commonly present in the plankton in this area, and its seasonal occurrence is described.The historical development of our knowledge ofB. principisand ofB. superciliaris, which have been confused, is discussed. The hydroid and the young medusae ofB. principisare shown to be identical with those described by Hartlaub and attributed by him toB. superciliaris.Several doubtful speciesof Bougainvilliamedusae described from British waters are considered and are identified with accepted species.Medusa ociliaandM. duodeciliaare probably synonymous withBougainvillia pyramidataandB. principisrespectively; andB. nigritellais identified withB. muscoides, B. simplexwithB. principis, B. dinemawithB. britannica., andB. charcotiwithNemopsis crucifera, itself a probable synonym ofN. bachei.The medusaB. alderiis a probable synonym ofB. ramosa.The hydroids and the medusae of the British species ofBougainvilliaare reviewed and compared; and records ofB. superciliarisandB. maclovianaare given.
The Distribution Of Visual Pigment Within The Retina In Two Teleosts
Authors: Denton E. J. , Muntz W. R. A. , Northmore D. P. M. 
Published: May 2009

The distribution of the visual pigments within the retina of the rudd, Scardinius erythrophthalmus, and dragonet, Callionymus lyra L., was studied by measuring the spectral absorbance of small areas of intact isolated retinas.The rudd retina contains two visual pigments, VP 5O71 and VP5352. There is a progressive change in the relative proportion of these two pigments in the dorso-ventral plane, and there are no sharply defined zones each with a different pigment mixture. The proportion of the A1-based pigment (VP 5071) is greater in the dorsal part of the retina.The maximal optical density of the pigment in the dorsal retina of the rudd was greater (about o·6) than it was in the ventral retina (about 0·3). The difference in the amount of light absorbed, however, is small compared to the intensity difference between the up-welling and downwelling light of the environment. When the relative proportion of the A1- and A2-based pigments was changed by altering the lighting conditions under which the animals were kept there was little or no change in the maximal optical density of the pigment.In the dragonet the retina shows a clear division into a ventral pink zone (maximal optical density about 0·5) and a dorsal zone that is much paler (maximal optical density about 0·2). The relative spectral absorbance of the two regions is similar, although one is said to be a pure cone region, and the other to be dominated by rods.The spectral absorbance curves for the intact retinas agreed well with results obtained with pigment extracts.
New Observations on the Lymph System of the PlaicePleuronectes Platessaand other Teleosts
Authors: Wardle C. S. 
Published: May 2009

The anatomy of the teleost lymph system is considered in relation to the observed flow of lymph. The plaicePleuronectes platessaL. was studied.The vessels described by anatomists as longitudinal ventral, dorsal and lateral lymph ducts do not pass lymph to the head but act as collecting sinuses; the lymph flows from these sinuses to the neural lymph duct via the interspinal ducts.At the junction of each interspinal duct and the neural lymph duct there is a simple valve. Lymph drains through this system as a result of a negative pressure developed in the neural canal by the respiratory movements of the gill apparatus.The rigid nature of the neural lymph duct and the valves where the interspinal ducts join it allow the negative pressure to develop from a negative positive gill generated pres-sure cycle in the cephalic lymph sinuses. Valves Unking cephalic lymph sinuses aid the return of lymph to the duct of Cuvier using the same pressure cycles.The drainage system is different in the salmonidae where the neural lymph duct is degenerate and the network of peripheral ducts serve as lymph return ducts. This can probably be explained by the occurrence of higher circulation pressures in the salmonidae.Lymph from the neural lymph duct is a clear fluid having a composition similar to that of blood plasma. Like blood, lymph clots, and contains normal blood levels of mobile leucocytes and thrombocytes and lymph reflects blood levels of lactate. Lymph contains nearly no erythrocytes and the protein concentration of neural duct lymph is 80–4% that of blood plasma.
Professor J. S. Alexandrowicz
Authors: Bone Q. 
Published: May 2009

Prof. Jerzy Stanislaw Alexandrowicz, who died at Plymouth on 28 October 1970, was one of the most distinguished histologists of the nervous system, whose series of memoirs upon invertebrate peripheral nervous systems stimulated much physiological and histo-logical research. He was born at Stoczki, in Poland, on 2 August 1886, and after matriculating in Warsaw studied medicine and natural science at the universities of Warsaw, Zurich, Munich, Heidelberg, Paris and Jena. He took his Ph.D. at Zurich under Lang, and his M.D. at Jena, under Biedermann, serving for a short period as a surgeon in the Military hospital at Belgrade, before being appointed to the department of descriptive anatomy at Wilno. He remained here during the war, and in 1918 served with the field hospitals coping with epidemic diseases brought to Poland from the East. He himself survived an attack of typhus. In 1919 he was appointed to organize and direct the department of descriptive anatomy at Wilno, and the next year rejoined the army to serve as the chief medical officer of a cavalry regiment in the fighting against Russia.In 1920 he returned to Wilno, as head of the department of histology, and remained there until 1929, when he moved to Lwow, again as director of the department of histology, in the Academy of Veterinary medicine. In 1933 he became Pro-Rector of the Academy, and in 1936 Reaor, finally leaving the university in 1937 to head the scientific and university department of the Ministry of Education. He quickly became Under-secretary of State for Education, and in 1938 relinquished this post to spend six months at the Stazione Zoologica, Naples, where he had previously worked on three occasions.
Dynamics and Growth of a Recent Invader into European Coastal Waters: the American Razor Clam,Ensis Directus
Authors: Beukema J.J. , Dekker R. 
Published: May 2009

Densities and growth rates ofEnsis directus(Bivalvia: Solenidae), a recent invader of the Wadden Sea, were monitored at 15 stations (12 transects and 3 squares) covering a wide range of intertidal levels and sediment types on Balgzand, a tidal-flat area in the western-most part of the Wadden Sea, during 1982–1994. In this period, recruitment was weak in all but one year (1991). Settlement took place in summer over a wide range of intertidal levels, but high survival of recruits was limited to stations below the level of mean low tides. Growth rates were also maximal at these low intertidal levels. In such areas they reached a mean length of about 6 cm in the first winter, about 12 cm in the second, and about 14 cm in the third winter. These growth rates were high compared with published records from other intertidal and shallow subtidal areas.Relatively exposed parts of the lower intertidal zone, characterized by clean sands and infrequent emersion, are a poorly occupied habitat of the Wadden Sea and offer an available niche to a new species that is well adapted to such harsh environmental conditions. In such areas,E. directushas become a dominant member of the benthos and in 1992 and 1993 reached high biomass and production values of >10 g AFDW m−2.
An Outline Of The Biology of the Squid Illex Coindetii in the Sicilian Channel (Central Mediterranean)
Authors: Jereb P. , Ragonese S. 
Published: May 2009

INTRODUCTIONThe genus Illex is likely to constitute a large portion of the annual world ommastrephid squid catches (Roper et al, 1984), even though specific official statistics are difficult to obtain. The broad-tail short-fin squid Illex coindetii is a widespread species ranging from the western to the eastern Atlantic (Roper et al., 1984) and east through the whole Mediterranean Sea (Mangold & Boletzky, 1987). Usually a by-catch of important fisheries, it is caught mainly by trawlers. Although its economic value is lower than that of other squid species (i.e. Loligo spp.), in the Sicilian Channel Illex coindetii may represent a valuable resource due to its abundance.In Italian waters, the available statistics (Cingolani et al., 1986) report that 2680 tonnes of ommastrephid squid were landed in 1982 (0.5% of the total landed catch). The main component of these was landed in Sicily (2183 tonnes), a consistently large part of which was no doubt Illex coindetii (Ragonese & Jereb, 1992). The catches came mainly from southern Sicilian waters (Sicilian Channel) where one of the major Mediterranean landing places is in Mazara del Vallo. Large trawlers (up to 200 gross tonnage) usually carry out long fishing trips (15–20 d), and Illex coindetii is caught mainly by those targeting Parapenaeus longirostris and Merluccius merluccius (Jereb & Ragonese, 1991).