bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tracking of Blue Lights by Hyperiid Amphipods
Authors: Land M.F. , Marshall N.J. , Diebel Carol 
Published: May 2009

INTRODUCTIONThe problems of observing the behaviour of mid-water animals are considerable. The depths involved are generally too great to allow free diving, and because the population density is low, useful observations from submersibles and remote cameras are rare. Animals brought to the surface are often in too poor a condition to behave at all normally. The hyperiid amphipods are one of the best groups to work with in trying to overcome these difficulties. They are relatively common and frequently observed from submersibles, where they congregate round the lights. They are tough, survive capture and behave well in aquaria at the surface (Land, 1992a). Compared with other groups, a reasonable amount is known about their habits, especially their associations with gelatinous animals on which they prey or have commensal relationships (Harbison et al., 1977; Madin & Harbison, 1977; Diebel, 1988). It is also known that they sometimes form swarms (Lobel & Randall, 1986).
Induction of Metallothionein Synthesis in the Gill and Kidney ofLittorina LittoreaExposed to Cadmium
Authors: Bebianno M.J. , Langston W.J. 
Published: May 2009

Induction of metallothionein synthesis inLittorina littoreaexposed to cadmium (400 µg I-1) is tissue dependent. Concentrations of the metal-binding protein increased by a factor of four in the gills and by a factor of three in the kidney.Gel filtration chromatography of heat-treated cytosolic extracts reveals that cadmium, accumulated in both the gills and the kidney, is bound principally to the newly formed metallothionein. Cadmium saturation of the protein (at an MT:Cd molar ratio of 1:5) and the approach of steady-state condition for Cd accumulation was indicated in the latter tissue, but there was little evidence for Cd equilibrium in gills.Metallothionein levels in the kidney ofL. littoreacan be determined on a routine basis in laboratory experiments and in field samples by differential pulse polarography of wholecytosol preparations: heat-treatment/centrifugation is sufficient to remove most of the interference from high-molecular-weight thiolic proteins. In contrast, the use of gelfiltration chromatography is recommended alongside polarographic analysis of the gill cytosol to enable quantification of, and compensation for, such interferences, and hence to ensure that only metallothionein is determined.Measurements of metallothionein induction in the kidney ofLittorinamay therefore prove useful in the determination of sublethal biological response to metal contamination. Background metallothionein concentrations of 3–4 mg g-1(measured polarographically) serve as a baseline against which samples from contaminated sites can be assessed.INTRODUCTIONExposure of marine organisms to metals such as cadmium can induce the synthesis of low molecular weight, cysteine-rich proteins, metallothioneins (MTs), which are capable of sequestering and detoxifying excess intra-cellular metal.
The Food of Seriola Dumerili (Pisces: Carangidae) in the Catalan Sea (Western Mediterranean)
Authors: Matallanas J. , Casadevall M. , Carrasson M. , Bolx J. , Fernandez V. 
Published: May 2009

Stomachs of 385 specimens of Seriola dumerili (Risso, 1810) have been analysed. Their coefficient of repletion is 50·8% in juveniles and 90·3% in adults. Juveniles feed almost exclusively on Teleostei with Engraulis encrasicholus and Sardina pilchardus as the main food; Cephalopoda (Loligo vulgaris and Sepiola sp.) and Crustacea (Squilla mantis) are also eaten. Adults feed on a great diversity of Teleostei headed by S. pilchardus and Merluccius merluccius.According to Smith-Vaniz (1986)Seriola dumerili is both epibenthic and pelagic, occurring at 18–72 m in small to moderate schools. Juveniles are associated with flotsam in oceanic or offshore neritic waters. Adults often live near reefs or at deep off-shore holes or drop-offs. It is found from the Mediterranean and the Bay of Biscay to South Africa, from Nova Scotia to Brazil, and also in the Arabian Gulf, Australia, Japan and the Hawaiian Islands.
The accumulation of radioactive caesium in crabs
Authors: Bryan G. W. 
Published: May 2009

SUMMARYThe accumulation of 134Cs and 42K from artificial sea water has been followed in crabs of the following species, viz. Carcinus maenas, Portunus puber, P. depurator, Polybius henslowi, Cancer pagurus and Corystes. cassivelaunm. In all cases 134Cs is taken up far more slowly than 42K but at equilibrium a higher concentration factor is attained by 134Cs. In Carcinus a value of about 8 is found for 134Cs and about 4 for 42K. Uptake of 134Cs in Carcinus is not affected by feeding on inactive food over a period of 1000 h. The relationship between the rates of uptake of the two isotopes is not the same in the different species and it is concluded that it would not be possible to predict with any accuracy rates of uptake for 134Cs in other species of crabs from the results of short 42K experiments.Uptake of 134Cs was followed in the blood and tissues of Carcinus and Cancer, and muscle is the principal limiting factor in the attainment of equilibrium by whole animals. Uptake of 42K by tissues has also been followed and in all species nearly all the inactive K appears to be readily exchangeable. At equilibrium in all species plasma/sea water and tissue/plasma 134Cs ratios nearly always exceed those for inactive K. The tissue/plasma 134Cs ratios in Carcinus are about twice those for K and the significance of this has been discussed.Loss of both isotopes in whole Carcinus is a slower process than uptake.Isotope accumulation takes place mainly across the body surface in unfed animals, but uptake of 134Cs from food is very rapid and complete and would considerably enhance the attainment of equilibrium in a natural environment.Selective excretion of 134Cs relative to K has been found in Carcinus, Cancer and Portunus puber.
Studies on the biology of limpets IV. The breeding of patella depress a pennant on the north Cornish coast
Authors: Orton J. H. , Southward A. J. 
Published: May 2009

SUMMARYThe breeding of Patella depressa was studied at Trevone, North Cornwall, for 4 years. Gonads were examined and assessed by methods described in a previous report on P. vulgata.In contrast to the common Limpet, P. depressa is a summer breeder in Cornwall. Gonad development begins in the spring and is complete by June or July. Spawning coincides with maximum air temperatures in July, August or early September. The autumn and winter period is passed with gonads in recognizable post-spawning and spent stages, and only a small proportion of completely resting neuter gonads is found in the early spring.Mass spawning takes place, and gametes are voided rapidly. No definite spawning stimulus can be shown, but, as with P. vulgata, there may be some relation between onset of spawning and the occurrence of wave action on the shore.The differences in breeding behaviour of P. depressa and P. vulgata reinforce the other differences between them and throw some doubt on the concept of super-species in Patella.
Notes on the mode of life of the Tellinidae (Lamellibranchia)
Authors: Holme N. A. 
Published: May 2009

SUMMARYEvidence from animals dug up on the shore, from observations on burrowing, or from shell shape indicates that the following species normally lie below the surface with their right valve uppermost: Tellina squalida, T. tenuis, T. fabula, T. donacina, and Arcopagia crassa. Information on the habits of the remaining Tellinidae has not been obtained.Animals placed on the surface of the soil with the left side up turn themselves over as they burrow. In Arcopagia the shell is turned over beyond the vertical before the animal enters the substratum, but in the remaining species studied the shell is gradually turned over so that it disappears below the surface almost vertically and subsequently completes the turning movement beneath the surface.The disposition of the siphons of Arcopagia may differ somewhat from that of T. tenuis as described by Yonge, and there is a need for further observation on the siphons of the other species.
Shell form in Venerupis rhomboides
Authors: Holme N. A. 
Published: May 2009

SUMMARYTwo forms of Venerupis rhomboides occur in Plymouth waters. A more slender form, corresponding to that described by Pennant, occurs in the Eddystone shell gravel, and a more robust form, corresponding to the Venus sarniensis of Turton, occurs at the mouth of the River Yealm. The two forms differ in ratios of shell height, width and lunule width relative to shell length. A population with intermediate ratios is found at 6-5 m in Plymouth Sound.Plots of height/length ratios of these and another intermediate sample on probability paper did not indicate that the intermediate populations were composed of mixtures of the two extreme forms, and it was provisionally concluded that these were all variants of a single species.If the height/length ratios of series of samples from different localities are plotted against depth of water on a logarithmic scale, an inverse relationship, approaching a straight line, is obtained. Regression lines for median ratios in the 3-4 and 4-5 cm length groups have been plotted separately, as there is some change in proportion with increasing length. These show a highly significant negative correlation between shell ratios and depth.From the regression lines it has been possible to obtain an estimate of the depth inhabited by even quite small samples of shells. Depth estimations have been made for eight samples, consisting mainly of dead shells. Six samples lay within the expected limits, and discrepancies in the other two samples are attributed to transport along the sea floor.The possible causes of the differences in shell ratios are discussed. Previous work suggests that shell ratios may be affected by different rates of growth. Soil grade, temperature, food supply, and light penetration are considered unlikely causes of the observed differences in shell ratios, and it is suggested that the pattern of growth may be affected by pressure.The Appendix contains a key to British species of Venerupis.
The effect of salinity upon the boring activity and survival of Limnoria (Isopoda)
Authors: Eltringham S. K. 
Published: May 2009

SUMMARYThe effect of salinity upon the wood-boring activity of Limnoria was investigated experimentally. Boring decreased linearly with salinity and ceased altogether below io%o. The limiting salinity varied inversely with the temperature, being 12%0 at 17-6 C and 15 %0 at 14-9 C (average temperatures). The boring activity was intensive in its early stages but after about 5 weeks fell to a lower constant rate.Survival experiments suggested that the low salinity was the direct cause of the reduced boring activity. The only lethal salinity found during the period of the experiments (65 days) was 6%0 which proved fatal in about 15-20 days. The next higher salinity tested was i2%0. No reduction in survival was found in concentrated salinities up to a value of 48 %0, the highest salinity examined.
Observations on the British species of Jaera (Isopoda:Asellota)
Authors: Naylor E. , Slinn D. J. , Spooner G. M. 
Published: May 2009

SUMMARYof winter phosphorus have represented differences in numbers of 6-month-old pilchard larvae; the winter phosphorus provides the link between herring recruitment and numbers of pilchard eggs, suggesting that there has been competition between the herring and pilchard stocks, in their juvenile stages. Thus it is suggested that the Plymouth herring fishery failed in competition with the pilchard stock and that the other biological events which took place in the early thirties were a consequence of this postulated competitive change.
Luminescence in polynoids III. Propagation of excitation through the nerve cord
Authors: Nicol J. A. C. 
Published: May 2009

Luminescent polynoids emit light from their elytra. These structures are arranged in two longitudinal rows covering most or all of the dorsal surface of the worm. Light emission is evoked by stimulation and appears as a single flash or series of flashes (Nicol, 1953, 1957).When a polynoid is subjected to tactile stimulation, scales anterior and posterior to the stimulated region emit flashes. The response is a reflex, the excitatory pathways of which involve peripheral receptors, nerve cord, and a peripheral ganglion in each elytrum on the efferent side of the arc (Bonhomme, 1942; Nicol, 1954).
On the hormonal inhibition of moulting in decapod Crustacea II. The terminal anecdysis in crabs
Authors: Carlisle D. B. 
Published: May 2009

In many if not most species of crabs (but not quite all) there is a limit to growth, when no more moulting or ecdysis is possible in normal circumstances. This condition of permanent anecdysis is known as the terminal anecdysis. In the spider crab Maia squinado, the last moult is the moult of puberty, when the animal finally attains sexual maturity, and this moult has different biometrical characteristics from the others. In Carcinus maenas, in contrast, the moult of puberty takes place when the animal is quite small and may be succeeded by about ten further moults before the terminal anecdysis begins.The immediate cause of the cessation of moulting in Maia squinado is shown to be the degeneration of the Y-organ, which secretes a moult-promoting hormone. In the absence of this gland and its secretion moulting can no longer continue. In Carcinus the Y-organ does not degenerate after the final ecdysis and the cause of the cessation of moulting is to be sought in the excessive production by the X-organ-sinus gland complex of the moultinhibiting hormone. This effectively prevents moulting from proceeding Removal of the X-organ-sinus gland complex in Carcinus allows ecdysis to continue, so that giant crabs can be produced in the laboratory by this means, and at the same time the life-span may be increased. The operation has no such effect on Maia. In either species injection of Y-organ extracts produces transiently the first signs of an approaching moult, in the form of a heightened blood-calcium level. In Carcinus repeated injection led to eventual ecdysis. The presence of the Y-organ is shown to be necessary for removal of the X-organ-sinus gland complex to stimulate moulting in Carcinus.Two separate methods of producing terminal anecdysis exist in crabs, both involving the hormones which normally regulate the moult cycle, but no reason is known for the existence of the phenomenon.
A new quantitative plankton net
Authors: Currie R. I. , Foxton P. 
Published: May 2009

The apparatus described in this paper was constructed for the purpose of sampling the zooplankton standing crop in the ocean in a quantitative manner.A meter is described, which will record both the depth and amount of water which a net filters as it is hauled vertically through the water. The meter records on a smoked glass cylinder.The meter is mounted in a brass drum which is positioned in front of the silk filtering section of the net. In front of the meter a long canvas sleeve carries the throttling rope which closes the net by the Nansen method.Calibration of the meter for depth is done by using reversing thermometers and lowering to a series of suitable depths. Flow calibration is easily accomplished in the field by towing the canvas sleeve and meter without the silk net.The method of smoking the glass cylinders and taking photographic records of them is described.From the records it is possible to study the complete behaviour of the net below water—what depth range it has fished, how much clogging occurred, the depth of closure, etc
Notes onMytilus galloprovincialisLamarck in Great Britain
Authors: Hepper B. T. 
Published: May 2009

Mytilus galloprovincialisLmk. is recorded as dominating the mussel population on the north coast of Devon and the north and south-west coasts of Cornwall from Instow to the Lizard. It was also found less frequently on the coast of South Wales from Angle to Cardiff and on the south coast of Cornwall from the Lizard to Plymouth.The chief distinguishing features ofM. galloprovincialisfrom Cornwall are summarized, in comparison withM. edulisL.M. galloprovincialisis apparently intolerant of estuarine conditions, but otherwise appears to be ecologically similar toM. edulis.M. galloprovincialisis not resistant to infection byMytilicola intestinalis, but appears to be less affected by the parasite than isMytilus edulis.The synonymy of the species is briefly discussed and it is concluded that, although earlier workers tended to confuseM. ungulatusL. (recorded also asM. ungulataandM. angulata) withM. galloprovincialisLmk., the two types are distinct.M. ungulatusis a name of doubtful validity applied by Linnaeus to a distorted form ofM. edulis.
The growth of Scrobicularia plana (da costa) in the Gwendraeth estuary
Authors: Green J. 
Published: May 2009

Populations of Scrobicularia plana with densities up to 1025 per m2 are found in the Gwendraeth Estuary.In a region where the population density was about 500 per m2 it was found that some specimens lived for 16‐18 years and reached a length of 54 mm. An approximate growth curve is given.There is very little successful settlement of spat in the sampling area; less than 2% of the shells were under 10 mm in length in July 1955. This low figure is attributed to the feeding activities of the dense adult population making the area difficult to settle in.
Comparisons of several methods of determining inorganic phosphate in oceanic sea water
Authors: Jones P. G. W. 
Published: May 2009

Arsenate was found to interfere with both of Murphy & Riley's methods of estimating phosphate in sea water. The magnitude of interference showed day-to-day variations.Five methods of estimating dissolved inorganic phosphate in sea water were compared in the northern North Atlantic. Differences observed between the methods were related to those found in similar earlier investigations in inshore waters by Jones & Spencer.
The component fatty acids of some sea-weed fats
Authors: Chuecas L. , Riley J. P. 
Published: May 2009

The component acids of the fats of the following marine algae have been investigated by gas-liquid chromatography:Rhodymenia palmata, Laurencia pinnatifida, Laminaria digitata, L. saccharina, Fucus vesiculosus, F. serratus, Pelvetia canaliculata, Ascophyllum nodosum. The principal saturated acids are palmitic and myristic acids, some contain ca. 2–5% of stearic acid; traces of C8 and C10 saturated acids are present, but C12 (and in all but one) C 20saturated acids are absent. The major unsaturated acids are octadecenoic and octadecadienoic acids (probably oleic and linoleic acids), but some species also contain appreciable amounts (up to 12%) of hexadecenoic acid. All the oils contain significant amounts of an eicosatetraenoic acid (probably arachidonic acid) and in some eicosatrienoic and/or eicosapentaenoic acids are also present in small quantities. Two acids of unknown constitution (possibly branched chain acids) are also present in minor amounts. No C22 unsaturated acids could be detected.INTRODUCTIONVery little is known about the component fatty acids of marine algae. Lovern (1936) examined the fatty acids from the fats of Fucus vesiculosus, Laminaria digitata and Rhodymenia palmata using lead salt crystallization and fractional distillation techniques (Table 2). With these methods, however, it was not possible to separate individual unsaturated acids having the same number of carbon atoms from one another. The mean unsaturation values of these fractions were therefore evaluated from their iodine values and expressed as the number of hydrogen atoms necessary to convert the fraction to the corresponding fully saturated state; thus ( — 4–0H) indicates an average unsaturation corresponding with two double bonds.
A Mark-Recapture Experiment on Queen Scallops, Aequ1Pecten Opercularis, on a North Irish Sea Fishing Ground
Authors: Allison E.H. , Brand A.R. 
Published: May 2009

A single-season mark-recapture experiment was carried out on queen scallops, Aequipecten opercularis (L.) (Bivalvia: Pectinidae) to assess the suitability of the technique for estimating population sizes and mortality rates of exploited populations. Tag-loss and tagging-induced mortality were 7.7% and 11.9% respectively. Non-reporting was negligible.In a single fishing season (June-December 1989) 25.4% of releases were recaptured alive. Mean density of commercial-sized queens was estimated as 0.47 m−2 over the fishing ground. Instantaneous rates of total (Z), fishing (F) and-natural (M) mortality, calculated from the monthly decline of recaptures during the fishing season, were 0.;41,0.21 and 0.20 per month respectively. The calculated M is very high but includes non-yield or indirect fishing mortality. Analysis of the age-frequency distribution of queens from an adjacent, largely unexploited, area indicated an M of only 0.036 per month (0.43 y−1). There was some indication of an increase in M in older year classes, associated with senescence.The mark-recapture methodology used here is suitable for this species, but single-release experiments place too much reliance on commercial catch-statistics.
Random Amplified Polymorphic Dna (Rapd) and Intraspecific Variation in Oerstedia Dorsalis (Hoplonemertea, Nemertea)
Authors: Sundberg Per , Andersson Susanne 
Published: May 2009

INTRODUCTIONThe littoral/sublittoral hoplonemertean (phylum Nemertea) species Oerstedia dorsalis (Abildgaard, 1806) is described as polymorphic in external characters (Örsted, 1844; Burger, 1895; Brunberg, 1964). Sundberg (1984) grouped specimens in three classes based on external morphology and asked, using multivariate morphometrics, if there was a consistent correlation between external and internal characters. Such a correlation would have indicated a restricted gene flow between the externally different morphs, and thus the possibility of a group of species instead of one, polymorphic, species.One of the forms in Sundberg (1984) appeared to be different from the other two morphs but the morphometric analysis was inconclusive. Later, Sundberg & Janson (1988) established by enzyme electrophoresis that this form was genetically different and it was later described as Oerstedia striata (Sundberg, 1988). A problem both in Sundberg (1984), and Sundberg & Janson (1988) was that one of the groupings (class ‘C’ in both studies) of specimens subsumed a number of morphs, all speckled or dotted but to varying degrees. These morphs may in fact represent different species, which would have been concealed in the electrophoretic and morphometric analysis as merely increased intraspecific variation. One of the ‘C’ morphs in Sundberg (1984) and Sundberg & Janson (1988) is light brown with numerous small dark brown/black dorsal spots. Based on one specimen from Anglesey, North Wales, Gibson (1988) described Oerstedia (Paroerstedia) nigrimaculata which is externally similar to this variety. Envall & Sundberg (1993) could not find any differences in internal characters between the type specimen of O. nigrimaculata and the brown form of O. dorsalis but hesitated to conclude that O. nigrimaculata is a variety of O. dorsalis.
The Biology of Laminaria Hyperborea. VIII. Growth on Cleared Areas
Authors: Kain Joanna M. , Jones N. S. 
Published: May 2009

INTRODUCTIONStudies of established populations of Laminaria hyperborea (Gunn.) Fosl. have indicated that there is often less change of growth rate with depth than might be expected to result from the decrease in irradiance (Kain, 1967; Lüming, 1969; Jupp & Drew, 1974). This has been attributed to self-limitation by the canopy of Laminaria fronds (Lüning, 1969; Kain et al. 1976). The removal of this canopy can result in fast growth in shallow water (Kitching, 1941; Svendsen, 1972) and a marked differential in growth rate over a small depth range (Svendsen, personal communication). A series of rocky subtidal areas at two depths off the Isle of Man was cleared of vegetation at various times (Kain, 1975a). This provided an opportunity to make growth measurements on individuals of known age in the absence of a canopy formed by older plants.