bluuebunny/crossref_metadata_2025 huggingface dataset:
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 Tees Estuary Investigations. Survey of the River Tees. Part II The Estuary, Chemical and Biological
Authors: Alexander W. B. , Southgate B. A. , Bassindale R.
Published: May 2009

In 1929 the Marine Biological Association began a survey of the River Tees Estuary, to study the various physical and chemical conditions and the types and distribution of animal and plant life. At the same time a tidal stream survey was carried out by the Hydrographic Department of the Admiralty. Later, for purposes of comparison, the scope of the enquiry was extended to a survey of the Kiver Tay, but on a less extensive scale.
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.
The Eggs and Newly Hatched Young of the Common Blennies from the Plymouth Neighbourhood
Authors: Lebour Marie V.
Published: May 2009

The three common blennies of Plymouth are the Shanny, Blennius pholis, the Gattorugine Blenny, Blennius gattorugine, and the Butterfly Blenny, Blennius ocellaris. These have their habitat from just below high-water mark downwards. Thus, B. pholis inhabits the rocky pools from near high-water mark to the regions left dry by the tides; B. gattorugine is also to be found between tide-marks, but not so high up as B. pholis, and is more frequent in those parts uncovered by the spring tides; whereas B. ocellaris inhabits the deeper water and is always covered by the tide; it is frequently to be found on the dredging grounds in the region of the Mewstone and beyond the Breakwater.
The Hydrogen Ion Concentration of the Muscles of Marine Animals
Authors: Furusawa K. , Tookey Kerridge Phyllis M.
Published: May 2009

Measurements have been made of the hydrogen ion concentration of the muscles of various marine animals immediately after death and 20–24 hours after. The results obtained are of the same order as those previously found for the muscles of the frog and the cat.
Preliminary Observations on the Relative Importance of the various Factors Responsible for the Death of Fishes in Polluted Waters
Authors: Pruthi Hem Singh
Published: May 2009

With the growth of modern, industry the problem of the influence of polluted waters on the bionomics of fishes is becoming very important. Fortunately, biologists anticipated this and many works on the subject have appeared, especially during the last twenty-five years. The polluting substances can be divided into two main classes, namely, (i) those that are directly poisonous to organisms, e.g. gas liquor, sulphites, oils, etc., and (ii) those that give rise to poisonous substances or otherwise make the water undesirable after putrefying, e.g. organic matter in solution and the decomposing bodies of plants and animals. The substances in the first category act in a relatively straightforward manner, and numerous investigators have studied them from several aspects (Shelford, '17; Matthews, '04; Powers, Wells, '15, etc.); it is with regard to those in the second class that many questions are yet unsettled and the present communication deals. We roughly know that the effect of the putrefying substances is to increase the hydrogen ion concentration and decrease the oxygen content of water. It has also been suggested that the byproducts of putrefaction themselves may be poisonous to animals.
A New Habitat for Loxosoma phascolosomatum Vogt
Authors: Atkins D.
Published: May 2009

Loxosoma phascolosomatum was first described under that name by Vogt (6) in 1876 when he discovered it at Roscoff on the posterior extremity of Phascolosoma elongatum and P. margaritaceum, where it forms a small tuft. It had probably been observed previously by Norman (4), and described by him in 1861 (3) as tentacular appendages of “Strephenterus claviger”; he found it on gephyreans dredged in 1858 from Bantry Bay. Barrois (2, p. 8) mentions that he also saw this species in 1874–75, before the publication of Vogt's paper, at Roscoff, where it was abundant on sipunculids. Since then it has been recorded as occurring on Phascolion by Andersson (1) in East Greenland, and by Norman (5) in East Finmark.
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

The 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.
Infections with Parasitic Copepods in North Sea Marine Fishes
Authors: Boxshall G. A.
Published: May 2009

A range of 62 species of marine fishes representing 34 families was examined for the presence of parasitic copepods. Forty-one species were found to harbour 39 species of copepod belonging to 9 families. The remaining 21 species of fishes were not infected. The incidence and intensity of infection were recorded and these provided material data on the host-parasite relationships. The site of infection and the developmental stage of the parasite were also recorded. The frequency distributions of number of copepods per host were calculated for Clavella adunca and Bomolochus confusus. The age of the host was shown to influence the frequency distribution of Bomolochus confusus. The host specificity of the copepod species was analysed and 70 % of the species were found to be specific for one host species or for different species of the same genus.
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.
Turbulent Convergent Tidal Fronts
Authors: Pingree R. D. , Forster G. R. , Morrison G. K.
Published: May 2009

A high concentration of certain planktonic animals was found in a frontal region in the English Channel. Temperature, salinity and current measurements and direct visual observations (underwater) describe the nature of the front. It is shown that water depth, season, strong tidal mixing and residence time are important factors leading to the formation and maintenance of a turbulent convergent tidal front.
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.
Remarks on the Presumed Example of Hybridization Between Two Species of Pagurus [Crustacea: Decapoda: Paguridae]
Authors: McLaughlin Patsy A.
Published: May 2009

A critical evaluation of the characters utilized in support of a report of hybridization between two sympatric European species of Pagurus is presented. These characters are contrasted with characters considered to be diagnostic for the species. Although, on the basis of present evidence, the possibility of hybridization is not wholly excluded, it is shown to be highly improbable.
Stygiomedusa fabulosa from the North Atlantic: its Taxonomy, with a note on its Natural History
Authors: Harbison G. R. , Smith K. L. , Backus R. H.
Published: May 2009

The largest recorded specimen of the mesopelagic scyphomedusa, Stygiomedusa fabulosa Russell 1959, was taken in the North Atlantic (49° 53' N, 33° 18' W). Umbrella diameter was 140 cm with an oral arm length of 164 cm. This specimen is morphologically intermediate between the nominal species of the genus, S. fabulosa and S. stauchi. This suggests that S. stauchi is not a distinct species. The midwater fish Thalassobathia peligica was captured in the same haul and could live in association with large scyphomedusae.
The Distribution of Neutral Lipids in Shark Tissues
Authors: Sargent J. R. , Gatten R. R. , McIntosh R.
Published: May 2009

Neutral lipid classes were analysed in the livers, muscles and sera ofDeania, Centroscymnus, Squalus and Prionace. All three squaloid sharks contained triglycerides and alkyldiacylglycerols and the two deep sea squaloids contained additionally hydrocarbons. Prionace contained triglycerides and hydrocarbons but no alkyldiacylglycerols. For a given species the class compositions of the lipids were similar in liver, muscle and serum, except that serum contained additionally cholesteryl esters and wax esters. Cholesteryl esters inSqualusserum were rich in oleic acid whereas wax esters were very rich in polyunsaturated fatty acids.Squalusserum contained a major and a minor lipoprotein species both of which transport all four neutral lipids in serum. It is concluded that, with the exception of cholesteryl and wax esters in serum, neutral lipids are distributed between shark tissues by a mechanism that is relatively non-specific with respect to lipid class.
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

Trace 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.
Blooms of Prorocentrum Micans (Dinophyta) in the Galway Bay area
Authors: Pybus C.
Published: May 2009

Dense populations of Prorocentrum micans are reported from the Galway Bay area in 1980 and 1981. At one location a density of llx106 cells dm-3 was found co-incident with a bright red colour in the water. High concentrations of chlorophyll a and high levels of dissolved oxygen were also associated with the blooms.
Further results from a tagging study of pelagic sharks in the north-east Atlantic
Authors: Stevens J. D.
Published: May 2009

A further 69 recaptures are reported from a tagging study of pelagic sharks initiated in 1970 in the north-east Atlantic. Galeorhinus galeus tagged in England were recaptured in the eastern Atlantic from southern Spain to north-west of Iceland. Among the 42 G. galeus recaptured the longest time at liberty was about 12 years and the greatest distance travelled was 2461 km. Among the 21 Prionace glauca recaptured the l ongest time at liberty was 10.7 years, and seven sharks moved distances between 4362 and 7176 km. One shark tagged in south-west England was recaptured in the South Atlantic off South America. An Isurus oxyrinchus was at liberty for 4–6 years and a Lamna nasus for up to about 13 years. Lamna nasus were recaptured from northern Norway to northern Spain. The growth rates of the tagged sharks were close to the predicted values for G. galeus, were slower for P. glauca and faster for L. nasus.
Geographical variation ofBalanus improvisusin biochemical and morphometric characters
Authors: Furman Eeva R.
Published: May 2009

Samples ofBalanus improvisuswere collected from 15 sites in the Baltic, the west coast of Sweden, the British Isles and North America. They were analysed with horizontal starch gel electrophoresis for 11 loci and with opercular plate morphometry for 10 metrical characters. Analyses of isozyme patterns revealed a high degree of genetic similarity amongst populations. The Baltic sites, however, showed less heterozygote deficiency than the British and American sites indicating higher stability and outcrossing in the Baltic. Morphometric characters showed somewhat more heterogeneity than isozymes. The Baltic was relatively more homogeneous by morphometrical characters than by isozymes compared with the other areas. Both analyses separated to some extent the three geographical regions from each other and clustered sites by salinity. Individuals at low salinity had relatively small opercular openings compared to individuals from high salinity.
Origin of bistramide a identified in Lissoclinum bistratum (Urochordata): possible involvement of symbiotic Prochlorophyta
Authors: Biard J.-F. , Grivois C. , Verbist J.-F. , Debitus C. , Carre J. B.
Published: May 2009

An attempt was made to determine whether bistramide A (=bistratene A), a polycycloether with biological activity isolated from Lissodinum bistratum Sluiter, originates from the ascidian itself or from its symbiont Prochlorophyta. A high-pressure liquid chromatography assay carried out on the whole ascidian, the ascidian without a portion of its Prochloron and the Prochloron themselves gave concentrations respectively of 0.182,0.166 and 0.850%. In view of these results, as well as of the capacity of Prochloron to synthesize complex nitrogenous products and the cytotoxicity of these products, it is hypothesized that bistramide A originates exclusively in Prochloron.
Sandeels in the diets of seals: application of novel and conventional methods of analysis to faeces from seals in the Moray Firth area of Scotland
Authors: Pierce G. J. , Boyle P. R. , Diack J. S. W. , Clark I.
Published: May 2009

Serological methods for prey identification have been applied to detection of residues of sandeel (Ammodytidae) protein in faeces of common seals (Phoca vitulina) and grey seals (Halichoerus grypus) from the Moray Firth, north-east Scotland. Antisera raised to muscle protein from Ammodytes marinus were evaluated by testing their reactions with protein extracts made from a range of North Sea fish species and protein residues in in vitro digestates, seal digestive tracts and seal faeces. It was concluded that, using fused rocket immuno-electrophoresis, linkage of precipitin peaks from unknown samples with peaks from standard sandeel extract was a reliable indicator of the presence of sandeel in the unknown sample. Seasonal variation in the incidence of sandeels in common seal diet in the Moray Firth was examined by identifying otoliths, bones, and proteins, and all three methods indicated that sandeels occurred in the majority of samples tested in the summer, but were less important during the winter. Proteins were detected in fewer samples than otoliths, particularly in February and March. Possible reasons for this difference are discussed. Serological identification of sandeel proteins is potentially applicable to dietary studies on all marine predators.
Shell and hinge ontogeny of the Antarctic bivalve Lissarca notorcadensis
Authors: Prezant Robert S.
Published: May 2009

Lissarca notorcadensis, a small pallial-brooding mollusc with a circum-Antarctic distribution, is frequently found attached by stout byssal threads to the spines of sea urchins. Here, complete ontogenetic series can be found. Using standard, structural definitions, the prodissoconch I of L. notorcadensis is small compared to the large prodissoconch II, a feature atypical of brooded young and possibly reflective of a planktotrophic past. Fine commarginal striae are found on prodissoconch II of this subtidal clam, which also possesses more pronounced commarginal striae on the dissoconch prior to brood release. The provinculum is retained and remains functional well into adulthood. A small central ligament pit is present through the postlarval stages. This develops into a large, triangular pit in adulthood that shows obvious growth lines. Calcareous, presumably aragonitic fibres develop in the ligament of specimens still retained in the adult brood. Five to six adult hinge teeth are formed on either side of the ligament. Alignment of shell valves by these well-developed teeth is augmented by retention of larval denticles. The functional and structural demise of the provinculum occurs between 4 and 7 mm shell height and results from denticle erosion and subumbonal shell overgrowth. Many canals permeate larval and adult valves, but external pores in the adult shell differ from those of the larval shell and could indicate mode of formation. Prodissoconch form, provinculum retention, and shell canals are considered primitive traits.
Antibacterial activity in the haemocytes of the shore crab,Carcinus maenas
Authors: Chisholm June R. S. , Smith Valerie J.
Published: May 2009

The presence of antibacterial activity in the haemocytes of the shore crab,Carcinus maenas(L.) (Crustacea: Decapoda), was investigated using a selection of Gram-positive and Gram-negative bacteria from geographically diverse waters. Preliminary investigations into the relationship between this activity and the prophenoloxidase activating system (proPO) were also carried out. Antibacterial activity against both Gram-positive and Gram-negative organisms were found to reside exclusively in the granular haemocytes and eight of the twelve bacteria tested were susceptible to this effect. Additional studies, usingPsychrobacter immobilis(=Moraxellasp.), revealed that the factor (or factors) responsible was 90% effective within 60 min and was also heat stable, independent of divalent cations, and non-lytic in character. Although antibacterial activity resides in the same cell population that carries the proPO system, there appears to be no relationship between antibacterial activity and phenoloxidase itself. Other components of the proPO system, however, may be involved.
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.
Sea lice (Caligidae) on wrasse (Labridae) from selected British wild and salmon-farm sources
Authors: Bron J. E. , Treasurer J. W.
Published: May 2009

The occurrence and intensity of infection of caligid species on the five species of wrasse commonly found in British waters are reported from twelve localities in the British Isles and from seven fish-farms in Scotland where wrasse are used to remove sea lice from salmon (Salmo salar L.). A low prevalence of infection was recorded for all wrasse species except ballan. Chalimus of Caligus centrodonti Baird were identified from fins of ballan, rock cook and goldsinny wrasse, this being the first host record for the latter two species. Single chalimus stages of Caligus elongatus Nordmann were identified from a ballan wrasse and a goldsinny wrasse and are similarly first records from these host species. No C. centrodonti were found on farmed salmon and conversely no Lepeophtheirus salmonis (Krøyer) were identified from wrasse kept in contact with infected salmon. This suggests that transfer of caligids between wrasse and salmon and vice versa does not pose problems for fish health on sea-farms.
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.
Phytoplankton biomass, light attenuation and mixing in the Shannon Estuary, Ireland
Authors: McMahon T. G. , Raine R. C. T. , Fast T. , Kies L. , Patching J. W.
Published: May 2009

Distributions of suspended matter, light attenuation and chlorophyll a were measured in the Shannon Estuary over the period 1988–1990. Light attenuation was found to be highly correlated with levels of suspended matter, and the availability of underwater irradiance was found to be the dominant influence on phytoplankton biomass and chlorophyll levels over most of the estuary. Though levels of suspended matter, and hence light attenuation, were highest in the upper estuary, depths of mixing were relatively shallow resulting in less light limitation of phytoplankton growth than elsewhere. Turbidity maxima in the upper estuary were associated with chlorophyll maxima, the magnitude of which appeared to be related to river discharge.
Comparative Studies on the Ecology of Asterina Gibbosa and A. Phylactica at Lough Ine
Authors: Emson R. H. , Crump R. G.
Published: May 2009

The distributions of Asterina gibbosa and A. phylactica in the Lough Ine area are described and compared. The species are shown to have different horizontal distributions with respect to wave exposure. Clear ecological separation is demonstrated where their distributions overlap as a result of micro-habitat preferences.
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.
Phase-Responsiveness of the Circatidal Locomotor Activity Rhythm of Hemigrapsus Edwardsi (Hilgendorf) to Simulated High Tide
Authors: Naylor E. , Williams Barbara G.
Published: May 2009

Phase-responsiveness to single pulses of simulated high tide has been tested for in the locomotor activity rhythm of Hemigrapsus edwardsi, a grapsid crab from a locality of equal semi-diurnal tides. The crab exhibits endogenous circatidal locomotor rhythmicity with only a weak circadian component. Exposure to a single 3 h ‘pulse’ of simulated high tide (immersion and low temperature, with or without light) in crabs kept otherwise in constant conditions (moist air; dim red light; 15°C), resulted in slight phase delays in the free-running rhythm when the tidal ‘pulse’ was applied in the first 2–3 h of the ‘expected’ high tide period. Tidal pulses initiated at and just after the expected time of high tide induce a phase advance. The results support the hypothesis of a phase-responsive curve on a tidal (12·4 h) rather than 24 h time-base. However, the phase advances and delays are small when compared with circadian phase response curves. It is suggested that the circatidal rhythms depend mainly upon repeated exposure to tidal variables for entrainment and that each individual tide is able to adjust the behavioural rhythm only slightly from its endogenous pattern. In this way, behaviour of populations of coastal animals is less susceptible to environmental perturbations associated, for example, with severe storms.
The Adhesion of the Barnacle,Balanus Balanoides,to Slate Surfaces
Authors: Yule A. B. , Walker G.
Published: May 2009

Techniques were developed to measure the adhesion of the barnacleBalanus balanoides(L.), over the post metamorphosis period. It was found thatBalanus balanoidesis capable of producing a proteinaceous adhesive material within one day of metamorphosis. This adhesive material was found to withstand applied forces of 1·7×105Nm−2before cohesive failure took place. The strength of the cement produced by older barnacles, measured at a time when the adult cement apparatus is known to be operating, was considerably greater and applied forces of 9·3 × 10 Nm were necessary to induce cohesive failure in the cement. The strength ofB. balanoidescement was thus shown to be at least one tenth of that of commercial adhesives which have tensile strengths in the region of 107Nm−2.
A Contribution to the Quantitative Study of Plankton
Authors: Allen E. J.
Published: May 2009

The well-known work of Hensen (1887) was the first serious attempt to determine the actual number of individual plankton organisms in sea-water. Hensen's method consisted in straining a vertical column of water through a net of fine-meshed bolting silk having 6,000 to 6,500 meshes per square centimetre, the average length of the side of a mesh being 50 µ. A carefully measured sample of the organisms retained by the net was taken and the number of organisms in it counted. From this, since the area of the mouth of the net and the distance through which it was drawn were known, the number of organisms in a unit volume (1 litre) of water could be calculated, with the help of a coefficient of filtration for the particular pattern of net employed, which was determined experimentally. Many small organisms, however, escaped through the meshes of the net, and Lohmann (1902, 1908) made a special study of these by filtering through hard filter paper or closely woven taffeta silk, by an examination of the filtering apparatus in the “houses” of Appendicularians, and finally, for the quantitative estimation of the smallest organisms of all, by subjecting samples of sea-water to the action of a centrifuge making 1,400 revolutions per minute for a period of 7 minutes. The use of the centrifuge has been continued by Gran (1915) and by Lebour (1917). For the full literature of the subject the reader is referred to Gran (1915) and Lohmann (1911).
In the course of my work on the cultivation of plankton diatoms (1910, 1911) I became convinced that even the quantitative method based on the use of the centrifuge fell very far short of giving the total number of organisms actually present in a sample of sea-water, and the results recorded in the present paper show that this is certainly the case.
The Development of the Species of Upogebia from Plymouth Sound
Authors: Webb Gladys E.
Published: May 2009

Upogebia deltura Leach and Upogebia stellata (Mont.) are both of common occurrence on the coasts of Devonshire and Cornwall, but in the adult stage they are not easily obtained, owing to their burrowing habits.
The larvæ, however, are very common in the tow-nets, occurring throughout the year with the exception of the midwinter months, and are particularly plentiful from June to August.
The two species are closely allied, and for some time it was believed that the differences between them might be merely sexual, and not specific (Bell 1853). They are now clearly recognised as separate and distinct species, and De Morgan (1910) has obtained males and females of both forms.
Upogebia deltura Leach may be distinguished by its greater size, sometimes five or six inches in length when full-grown, as well as by its broad abdomen with soft abdominal pleura. The two joints of the chela on the first thoracic leg are almost equal in length.
Upogebia stellata (Mont.) is an altogether smaller and more slender animal, seldom exceeding two and a half inches in length. The abdomen is narrower, and the fixed finger of the chela very much shorter than the dactylus. There is also a small point on the side of the carapace, just over the base of the second antenna, which has been established as a specific character by De Morgan (1910).
In the living state the body of the animal is covered with orange-red spots (hence its name stellata), while Upogebia deltura Leach is of a uniform dirty cream colour.
A Suggested Scheme for the Investigation of Marine Bacteria
Authors: Holden H. S.
Published: May 2009

Whilst employed at the Royal Naval Hospital, Plymouth, I have been kindly granted facilities for the investigation of marine bacteria by Dr. E. J. Allen, Director of the Marine Biological Laboratories, and although the pressure of other duties has made progress extremely slow the experience obtained with different media will perhaps be of use to future workers.
Seashore Diptera
Authors: Yerbury Colonel J. W.
Published: May 2009

Though it is easy to write down this heading, it is by no means so to define it. The simplest and best definition seems to be “A dipteron which spends a considerable portion of its existence in salt or brackish water,” but our present chaotic knowledge of the early life histories of shore diptera does not advance us far towards clearing up the doubtful period, and we are thrown back on the shore frequenting perfect insects, many of which are of wide distribution.
Further Notes on the Young Gobiidæ from the Neighbourhood of Plymouth
Authors: Lebour Marie V.
Published: May 2009

The above paper on the Plymouth gobies (p. 48) was finished and in print before the new work of C. G. J. Petersen (“Beretning til Land brugsministeriet fra den danske biologiske Station,” XXVI, 1919) came to hand. Although a second description and differentiation of the common forms is now unnecessary after his accurate and detailed account of them, yet as a corroboration of his identifications and as a record of the occurrence and distribution of the young gobies to be found at Plymouth (three of which are not described by Petersen), it seems advisable to keep the whole of my work intact, although in some measure it contains a repetition of the conclusions arrived at by him. I have therefore altered nothing, except adding the words “up to 14 mm.” with regard to Gobius pictus in the table, p. 79, and merely confine myself to a few notes in this appendix with regard to any slight differences between his specimens and those from Plymouth. The three species not described by Petersen, namely Gobius elongatus, Gobius Jeffreysii and Gobius paganellus are apparently, with the exception of Gobius Jeffreysii, not present at all in the Danish waters. On reading his conclusions as to the specific value of the number of vertebræ and fin rays I feel still more strongly that the form hitherto known as the deep water form of Gobius minutus, and which I have here distinguished as Gobius elongatus, is a true species, although closely related to Gobius minutus.