bluuebunny/crossref_metadata_2025 huggingface dataset:
A preliminary report on the Plymouth marine and Brackish-Water Rotifera
Authors: Hollowday E. D.
Published: May 2009

Six species of rotifer, including one oceanic species and representing four genera, are recorded for the first time from Plymouth. Remarks are made on various interesting features of their anatomy, details are given of their times of occurrence at Plymouth, with notes on their location and known distribution in other parts of the British Isles, and in foreign waters.

Attention is called to the apparent poverty of the Plymouth marine and brackish-water Rotifera as compared with that of Liverpool, investigated at length by Galliford. It is stressed that no exact conclusions as to the reason for this can be made until after a more exhaustive survey, as some likely habitats adjacent to the Sound were not investigated. Attention is also called to the caution which must be exercised in terming rotifers marine, as most of those collected in coastal waters appear at present to be confined to areas where a considerable amount of fresh water is discharged into the sea. At least two species, one of which occurs in the Sound in May, are known to be truly oceanic, having been found in mid-Atlantic.

It is suggested that ‘brackish’ and ‘estuarine’ are the terms most applicable to the majority of coastal rotifers in the present state of our knowledge.
Population-dispersion inTellina Tenuisda Costa
Authors: Holme N. A.
Published: May 2009

A population of the lamellibranchTellina tenuisin the Exe estuary is shown to be uniformly distributed, indicating a significant degree of ‘over-dispersion’.

By plotting the position of each shell in squares ofm.2area it is shown that fewer individuals than would be expected occur less than 1 in. from their nearest neighbour, and none occurs closer than 0·6 in.

When the population density was artificially increased on the shore the same characteristic spacing was found at a moderate density, but not at a rather higher density.

It is suggested that spacing is correlated with the foraging activities of the inhalent siphon on the soil surface.

Very dense populations have been found by Stephen in other areas, indicating that the size of the ‘territory’ does not limit density. His results show no evidence of the same phenomena as observed in the Exe.
Gregariousness during settlement in the barnacle Elminius modestus Darwin
Authors: Knight-Jones E. W. , Stevenson J. P.
Published: May 2009

A gregarious tendency during settlement, similar to that already demonstrated in oyster larvae, was suspected in Elminius, because cyprids settled in groups during the initial stages of colonization of surfaces (crowded later arrivals showed a spacing-out tendency) and because settlement on test-plates was peculiarly sparse at stations with a muddy bottom, where barnacles were absent.

Settlement was much heavier on areas of smooth glass, which already bore recently settled barnacles, than on similar adjoining areas which were bare.

When barnacled microscope slides were stuck to one set of glass plates, bare slides to another and the two sets exposed side by side, settlement was consistently much heavier on the plates which bore the barnacled slides. The mean density of settlement on the bare slides and the surrounding plates was uniformly low, except for a greater density immediately adjoining the slides, probably due to sheltering alongside their edges. On the barnacled slides density of settlement was much higher and on the plates immediately alongside still more so, whilst at increasing distances from the slides it became gradually smaller but was still much heavier than on the plates with the bare slides. This suggests that the sensory basis for gregariousness can act at a distance. It may possibly be olfactory.
The Distribution of Octopus Vulgaris Lamarck in British Waters
Authors: Rees W. J.
Published: May 2009

In Britain Octopus vulgaris occurs on the Channel coast and only very rarely on other coasts. In Brittany and the Channel Islands it frequently makes its lair at low water, but on the English side of the Channel it does not come so close inshore except in abnormal years of high sea temperatures.

The discovery of Octopus larvae of various sizes, from newly hatched to 6·0 mm. (mantle length), in plankton hauls taken to the north of the Channel Islands, proves that the species has a much longer planktonic life than hitherto supposed.

The water circulation in the English Channel, as indicated by drift bottles, is admirably suited to the dispersal of larvae to our shores from breeding centres on the coasts of Brittany and the Channel Islands.
The seasonal variation in the cellulose content of the common Scottish Laminariaceae and Fucaceae
Authors: Black W. A. P.
Published: May 2009

Monthly samples of the common British Laminariaceae and Fucaceae taken during 1946 have been analysed for cellulose.

The cellulose content has been found to increase with the depth of immersion of the weed.

In the Laminariaceae, both in the stipe and frond it undergoes marked seasonal variation, exhibiting two maxima, March/April and September/October with a distinct minimum in June/July.

In Laminaria cloustoni, in March, maxima of 5·7 (dry basis) occur in the fronds and 10·3% in the stipes with minima, in June, of 4·1 and 8·4% respectively. In Laminaria saccharina the cellulose content (dry basis) varies between 4–5% in the frond and 7–8% in the stipe and in Laminaria digitata between 3–5% in the frond and 6–8% in the stipe.
A Biological Study of Fucus Vesiculosus L. and F. Serratus L.
Authors: Knight Margery , Parke Mary
Published: May 2009

A certain variation in level of the fucoid zone with latitude is demonstrated. The belt of Fucus vesiculosus and F. serratus lies lower on the Devon coast than on either the Manx or the Argyll coast.

The conditions for the optimum germination of fertilized eggs are dissimilar to those for maximum rate of frond-extension.

Normal growth-rates have been established for both species for the first 3 years of life. In F. vesiculosus the average rate of elongation per week is 0·48 cm. on the Devon coast, 0·45 cm. on the Manx coast and 0·68 cm. on the Argyll coast. In F. serratus the average rate of elongation per week is 0·49 cm. on the Devon coast, 0·68 cm. on the Manx coast and 0·85 cm. on the Argyll coast. The rate of growth is shown to vary with the conditions of the environment. Shelter from rough water tends to enhance growth-rate, and there is an indication that greater stature is achieved by the plants from the Argyll station than from either of the other stations.
On the Rearing and Breeding of Gammarus in Laboratory Conditions
Authors: Sexton E. W.
Published: May 2009

The following paper has been prepared in the hope that it will be of assistance to anyone desirous of carrying out experiments on Heredity with Gammarus chevreuxi. This Amphipod has been the subject of study at the Plymouth Laboratory since 1912, and the following notes are chiefly concerned with rearing and breeding it under Laboratory conditions.

Details of the work will be found in the papers mentioned in the bibliography on page 54.
The Vertical Distribution of Marine Macroplankton. VI. Further Observations on Diurnal Changes
Authors: Russell F. S.
Published: May 2009

In 1925 observations were carried out on two consecutive nights, June 17–18th and 18–19th, to study the diurnal changes occurring in the vertical distribution of certain marine plankton animals. Serial hauls were made with the stramin ring-trawl in the manner described in a previous publication (1). The series were so timed that they were made approximately in daylight, dusk, darkness, dawn and daylight on the two days in question. The actual details of the collecting, together with the fishing depths shown by the Admiralty depth recorder, are to be found in a previous paper on the behaviour of young fishes on the same occasion (2).
The Post-Larval Development of Loimia medusa Sav
Authors: Wilson Douglas P.
Published: May 2009

1. The larva of a Terebellid which is very common in plankton from the Plymouth district during spring has been reared and proved to be the young of Loimia medusa Sav. This larva is characterised by its very large gelatinous tube.

2. The development of the external structures is described from a stage in which the first tentacle was just appearing to a juvenile stage in which all the main characters of the adult had been assumed.

3. The building of the first sandy tube on the bottom is described.

4. The development of the bristles and uncini are dealt with in some detail and a comparison made with the corresponding development in Nicolea zostericola. Evidence of the suppression of a pair of larval bristle-bundles in Loimia is indicated.

5. Previous records of Loimia larvse are discussed.

6. McIntosh's separation of our British Loimia to a new species, L. montagui, is shown to be probably unjustified.
Seasonal Variations in the Phosphate and Silicate Content of Sea Water during 1926 and 1927 in Relation to the Phytoplankton Crop
Authors: Atkins W. R. G.
Published: May 2009

1. A comparison of the strength of the wind, Beaufort Scale, and of its direction during the periods when the vernal diatom outburst caused phosphate depletion of the surface water, has failed to indicate that there is any connection between either strength or direction and the date of the outburst. The spring sunshine still appears to be the important factor at El.

2. The sequence of the years studied as regards the main spring diatom outburst deduced from phosphate depletion at Station El is as follows: 1924, early March; 1926, late March to early April; 1925, early April; 1923, early May.
Herring Investigations at Plymouth. II. The Average Number of Vertebrae for Herrings from the English Channel and South-East of Ireland
Authors: Ford E.
Published: May 2009

The published observations of other workers, on samples of herrings taken from the area under consideration, whether they relate to the study of such morphological characters as the number of vertebræ and keeled scales, or are chiefly concerned with the examination of the growth of the fishes as indicated by their scales, demonstrate very clearly that the eastern, central and western sectors of the area are visited by herrings which differ in character. It will be convenient to summarise the opinions of these workers under the headings of the statistical regions in which the samples were taken. The reader is referred to the chart on page 269, which shows the geographical extent of the regions dealt with.
Observations and Experiments on Sex-Change in the European Oyster (o.edulis). Part III. On the Fate of Unspawned Ova. Part IV. On the Change from Male to Female
Authors: Orton J. H.
Published: May 2009

An analysis of the quantity and distribution of unspawned eggs in the gonad of o. edulis recorded in Table IV, 1, 1927 (of oysters with young) and Table IX, 1,1927 (of post-spawned oysters), gives useful information regarding the occurrence and fate of unspawned ova as may be seen from the figures given in Table A.
Chemical Constituents of Biological Importance in the English Channel. Part III. June-December, 1932. Phosphate, Silicate, Nitrate, Hydrogen Ion Concentration, with a Comparison with Wind Records
Authors: Cooper L. H. N.
Published: May 2009

In August, 1932, marked stratification of the water in the English Channel led to an unusual distribution of minor chemical constituents. Two thermoclines were present, between which high silicate values were found, indicating rapid re-solution of silica as found in former summers; pH was also very high at 15 metres.

In or about December in four years, nitrite in inshore waters has been found much in excess of that present in the open Channel.

The “mean cube Beaufort number” is suggested as a useful practical measure of sea disturbance. Three out of four midwinter plankton outbursts, inferred from a fall in the phosphate content of the water, have followed periods of sunny weather with little wind.
The Seasonal Distribution of Macroplankton as shown by Catches in the 2-metre Stramin Ring-trawl in Off-shore Waters off Plymouth
Authors: Russell F. S.
Published: May 2009

In past years during the study of the vertical distribution of macroplankton much information has been obtained on the abundance of the different animals in the catches at different times of the year. Results have already been published to show the seasonal distribution of pelagic young fish (4), and also on the abundance and composition of the Sagitta population (5, p. 565). In this latter study the change over from the predominance of Sagitta clcgans to that of S. sctosa during the years 1930 to 1932 is striking. During the examination of catches it has been noticed that each year has been characterised at some time by the abundance of a species which may occur only in small numbers, if at all, in other years. This has been especially noticeable in the composition of the medusa population. It is necessary to follow these changes through a number of years to see if the presence of certain plankton organisms cannot be used as an index of conditions that may lead to other fluctuations such as those of the fisheries.
The Food Consumed by Shags and Cormorants around the Shores of Cornwall (England)
Authors: Steven G. A.
Published: May 2009

1. 188 Shags and 27 Cormorants, which had been feeding around the shores of Cornwall and whose stomachs contained identifiable food organisms, have been examined.

2. The Shags were found to have been feeding principally upon Sand Eels (Ammodytes spp.), and other non-marketable fishes.

3. The proportion of flatfishes and other economic species which had been devoured by the Shags was negligible.
The Magnesium and other Inorganic Constituents of some Marine Invertebrates
Authors: McCance R. A. , Shipp H. L.
Published: May 2009

The sodium, potassium, calcium, magnesium and iron of a number of marine invertebrates have been determined and some of the findings are very briefly discussed.

The common winkleLittorina littoreacontains 330–510 mg. of magnesium per 100 g. of live weight. All the organs appear to contain these high concentrations. Boiled specimens of whelks contained about 160 mg. of magnesium per 100 g.

We should like to thank the Director and Staff of the Laboratory of the Marine Biological Association for their assistance. R. A. McC. has held a part-time grant and H. L. S. a full time grant from the Medical Research Council during this work.
Abnormal Eyes in WildGammarus zaddachiSexton
Authors: Bassindale R.
Published: May 2009

Of 198 specimens ofGammarus zaddachicollected in the Estuaries of the Rivers Earn and Tay four individuals had abnormal eyes. This is the first record of abnormal eyes in wild specimens of a Gammarus species, although Laboratory strains ofG. chevreuxihave developed them.

The investigation described in this paper was carried out as part of the programme of the Water Pollution Research Board of the Department of Scientific and Industrial Research, and is published by permission of the Department. My thanks are due to Dr. E. J. Allen and to Mrs. E. W. Sexton for their assistance in preparing the paper.
Observations on the Reactions of Marine Plankton to Light
Authors: Spooner G. M.
Published: May 2009

1. The most noticeable response of marine plankton to light, under laboratory conditions, is the formation of groups on the lighted (or opposite) side of the vessel containing them.

2. Specimens from such groups were tested under different conditions of illumination, and in all cases they moved in thedirectionof the light quite irrespective of accompanying changes ofintensityin the surroundings.

3. Groups form around the line of direction of the light, or the resultant direction when the light is scattered or falling from more directions than one, this being the direct result of individuals moving along the mean path of incidence of the light.

4. The behaviour of individuals was examined more closely to distinguish between the two possible ways in which the directed movement could have been brought about, viz. (i) reactions to bilateral inequalities of illumination (here called “true topotaxis”), and (ii) reactions to changes in total illumination of light-receptors (a type of “phobotaxis”). For a number of species it was clearly a case of “true topotaxis,” and very probably for at least the majority of the rest.

5. In two very different cases, namely,Acartia clausiandPoecilochaetus serpens, there was no orientation of the body, but nevertheless efficient orientation of the path of movement. It is believed that this is the first occasion on which such behaviour has been described.

6. The observations described point to the fact that movement in the direction of incidence of the light, however this may be affected, is general among a wide range of the smaller, free-living, bilaterally symmetrical, marine animals, and would tend to dominate other possible response to light. This behaviour on the part of individuals provides a substantial basis for attempted explanations of the correlations, that have been demonstrated by ecological workers, between the vertical distribution of populations and light-intensity.
Records of pilchard spawning in the English Channel
Authors: Corbin P. G.
Published: May 2009

The pilchard, Clupea pilchardus Walbaum, is known to spawn in summer in the southern North Sea in the neighbourhood of the Sandettié Bank (Buchanan-Wollaston, 1911; Furnestin, 1939a, 1945) and in the eastern English Channel off Beachy Head (Furnestin, 1939a, 1945). Furnestin (1939b, 1945) concludes from these records that spawning is in all probability continuous throughout the Channel from the southern North Sea to the Celtic Sea. There appear, however, to be no previous references to pilchard spawning in the central part of the English Channel. The following records from the area are of interest therefore, and provide confirmation of Furnestin’s conclusion.
Pisces
Authors: Steven G. A.
Published: May 2009

Some records are given of fishes, occasional or rare in the area, recently caught in the western part of the English Channel. The nomenclature is that used in the Plymouth Marine Fauna (Mar. Biol. Assoc., 1931) based on Duncker, Ehrenbaum, Kyle, Mohr and Schnakenbeck's list in Die Tierwelt der Nordund Ostsee (1925–29). An asterisk indicates species that do not appear in the Plymouth Marine Fauna.
Additional records of Laminaria ochroleuca De la Pylaie
Authors: Spooner G. M.
Published: May 2009

Laminaria ochroleuca De la Pylaie was recently added to the British flora by Dr Mary Parke (1948), who found it to occur freely in the sheltered parts of Plymouth Sound. It had first come to notice in 1946 and is possibly quite a recent introduction to the country, though it may have escaped notice for some years. The species can now be recorded from two other localities: Salcombe Estuary (South Devon), and Helford River (West Cornwall).
On the nutrition and metabolism of zooplankton. V. Feeding efficiency ofCalanus finmarchicus
Authors: Corner E. D. S. , Cowey C. B. , Marshall S. M.
Published: May 2009

Nitrogen retained and nitrogen excreted byCalanus finmarchicus(Gunnerus) have been measured at all stages of development from egg to adult; and the percentage of food digested by adult females grazing algal diets has been estimated by two separate methods. The data have been used to calculate gross efficiency of growth by the young stages as well as that of egg-production by the adult female. They show that during a life-span of approximately ten weeks the animal uses 24% of the nitrogen it captures as food in order to build new tissue and produce eggs; the remaining larger fraction is lost as faecal pellets, moults and excreted end-products of metabolism.
Two new marine species of Paraphysomonas
Authors: Lucas I. A. N.
Published: May 2009

Diagnoses and descriptions are given of two new species of marine planktonic flagellates of the class Chrysophyceae; Paraphysomonas imperforata and P. foraminifera. Both possess unequalflagella, the longer pantonemic, the shorter simple. Chromatophores and stigma are absent, phagotrophic nutrition occurring. Surface scales examined by electron microscopy are the best means of identification, those of the latter being perforated by many holes. Each scale of both species has a central dome, bearing a long spine, and a shallow annular fold with a radius half that of the scale.
The pigments of some marine phytoplankton species
Authors: Riley J. P. , Wilson T. R. S.
Published: May 2009

Thin-layer chromatographic procedures using silica gel and glucose have been employed for the examination of the pigments of twenty-three species of marine phytoplankton, drawn from a number of classes. Several new xanthophylls have been found including one similar to fucoxanthin which is the principal pigment in an, as yet, undescribed member of the Haptophyceae. The pigment array of a species of Olisthodiscus sp. (Plymouth no. 239) differs considerably from that of members of the Xanthophyceae and this species is probably incorrectly classified.
On the occurrence of the scyphomedusan Pelagia noctiluca in the English Channel in 1966
Authors: Russell F. S.
Published: May 2009

The oceanic scyphomedusa Pelagia noctiluca (Forskål) was exceptionally abundant in the coastal waters of Devon and Cornwall in the year 1966. Very young stages were taken only in the months of October, December, January and early February, indicating that the medusa has a restricted breeding season.
The specific identity of the algal symbiont in Convoluta roscoffensis
Authors: Parke Mary , Manton Irene
Published: May 2009

The algal symbiont of Convoluta roscoffensis (Graff) has been studied with the light and electron microscopes both in situ in worms collected from four localities on the coast of Brittany and in various forms of isolates in culture. The same organism has also been obtained from populations of free-living monads collected from sand and water samples adjacent to the Convoluta colonies. Its structure and behaviour in culture are described and illustrated. Platymonas convolutae sp.nov. is a very distinct species with a rough-surfaced theca and a pyrenoid with some new characters not previously recorded in other members of the group. Some new information on scale and theca production from the Golgi system has also been obtained.
Cleaning symbiosis among British fish with special reference toCrenilabrus melops(Labridae)
Authors: Potts G. W.
Published: May 2009

Three new examples of cleaning symbiosis are recorded among the British labridae,Crenilabrus melops, Ctenolabrus rupestrisandCentrolabrus exoletus. The first two have only been seen in aquaria although parasites in the stomach ofC. melopscaught offshore suggests cleaning activity occurs in their natural environment.C. melopshas been observed in the public aquarium taking parasites from the bodies of a number of host fish most commonly the pink bream (Pagellus centrodontus). Most cleaning activity occurs after the lights are first turned on when the hosts remain stationary to be cleaned. At this time the incidence of parasites on their bodies is most obvious. Certain areas of the body are cleaned in preference to others. Details are given of cleaning symbiosis by the pipe fishEnterlurus aequoreus, Syngnathus typhleandS. acus.
Relationships between the sex and degree of maturity of marine crustaceans and their lipid compositions
Authors: Morris R. J.
Published: May 2009

The results of decapod lipid analyses have shown that females and gravid females generally contain high levels of monounsaturated acids and that the eggs of some of these decapods are composed mainly of phospholipid and triglyceride. These are probably present mainly as energy reserves. The percentages of saturated fatty acids are not found to vary with either maturity or sex, whereas the composition of the polyunsaturated acids are affected by both sex and maturity differences. Females are generally much lower in their content of polyunsaturated acids than juveniles and males, the males showing a greater requirement for 20:5 acid compared to the females.

For the euphausiids there is a slightly different picture, the monounsaturated acids appear as the stable fraction and forEuphausia krohniithe juveniles are similar to the females in their content of the polyunsaturated acids.

Neomysis integeris quite unlike the oceanic crustaceans showing a very specific difference in fatty acid composition between the males and females, the juveniles being rather intermediate in composition.
The meiofauna of a flatfish nursery ground
Authors: McIntyre A. D. , Murison D. J.
Published: May 2009

The meiofauna was studied over a 10-year period on a flatfish nursery ground between the high-water mark and a depth of 10 m below low-water springs.

The sediment was well sorted sand, with median diameter from 210 to 279 μ in the intertidal area and 160 to 208 μ in the subtidal. It was composed of medium rounded quartz, with the calcium carbonate content mainly 0·25 to 2·20% by weight. Porosity was 33·39% and the coefficient of permeability ranged from 1·66 to 2·33 × 10–2 cm per sec, indicating good drainage. The sand was usually over 90% water-saturated, and seldom less than 60%. The annual average concentration of particulate organic carbonwas 205 μg/g sand in the intertidal, and 684 μg/g at 5 m depth. Corresponding values for chlorophyll a were 0·75 and 4·50 μg/g.
The N.I.O. combination net (RMT 1 + 8) and further developments of rectangular midwater trawls
Authors: Baker A. de C. , Clarke M. R. , Harris M. J.
Published: May 2009

An opening and closing net system is described in which 1 m2 and 8 m2 rectangular trawls are combined in the same framework; details of the acoustic telemetering and release equipment are included. A brief account of the application of the rectangular system to larger and to more specialized trawls is given.
Sond cruise 1965: Factor and cluster analyses of the plankton results, a general summary
Authors: Angel M. V , Fasham M. J. R
Published: May 2009

1. The data for five planktonic taxa sampled during the SOND cruise (autumn 1965) by R.R.S. ‘Discovery’ in a day and a night series of horizontally towed nets have been analysed by factor and cluster analyses.

2. The factor analyses of hauls showed that there were five biologically distinct zones in the water column between the surface and 1000 m. The zones were more distinct in the day series than in the night.

3. Factor analyses of the individual taxa gave sensible groupings of species and the factor score plots gave ‘averaged’ depth distributions for each group.

4. Cluster analyses of the individual taxa gave results consistent with the factor analyses. Both methods gave groupings which fitted the zonation patterns of the hauls, except for the two zones between 100 and 460 m at night.

5. Only cluster analyses could be carried out on the total data matrices. Although satisfactory interpretation was only possible with the aid of the analyses of the individual taxa, the zonation and species groupings were again largely retained.

6. The zonation of the planktonic taxa is shown to be very similar to that described for nektonic species sampled on the same cruise.

7. The usefulness of these analytical methods is compared with the conclusions of other investigators. It is concluded that the rotation of the matrices to simple structure in the factor analysis gave a marked improvement in the ease of interpretation.

8. For this data, principal component analyses gave very similar results to the full factor analyses.
Further studies on the effects of stress in the adult on the eggs of Mytilus edulis
Authors: Bayne B. L , Holland D. L. , Moore M. N. , Lowe D. M. , Widdows J.
Published: May 2009

Mussels (Mytilus edulis L.) were held under five different experimental conditions for 8 weeks during which measurements of physiological condition, and certain cytological and cytochemical observations, were made. The mussels were then induced to spawn and the numbers of eggs released, the weights of these eggs, and their biochemical composition, were determined. During the experiment new gametes were developed by mussels under all conditions, but there was also a simultaneous regression and resorption of previously formed gametes, particularly in mussels under the greatest stress from high temperature and lack of food. The degree of stress experienced by the animals was measured as the scope for growth, or the energy available for somatic growth and the production of gametes. The distribution and activity of lysosomal enzymes within the Leydig tissue of the mantle suggested that autolysis of these cells occurred, coupled to the mobilization of glycogen for gametogenesis. Mussels under stress produced fewer and smaller eggs, in smaller follicles, than mussels not under stress. The biochemical composition of the eggs (as µg of biochemical component per mg of egg) did not vary consistently with adult condition, but eggs from stressed females had less lipid and protein than eggs from normal females. It is suggested that these relationships between the physiological condition of the adult, gametogenesis, fecundity and the biochemical content of the eggs are important for understanding the impact of the environment on ecological fitness.
The detection of heightened sea-water copper concentrations by the mussel Mytilus edulis
Authors: Davenport John , Manley Andrew
Published: May 2009

An acute toxicity threshold of 0·09–0·10 ppm added copper was determined for specimens of Mytilus edulis from the Menai Strait which were exposed to copper (as CuSO4) in a flowing sea-water system.

Results are presented which show that the closure response of the mussel to added copper is a three-part process. First, a sharp adduction of the shell valves is seen at a mean total copper concentration of only 0·021 ppm, then as the copper concentration rises, ‘testing’ behaviour is observed and finally the shell valves close to isolate the animal from its environment. The complete valve closure mechanism only operates at added copper concentrations of 0·2 ppm or more. The initial behavioural reaction of valve adduction at low concentration occurred at a significantly higher mean total copper concentration (0·16 ppm) in mussels which had been previously acclimated to 0·02 ppm total copper in sea water for 10 days.
Seasonal phytoplankton production in the western English Channel 1964–1974
Authors: Boalch G. T. , Harbour D. S. , Butler E. I.
Published: May 2009

Over a period of 10 years, 1964–74, primary production has been measured at three stations across the western English Channel using the 14C method. Results for carbon fixation, cell counts and mean seasonal production are illustrated. Statistical analyses show that, at two of the three stations, carbon fixation in 1966 was significantly greater than expected and that annual production differs significantly at each of the stations. The variations observed are discussed in relation to other changes recorded in the area during the same period. A deck incubator used for simulated in situ14C experiments is illustrated.
An exposure scale for marine shores in western Norway
Authors: Dalby D. H. , Cowell E. B. , Syratt W. J. , Crothers J. H.
Published: May 2009

A rocky shore exposure scale, intended primarily for use in the Fensfjord area, Western Norway, has been prepared. This scale is developed from an earlier scale devised by Ballantine for Milford Haven, Wales, making use of species abundance curves along the wave exposure gradient. Independent evidence for the validity of the scale is provided by shell shape variation in Nucella lapillus and by the height of the black lichen zone in the supralittoral fringe. The successive steps in the preparation of the scale are outlined, definitions of the exposure grades are given in tabular form for the restricted set of species analysed numerically and descriptions are provided in an extended form to provide a fuller picture for users of the scale. It is believed that the scale will prove applicable to other rocky shores around the North Sea.
Tidal flows around the Channel Islands
Authors: Pingree R. D. , Mardell G. T.
Published: May 2009

The tidal streams in the Channel Islands region are rotary anticlockwise. At spring tides anticlockwise Eulerian residual currents of about 20 cm s–1 develop around Guernsey which indicate that frictional effects exceed those due to the Earth's rotation in the generation of Eulerian residual currents in this shallow-water situation. Lagrangian anticlockwise residual currents can exceed 60 cm s–1 at spring tides, indicating that Stokes-induced currents are larger than the Eulerian residual currents around Guernsey. Remote sensing studies show anticlockwise-directed jets which also indicate an anti-clockwise circulation around the island. A tidal circulation pattern for the Channel Islands area is presented based on anticlockwise gyres around all the major topographic features in the region. This pattern off low is consistent with the formation of the well-known front between Guernsey and Jersey and the residual currents derived from a numerical model.
Hatching in two monogenean parasites from the common dogfish (Scyliorhinus canicula): the polyopisthocotylean gill parasite,Hexabothrium appendiculatumand the microbothriid skin parasite,Leptocotyle minor
Authors: Whittington I. D.
Published: May 2009

The common dogfish (Scyliorhinus caniculaL.) is caught regularly at Plymouth and is parasitized by two monogeneans, the gill-parasitic polyopisthocotyleanHexabothrium appendiculatum(Kuhn, 1829) Nordmann, 1832 and the skin-parasitic microbothriidLeptocotyleminor (Monticelli, 1888) Gallien, 1937. Unsuccessful attempts have been made to hatch the larvae of both of these parasites, e.g. Euzet (1957) and Wiskin (1970) forH. appendiculatum, and Llewellyn (1963) and Kearn (1965) forL. minor. Euzet (1957) and Kearn (1965) found that larvae developed within the eggs ofH. appendiculatumandL. minorrespectively but that these larvae failed to hatch.
A chemoreceptive function for the anterior dorsal fin in rocklings (Gaidropsarus and Ciliata: Teleostei: Gadidae): electrophysiological evidence
Authors: Peters R. C. , Van Steenderen G. W. , Kotrschal K.
Published: May 2009

Gross activity recordings from the recurrent facial nerve were made in unrestrained specimens ofGaidropsarusandCiliataby means of implanted silver-wire electrodes. Responses to tactile stimuli could be evoked almost anywhere on the skin. Application of the contents of the urinary bladders of other rocklings, water in which other rocklings were kept, and (diluted) human saliva to the anterior dorsal fin evoked strong responses. Responses to more elementary chemical stimuli like amino acids, salts, aldehydes, and acids, were much weaker or absent. The results favour a special chemoreceptive function of the vibratile anterior dorsal fin.
Geographic variation in allele frequencies at three loci in Chlamys opercularis from Norway to the Brittany coast
Authors: Beaumont A. R.
Published: May 2009

Geographic variation of allele frequencies at four loci in Chlamys opercularis was investigated using electrophoresis on polyacrylamide gels. Large differences were observed between populations at a protein locus, while some small but significant variations occurred at the phosphoglucomutase-2 and octopine dehydrogenase loci. The leucine aminopeptidase locus appeared monomorphic. On the basis of mean genetic identities derived from three loci in nine populations and hydrographic data on coastal current systems, it is proposed that there are at least four relatively genetically isolated populations of this scallop around the British Isles, namely (1) North and West Scottish coast, (2) the Irish Sea, (3) the Celtic Sea (Brittany coast) and (4) the English Channel. It is argued that both random genetic drift and selection may play a significant part in the establishment and retention of large allele frequency differences between isolated populations of this species.
On growth of the octopusEledone cirrhosa
Authors: Boyle P. R. , Knobloch Daniela
Published: May 2009

The growth of the octopusEledone cirrhosahas been studied in a population from the North Sea off Aberdeen. Data are presented for the growth of individuals isolated in aquarium conditions; the growth of size classes in thefieldpopulation; and preliminary information on the growth relationships of gonad, somatic, cardiac and brain components of the body.

At 15 °CEledone cirrhosais capable of growing from 10 to 1000 g in 270 days. From octopuses which feed readily in captivity, weight specific growth rates of up to about 3–5 % day-1for animals of 100 g body weight are recorded, falling to a maximum of about 1–5 % day-1at body sizes above 500 g. Females stop growing when sexually mature, but in the sample captured they were consistently larger than males, a feature which may account for the 7:1 bias towards the incidence of females. On a wet-weight basis, the mean food incorporation into growth is 37 % of the food ingested, which is 49% of the gross weight of crabs killed. Field data for 1978/79 suggest that animals recruited to the population at the beginning of the year grew steadily until December, overwintered without growing, then grew rapidly for several months in the subsequent year before disappearing from the samples. The estimated average age of those animals and by implication, the life span, is 20 months.
A series of North Sea benthos surveys with trawl and headline camera
Authors: Dyer M. F. , Fry W. G. , Fry P. D. , Cranmer G. J.
Published: May 2009

During a series of North Sea demersal fish surveys, a headline camera was used to photograph the sea-bed at intervals of 1 min, throughout the duration of 60 min trawls. A successful series of underwater photographs were obtained at 119 stations throughout the North Sea. In addition, the benthos caught at 317 stations was recorded.

A total ofca. 30 species could be identified on the underwater photographs, and of these ten species were sufficiently common or locally abundant for estimates of local population densities to be made. Distributions throughout the North Sea based on specimens trawled and specimens photographed were compared.
Seasonal observations on moulting and maturation in Stage V copepodites of Calanus finmarchicus from the Firth of Clyde
Authors: Grigg H. , Bardwell S. J.
Published: May 2009

Stage V copepodites of Calarms finmarchicus collected from the Firth of Clyde during April–August 1978 and October 1979–January 1980 moulted to adults in the laboratory. The interval between capture and ecdysis was longer on average and less variable during the months July–November (when overwintering stocks build up in the Firth) than April–June. Overwintering Stage V copepodites moulted earlier in the laboratory than in the sea; this is not associated with differences in environmental factors known to affect developmental rate and may have been induced by stress associated with capture or handling. A similar induction of moulting is not evident in spring and summer generations.
Long-term population trends of the benthic macrofauna in the offshore mud of the Northumberland coast
Authors: Buchanan J. B. , Kingston P. F. , Sheader M.
Published: May 2009

The changes in the number of species, the number of individuals and the production of a benthic mud association have been studied for a 4-year period. The numbers of species and the total estimated production appear to have remained substantially stable, but the number of individuals has more than doubled over the period. When considering the high ranking producers, it is clear that not all of these have contributed to the general rise in numbers of individuals. Two species, Ammotrypane aulogaster and Abra nitida have shown an abrupt fall in population numbers and biomass. At the beginning of the investigation in 1971, these species figured importantly in the production estimates with 20 and 6% respectively of the total production. After 1971, both were effectively eliminated from the production of the association.
The burrowing behaviour of newly-settled lobsters, Homarus vulgaris (Crustacea-Decapoda)
Authors: Berrill M.
Published: May 2009

Young Homarus vulgaris were reared in the laboratory up to stage V. All settled during stage IV by burrowing under stones placed on a sand or mud substrate. Half of the 100 animals studied burrowed within 6 days of reaching stage IV and did not subsequently vacate the burrow. The burrows were made with two openings on opposite sides of the stone which, in the case of the sand burrows, served as a roof. The burrows were made by the same methods as previously described for young and adult H. americanus
The nutrient status of algal cells in continuous culture
Authors: Droop M. R.
Published: May 2009

Chemostats were used to study the relation between growth rate, the rate of nutrient uptake and internal and external nutrient concentrations of two nutrients simultaneously. (Monochrysis lutheri: phosphorus and vitamin B12.)

Growth rate and internal concentrations of both limiting and excess nutrients are related by simple rectangular hyperbolas.

Control was shown to follow a threshold rather than multiplicative pattern; that is, non-limiting nutrients exert no control at all over the pattern of growth. The limiting nutrient was the one that showed the smallest cell quota: subsistence quota ratio.

Monochrysispopulations exhibited two modes of growth. ‘Slow adapted cells’ differed from ‘fast adapted cells’ in the values of the constants for the above relation.

Uptake of both limiting and non-limiting nutrients was found to be controlled by internal as well as external substrate concentrations. There was thus a limit to luxury consumption of one nutrient when growth was limited by another.

The mathematical model formulated for growth in a chemostat (equations (23)–(29)) allowed prediction of external and internal substrate concentrations and rates of uptake of two nutrients and of biomass, given only the input concentrations of the two nutrients and the dilution rate. This model should apply equally well to growth in batch cultures; its possible application to natural populations was discussed.
Structure, growth and distribution of the squidBathothauma lyrommaChun
Authors: Aldred R. G.
Published: May 2009

Eighty-seven specimens ofBathothauma lyrommafrom the ‘Discovery’ collections have provided new information on this unusual species. The size range represented is sufficient to trace the development from small larvae to near adult. Information on sexual development is also given. Twenty-nine specimens from opening-closing nets show thatBathothaumaoccupies the depth range 100–1250 m, with smaller specimens living at shallower depths than the larger ones.
Notes on the Herring, Long-line, and Pilchard Fisheries of Plymouth during the Winter 1889–90
Authors: Roach William
Published: May 2009

[The herring fishery is carried on at Plymouth during the winter months, when the adult herring seek the inshore waters for spawning. Besides these, however, the so-called “harbour herring” are taken in the summer and autumn; these appear to be the produce of the last spawning season, i.e. six months to a year old. Mr. Cunningham has shown me specimens taken in the Cattewater in May, 1889, which vary from 3½ to 5 inches in length. Those which are at present being brought to the Laboratory (September, 1890) are 9 or 10 inches in length, but their reproductive organs are still at an extremely early stage of development. Further observations on these harbour herring are much needed, and are being gradually made.
Notes on the Hydroids of Plymouth
Authors: Bourne Gilbert C.
Published: May 2009

During the two years which I spent at Plymouth I collected a number of notes on the occurrence and distribution of the Hydroidea of the district, with the intention of giving a full account of the representatives of the group in the Plymouth area. My unexpected departure has prevented my carrying out this intention, but it has seemed to me worth while to publish my notes, fragmentary as they are, in the hope that they may be useful to my successors, and particularly because the list of the Hydroidea given in Part ii of the first series of this Journal is very imperfect. The list of species now given is incomplete, and had I had the time to search more closely for the inconspicuous and deep-water forms I should have been able to add largely to it. One species, which I only succeeded in obtaining twice, appears to be new to science.
Observations on the Distribution of Plankton Animal Indicators made on Col. E. T. Peel's yacht “St. George” in the Mouth of the English Channel, July, 1935
Authors: Russell F. S.
Published: May 2009

In July, 1935, a cruise was made in Col. E. T. Peel's yacht St. George to study the distribution of certain plankton animal indicators in the mouth of the English Channel.

Three bodies of water were clearly shown by their plankton content:

(1) water characterised by the presence of Sagitta elegans, Clione, Themisto graclipes, Euphausian larvæ, Stephanomia and Aglantha; (2) Biscay water, on this occasion characterised by Noctiluca and a paucity of zooplankton; and (3) Channel water characterised by the presence of Sagitta setosa and absence of other indicators.

It has been shown that the study of certain plankton animals should prove of help in understanding the hydrography of the Channel mouth region.
On the Hydroid ofLaodicea undulata(Forbes and Goodsir)
Authors: Russell F. S.
Published: May 2009

In1866 Hincks described the hydroidCuspidella humilis: later, in hisHistory of the British Hydroid Zoophytes(1868, p. 210), he added two further species to the genus,C. grandisandC. costata. At that time the reproduction of Cuspidella was not known.

Metschnikoff (1886, p. 83 and Taf. V, Fig. 1) described the development of the eggs ofLaodicea cruciataand reared them to the hydroid stage. These had sessile hydranths and elongated polyps with ten slender tentacles, long and short alternating. Metschnikoff remarked on their similarity to Cuspidella.
On a New Species of Medusa, Eucheilota hartlaubi n. sp.
Authors: Russell F. S.
Published: May 2009

In November, 1933, a few medusæ were found in the plankton off Plymouth belonging to the genus Eucheilota. The only species of this genus so far recorded from northern European waters is Eucheilota maculata Hartlaub. The medusæ differed in several respects from this species, one constant difference being that the marginal vesicles never contained more than one concretion. In this respect they resembled E. duodecimalis A. Agassiz, but differed in having a much greater number of tentacles and marginal vesicles.

In October, 1934, the medusæ appeared again in considerable numbers and it was now possible to establish the constant features of the species which has apparently never been described before, except possibly for a drawing given by Hartlaub without a description (see below).
Note on the Ubiquitous Cercaria from Littorina rudis, L. obtusata and L. littorea
Authors: Rees W. J.
Published: May 2009

This cercaria was found to be very common in specimens of Littorina rudis (Maton) and L. obtusata (Linné) collected at Aberystwyth during February and March, 1935, occurring in twenty out of fifty specimens of L. rudis and in four out of forty specimens of L. obtusata. It was, on the other hand, very rare in L. littorea, only two infested individuals being found out of a total of two thousand molluscs examined. In all three species of mollusc the parts of the digestive gland most heavily infested appeared white or creamy-white in colour.

The form described here appears to be almost identical with Cercaria ubiquitoides recorded by Stunkard (1932) from L. littorea and L. rudis occurring on the coast of Brittany. Certain differences are found between my specimens and those of Stunkard. It is difficult to determine whether these differences are individual or specific because there are so few larval characters in cercariæ of the Ubiquita group which can be used for separating species. The problem is rendered more difficult by the close resemblance of the adult trematodes (species of the genus Spelotrema).