bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlates of Growth and Feeding in Laboratory-MaintainedEledone Cirrhosa(Cephalopoda: Octopoda)
Authors: Houlihan D.F. , Kelly K. , Boyle P.R.
Published: May 2009

Octopuses (Eledone cirrhosa(Octopoda: Cephalopoda)) held in an aquarium were subjected to varying conditions of feeding and starvation to evaluate putative indices of feeding and growth. Specific growth rate (%d−1) was linearly related to feeding rate (% of the body mass d−1) in animals with a mean body mass of 250 g at 15°C. Maximum growth rates varied between > 2% d−1(body weights < 300 g) to < 1% d−1(body weights ≤ 900 g) but specific growth rates were not related to body weight. Growth rates became negative (weight loss) after one week without food.

The digestive gland index (DGI) was significantly correlated with short and long-term feeding and specific growth rates, and with body weight. Muscle RNA concentration was linearly correlated with growth rate during the previous 1–3 weeks but not with feeding rate. RNA:protein ratios were not different between mid-arm and mantle sample sites but arm tip values were significantly higher. RNA:protein ratio was related to body weight only in feeding animals. It is concluded that DGI is an index of feeding rate and that RNA:protein ratio can be used as an index of recent (~ 4 weeks) growth rate.
Predicting Calanus Finmarchicus Abundance from a Climatic Signal
Authors: Planque B. , Reid P.C.
Published: May 2009

Long-term fluctuations in the abundance of the copepod Calanus finmarchicus in the north-east Atlantic are compared to the North Atlantic Oscillation index over the period 1958–1995. The strong climate-plankton link previously observed is confirmed and a simple linear regression model is constructed with the aim of predicting the abundance of the species several months in advance. For the years 1993–1995 the model predictions are in accordance with observations, but not in 1996 when the abundance of C. finmarchicus fell, although the climatic scenario indicated that a sharp increase should have occurred. The potential causes of this discrepancy are discussed.
The Cephalopod by-Catch of Deep-Water Trawling on the Hebrides Slope
Authors: Boyle P.R. , Collins M.A. , Williamson G.R.
Published: May 2009

Deep-water trawling for fish species on the shelf slope off Scotland results in a by-catch of rare cephalopod species. The cirrate octopus Opisthoteuthis grimaldii is normally present below 800 m; at least one other species of cirrate and five species of incirrate octopus are found; significant extensions of range and depth are recorded. An incidental catch of the ommastrephid squid, Todarodes sagittatus, included a fully mature specimen and is indicative of its probable breeding locations. The results highlight the many taxonomic and systematic uncertainties surrounding the rarer cephalopod forms, and emphasize the utility of the fishing by-catch.
Chaunoteuthis Mollis: Re-Examination of a Mediterranean Specimen and its Identity with Onychoteuthis Banksii (Cephalopoda: Onychoteuthidae)
Authors: Bello Giambattista
Published: May 2009

A specimen of Chaunoteuthis mollis (Cephalopoda: Onychoteuthidae), a mature mated female, from the Straits of Messina was examined. Measurements and indices were compared with those of Onychoteuthis banksii reported by previous authors. The differences found were attributed to the degeneration of the C. mollis specimen, due to sexual maturation. Two subocular (one under each eye) and two visceral photophores, similar to those of O. banksii, were present in the C. mollis specimen. The size of the posterior visceral photophore of C. mollis fit the regression line correlating posterior photophore diameter to mantle length in O. banksii. These results corroborate the hypothesis, put forward by other authors, that C. mollis represents the mature female of O. banksii.
A Note on Manganese in Marine Plankton
Authors: Cooper L. H. N.
Published: May 2009

Although to many organisms manganese is known to be of great importance (Berkeley, 1922; Brenchley, 1927; Hopkins, 1930) its part in the economy of the sea is unknown. Some attempts were therefore made in 1934 to estimate the manganese in marine plankton using the residues from the determinations of phosphorus (Cooper, 1934; Harvey et alia, 1935). The residues from the triplicate digests from each cruise were combined and concentrated from about 200 to 70 ml. The concentrates were then examined quantitatively for manganese by the periodate method of Willard and Greathouse as described by Yoe (1928). In all cases but one the concentration of manganese was less than could be detected with certainty (Table I). In the absence of confirmatory data the figure of 5γ per litre of the diatom catch of May 15th must be regarded as suspect and attributable to chance contamination. Thus in these catches at L4 (5 miles off shore) during the spring outburst in 1934 manganese amounted to less than three parts per million million parts of water filtered, equivalent to one-thousandth or less of the phosphorus content.
Hemiurus communis in Acartia
Authors: Lebour Marie V.
Published: May 2009

In tow-nettings from Plymouth Sound, June 20th, 1935, Acartia clausi were abundant and inside these copepods, emerging from them and free in the water were very large numbers of larval trematodes, easily identified as Hemiurus communis. This is not a new record, for this parasite has already been described from the same Copepod in Plymouth waters in May and February (Lebour, 1923), but it has always been rare. In no case have more than two parasitised specimens been seen from these regions, and no seasonal appearance has been noticed. Much has been written about these trematodes which grow in the bodies of copepods until they are of such a large size that they inevitably kill the host and just before it dies emerge from between the joints, if not eaten before this with the copepod, but I think this is the first time that they have been recorded in any quantity at one time. Since my first communication Steuer (1928) has written about the geographical distribution of these hemiurids parasitising copepods and is of the opinion that all those in Northern seas belong to Hemiurus lühei and H. communis. In the Mediterranean the hemiurids known have not yet been found in copepods but usually in Sagitta, or are found living freely in the sea and these probably belong to H. rugosus which lives in the adult state in the pilchard.
Notes on the Ostracod fauna of Plymouth
Authors: Elofson Olof
Published: May 2009

On June 15 and 20, 1938 Mr W. J. Rees of the laboratory of the Marine Biological Association, Plymouth, collected some mud samples at Mewstone and Rame Mud near Plymouth for Mr J. Hult, Uppsala. By kind permission of the director of the laboratory and of Mr Hult I have examined the Ostracoda contained in the samples.
On some Medusae of the genera Podocoryne and Phialopsis
Authors: Russell F. S.
Published: May 2009

It is generally assumed that there are two species of the genus Podocoryne, in northern waters, in which free swimming medusae are produced, P. carnea M. Sars and P. areolata Alder. Of these, the hydroid of P. carnea is known for certain, and that of P. areolata is thought to be the hydroid described by Alder under that specific name. Recently, I have found that there are two more species of Podocoryne medusae in British waters, P. hartlaubi Neppi & Stiasny and P. minima (Trinci). There are, therefore, two more hydroids to be found and it will be shown that the identity of the hydroid of the so-called medusa P. areolata must remain in doubt.
The breeding of oysters in tanks
Authors: Hughes Edward
Published: May 2009

The following paper is a record of certain work which was carried out at the River Yealm during 1939. No claim is made for original work, but it may serve some useful purpose as a record.

Oysters from die River Yealm have been used in most of the experimental work carried out on the breeding of oysters at Conway. But, for some unknown reason, there has never been any relevant growth of native oysters in the Yealm. The beds are stocked every year with three-year-old Brittany oysters. These oysters thrive well in the Yealm and are of considerable commercial value.

Certain old tanks at the Fisheries have been altered and repaired for the purpose of cleansing prior to their despatch to die London market. These tanks are in use for this purpose approximately from the end of August until die beginning of May. Therefore they are unused for approximately four mondis during die breeding season.
Rearing animals in captivity for the study of trematode life histories. II
Authors: Rothschild Miriam
Published: May 2009

The advantage of using laboratory-reared animals in the elucidation of trematode life histories is now generally recognized (Palombi, 1938; Stunkard, 1938, etc.). Further researches seem to emphasize this point. No matter how carefully controls are examined and no matter how precise is the morphological comparison between cercaria, metacercaria and adult fluke, the fact that the intermediate and final hosts have been exposed to previous infection in the wild—particularly by closely related species of worms—immediately detracts from the value of the experiments.
An Account ofMarinogammarus(Schellenberg) gen.nov. [Amphipoda], with a description of a new species,M. pirloti
Authors: Sexton E. W. , Spooner G. M.
Published: May 2009

The genusGammarus, instituted by Fabricius in 1775, has come to include a large number of species—so many and so varied, in fact, that the necessity for a revision of the genus is well recognized. An extensive examination of the taxonomic literature has inevitably led to the conclusion that several more or less well-defined groups of species can be recognized among the total assemblage, and that some of these at least should be separated off as distinct genera.
Porphyrin pigments of some deep-sea medusae
Authors: Bonnett Raymond , Head Erica J. , Herring Peter J.
Published: May 2009

Many marine animals that live at depths greater than about 500 m are deeply coloured (generally red, brown, black or purple) even though there is little or no down-welling light in these regions (Clarke & Denton, 1962). The nature and function of many of these pigments are obscure. Partly, no doubt, because of the difficulty of provenance, there have been very few chemical and biochemical investigations on such pigments (see Crozier (1974) for a review of pigments in fishes). We report here an investigation of the pigments of meso- and bathypelagic medusae. The work was initiated following preliminary identification of protoporphyrin in Atolla wyvillei and Periphylla periphylla (Herring 1972): the present work confirms and considerably extends these observations (Head, 1976, M.Phil. Thesis, University of London).
Mode of life and behaviour ofMontacuta phascolionis, a bivalve commensal with the sipunculanPhascolion strombi
Authors: Gage J. D.
Published: May 2009

The tiny bivalve molluscMontacuta (Tellimya) phascolionis(Dautzenberg & Fischer) belongs to the family Montacutidae, which is usually classified in a grouping of a superfamily rank, the Galeommatacea (= Erycinacea, Leptonacea or Leptonoidea) and includes many small and rather obscure species that are found associated with a wide variety of usually burrowing marine invertebrates (see Boss, 1965).M. phascolionisrecently has been referred to the genusTellimya(Chavan, 1960, 1969; Bowden & Heppell, 1968) or removed from the Montacutidae altogether and put into a new monospecific genus,Phascoliophila(Nordsieck, 1969). It is clear that a comprehensive revision of the Montacutidae is badly needed in order to establish the correct position of the present species within the family. However, the present author feels it justified in the interim to follow Ponder (1968) in recognizingTellimyaas a subgenus ofMontacutathat includes the speciesphascolionis.
Baroclinic eddies bordering the celtic sea in late summer
Authors: Pingree R. D.
Published: May 2009

Infra-red images of sea surface temperature indicate that shelf sea frontal regions around the British Isles are characterized by cyclonic eddies with typical wavelengths between 20 and 40 km and growth time scales in the order of a day. A similar analysis for the shelf-break region of the Celtic Sea based on the interpretation of structures observed in infra-red sattllite images and a survey at sea shows that this region is also characterized by eddies. These eddies are usually associated with a general lowering of sea surface temperature that occurs over the shelf-break region in late summer. In this paper, observed eddy scales are compared with estimates based on theory originally developed for large-scale (3000 km wavelength) atmospheric eddies and the role of eddies in cross-frontal exchange is examined in more detail.
The identification of faunal gradients and associations of meiobenthic copepods by multivariate analyses
Authors: Moore Colin G.
Published: May 2009

Amongst Gunnar Thorson's concluding remarks in his review on marine-bottom communities (Thorson, 1957) he noted that a sequel to the study of macrobenthic parallel communities should be a detailed analysis of the meiobenthos and microbenthos within these communities, adding that the work by Remane and his collaborators in shallow water and on beaches in Kiel Bay indicated that the meiobenthos is likely to show a pronounced uniformity within these communities. Many qualitative sub tidal meiobenthic surveys have followed (e.g. Gerlach (1958) for the nematodes; Por (1964) for the copepods) but it is only very recently that wide-scale quantitative work of the type pioneered by Petersen (1913) for the macrofauna has been applied to the meiofauna (Drzycimski (1969) and Soyer (1970) for the copepods; Ward (1973) and Tietjen (1977) for the nematodes). Around the coasts of Great Britain the only subtidal meiobenthic survey is that by Ward (1973,1975) of the nematode genera of Liverpool Bay, although quantitative faunal and environmental data are available for a number of sublittoral stations (Mclntyre (1964) and Wells (1965) for muddy deposits in Loch Nevis and the Fladen North Sea ground; Warwick & Buchanan (1970) for fine sand and silt deposits off the Northumberland coast; and Mclntyre & Murison (1973) for shallow fine sand in Firemore Bay).
Structure and ultrastructure of muscles in the priapulid Halicryptus spinulosus: functional and phylogenetic remarks
Authors: Carnevali M. Daniela Candia , Ferraguti Marco
Published: May 2009

The Priapulida phylum is a rather homogeneous small group of marine invertebrates, living buried in sand and mud of cold waters. These worms present great difficulty in determining their systematic position: in the first instance, Priapulida were considered to be pseudo-coelomates, and classified among the Aschelminthes (Hyman, 1951). How ever, later studies (Shapeero, 1961) have pointed out that the body cavity is actually a coelom, and not a pseudo-coelom. Consequently it seems improper to include Priapulida among Aschelminthes, even if their real position still remains undefined. Today most authors tend to consider priapulids as the last relicts of an originally larger group, forming a separate phylum (van der Land, 1970). We can assume some connexions with other minor Protostoma, but not to an extent sufficient to consider a possible group affinity (Grassé, 1959). The general anatomical organization of a priapulid is now well known (van der Land, 1970), but the only detailed microscopical descriptions are those of the genus Priapulus (Mattisson, Nilsson & Fange, 1974) and the genus Tubilucus (Kirsteuer & van der Land, 1970). We have only incomplete data and summary descriptions concerning the other existing genus. Ultrastructural researches are even more scarce; electron microscope studies could clarify the submicroscopical organization of these animals and allow comparisons with other groups. Afzelius & Ferraguti (1978), for instance, have shown that the sperm of Priapulus caudatus present a very primitive pattern, resembling that of the sperm of many other marine invertebrates with external fertilization. The muscular systems are also useful for researches of phylogenetic correlations: it is, in fact, possible to correlate the ultrastructural organization of the muscles with the systematic position of their respective animals (Hanson & Loewy, 1960; Lanzavecchia, 1977). For the muscular systems of priapulids the only pertinent data are those of Mattisson et al. (1974) on Priapulus caudatus. A detailed analysis of the muscles of other species seems therefore necessary to set up a general picture of the situation in Priapulida. In these animals the muscles are organized to form a typical hydraulic system. The hydraulic systems present one of the most topical problems, from both the morphological and functional points of view (Hammond, 1970; Chapman, 1975).
Mediomastus fragilis Rasmussen (Polychaeta: Capitellidae), a species newly recorded from British Waters
Authors: Warren Lynda M.
Published: May 2009

Mediomastus Hartman (1944) is a genus of capitellid polychaetes with ten species of which only M. fragilis, described from the Danish Isefjord by Rasmussen (1973), has been found in European waters. In 1963 Clark & Dawson recorded the presence of an incomplete specimen of a capitellid from the west coast of Scotland and tentatively assigned it to Mediomastus. However, collections made by Dr P. E. Gibbs (Marine Biological Association, U.K.) in the Shetlands during April 1974 revealed a large number of capitellids subsequently identified as fragilis. More recently M. fragilis. has been recorded in large numbers during sampling programmes carried out by Dr A. Walker (Marine Science Labs., University College of N. Wales, Menai Bridge) in Dublin Bay and Liverpool Bay, and Mr J. Hunter (Highland River Purification Board, Dingwall, Ross-shire) has collected specimens from Dornoch Firth and Cromarty Firth, Easter Ross.
Cytochemical studies of acid phosphatase in etching cells of boring sponges
Authors: Pomponi Shirley A.
Published: May 2009

Etching cells of boring sponges effect the excavation of calcium carbonate substrates by partial chemical dissolution. They are characterized by the same features found in active osteoclasts, the cells which effect bone resorption in vertebrates. These similarities include a region of numerous cell processes and a system of cytoplasmic bodies, vesicles, and vacuoles which are structurally connected with a tubular system and with extra-cellular channels (Pomponi, 1979). An extensive rough endoplasmic reticulum, Golgi complex, and lysosomes indicate that a lysosomal system is operative (Pomponi, 1979). The lysosomal system has been implicated as the primary mechanism in the destruction of calcined tissue by osteoclasts (Vaes, 1968; Hancox, 1972, Gothlin & Ericsson, 1976; Holtrop & King, 1977). Vaes (1968) proposed that acid hydrolases of lysosomes are active in the resorption of the organic matrix of bone.
Long-term observations on the intertidal lichenLichina pygmaeaAg.
Authors: Boney A. D.
Published: May 2009

In a previous paper (Boney, 1961) an account was given of some experiments and observations carried out on the lichenLichina pygmaeaAg. growing above M.T.L. on the east-facing side of the Church Reef (= Blackstone Rocks) at Wembury, South Devon. The experiments were initiated in the summer and autumn of 1952 and 1953. Experimental sites were prepared by removing rectangular areas of lichen growth from within larger mats, and by clearing away half the lichen growth from small circular patches of about 10 cm diameter. Subsequent observations were re-ported after intervals of 4–7 years (to July 1960). The more obvious results of the clearances made within lichen mats were the failures of the surrounding plant growths to recolonize the cleared areas after 4 years and the disappearance of lichen cover from the borders of one of the cleared areas. The presence ofFucus spiralisL. plants growing in mats near cleared areas indicated that the damage inflicted on the lichen growths had set in train an irreversible series of events. With small circular patches of about 10 cm diameter cleared of half their lichen cover no changes were observable after seven years in both the cleared areas and in the remaining lichen growth. Since 1963 my visits to the experimental sites have been somewhat sporadic. The present note describes observations made up to July 1976, 24 years after initiation of the first clearance experiments.
A non-fatal method of sex determination for patellacean gastropods
Authors: Wright W. G. , lindberg D. R.
Published: May 2009

During our studies of the reproductive cycles in limpets (family Acmaeidae) we have been confronted by the lack of a method to determine sex without killing the animals. Previous studies have relied upon dissection or histological sectioning to determine sex. This note describes a technique which allows the determination of sex in patellacean limpets without killing the animal.

The tools needed are a syringe (1 cc) with a hypodermic needle (we have found that a 26 gauge, 16 mm needle works well with specimens larger than 10 mm in length), and a glass microscope slide. After removing the limpet from the substratum the shell is held with the aperture down. As the animal extends its foot downward it exposes and stretches the sides of the body wall. When the posterior portion of the body wall is fully exposed the needle is inserted approximately one third of the way up the body wall towards the shell attachment muscle. The orientation of the needle should be in line with the plane of the aperture. Penetration of the gonad can be felt by a ‘breaking through’ or sudden decrease in resistance to the progress of the needle. Care should be taken to avoid penetrating further than necessary because other organs can be easily damaged. Drawing the sample requires more force and time (approximately 10 s) than one would expect. When withdrawing the needle constant tension on the syringe plunger is necessary to keep the sample in the needle. The contents of the needle are then emptied on to the glass slide.
The influence of season and barnacles on the algal colonization of Patella vulgata exclusion areas
Authors: Hawkins S. J.
Published: May 2009

Patella vulgata were excluded from barnacle dominated areas at Port St Mary, Isle of Man by wire fences attached to the rock in September 1977, December 1977, April 1978 and July 1978. The sequences of algal colonization of these exclusion areas differed markedly with season: in autumn diatoms were followed directly by Fucus, in winter and spring diatoms were followed by green algae and then Fucus, and in late summer Fucus sporelings arose directly on the barnacles. There was no evidence that the initial stages were necessary for the subsequent recruitment of Fucus.
Cylinder-scales in marine flagellates from the genus Chrysochromulina (Haptophyceae = Prymnesiophyceae) with a description of C. pachycylindra sp. nov.
Authors: Manton I. , Oates K. , Course P. A.
Published: May 2009

A new species of Chrysochromulina Lackey with exceptionally long cylinder-scales distributed evenly over the cell is described and illustrated with electron micrographs of shadowcast whole mounts of wild material from the Galapagos Islands, South Africa and the English Channel. In all cells, the cylinder-scales are underlain and outnumbered by highly characteristic plate-scales, each with a conspicuous infra-marginal ridge on the distal face. Some consistent dimensional and other differences between periplasts from Africa and the Galapagos Islands are noted, with the British equivalents approximating more closely to the former though with minor differences from both. The observations are interpreted in a preliminary way, but further comment including comparisons with other taxa will follow.
The kinetics of growth control in a colonial hydroid
Authors: Stebbing A. R. D.
Published: May 2009

It is suggested that the cumulative view of growth in which some index of biomass is plotted against time tends to obscure temporal variations in the growth process that might provide evidence of how it is controlled. Experiments with the colonial hydroidCampanularia flexuosashow that the action of a growth control mechanism can be demonstrated by considering changes in specific rates of growth determined at frequent intervals in time. However, it is also necessary to disturb the growth process slightly in order to initiate the action of the control mechanism, and having done so, to isolate the effect of the disturbance on growth and thus the action of the control mechanism. This is done by expressing the specific growth rate of organisms whose growth is disturbed as a percentage of that of control organisms of the same age.
Body cooling as a supplement to anaesthesia for fishes
Authors: Williamson R. M. , Roberts B. L.
Published: May 2009

Whole body cooling of dogfish initially anaesthetized with MS 222 produced total immobility and permitted prolonged surgical procedures. Additional anaesthesia was not required, and on rewarming recovery was rapid.

Electromyographic recordings of jaw-closing and fin-elevating reflexes of the dogfish during body cooling indicated that processes within the central nervous system were being blocked and that the effect was most pronounced on polysynaptic reflexes.
The family Paraonidae (Polychaeta) in british waters: a new species and new records with a key to species
Authors: Hartley J. P.
Published: May 2009

Aricidea laubieri sp.nov. and six other species of the Paraonidae new to the British Isles were found during benthic surveys in the Celtic and North Seas. These increase the number of British representatives of the family to 15. New records of a further seven species are given, which in several cases extend the known geographical or bathymetric range. The identity of some previous records attributed to Aricidea Jeffreysii (McIntosh, 1879) and to Aricidea suecica Eliason, 1920, is discussed. A dichotomous key to British species is presented.
Gametogenic cycle and population structure of Nereis (Hediste) diversicolor and Nereis (Nereis) pelagica from north-east England
Authors: Olive P. J. W. , Garwood P. R. G.
Published: May 2009

The development of the oocytes of Nereis (Hediste) diversicolor and Nereis (Nereis) pelagica takes up to 18 months from their first appearance in the coelom to maturity, and in the natural conditions experienced by the population studied in north-east England the females are in their second year before the oocytes begin to appear. The duration of spermatogenesis is less than that of oogenesis, taking up to 6 months for completion. This information permits a more rigorous interpretation of the size frequency data which have been obtained from a biometrical study of the jaws. In the populations of both species the majority of individuals seem to reach maturity when 3 years old.
Five species of polychaete new to British waters
Authors: Hartley J. P.
Published: May 2009

In the course of benthic surveys carried out around the U.K. by the Oil Pollution Research Unit, a number of species of polychaete not previously recorded from British waters were found. A new species of Aricidea and six other species of the Paraonidae new for Britain have been described by Hartley (1981), and this note records a further five species taken either in the Firth of Forth (56° 19′ N, 3° 34.8′ W, 2–5–5 m depth, fine sand) or in the Forties oilfield (57° 44.0′ N, o° 54°0′ E, 100–130 m depth, fine to muddy sand) with 0.1 m2 Van Veen/Day grabs in September 1979 and June 1978 respectively. The sieve mesh used was 0.1 mm diameter.
The mechanics of the clupeid acoustico-lateralis system: frequency responses
Authors: Denton E. J. , Gray J. A. B. , Blaxter J. H. S.
Published: May 2009

The mechanical responses of several structures in the auditory and lateral-line systems of the sprat Sprattus sprattus(L.) and the herringClupea harengus L. to oscillatory pressure changes have been observed over a range of frequencies from 0·014 t0 2600 Hz. The pressures required to give constant responses of the bulla membrane, and the lateral recess membrane varied relatively little between 0·014 and 1000 Hz; above 1000 Hz the sensitivity fell quickly as frequency increased.
Some biochemical and physiological aspects of growth and gametogenesis inCrassostrea gigasandOstrea edulisgrown at sustained elevated temperatures
Authors: Mann Roger
Published: May 2009

Crassostrea gigas (Thunberg) andOstrea edulis L.were grown at sustained temperatures of 12°, 15°, 18° and 21°C for a period of 19 weeks. Regular assays of weight specific ammonia excretion rate were made, following which animals were sacrificed for estimation of dry meat weight, dry shell weight, biochemical composition (percentage carbon, nitrogen, carbohydrate, ash) and gonadal development (histological assessment). Crassostrea gigas grew from an intial live weight of 5·2 g to values of 23·5, 28·2, 34·6 and 38·7 g at 120, 150, 180 and 21 °C respectively.
Hinge morphogenesis in the shells of larval and early post-larval mussels (Mytilus edulis L. and Modiolus modiolus (L.))
Authors: Lutz Richard A. , Hidu Herbert
Published: May 2009

Scanning electron and optical microscopic examination of the hinge apparatus and primary ligament pit of two Recent mytilids (Mytilus edulis and Modiolus modiolus) revealed a similar sequence of ontogenetic changes in both species from the prodissoconch I stage through metamorphosis. Hinge-line dentition was absent at the prodissoconch I stage. Provinculum length and complexity increased throughout larval development with progressive lateral thickening characteristic of the family Mytilidae.
The ultrastructure and taxonomy ofRhizochromulina marinagen. et sp.nov., an amoeboid marine chrysophyte
Authors: Hibberd David J. , Chretiennot-Dinet Marie-Josèphe
Published: May 2009

A new member of the Chrysophyceae,Rhizochromulina marina gen. et sp.nov. is described by means of both light and electron microscopy of cultured material. Vegetative cells are non-flagellate and amoeboid with many fine beaded filipodia and a single golden-brown chloroplast. Zoospores are fusiform in shape and genuinely uniflagellate with no emergent vestigial second flagellum. They appear to possess the most reduced and phylogenetically advanced type of motile cell organization yet found in the Chrysophyceae.
Further Observations on choanoflagellates in the genus Calliacantha Leadbeater, with Special reference to C. multispina sp.nov. from South Africa and Britain
Authors: Manton I. , Oates K.
Published: May 2009

A species believed to be more primitive than C. natans (Grontved) (type species of Calliacantha Leadbeater) has been described and illustrated by means of light and electron microscopy of dry whole mounts prepared in situ from freshly gathered sea water, mainly in South Africa but supplemented by one gathering from Britain.
Ultrastructural study of zooxanthellae of three species of Acantharia (Protozoa: Actinopoda), with details of their taxonomic position in the prymnesiales (Prymnesiophyceae, Hibberd, 1976)
Authors: Febvre Jean , Febvre-Chevalier Colette
Published: May 2009

In the Acantharia, two different symbiotic algae are known. One is a dinoflagellate with a typical mesocaryon and the other, studied here, exhibits the characters of the Prymnesiophyceae (Haptophyceae).

Detailed descriptions of the non-motile and presumed premotile stages of this symbiont are given, with special reference to the haptonema, the scales and the plastid.

Comparisons are made with other members of the Prymnesiophyceae and the systematic position of the symbiotic alga is discussed.
The relationship between inorganic and organic nutrients in sea water
Authors: Butler E. I. , Knox Susan , Liddicoat M. I.
Published: May 2009

The seasonal variations of dissolved inorganic and organic N and P in the waters of the English Channel during an 11-year study are discussed. The N results show that as NO3 is utilized by phytoplankton there is an increase in the concentration of the dissolved organic N fraction and there are always significant amounts of dissolved N in some form in the water.
Observations on the Diet, Feeding Mechanisms, Digestion and Food Reserves of the Entocommensal RhynchocoelanMalacobdella Grossa
Authors: Gibson Ray , Jennings J. B.
Published: May 2009

The diet and feeding mechanisms, digestive processes and nature and distribution of the food reserves of the entocommensal rhynchocoelanMalacobdella grossa(O. F. Müller) have been studied by histological, histochemical and biochemical methods.

The species is predominantly an unselective microphagous omnivore and possesses two distinct feeding methods. Small particles such as bacteria, algae, diatoms and protozoa constitute the bulk of the diet and are filtered from sea water by means of a pharyngeal ciliary mechanism that does not involve the use of mucus; larger particles, mainly crustacean larvae, are caught by the proboscis and subsequently ingested intact without further treatment.

Digestion occurs in the intestine and combines extra- and intracellular processes which involve mainly carbohydrases apparently secreted by gastrodermal gland cells. This emphasis on carbohydrate digestion, atypical in rhynchocoelans, can be correlated with the species diet.

Fat and glycogen constitute the food reserves, with the former being the principal store and mainly deposited within the gastrodermal columnar cells.
Spontaneous Rhythms in the Motoneurons of Spinal Dogfish(Scyliorhinus Canicula)
Authors: Roberts B. L.
Published: May 2009

The swimming musculature of spinal dogfish,Scyliorhinus canicula(L.), was paralysed with curare while recordings were made of the motor activity in the abdominal spinal nerves. Spontaneous, periodic motor bursts of long duration and decreasing frequency were detected during the first 2 h or so of the experiment. The spinal neurons were incapable of sustaining motor activity for more than 1 or 2 h and were dependent on proprioceptive feedback to maintain their excitability; their discharge frequency could, however, be enhanced by un-patterned sensory stimulation.

The spinal neurons on each side of the cord are sufficiently organized to dis-charge alternately but the longitudinal co-ordination of the locomotory wave is disrupted in the absence of phasic sensory excitation.

INTRODUCTION

It has been assumed that the locomotory movements of spinal dogfish, which persist with undiminished vigour for several hours, are co-ordinated in one of two ways. One possibility is that the entire periodic motor output is formulated by the nerve cells of the spinal cord (Gray & Sand, 1936 a, b; Le Mare, 1936); alternatively, it is conceivable that the motor pattern is triggered by sensory signals fed back to the spinal cord by proprioceptors stimulated during locomotory movements (ten Cate, 1933; Lissmann, 1946a, b).

Lissmann attempted to distinguish between these two general hypotheses by cutting all the dorsal roots of spinal dogfish and thereby isolating the spinal neurons from sensory stimulation. His experiments showed that the spinal animal would swim normally even when a considerable number of dorsal roots had been sectioned but as complete de-afferentation produced im-mobile preparations he concluded'that the motor rhythm was ultimately dependent on proprioceptive activity.
The Spinal Nerves of the Dogfish (Scyliorhinus)
Authors: Roberts B. L.
Published: May 2009

The locomotory musculature of dogfish is innervated by the segmental spinal nerves. The sensory and motor innervation of the abdominal musculature was studied in a preparation consisting of a strip of the abdominal body wall innervated by the ventral rami of the spinal nerves.

Each ventral ramus consists of two separate nerve bundles which were found to be peripheral extensions of the dorsal and ventral spinal roots. Recordings from the sensory bundles showed that there are few sensory endings in the musculature and body wall of the dogfish. It was possible to differentiate between ephemeral responses produced by cutaneous free-nerve endings and prolonged discharges which were generated by more specialized sensory endings. In some details these endings were found to be unlike either muscle spindles or tendon organs. Further, skinning experiments suggested that these mechanoreceptors lay in the skin or the very outer layers of the myotome.

Histological searching, together with physiological isolation of units, suggested that these receptors were the corpuscular endings distributed sparsely amongst subcutaneous tissue. These endings are apparently the same as those described by Wunderer (1908) in the fins of elasmobranchs.
Component Fatty Acids of the Total Lipids of Some Marine Phytoplankton
Authors: Chuecas L. , Riley J. P.
Published: May 2009

A range of 27 marine phytoplankton species, representative of several of the principal classes, has been grown under similar conditions in Erd-Schreiber medium with abundant nutrients. Harvesting was carried out 20 days after inoculation while vigorous growth was proceeding. The component fatty acids of the lipids extractable with chloroform-methanol were determined by gas-liquid chromatography. In all, 40 fatty acids were determined. It is likely that the component fatty-acid distribution may be valuable for taxonomic purposes. Thus, specific fatty-acid assemblages may characterize particular Phyla or even classes. For example, the Bacillariophyceae are differentiated from the other organisms examined by the virtual absence of 18:2, 18:3 and 1814; the Cryptophyta are distinguished by their high content of 20:1. The fatty-acid arrays of species belonging to the same genus are frequently very similar, e.g.Dunaliella primolectaandD. tertiolecta.
The Component Combined Amino Acids Of Some Marine Diatoms
Authors: Chuecas L. , Riley J. P.
Published: May 2009

An investigation has been made of the occurrence of 25 amino acids in the hydrolysates of five species of diatoms which had been grown in Erd-Schreiber medium. Their distribution pattern in general resembles that found in other species. However, there are characteristic differences; thus, they contain more serine and 2-amino iso-butyric acid than the other species of phytoplankton.
The Absorption of Zinc and Other Metals by the Brown Seaweed Laminaria Digitata
Authors: Bryan G. W.
Published: May 2009

The absorption of zinc has been studied in the brown seaweed Laminaria digitata (Huds.) Lamour., with use of the radionuclide 65Zn and atomic absorption analysis. No evidence of the regulation of zinc by the plant has been found. Absorption of zinc or 65Zn is a gradual process of accumulation which may continue throughout the life of the plant and is not accompanied by the exchange of zinc. As a result, once it has been absorbed, zinc or 65Zn shows little tendency to be lost from the plant. The amounts of zinc or 65Zn which can be accumulated from sea water containing different concentrations of zinc and the effects on these of growth, light and competition from other metals have been studied. Possible sites at which zinc might be bound have been discussed, and the experimental results have been compared with the situation found in the field.
Rissoid Larvæ as Food of the Young Herring. The Eggs and Larvæ of the Plymouth Rissoidæ
Authors: Lebour Marie V.
Published: May 2009

Thefree-swimming young of the Rissoidse are particularly important in the plankton for there is always one or more species present in any month and they usually occur in great abundance. The various species live between tide-marks, in the laminarian and coralline zones and in deeper water in several fathoms depth; wherever tow-nettings are taken they usually contain some species of this family. The inshore waters, however, are the richest in rissoids. Even in winter certain species are common round the Plymouth coasts. Some years ago it was found that very young herring just before losing the yolk-sac and about a fortnight old had been eating small rissoids, evidently almost newly hatched (Plate I, Fig. 1). The herring up to a length of about 12 mm. and just after the yolk-sac had disappeared altogether continued to eat them but usually after this size they ate only small Crustacea. From 1917 to 1921 it was found that out of 140 young herring examined, 91 had fed on these small gastropods. In later years they were also found feeding on them (Lebour, 1921, 1924). Other minute planktonic organisms were eaten, including algæ, tintinnids, copepod and cirripede nauplii and very small adult copepods; also a minute bivalve larva but no other gastropod, although other veligers were present in the plankton, Patella being specially common. The young herrings hatch out from December to February, therefore these little gastropods must also hatch at this time and this proves to be the case for in the plankton there are large numbers of these very young veligers (Plate I, Figs. 7–8). Later on, in spring, older stages of the same mollusc abound and are quite the commonest veligers in the plankton near the coast (Plate I, Figs. 17–19). In the summer they have almost entirely disappeared.
The Eggs and Larvæ of some British Turridæ
Authors: Lebour Marie V.
Published: May 2009

In a previous paper (Lebour, 1933) the eggs and larvæ of Philbertia (Comarmondia) gracilis were described, showing lens-shaped sessile eggcapsules and a planktonic larva with elaborately sculptured shell and large brightly spotted velum, which remained as a veliger until it had attained several whorls and was of a large size before metamorphosis. Lens-shaped capsules are apparently typical of the group (Jeffreys, 1867, and observations at Plymouth) and finely sculptured embryonic shells with several whorls are already known in many species (Jeffreys, 1867; Cossmann, 1895; Thiele, 1929). Researches in the Plymouth plankton show that members of this family are common and are some of the largest and most conspicuous gastropod larvæ. They are therefore of considerable economic importance in the sea.
On the Occurrence of the Siphonophores Muggiœa atlantica Cunningham and Muggiæa kochi (Will) in the English Channel
Authors: Russell F. S.
Published: May 2009

In 1892 Cunningham described a new species of Siphonophore, Muggiœa atlantica, which was first noticed by him in the waters of the English Channel off Plymouth in the autumn of 1891. Since then there have been records from time to time of the occurrence of this species at Plymouth (see Plymouth Marine Fauna, 1931, p. 84), and its distribution in the English Channel and Irish Sea in 1904 was worked out by Gough (1905).
Seasonal Changes in Biomass of Calanus finmarchicus in the Plymouth Area in 1930
Authors: Bogorov B. G.
Published: May 2009

1. The present paper deals with changes of biomass and size of Calanus finmarchious throughout the year the Plymouth area.

2. The material was supplied by regular oblique hauls during 1930; Stage V and adult males and females having been examined. Calanus finmarchicus occurred throughout the year reaching its maximum value in May, being abundant from the middle of April to the middle of September.
On the Relation of the Substratum to the Metamorphosis of Scolecolepis fuliginosa (Claparède)
Authors: Day J. H. , Wilson Douglas P.
Published: May 2009

Laboratory experiments indicate that larvæ of Scolecolepis fuliginosa when ready to metamorphose, are able, if necessary, to postpone metamorphosis until a substratum suitable for adult life is reached, meanwhile continuing to swim and grow for a period that may be as long as several weeks.
Nitrates in Aquarium Water
Authors: Honig C.
Published: May 2009

The formation of nitrate in the water of an aquarium tank stocked with fish was followed. As much as 1 gram per litre expressed as sodium nitrate was found.

By adding lactate or tartrate to the water the development of denitrifying bacteria brought about almost complete removal of the nitrates and nitrites in the water.

The experiments form part of an investigation made under the direction of Dr. Jan Smit.
Hydrography of the Mouth of the English Channel, 1929–1932
Authors: Harvey H. W.
Published: May 2009

Since 1921 hydrographic data have been collected by the S.S. Salpa and several merchant vessels, the records being published in the Rapport Atlantique and the Bulletin Hydrographique each year. A description of the conditions in the mouth of the Channel—the varying temperature, salinity, and movements of the water masses—during the years 1925–1928 was published in this Journal, Vol. XVI., pp. 791–820, and included a review of the objects of these investigations and the methods used in working up the collected data. This present publication forms a continuation of this. The same methods of dealing with the data have been used.
The Variation of Excess Base with Depth in the English Channel with reference to the Seasonal Consumption of Calcium by Plankton
Authors: Cooper L. H. N.
Published: May 2009

In the English Channel in summer a small difference in specific alkalinity between the surface and bottom waters has been established by a statistical method. This is not due to re-solution of bottom deposits of calcium carbonate with which the water is supersaturated. It is attributed to removal of calcium from the surface waters by plankton and an attempt has been made to calculate the production of calcareous plankton.
The Biology of Balanus balanoides. I. Growth rate and its relation to Size, Season and Tidal Level
Authors: Moore Hilary B.
Published: May 2009

1. The volumes of Balanus balanoides, at three levels of the shore, have been observed for a year.

2. The young barnacles grow very much faster than older ones.

3. The growth rate varies greatly with age, season and tidal level, but in general there is a period of maximum growth in the summer, and very little growth in the winter.

4. Growth, except during the first year, is greatest higher up the shore.

5. Young barnacles, which settle too late in the year, have their growth retarded by the summer heat, but almost catch up in size the earlier settled spat, by the beginning of the next year.

6. The growth rates found are intermediate between those recorded from Herdla (near Bergen), and those from near St. Malo.

7. Most of the lower- and middle-zone barnacles die in their third year, but those from the extreme top zone may live for five years or more.
A Comparative Study of Metridium senile (L.) var. dianthus (Ellis) and a Dwarf Variety of this Species occurring in the River Mersey, with a discussion on the Systematic Position of the Genus Metridium
Authors: Rawlinson Ruth
Published: May 2009

1. A special study has been made of a small Metridiuni-like anemone found at Dingle, Liverpool, in comparison with the typical form of Metridium senile (L.) var. dianthus (Ellis).

2. Penicilli, formerly believed to be absent from the acontia of typical M. senile, have been discovered in abundance in the young, but rarely in the adults. In young and sexually mature specimens of the Dingle anemone they are also abundant.

3. There is close agreement between the anatomy of the Dingle form and the typical M. senile.

4. A considerable amount of variation occurs in the Dingle anemone, as in M. senile var. dianthus and M. marginatum, Mime-Edwards.

5. The resemblances and differences between the Dingle form and M. senile indicate that the former is a dwarf variety of the latter.

6. The discovery of an abundance of penicilli in the acontia of young typical M. senile and mature specimens of the Dingle variety, in conjunction with the great amount of variation in the genus Metridium, suggests that a reconsideration of the systematic position of the genus is necessary and would justify either the restriction of the family Metridiidæ to the single genus Metridium, or else the fusion of the Metridiidæ with the Sagartiidæ. The sum of the evidence appears to lie in favour of placing the genus in a family by itself.