bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the population biology of the common shrimp Crangon crangon (L.) (Crustacea: Caridea) in the Severn Estuary and Bristol Channel
Authors: Henderson P. A. , Holmes R. H. A. 
Published: May 2009

A 5-year study of the population biology of the common shrimp Crangon crangon (L.) in the Bristol Channel is reported. Samples were collected from three commercial fishermen and from the filter screens of five power stations taking water from the estuary.The Severn Estuary and Bristol Channel were found to contain a single shrimp population which undertook regular seasonal migrations in order to avoid low salinities and to reproduce. Previous studies had assumed that the regions held separate populations which migrated to avoid low winter temperatures.
The Occurrence, Ecology and Life History of Tigriopus fulvus (Fischer)
Authors: Fraser James H. 
Published: May 2009

The peculiar and exacting environment of Tigriopus fulvus is discussed and a census of Tigriopus from a series of pools in the Isle of Man is given.Experiments have been made determining the resistance of Tigriopus to desiccation and its revival in favourable circumstances.The life history has been worked out, times taken in development noted, and the various stages compared and contrasted with those described by Guiglia.Sex can be determined at the fourth copepodid stage. Females are normally fertilised as fifth copepodids, but the males are not functional until the adult stage. A single female may produce several egg sacs giving rise to living nauplii from a single fertilisation.There is no evidence for parthenogenesis.
The Seasonal Abundance of the Pelagic Young of Teleostean Fishes in the Plymouth Area. Part III. The Year 1935, with a Note on the Conditions as Shown by the Occurrence of Plankton Indicators
Authors: Russell F. S. 
Published: May 2009

Records are given on the abundance of the pelagic young of teleostean fishes off Plymouth as shown by half-hour oblique hauls with the 2-metre stramin ring-trawl.In comparison with similar observations made since 1924 the year 1935 has been the poorest yet recorded.A parallel between the quantity of phosphate in the water at the beginning of the year and the abundance of young fish is further confirmed. In January, 1935, the winter maximum phosphate value was the lowest yet recorded.
An Investigation of the Seaweeds within a Marked Zone of the Shore at Aberystwyth, during the Year 1933–34
Authors: Lewis Edith A. 
Published: May 2009

The following piece of research has been undertaken at the suggestion of the Conway Fisheries Eesearch Station of the Ministry of Agriculture and Fisheries.For some years experiments have been in progress at Conway in connection with oyster breeding. During the oyster season, from May to August, when the tanks of the Kesearch Station are not being used for mussel cleansing, cultural work on the oyster (Ostrea edulis) has been carried out. One of the greatest difficulties is the feeding of the larvae in the free swimming state and this problem affects both tank culture and culture on a smaller scale. In some years a settlement of spat has taken place, but it is not known what conditions made that phenomenon possible. It has been suggested that the available food supply might be of importance, since both detritus on the one hand, and seaweed spores and gametes on the other, have been regarded as constituting the food of larvae (Martin, 1923). As nothing over 10μ can be ingested by the larvae, there is a limit to the spores and gametes which may be used.
The Preservation of Fishing Nets by Treatment with Copper Soaps and Other Substances. Part III
Authors: Atkins W. R. G. 
Published: May 2009

1. Frequent treatment with cutch is injurious, but Olie's method (cutch and ammoniacal copper sulphate) applied every four months preserved cotton netting for six years and eight months in Aquarium sea-water.2. Varieties of cutch tested showed differences which were quite insignificant in comparison with the improvement effected by adopting One's method, which was effective with all on cotton.3. A single treatment by Olie's method preserved trawl twines of Benares sann hemp, New Zealand Phormium fibre and of sisal (E. African) for 34, 34 and more than 48 months respectively under conditions such
that the untreated twines perished in less than five months.4. Cotton treated with cutch alone is but little improved by a dip in crude phenols, but a neutral tar oil obtained from the “Coalite” low temperature distillation process was found useful.
The Preservation of Fibre Ropes for Use in Sea-Water
Authors: Atkins W. R. G. , Purser J. 
Published: May 2009

1. For the preservation of ropes the importance of the preservative against bacterial decay being also an internal lubricant for the rope fibres must be remembered.2. Tests have been carried out for one year in sea-water, which was much contaminated by sewage at times, under Plymouth Pier and in cleaner water of a tidal basin outside Plymouth Sound Breakwater for 10½ months, using 2-inch and 0-6-inch ropes respectively; the latter was manila, the former were manila, hemp, sisal and coir.3. The preservatives included cutch, cutch bichromate, cutch ammonia copper sulphate, coal tar distillates, including those of the Coalite process, also hardwood and softwood tars. The tars and tar oils were tried alone and mixed with copper soaps, naphthenate (Cuprinol and Shell products), oleate and resinate, also zinc and iron naphthenates (Cuprinol). The naphthenates and oleate are good lubricants.4. Very good results were obtained with green Cuprinol containing tar and with 10 per cent copper oleate in a light coal tar; slightly inferior were 10 per cent copper resinate in Coalite heavy oil or in creosote oil as now used largely in Plymouth; also 10 per cent copper oleate with 20 per cent of Coalite tar in Coalite neutral oil, b.p. 100–245° C, which i s a very cheap solvent. All these maintained the thin manila rope at or above 70 per cent of its initial strength after 10½ months; the untreated control was down to 13 per cent.
Experiments in the Sea on Rate of Growth of some Crustacea Decapoda
Authors: Orton J. H. 
Published: May 2009

From experiments in the sea with wire cages and boxes with perforated zinc sides and tops more than 100 individuals of certain Crustacea which had grown inside the apparatus have been obtained at various subsequent dates.Minimal mean rates of growth are obtainable from the difference between maximum size at immediate entry and size at a given later date, and the approximate age by an allowance for age at entry plus the maximum time occupiable in the experimental apparatus. It was found that C. maenas spawned early in the year may attain a carapace width of 30 to 40 mm. by the following winter. In experiments extending over twelve months from July to July male C. maenas attained a carapace width of 43 to 53 mm. and females 37 mm. at an estimated maximum age of 15 months.
Summary of a Report on a Survey of the Fal Estuary Oyster Beds: (November, 1924),: With Notes on the Biology of the Oyster (O. edulis)
Authors: Orton J. H. , Stevenson D. Bartley 
Published: May 2009

The spatfall in 1924, as in 1923, was very slight and from the point of view of the oyster-producer was a failure, and was little better in 1922.The growth of oysters in the summer of 1924 was unusually great; this has had the effect of bringing a large proportion of small oysters to a legally takeable size.The dredging results have, therefore, been much better than they were expected to be in the season of 1924–25, but the effect has been to deplete the beds still more of reserve stocks of small.Practically all the present stocks of small oysters are of a size between 2 and 2½ inches.With only average growth in 1925 and 1926 a large majority of these small oysters will have attained a size which will not pass through a 2½-inch ring; hence the beds are in a dangerous state.If, therefore, dredging continues under the present conditions, almost the whole of the present stock of small will have grown to large oysters and be cleared off the beds in the season of 1926–27.It is shown that although oysters may grow to a size of 2½ inches at Falmouth in small numbers in three summers, yet four summers are required before a fair proportion of spat can be expected to attain a size of 2½ inches.
Studies of the Plymouth Brachyura. I. The Rearing of Crabs in Captivity, with a Description of the Larval Stages of Inachus Dorsettensis, Macropodia longirostris and Maia squinado
Authors: Lebour Marie V. 
Published: May 2009

It is difficult to rear crabs from the egg, and few experiments of the kind have been successful. It is intended in these studies of the Plymouth Brachyura to rear as many species as possible from the berried crab, and thus to ascertain without doubt the larvæ of each species in all stages, so that they may be recognisable in the plankton.The members of the Oxyrhyncha so far observed in the Plymouth district are the following:-Inachus Dorsettensis (Pennant), Inachus Dorynchus Leach, Macropodia longirostris (Fabricius), Macropodia Egyptia A. Milne-Edwards, Macropodia rostratus (L.), Achæus Cranchii Leach, Maia squinado (Herbst), Pisa biaculeata (Montagu), Hyas araneus (L.), Hyas coarcticus Leach, Eurynome aspera (Pennant).
Some Observations on the Effects of Temperature and Salinity Upon the Growth ofCardium EduleandCardium GlaucumLarvae in the Laboratory
Authors: Kingston Paul 
Published: May 2009

SummaryThe larvae of bothCardium edule, Linné, andCardium glaucum, Bruguière, have been reared to metamorphosis under laboratory conditions.Successful artificial fertilization has been shown possible, in both species, in the termperature range 10 to 20 °C. The larvae ofC. eduleshow poor growth at 10 °C, good growth between 15 and 20 °C and erratic growth at 30 °C.C. glaucumlarvae show negligible growth at 10 °C, but are able to grow well between 15 and 31 °C; limited numbers of larvae were reared to metamorphosis at 33 °C.The optimal salinity for rearing the larvae of both cockle species was found to be between 30 and 35 ‰. AlthoughC. glaucumlarvae were slightly more tolerant of salinity extremes, both species were able to withstand a wider range of salinities than those satisfactory for growth.
On the Nutrition and Metabolism of Zooplankton IX. Studies Relating to the Nutrition of Over-WinteringCalanus
Authors: Corner E. D. S. , Head R. N. , Kilvington C. C. , Marshall S. M. 
Published: May 2009

Studies were made relating to the problem of howCalanusfeeds during winter in the Clyde sea-area. Different diets were assessed in terms of sustaining the levels of body nitrogen and phosphorus inCalanus helgolandicus(Claus) over a period of several days. The test diets, all equivalent to the same level of particulate nitrogen in sea water, were: (1) suspended matter collected from the Clyde sea-area in winter; (2) particulate material produced in a foam-tower by bubbling sea water enriched with soluble extracts of plant cells; (3) living nauplii of the barnacleElminius modestusDarwin; (4) dead nauplii of this species.It was found that neither body nitrogen nor body phosphorus was sustained by diet 1; that body nitrogen, but not body phosphorus, was sustained by diet 2; that both were sustained by either of diets 3 and 4.With livingElminiusnauplii as the food, eachCalanuscaptured the equivalent of 25 % of its body nitrogen and 47·3 % of its body phosphorus daily: with dead nauplii as the food the corresponding values were 34·4 and 44·5%. These rations are much higher than those found in an earlier study ofCalanusgrazing on a spring diatom increase in the Clyde (Butler, Corner & Marshall, 1970) and demonstrate that animal diets are readily captured.In general, the results indicate thatCalanuscould survive the winter in the Clyde sea-area by feeding carnivorously.
Two New Deep-Sea Cirripedia (Ascothoracica and Acrothoracica) From the Atlantic
Authors: Newman William A. 
Published: May 2009

Two new deep-sea barnacles (Cirripedia) are described. The first, from approximately 5200 m in the Southwest Atlantic, belongs to the most generalized genus of the order Ascothoracica, Synagoga. The two previously known species, S. mira from the Mediterranean and S. metacrinicola from Japan, are from relatively shallow water. The new species is not only more generalized than either of these, but it exceeds previous depth records for any ascothoracican by more than 1000 m. It is apparently a sequentially protandric hermaphroditic ectoparasite, knowledge of which helps clarify difficulties in interpreting the life histories of certain more highly evolved endoparasitic forms. On the other hand, its markedly generalized features bear heavily on considerations of the origin of the Maxillopoda.The second new species, from approximately 1500 m in the Bay of Biscay, belongs to the most generalized genus of the order Acrothoracica, Weltneria. It is closely related to W. hessleri known from 1000 m off Bermuda and the two are unique in being the only true deep water members of the order. The new species is remarkable in inhabiting a friable, clayey substrate - all other acrothoracicins are known to burrow only in relatively solid forms of calcium carbonate. However, both have a calcified rostral plate, and this indicates that the Acrothoracica stem from scalpellid rather than cyprilepadid or iblid Lepadomorpha.
The Occurrence of Some Trace Metals in Coastal Organisms With Particular Reference to the Solent Region
Authors: Leatherland T. M. , Burton J. D. 
Published: May 2009

Measurements have been made, by neutron activation analysis, of arsenic, cadmium, antimony, mercury and zinc in organisms and bottom muds, mainly from Southampton Water and the Solent. The values are on a dry weight basis and refer to whole organism soft tissues unless otherwise stated.Concentrations of mercury in algae ranged from 0·07 to 0·22 ppm and those in animal tissues from 0·06 to 1·9 ppm. The distribution of the element in various tissues ofMercenaria mercenariawas rather uniform, except that the concentration in the gills was about 2·5 times that in the whole organism. Variations amongst organisms from different parts of the Solent area and comparisons with other regions suggested some possible influences of local waste discharge, but there was no evidence of major effects. Anoxic muds contained higher concentrations of mercury than occurred in unreduced surface layers, suggesting mobility in interstitial waters of the uppermost zone and fixation under reducing conditions.
Seasonal Changes in Population Density and Vertical Distribution of prosobranch veligers in offshore Plankton at Plymouth
Authors: Fretter Vera , Shale D. 
Published: May 2009

Vertical and horizontal hauls were taken at approximately fortnightly intervals from April 1969 to April 1970 at L 3 (lat. 40° 17.7′ N, long. 4° 11.2′ W) and L 4 (lat. 50° 15′ N, long. 4° 12.5 W). Thirty-two species of prosobranch veliger were present at L 35 these larvae were not as numerous at L 4 and only 26 species were recorded. The number of species was highest in the summer: the number of veligers was highest in February. After mid October both the number of species and the abundance of veligers decreased rapidly and remained low until early February. Veligers of some species occurred later at L 3 and L 4 than in more inshore waters and these were probably individuals carried beyond tidal influences which would normally lead to settlement on the shore. They includedLacuna vincta, Littorina littoreaandL. neritoides.Veligers of all ages were found at all depths. At their time of greatest abundance veligers of many species occurred maximally at 5 or 10 m, with a variable decrease towards greater depths and a sudden one towards the surface. This distribution later changed giving a proportionally greater number at greater depth. When numbers were low the larvae scattered through the water column with little or no indication of a preferred depth. An examination of the age composition of veligers of rissoids,Natica alderi, Nassarius reticulatusandPhilbertia linearisfrom certain catches showed that the surface accumulation at the time of abundance was composed of a high percentage of young veligers: in an ageing population there was a higher percentage of larvae, especially the older ones, at greater depths, except forNassarius reticulatuswhich consistently showed maximal numbers above 10 m until the larvae became scarce.
The Distribution of trace metals and fauna in the firth of clyde in relation to the Disposal of Sewage Sludge
Authors: Halcrow W. , Mackay D. W. , Thornton I. 
Published: May 2009

SummaryTrace metals have been determined in the sediments, waters and fauna of a sewagesludge disposal area in the Firth of Clyde. Enhanced values of organic carbon and several metals were found in the sediments of the immediate deposit area. The results are discussed in relation to local background variations and compared with data from the Solway Firth. Trace-metal concentrations in the waters of the deposit area were higher than those from further off shore in the Clyde.Epifaunal species showed rather erratic variation in trace metal content, unrelated to total or readily extractable trace metals in the underlying sediment. The tracemetal content of demersal fish species was not significantly different from figures reported for elsewhere in the United Kingdom.The distributions of some in-faunal and epifaunal species in the area are described.It is concluded that the effects of sewage sludge disposal in this area are local, gross changes being limited to an area of about 20 km2 of sea-bed. However, little is known of the overall effects of toxic wastes particularly at threshold levels, and further monitoring is required.
Microscopy of the absorptive cells and gut-associated lymphoid tissue of the flounder Platichthys flesus
Authors: Jenkins P. G. , Pulsford A. L. , Harris J. E. 
Published: May 2009

A light and electron microscopic study of the enterocytes and gut-associated lymphoid tissue (G ALT) of the flounder Platichthys flesus showed regional differences in the structure of the epithelial cells. Epithelial villi decreased in height and spatial complexity, but increased in overall thickness in the posterior intestine. There were no specialized cells comparable with mammalian M cells. Periodic acid Schiff (PAS) activity increased in the enterocytes and goblet cells in the anterior intestine where alkaline phosphatase activity was most pronounced in enterocytes. Adjacent cells were joined by tight junctions.Gut-associated lymphoid tissue was composed of isolated leucocytes in the epithelium and lamina propria with no accumulations. Numbers of intra-epithelial leucocytes were not statistically different in the various regions of the intestine. Five leucocyte types were distinguished among the gut-associated lymphoid tissue although lymphocytes and granulocytes were the most common. Granulocytes were positive for the Romanowsky stains with PAS/Alcian blue positive granules. Blast cells similar to large lymphocytes were unevenly distributed through the different regions of the intestine. Plasma cells were more numerous in the epithelium than in the lamina propria. Macrophages were rarely detected.
Trophic structure within the Bristol Channel: seasonality and stability in Bridgwater Bay
Authors: Henderson P. A. , James D. , Holmes R. H. A. 
Published: May 2009

A general description of the trophic inter-relationships and the food web within Bridgwater Bay, Somerset, England, is presented. This Bay is a lower estuarine site within the Bristol Channel. Particular attention is given to the use of the area by fish and larger crustaceans which are the dominant animal groups. Using data collected over a ten-year period of monthly sampling, the relative average biomass of all fish and larger crustaceans found within the Bay is calculated for each month of the year. These averages are used to produce food webs which also show species relative abundance for each calendar month.It is shown that the trophic structure follows a seasonal cycle due to migration. The application of the concept of stability within such a dynamic system is discussed. The role of compartmentalization of the ecosystem into a number of loosely connected groups as an aid to overall stability is discussed. While there is no evidence that contemporaneous compartments exist, it is argued that inter-specific interactions are temporally limited because of the different periods of annual residence of the species. It is suggested that the stability and resilience to interference shown by these estuarine systems is enhanced by temporal partitions.
The ecology of a coastal Phaeocystis bloom in the north-western English Channel in 1990
Authors: Davies Anthony G. , Madariaga I. De , Bautista Begoña , Fernández E. , Harbour D. S. , Serret P. , Tranter P. R. G. 
Published: May 2009

The evolution of a Phaeocystis bloom off Plymouth in spring 1990 is described. Data were obtained (1) during weekly visits to station El to measure physical parameters, nutrient concentrations, primary production and grazing pressure and (2) by regular tows of an Undulating Oceanographic Recorder around a circuit of five stations including El to detect stratification, monitor the geographical distribution of chlorophyll and determine vertical profiles at each station.The data show that the Phaeocystis bloom emanated from near-shore, its spread towards the south-east correlating with the wind direction prevailing at the time. Due to bad weather, seasonal stratification had not been established at the time of the bloom so that a major diatom outburst had not occurred and nutrients remained high as the Phaeocystis moved offshore.Zooplankton populations at El, averaged over 50 m, decreased whilst Phaeocystis was present, resulting in very low grazing pressure. Termination of the bloom was not, therefore, due to consumption by herbivores. It was, instead, caused by Phaeocystis colonies becoming nutrient-depleted and releasing single cells which were transported downwards. As a result of this, chlorophyll concentrations near the bottom remained high for some time after the Phaeocystis had disappeared from the surface water.A scenario is proposed to explain the observations in terms of our current understanding of the ecophysiology of Phaeocystis.
Some Dimensions of the Angular Acceleration Receptor Systems of Cephalopods
Authors: Maddock Linda , Young J. Z. 
Published: May 2009

The shapes and dimensions of the statocysts of cephalopods have been measured and compared with the semi-circular canals of vertebrates. The cavities grow much more slowly than the body as a whole, but there are knobs, anticristae, which restrict the cavity, and these grow relatively faster. This ensures that the flow of endolymph across the cupulae remains small. Where the liquid is constrained within canals the radius of curvature of the whole canal,R, is similar to that of fishes, whereas its internal radius, r, is twice as large in non-buoyant and four times as large in deep-sea buoyant cephalopods as in fishes of similar size. As in fishes the restriction is greatest in the horizontal plane, providing for operation at higher frequencies in turning about the yaw axis.The statocysts of seven species ofLoligoall have similar proportions. The largest individuals of 16 genera of non-buoyant squids also have these same relative dimensions. The statocyst ofSepiais more like that of non-buoyant than of other buoyant cephalopods but yet differs significantly from that ofLoligoat all sizes. On the other hand 21 genera of squids known to be neutrally buoyant are very different. Their statocysts are often larger than in the non-buoyant forms and there is less restriction of the cavity by anticristae. The greater flow of endolymph acting across the cupulae presumably provides greater sensitivity at the lower frequencies of turning of these deep-sea animals.The data suggest that the cristae of the cephalopod statocyst may operate in the frequency band where they act as angular accelerometers whereas the vertebrate semi-circular canals operate at higher frequencies as angular velocity meters.