bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive maturity in fresh and aquarium-heldEledone cirrhosa(Cephalopoda: Octopoda)
Authors: Boyle P. R. , Knobloch Daniela
Published: May 2009

FemaleEledone cirrhosaheld in aquarium conditions for periods of time of five daysand over show relatively enlarged ovary sizes. Values for ovary index considerably exceed thoseof freshly caught animals and the incidence of the final stage of maturity, in which eggs pack the oviducts, is greater. A comparison of maturity indices for fresh and aquarium males was inconclusive. The range of factors associated with aquarium conditions is briefly reviewed and it is concluded that studies of cephalopod reproductive maturation must distinguish fresh and aquarium animals.

Introduction

External factors effective in inducing sexual maturation in cephalopods have been suggested several times. The influence of the absence of light has been implicated since the experiments of Wells & Wells (1959) showed that blinded Octopus vulgar is matured precociously. An effect of short day length in stimulating the optic glands of Sepia has been found by Defretin & Richard (1967) and Richard (1967) but this is not clearly the case for Octopus (Buckley, 1977). Octopuses kept in aquarium conditions for lengthy periods are said to have larger relative gonad sizes than those fresh from the sea (Wells & Wells, 1975). One of the factors associated with aquarium conditions is often a degree of starvation, and this circumstance alone is held to be a factor in inducing precocious sexual maturation in Eledone (Mangold & Boucher-Rodoni, 1973).

In the course of recent studies on the growth and reproduction of Eledone cirrhosa from the North Sea (Boyle & Knobloch, 1982,1983,1984) animals which had remained in aquarium conditions for 5 days or over were separated from the analysis.
Measurement of gill area in fishes: practices and problems
Authors: Hughes G. M.
Published: May 2009

An account is given of a commonly accepted method for measurement of the gill area of fishes. A number of practical hints are included together with some warning about possible sources of error. In particular, these include sampling methods and reduction of errors due to shrinkage. Emphasis is given to the importance of weighting in the calculation of gill area. Problems which arise in comparisons of gills from different species are discussed and attention is drawn to possible errors that can be introduced by the reduction of all data to a given body weight offish. Such dangers are especially present where comparisons are made between fishes which may differ in weight by as much as four orders of magnitude.
Spatial pattern in barnacle settlement: day to day changes during the settlement season
Authors: Wethey David S.
Published: May 2009

Spatial pattern of settlement of cyprids of the barnacleBalanus balanoides(L.) was examined from photographs taken every low tide during the first 20 days of the settlement season. The locations of pits and cracks and the bases of detached adults were mapped in order to measure specificity of settlement in relation to surface contour and chemical cues associated with conspecifics. Cyprids were identified as to their date of settlement. Distances to nearest neighbours were computed for newly settling cyprids relative to each other, for newly settling cyprids relative to previously settled cyprids, and for newly settling cyprids relative to newly metamorphosed spat.
Weights and Lengths of Sepia Officinalis Trawled by the Laboratory's Boats, 1978–1983
Authors: Mattacola Linda Maddock A. D. , Maddock Linda , Denton E. J.
Published: May 2009

Between April 1978 and July 1983 a total of 211 cuttlefish, Sepia officinalis L., was collected in the waters off Plymouth as part of a study of the cuttlebones (Denton & Gilpin-Brown, 1961). The following data were recorded for each specimen: sex, mantle length, the wet weights of the whole animal and the cuttlebone, and for females the weights of the eggs and nidamental glands. The presence of spermatophores in males was also noted. There are rather few records for the winter months; although Sepia were caught at this time they were often required for other studies. It is hoped to obtain more specimens for these months in later years.
An Apparent Lack of Response By Metazoan Meiofauna to Phytodetritus Deposition in the Bathyal North-Eastern Atlantic
Authors: Gooday A.J. , Pfannkuche O. , Lambshead P.J.D.
Published: May 2009

Metazoan meiofauna were studied in replicated multiple-corer samples obtained at a bathyal site (1320–1360 m depth) in the Porcupine Seabight (51°36′N 13°00′W) before (April) and after (July) the delivery to the seafloor of a phytodetrital pulse originating from the 1982 spring bloom. In all samples the metazoan meiofauna was dominated by nematodes; harpacticoid copepods and their nauplii were the second most abundant taxon. Population densities and biomass were very similar in both sample sets, the only significant differences being in the numbers of ostracods (higher in April) and nauplii (higher in July). Furthermore, vertical distribution patterns in the top 5 cm of sediment indicate that the meiofauna did not migrate towards the sediment surface following the phytodetrital pulse. The lack of a metazoan meiofaunal response contrasts with published evidence, based on the same samples, for a substantial increase in the foraminiferal abundance following the sedimentation event. Thus our results suggest that metazoans (as a whole) fail to exploit and utilize phytodetritus as rapidly as foraminifera. This probably reflects the energetic expense of egg production coupled with frequently slower rates of somatic growth among metazoans. In addition, foraminifera may outcompete metazoans for detrital food because they possess extremely efficient food-gathering organelles (granuloreticulate pseudopodia) and are able to raise their levels of metabolic activity very rapidly. However, metazoan responses at the species level, or over longer time periods (>3 months), would not have been detected and so remain a possibility.
Bathymetric and Seasonal Patterns in the Sublittoral Megafauna off Central Chile
Authors: Gallardo V.A. , Roa R. , Carrasco F.D. , Cañete J.I. , Briones-Enrfquez S. , Baltazar M.
Published: May 2009

The sublittoral off central Chile represents a dynamic border separating an oxic surface equatorward current and an oxygen-poor poleward undercurrent. This investigation dealt with whether megafaunal assemblage structure and its temporal and bathymetric distribution were affected by this feature. The problem was approached by investigating the empirical relations between an assemblage index of abundance and physical factors of the environment. The megafauna off Conceptión Bay, central Chile (36°32′S) was thus sampled with an Agassiz trawl on eight cruises performed during 1991 and 1992 at three fixed stations (40, 64 and 96 m depth). Simultaneous reference samples of sea-water were taken to measure temperature, salinity, and dissolved oxygen. Descriptive assemblage attributes, diversity indices, and principal component analysis (PCA) for assemblage study were used. Moreover stepwise linear regression, with the first principal component of the specific abundance matrix as dependent variable was used to study relationships between temperature, salinity and dissolved oxygen and an assemblage of 23 species. Species richness, biomass and abundance decreased significantly with depth while diversity was highest in the intermediate depth station. Discontinuities were thus evident between the shallow, intermediate and deep stations. The grouping of samples in the plane formed by the first and second principal components showed a similar bathymetric discontinuity. In the Euclidian plane, a seasonal cycle of variation of the shallow sampling site was evident. Between 46 and 64 m depth lies a boundary separating different states of the same assemblage, the shallow seasonally variable and the deep constant. The intermediate station shares characteristics of both these stations reflecting a more variable environment. The overall bathymetric and the shallow seasonal patterns of variation were statistically linked to dissolved oxygen.
The Size Structure of Deep-Sea Meiobenthos in the North-Eastern Atlantic: Nematode Size Spectra in Relation to Environmental Variables
Authors: Soltwedel T. , Pfannkuche O. , Thiel H.
Published: May 2009

The size distribution of benthic nematodes was investigated along different gradients of food availability in various regions of the north-eastern Atlantic: I, across the continental margin and II, with increasing distance from the continental rise. An overall trend for miniaturization with increasing distance from the food source was found. Moreover, our results indicate that seasonally varying food supply or a periodically pulsed input of organic matter to the sea floor affects nematode size spectra. The hypothesis is proposed that the life cycle of deep-sea nematode species and hence the size structure of their populations are related to seasonal energy availability. This dependence might result in one year life spans of deep-sea nematodes and probably other meiofauna.
The Culture of Eggs and Embryos of Amphipod Crustaceans: Implications For Brood Pouch Physiology
Authors: Morritt David , Spicer John I.
Published: May 2009

A technique is described for thein vitroculture of the eggs and embryos of amphipod crustaceans. The technique was used, with mixed success, to culture the eggs of four species of amphipod (Gammarus duebeni, Orchestia gammarellus, Gammarus pulexandEchinogammarus pirloti) through to hatching. Eggs of the brackish waterG. duebenishowed good hatching success in culture (70–75%) over a wide range of experimental salinities (75–1250 mOsm kg1). The eggs ofO. gammarellusshowed higher mortality rates in culture (compared withG. duebeni), especially in more dilute salinities (300 mOsm kg1) in which they swelled greatly prior to disintegration. Survival and true growth (as distinct from osmotic swelling) ofO. gammarellusembryos in dilute salinities were significantly im-proved by introducing embryos into culture at a later stage of development. Antibiotic treatment had no demonstrable effect on embryo survival or growth. Whilst difficult to culture using this method, the eggs of the fresh water G.pulexshowed best hatching success on a very dilute saline medium (~40 mOsm kg1). The results are discussed in relation to the development of embryonic osmoregulation, the implications for brood pouch function and the potential for female control of the embryonic environment, especially in semi-terrestrial species.
Spatial Resolution Determined by Electrophysiological Measurement of Acceptance Angle in two Species of Benthic Decapod Crustacean
Authors: Shelton P.M.J. , Gaten E.
Published: May 2009

Angular sensitivity functions were determined electrophysiologically for retinula cells in Nephrops norvegicus and Munida rugosa. For such aquatic species it is shown that reliable measurements cannot be obtained unless the eyes are submerged. In both cases, for submerged eyes, there is a significant reduction in retinula cell acceptance angles with light adaptation. In N. norvegicus the change is from 11·3° dark adapted (DA) to 8·85° light adapted (LA). In M. rugosa there is a larger difference, 12·5° (DA)–6·58° (LA). The changes in acceptance angle with adaptational state can be attributed to differences in screening pigment position between light- and dark-adapted eyes. In N. norvegicus only the retinula cell proximal pigment is migratory. The small change in acceptance angle with adaptation is consistent with the fact that the eye uses superposition optics even when light-adapted.
A New Species ofOchetostoma(Echiura, Echiuridae) Found in the Azores With Notes on its Ecology
Authors: Rogers Alex D. , Nash Richard D.M.
Published: May 2009

INTRODUCTION

Approximately 145 species of the phylum Echiura have been described to the present date (Popkov, 1992). Since Stephen & Edmonds' (1972) monograph detailing the known species of Echiura, few new species have been described. The majority of these have been members of the family Bonelliidae from the deep-sea (i.e. Murina, 1976, 1978; DattaGupta, 1977,1981; Biseswar, 1992) with a few exceptions (e.g.Thalassema malakhoviin Popkov, 1992 andOchetostoma natalensein Biseswar, 1988).
The Effect of Decreased Ration on Feeding Hierarchies in Groups of Greenback Flounder (Rhombosolea Tapirina: Teleostei)
Authors: Carter C.G. , Purser G.J. , Houlihan D.F. , Thomas P.
Published: May 2009

The aims of the present study were to investigate food consumption, growth and the dynamics of feeding hierarchies in the same groups of juvenile greenback flounder (Rhombosolea tapirina:Teleostei) fed either high or low rations. Differential food consumption by individual greenback flounder held in groups of 20 showed the presence of feeding hierarchies in which individuals consumed between 0 and 22% of the available food. Inter-individual differences in food consumption resulted in different growth rates leading to growth depensation (measured as an increase in the coefficient of variation for weight). Intra-individual differences in food consumption tended to be larger for flounder which consumed a lower share of the available food. When the group ration was reduced the inter-individual and intra-individual variations in food consumption increased. Consequently, the relationship between inter-individual and intra-individual variation in food consumption tended to become stronger at lower food availability and indicated an increase in the strength of the feeding hierarchies. This study suggests that individual differences in food consumption, mediated through exploitation competition, contribute to growth depensation in this species of flatfish.
Female Mimicry as a Mating Tactic in Males of the Blenniid Fish Salaria Pavo
Authors: Gonçalves Emanuel J. , Almada Vitor C. , Oliveira Rui F. , Santos António J.
Published: May 2009

In this paper we present evidence for female mimicry in a population of Salaria pavo (Pisces: Blenniidae). Parental males differ markedly from females by the presence of a large crest on the head and anal glands on the two spiny rays of the anal fin. We found a proportion of smaller and younger males that are almost identical to females both in morphology and behaviour. These ‘female-like’ males lack secondary sexual characters and actively court parental males, displaying the female's colour pattern and courting behaviour. These males are sexually mature and their gonadosomatic indices are higher than those of parental males. Female mimicry is considered to be a functional way to achieve sneak fertilizations.
The First Records of the Blue RunnerCaranx Crysos(Pisces: Carangidae) in British Waters
Authors: Swaby Silja E. , Potts Geoffrey W. , Lees John
Published: May 2009

In September 1992 a blue runner (Caranx crysos) (37 cm) was caught off Portland Harbour, Dorset, by an angler. Initially the specimen was not recognized as a rarity and it was damaged while being prepared as bait for a lobster pot. Fortunately it was retrieved and sent to the Ministry of Agriculture Fisheries and Food (MAFF) laboratory at Lowestoft where it was identified. In August 1993, a second blue runner (29 cm), (see Figure 1) was hand-lined in St Ives Bay, Cornwall by Mr Astrinsky, of Penzance. It was also taken to a MAFF office, at Newlyn, for identification where one of the authors made a provisional identification before sending it to the British Marine Fishes Database at the Marine Biological Association for final verification. These two fishes are the first records of the blue runner C.crysosfrom British waters, and represent a northerly extension to its range.
Feeding Pattern ofSepia Officinalis(Cephalopoda: Sepiodidea) In The Ria De Vigo (Nw Spain)
Authors: Castro B.G. , Guerra A.
Published: May 2009

The importance of feeding pattern is well documented in fish (Jenkins & Green, 1977; Simenstad & Cailliet, 1986) but there are not many reported studies in cephalopods. Feeding patterns, as defined by Jenkins & Green (1977) have been studied, to our knowledge, only in Todarodes pacificus (Okiyama, 1965), Loligo pealei (Vovk, 1972), Loligo opalescens (Karpov & Cailliet, 1978), Illex illecebrosus (Amaratunga et ah, 1979; Amaratunga, 1980) and Nototodarus gouldi (O'Sullivan & Cullen, 1983). Boyle (1983) dealt with aspects of feeding in several cephalopod species but not specifically with feeding pattern. Aspects of feeding in Sepia officinalis have been reviewed by Nixon (1987). The present work describes the daily feeding pattern in Sepia officinalis from data collected in the field.
A Comparison of the Intertidal Harpacticoid Copepod Assemblages of Sandy Beaches in Galway Bay (Ireland) And Northern Brittany (France)
Authors: Bodin P. , Jackson D.F.
Published: May 2009

The comparative research programme on harpacticoid copepod assemblages of the west coast of Ireland and northern Finistere began in 1982. During 1981 in Galway, D. Jackson sampled three sandy beaches around Galway Bay (Figure 1), Grattan Road Strand, Silver Strand and An Poll Brean (on Mweenish Island) near Carna (simply called Carna in the following text) and was preparing his PhD thesis (Jackson, 1985). Between 1978 and 1984 in Brittany, P. Bodin had been conducting a long-term ecological survey (Bodin, 1988) of three sandy beaches polluted by the 'Amoco Cadiz' oil spill; Brouennou, Corn ar Gazel and Kersaint (Figure 2). As these six beaches shared common characteristics of granulometry, salinity, temperature and hydrodynamics, it was decided to undertake a comparative study of the systematics, ecology and biology of their harpacticoid copepod assemblages.
Rapid Hatching Induced By Light Intensity Reduction In The Polyopisthocotylean Monogenean Plectanocotyle Gurnardi From The Gills Of Gurnards (Triglidae), With Observations On The Anatomy and Behaviour of The Oncomiracidium
Authors: Whittington Ian D. , Kearn Graham C.
Published: May 2009

The eggs of the polyopisthocotylean monogenean Plectanocotyle gurnardi (van Beneden & Hesse, 1863) Llewellyn, 1941, from the gills of gurnards (Triglidae) develop and hatch readily when maintained in the laboratory. However, the impression was gained that some or all of this hatching might be the consequence of inadvertent shadowing or accidental mechanical disturbance of the eggs by the investigators. Since similar stimuli are known to induce hatching in some other monogeneans (see Kearn, 1982; Whittington & Kearn, 1988) and since such stimuli are likely to be generated by the activities of potential hosts, it was decided to embark on a more detailed investigation of hatching in P. gurnardi and to attempt to learn more about the behaviour of gurnards. During these investigations, the availability of freshly hatched larvae of P. gurnardi presented an opportunity to study their behaviour and to expand our knowledge of their anatomy.
A Note on The Distribution and Diet of Deep-Water Rays (Rajidae) in An Area of The Rockall Trough
Authors: Gordon J.D.M. , Duncan J.A.R.
Published: May 2009

The demersal fish populations of the slopes of the Rockall Trough (250 to 3000m) have been sampled by a number of different types of trawl (Gordon & Duncan, 1985; Gordon, 1986). The diets of most species have been described (Mauchline & Gordon, 1980, 1983a,b, 1984a,b,c) and aspects of the trophic ecology discussed (Mauchline & Gordon, 1985, 1986). Rays were relatively uncommon in the early sampling but the more recent use of a Marinovitch semi-balloon trawl with mud rollers and chain on the footrope has increased catches. This paper describes the distribution and diet of 12 species of ray from the slopes of the Rockall Trough.
Salinity Effects on Brood Maturationo of the Mysid CrustaceanMesopodopsis Slabberi
Authors: Greenwood J.G. , Jones M.B. , Greenwood J.
Published: May 2009

Surprisingly little is known about the influence of salinity on embryo development in crustaceans despite its obvious potential importance to species which breed in inshore estuarine waters. Evidence from the literature is that embryo salinity tolerance may differ from that of later stages in the life history (e.g. Kelley & Burbanck, 1976; Rosenberg & Costlow, 1979; Hartnoll & Paul, 1982; Jones & Simons, 1982; Wearet al., 1986) and such differences may impose restrictions on distribution. Wittmann (1984) referring to mysids, emphasised that an understanding of incubation period and factors influencing it "appears to be a key factor for the understanding of variations in the length and timing of the breeding season, age of maturity, frequency of broods, numbers of young per brood, egg size, and adult body size".
A Rod-and-Line Fishery for Herrings at Plymouth, 1937–1953
Authors: Kelley D.F.
Published: May 2009

Occasional small specimens of herring have, since at least 1875, been taken by Plymouth anglers in winter under harbour lights. In 1937 larger herrings appeared, and a specialised rod fishery developed which continued, apart from the war years, until 1953, when it collapsed suddenly.
Biometrics, Carbon and Nitrogen Content in Two Cnidarians: Urticina Felina and Alcyonium Digitatum
Authors: Migné A. , Davoult D. , Janquin M.A. , Kupka A.
Published: May 2009

A biometrical study was conducted on two common cnidarians: Alcyonium digitatum (Octocorallia) and Urticina felina (Hexacorallia). The aim was to relate both the carbon and the nitrogen content of these species to a simple and rapid measurement. As the simplest measurement that can be done on A. digitatum is a measurement of size, relationships were determined between the height of a colony and its organic carbon (OC=0.0002 H2.0254, n=104, γ2=0·923) and nitrogen (N=0.00004 H2.0283, n=104, γ2=0.928) content. As no constant size could be determined on sea anemones, linear relationships were established between dry weight (DW) and organic carbon (OC=0.419 DW, n=65, r=0.995) and nitrogen (N=0.095 DW, n=65, r=0.997) content in U. felina. All these relationships were highly significant (P<0.1%) and appeared useful to express biomass of the two species in terms of carbon or nitrogen and then to consider dynamic processes such as respiration or excretion as fluxes of carbon and nitrogen.
Brooding and Larval Developmental Periods of the Callianassid Ghost Shrimp, Callianassa Japonica (Decapoda: Thalassinidea)
Authors: Tamaki Akio , Tanoue Hirotaka , Itoh Junichi , Fukuda Yasushi
Published: May 2009

Estimations of the brooding and larval developmental periods of the callianassid ghost shrimp, Callianassa japonicu Ortmann (Decapoda: Thalassinidea), under field conditions, were made on an intertidal sandflat in western Kyushu, Japan, during the breeding seasons (June-October) of 1992–1994. Females bearing eyed embryos were able to deposit a further batch of eggs 1–5 d after releasing larvae, and it is concluded that such egg deposition was preceded immediately by mating. Based on rearing experiments carried out in the field, the brooding period was found to occupy between 13 and 22 d during June to October, at pore water temperatures of 20.5-27.5°C and salinities of 33.0–34–5‰, a shorter period than those reported for seven other callianassid species. Based on temporal changes in the densities of larvae released by females and newly-settled juveniles on the sandflat, time-lags between the release and settlement events suggested the period of planktonic development with six zoeal stages and the 1st post-larval stage to range from 20 to 25 d during mid-June to mid-August, at water temperatures of 18.5-24.5°C and salinities of 32.0–35.0‰. This is the second shortest larval period among those reported for seven other callianassid species that have five or six zoeal stages.
Chemical Communication and Behavioural Interaction Between Sexually Mature Male and Female Shore Crabs (Carcinus Maenas)
Authors: Bamber S.D. , Naylor E.
Published: May 2009

A new behavioural bioassay system has been used to examine chemical communication in the crab Carcinus maenas (Crustacea: Brachyura) and has demonstrated the sexually and temporally specific nature of a putative sex pheromone. Mature premoult and postmoult females evoked sexual behavioural responses from receptive male crabs. No response was obtained when intermoult female and premoult and postmoult male crabs were tested. Postmoult females continued to be chemically attractive to male crabs with a similar intensity to that of late premoult females for >8 d following moulting, and then with a reduced intensity for >14 d. Male C. maenas successfully entered copula with females >13 d after the female moult.
Laboratory Behaviour of Mosshead Sculpins Clinocottus Globiceps Toward Their Sea Anemone Prey
Authors: Yoshiyama Ronald M. , Knowlton Ann L. , Welter Jill R. , Comfort Stephanie , Hopka Billie Jo , Wallace W. David
Published: May 2009

Mosshead sculpins, Clinocottus globiceps, of the North American Pacific coast commonly feed upon sea anemones and in doing so make frequent body contact with the anemone tentacles. An attempt was made to determine if some sort of acclimation process, as seen in certain pomacentrid anemone fishes, is necessary for C. globiceps to engage in such repeated contacts. The laboratory experiments with C. globiceps and three species of anemones (Anthopleura xanthogrammica, A. elegantissima, Urticina crassicornis) revealed no obvious and consistent acclimatory behaviours by the fish toward anemones following a period of enforced isolation from anemones. Actions by C. globiceps toward anemones included frequent bites to tentacles, touches to tentacles without biting (whether intentional or not), and bites to the anemone's base or column. Tentacle bites occurred, on average, significantly earlier than tentacle touches in trials with Anthopleura elegantissima. There was no evidence that either tentacle bites or tentacle touches occurred earlier than the other in trials with A xanthogrammica and U. crassicornis. In paired trials where individual

C. globiceps were tested first with A. xanthogrammica and then with U. crassicornis, the fish showed no significant difference in response to the two anemone species, either in the frequencies of different types of actions (bites or touches) or in the average order in which tentacle bites or tentacle touches occurred. Experiments were also conducted to compare the degree to which different sculpin species avoided contact with anemone (A. elegantissima) tentacles. Clinocottus globiceps seemed more tolerant of contact with tentacles than were the other sculpins, and only C. globiceps appeared intentionally to touch tentacles, sometimes leaning against or biting them.
Notes on Some Branchial Isopods Parasitic on Upogebiid Mud-Shrimps (Decapoda: Thalassinidea)
Authors: Astall C.M. , Taylor A.C. , Atkinson R.J.A.
Published: May 2009

Bopyrids are highly modified epicaridean isopod ectoparasites with the adult females showing extreme specialization of body form when compared with free-living isopods (Shiino, 1965). The smaller males are similar to free-living isopods, retaining the basic cryptoniscus larval form (Naylor, 1972), and are typically found in the brood chamber of the female or attached to the ventral surface of the female's pleon (Salazar-Vallejo & Leija-Tristán, 1989).

Whilst examining the branchial morphology of the upogebiids,Upogebia stellata(Montagu),Upogebia deltaura(Leach) andUpogebia pusilla(Petagna) as part of a wider study of the physiological ecology of thalassinidean mud-shrimps, some shrimps were observed to have a branchial gall (distended branchiostegite) containing a bopyrid parasite. In this short note we add to the previous records of two bopyrid species and briefly discuss the host/parasite relationship.

Parasitized material examined:U. stellata(three males, two females) collected subtidally using an anchor dredge from White Bay, Isle of Cumbrae, Scotland (55°48'N 4°55'W) at depths of 25–30 m. A single male specimen ofU. deltaurawas caught using a box corer from the Irish Sea (54°7'N 3°27'W).Upogebia pusilla(one male, one female) were collected intertidally from the Arcachon Basin, France (44°40'N l°10'W) by Professor J.P. Truchot. Prior to examination, the mud-shrimps were preserved in 10% buffered formalin, the parasites removed, rinsed with distilled water and transferred to 70% ethanol. Some preserved material was also available from the Robertson Collection housed at the University Marine Biological Station Millport.

Parasitized mud-shrimps had an enlarged branchial chamber, or branchial gall, a result of branchiostegite deformation caused by the presence of the parasite. When the parasite was removed from the branchial chamber, the gills appeared splayed and flattened but showed no other signs of disturbance or damage.
Sex Ratio Variation in the Intertidal Isopod,Jaera Albifrons
Authors: Piertney Stuart B. , Carvalho Gary R.
Published: May 2009

Thirty ‘rock-populations’ of the intertidal isopod,Jaera albifrons(Isopoda: Asellota), from South Wales area were found to display a significant and persistent sex ratio bias, with females outnumbering males by up to 12 to 1. This thelygeny was not mirrored in broods that were isolated in aquaria after insemination, nor in broods that developed under various temperature and light regimes. Such a discrepancy suggests that the mechanism generating sex ratio biases in natural populations is not innate, nor is influenced by cytoplasmic or environmental factors. The possible causes of thelygeny in natural populations are discussed.
Effects of Copper on the 48-H Embryonic Development of the Bivalve Scrobicularia Plana
Authors: Ruiz J.M. , Bryan G.W. , Wigham G.D. , Gibbs P.E.
Published: May 2009

Static toxicity tests (20.5 ±1°C, 24 ±2% salinity) were run to assess the toxicity of copper to the embryonic development of Scrobicularia plana (Mollusca: Bivalvia); the end point of interest was the production of D-larvae after 48 h culture. While a nominal concentration of 10 μg Cu I1 was not found to be toxic, an EC90 (concentration preventing 90% of the experimental population from achieving the end point defined) can be set at ~20 μg Cu I1. For this end point, copper is indicated to be 16 times less toxic than the antifoulant tributyltin (TBT). Moreover, copper has probably little relation with the reported recent decline of S. plana throughout northern Europe.
On the Occurrence of grey mullet postlarvae off Plymouth
Authors: Demir Neclâ
Published: May 2009

Seven postlarvae and one juvenile of the golden mullet and two postlarvae of the thicklipped mullet, ranging from 60 to 27 mm and from 14-88 to 21-44 mm in length respectively, were found in plankton collections taken in the Plymouth area on 10 October and 14 November 1969. The morphological characters of these specimens are described and illustrated, and the presumptive spawning periods of the two species are briefly discussed in this paper.
On the symbiosis betweenAmphidinium klebsii[Dinophyceae] andAmphiscolops langerhansi[Turbellaria: Acoela]
Authors: Taylor D. L.
Published: May 2009

INTRODUCTION

Algal-invertebrate symbiosis is common among species of acoelus Turbellaria in both marine and freshwater environments (Droop, 1963; Buchner, 1965; McLaughlin & Zahl, 1966). Associations involving these organisms exhibit broad variations in the amount of integration achieved through the reciprocal relations of hosts and symbionts. In the symbiosis involvingConvoluta roscqffensisGraff, the maximum degree of intimacy is achieved, and the host appears totally dependent on its symbiont for its nutritional requirements (Keeble & Gamble, 1907; Keeble, 1910). This type of closed symbiosis is unknown in other invertebrate phyla and may even be unique among turbellarians. Similarly, the association betweenAmphiscolops langerhansi(Graff) and a unicellular alga is a typical example of the more common, open or facultative symbiosis. Both species (with their algal partners) are potentially useful as investigative tools in the study of cellular interaction in algal-invertebrate symbiosis, and may provide the basis for understanding the broader aspects of cellular integration in metazoan tissues. Recent studies ofC. roscqffensisprovide a basis for understanding the biology of the symbiosis which it sustains (Parke & Manton, 1967; Provasoli, Yamasu & Manton, 1968; Provasoli, Yamasu & Mabuchi, 1969). The present communication is intended to provide similar information on the association found inA. langerhansi.
Further observations on the buoyancy of Spirula
Authors: Denton E. J. , Gilpin-Brown J. B.
Published: May 2009

INTRODUCTION

In earlier papers we have given an account of work on the three kinds of chambered shells which are found in living cephalopods, i.e. those of Sepia, Nautilus and Spirula, and shown that, although these animals differ markedly from one another in the structure of the shell and its position in the animal, there are nevertheless great similarities in the pattern of events leading to the formation of a new chamber and the way in which liquid is pumped out of it and gas diffuses into it (Denton & Gilpin-Brown, 1961 a, b, c; 1966; Denton, Gilpin-Brown & Howarth, 1961, 1967). We advanced the hypothesis that this pattern must have been the same for all the chambered shelled cephalopods, including the fossil nautiloids, ammonites and belemnites.
The accumulation and excretion of radioactive caesium by the plaice(Pleuronectes platessa)and the thornback ray(Raia clavata)
Authors: Jefferies D. F. , Hewett C. J.
Published: May 2009

INTRODUCTION

The caesium radionuclides, caesium-137 and caesium-134, are important constituents of aqueous radioactive effluents discharged to the environment of the United Kingdom from fuel re-processing plants and nuclear power stations (Howells, 1966; Mitchell, Harvey & Smith, 1968; Harvey, Baker & Mitchell, 1969). Their accumulation by marine fishes has been the subject of several previous studies, beginning with that of Chipman (1959) who noted that caesium-137 was accumulated in the flesh of the killifish(Fundulus heteroclitus)and that accumulation continued even after a period of 72 days. Similarly, Hiyama & Shimizu (1964) showed that the muscle of the common goby(Acanthobus flaviamus)continued to accumulate caesium-134 from sea water after periods of 30 days. Baptist & Price (1962) have examined the whole body uptake of caesium, by absorption from sea water, in two marine species, the flounder(Paralichthys dentatus)and the Atlantic croaker(Micropogon undulatus), and they also investigated the accumulation, tissue distribution and excretion of caesium-137 in the croaker, the little tuna(Euthynnus alleteratus)and the bluefish(Pomatomus saltatoux), following oral administration of single doses. These authors concluded that the heart, liver and spleen of the croaker absorbed caesium-137 from sea water at a faster rate than the muscle, and that orally administered caesium-137 was rapidly absorbed from the digestive tract. Tissue distributions were similar in the croaker, bluefish and tuna. The retention of caesium-137 in croaker tissue was described as a multiple rate process. In later experiments Hiyama & Shimizu (1969) compared turnover rates in various organs and tissues following uptake from sea water and from single injection experiments, and obtained good agreement between the values from the two methods.
Nematode associations in the Exe estuary
Authors: Warwick Richard M.
Published: May 2009

INTRODUCTION

The problems involved in the identification of freeliving marine nematodes have stood in the way of ecologists for some time. Although considerable advances are now being made on the continent (particularly in Kiel Bay and the Mediterranean) and in North America, our lack of knowledge of the British species is still lamentable. In order to rectify this state of affairs to some extent, a study of the distribution of nematodes in the Exe estuary was planned to cover as wide a spectrum of physical and chemical conditions as possible, ranging from fine muds with a low interstitial salinity at the head of the estuary to coarse sands with a high salinity at the mouth. It is hoped that the characterization of the fauna of various habitats in the estuary will form a basis for further ecological studies in other areas. Not surprisingly, a large proportion of the species found were new British records, and some new to science. The fourteen species of this latter group discussed in this paper are described elsewhere (Warwick, 1970).
Ecology and population studies of some intertidal and sublittoral sand-dwelling amphipods
Authors: Fincham A. A.
Published: May 2009

INTRODUCTION

Certain sand-dwelling amphipods occur either in the intertidal or in the sublittoral zone and extreme low-water springs (E.L.W.S.) has been taken as a convenient dividing line between these two habitats. Previous workers have concentrated mainly on one or other of these contiguous regions. General studies of the in-fauna of intertidal sand on the Isle of Man include those of Pirrie, Bruce & Moore (1932), Jones (1948) and Southward (1953). The in-fauna of sublittoral sandy deposits around the Isle of Man has been studied by Jones (1940, 1951, 1956) and Fincham (1969a). However, Mclntyre & Eleftheriou (1968) working at Firemore Bay, Loch Ewe showed that the intertidal and shallow-water sand regions should be regarded as a unit. Faunal distributions were not always discontinuous about E.L.W.S.
Long Term Trends in the Occurrence of Phaeocystis Sp. in the North-East Atlantic
Authors: Owens N.J.P. , Cook D. , Colebrook M. , Hunt H. , Reid P.C.
Published: May 2009

The effects of nutrient enrichment of natural water bodies range from small increases in plant biomass and production, to gross deterioration of water quality. The input of nutrients (e.g. nitrogen and phosphorus) to the sea off NW Europe (especially the North Sea) has increased dramatically over the last three or four decades (Folkard & Jones, 1974; Bennekom et al., 1975; Postma, 1978; Cadee, 1986a) but there is uncertainty about the effects on the ecosystem. One possible effect might be to induce changes in the phytoplankton community. Such an effect has been reported for the North Sea, where increases in flagellate algae have been observed (Gieskes & Kraay, 1977; Postma, 1985; Cadee, 1986b; Batje & Michaelis, 1986). Phaeocystis is one such alga, and its purported involvement in the formation of large quantities of foam, observed on European beaches (Batje & Michaelis, 1986; Weisse et al, 1986), together with evidence that the alga is a source of atmospheric sulphur compounds (Barnard et al, 1984) (with implications for atmospheric acidity), has attracted particular attention and concern
A Sibling Species Group of Hydractinia in the North-Eastern United States
Authors: Buss Leo W. , Yund Philip O.
Published: May 2009

Many symbiotic organisms are narrowly distributed on one or a few host species. These associations are intriguing, as they invite the development of hypotheses regarding the pattern and process of speciation and serve as laboratories for the testing of methods of phylogenetic reconstruction (Kraus, 1978; Futuyma & Slatkin, 1983; Stone & Hawks worth, 1986). The evolution of host-specificity in the sea may be expected to be severely constrained by the difficulty of achieving reproductive isolation in taxa whose gametes are freely released into the water column and/or whose larvae are potentially widely distributed (Scheltema, 1977). Yet this difficulty may well be overestimated, given the recent demonstrations of limited gamete (Pennington, 1985; Yund, in press) and larval dispersal (Knight-Jones & Moyse, 1961; Ryland, 1981; Olsen, 1985; Jackson & Coates, 1986; Grosberg, 1987). Indeed, if gamete and larval dispersal are as limited as has recently been contended (Jackson, 1986), local isolation of populations may be a routine occurence, offering repeated opportunities for speciation.
Assimilation of Dietary Sterols and Faecal Contribution of Lipids by the Marine InvertebratesNeomysis Integer, Scrobicularia PlanaandNereis Diversicolor
Authors: Bradshaw Stuart A. , O'Hara Sean C.M. , Corner Eric D.S. , Eglinton Geoffrey
Published: May 2009

Feeding by marine invertebrates affects dietary lipids as they pass through the gut (Volkmanet al, 1980s; Tanoueet al, 1982; Prahlet al, 1984a, b,1985; Nealet al, 1986; Harvey et ah, 1987,1989). Not only do animals appear to alter the dietary lipids but they also contribute their own lipids to the egested material. Faecal pellets are thus likely to have a lipid composition which has contributions from the ingested food material, the animal itself and the microbial populations residing in the animal's alimentary system.
The Drift Amphipod Hyale Grimaldii in Irish and British Waters
Authors: Mcgrath D. , Myers A.A.
Published: May 2009

Lincoln (1979) listed four species of Hyale Rathke from British and Irish waters. A fifth species Hyale grimaldii Chevreux has recently been collected from among goose barnacles, Lepas anatifera L., attached to drift timber washed ashore on a rocky beach in Co. Galway, west coast of Ireland. This record was referred to previously in an abstract by McGrath (1984) but no details of the occurrence or material collected was given. An earlier unconfirmed record of H. grimaldii from Scotland is listed among the Reid collection by Sanderson (1973). H. grimaldii was originally described by Chevreux (1891) from two males found among algae attached to drift timber at sea in the Atlantic, north east of the Azores. Subsequently, the species has been recorded on a number of occasions in the Mediterranean (Chevreux & de Guerne, 1893; Cecchini, 1928; Ruffo, 1946; Berner, 1976) and from the Azores, on a coconut cast ashore (Mateus & Afonso, 1974). All records of the species are from objects floating at sea or washed ashore.
Chloroplasts as symbiotic organelles in the digestive gland ofElysia viridis[Gastropoda: opisthobranchia]
Authors: Taylor D. L.
Published: May 2009

An investigation into the histochemistry and ultrastructure of the digestive gland ofElysia viridishas revealed the presence of two types of epithelial cells, one of which contains numerous, structurally intact algal chloroplasts. Chromatographic studies indicate that these chloroplasts are derived from the animal's specific food, the algaCodium tomentosum. Following ingestion by the animal these do not appear to be digested or excreted, but accumulate and are maintained in the digestive cells. Autoradiographic studies suggest that they may be of some benefit to the animal as symbiotic organelles. Such a phenomenon may prove to be widespread among related species of Opisthobranchia.
Toxicity of oil-spill removers (‘detergents’) to marine life: an assessment using the intertidal barnacle Elminius modestus
Authors: Corner E. D. S. , Southward A. J. , Southward E. C.
Published: May 2009

The oil-spill removers BP 1002, Gamlen, Slipclean and Dasic have been tested for toxicity using the barnacle Elminius modestus Darwin. All four substances were more toxic than the laboratory detergent Teepol-L, and Kuwait crude oil. BP 1002 was the most toxic of the oil-spill removers, and Dasic the least, but all were poisonous at concentrations between 2 and 10 ppm.
Respiration and nitrogen excretion by some marine zooplankton in relation to their life cycles
Authors: Conover R. J. , Corner E. D. S.
Published: May 2009

Rates of respiration and nitrogen excretion have been measured for freshly caughtCalanus finmarchicus(Gunnerus),Calanus hyperboreus(Krayer),Metridia longa(Lubbock) andPareuchaeta norvegica(Boeck), from the Gulf of Maine at all seasons. The dry weight, total (Kjeldahl) nitrogen, and fat were also determined for the same animals. Seasonal variation in weight-corrected respiration and nitrogen excretion followed a similar pattern for all four species, being high in the spring and decreasing gradually through summer and fall to a winter minimum. However, the relative proportions of oxygen utilized to nitrogen excreted were different from season to season for each species. InCalanusspp., O: N ratios by atoms were highest in May, immediately after the spring bloom of phytoplankton, when the animals were rich in fat. WithC. hyperboreusthe ratio then declined gradually through summer and fall to a low point just before the spring bloom (March and April) when populations contained the least amount of fat; but withC. finmarchicusthe ratio fell much more rapidly, remaining near 17 through summer and fall and increasing again with the production of the overwintering generation. InMetridia and Pareuchaetathe O:N ratios did not show as much seasonal variation, although there was a pronounced increase for Metridia just after the spring bloom. Both species usually had higher respiration and excretion rates and lower O:N ratios compared with Calanus spp.
Formation of uroporphyrin from porphobilinogen by the heart-body tissue and coelomocytes of the polychaete Neoamphitrite figulus
Authors: Kennedy G. Y. , Dales R. Phillips
Published: May 2009

Suspensions of heart-body tissue and of coelomocytes in solutions of porphobilinogen produced uroporphyrin. This affords additional evidence for the haematopoietic function of the heart-body, and for the view that the free porphyrins found there and in the haemoglobin-containing coelomocytes are formed by these tissues' own activity in haem synthesis.
The bottom fauna of a flatfish nursery ground
Authors: McIntyre A. D. , Eleftheriou A.
Published: May 2009

The macrofauna, defined as infauna retained on a ½ mm sieve, was investigated on a flatfish nursery ground at less than 10 m depth in a Scottish westcoast sea loch during spring and late summer of 1965. The substratum consisted of well-sorted sand of 180–260 μ median diameter, and the infauna had a mean density of 755 individuals and biomass of 1·3 g dry weight/m2 on the beach and 3055 individuals and 3·7 g dry weight in the sublittoral. There was little overall change in the biomass during the period studied, increases in amphipods and some polychaetes being balanced by decreases in other polychaetes, and in Tellina for which no recruitment took place. The distribution of the fauna was studied in detail between high-water mark on the beach and a depth of 10 m below low-water springs. There were 62 species on the beach and 116 on the sublittoral sand. The number increased as the water deepened, the poorest zone being just below low-water mark. Most species showed a distinct zonation. The epifauna of the sand, which was dominated by juvenile stages of plaice and dabs, is briefly described
Chemical changes in sea water off plymouth during the years 1962 to 1965
Authors: Armstrong F. A. J. , Butler E. I.
Published: May 2009

Analyses of sea water collected during the years 1962–65 at International Hydrographic Station E. I are given here in the same form as in earlier reports. Temperature, salinity, nitrate, phosphate, and silicate were examined. Some values of suspended carbon and chlorophyll are also included.

Salinities were markedly higher in 1965 than in the previous 3 years. All 4 years showed a low value for maximum winter phosphate levels.
Long-term effects of low concentrations of an oil-spill remover (‘detergent’): studies with the larvae of Sabellaria spinulosa
Authors: Wilson Douglas P.
Published: May 2009

The ‘detergent’ BP 1002 at concentrations of 1 ppm was detected immediately by the larvae of Sabellaria spinulosa which were intensely irritated by it. In loosely covered vessels, allowing the solvent fraction to evaporate, larvae seemed at first to recover but died several weeks later, the control larvae remaining active and normal. The surfactant and stabilizer fractions at concentrations of 2·5 ppm killed the larvae within a day or two.
Structure, histochemistry and formation of the podocyst and cuticle of Aurelia aurita
Authors: Chapman David M.
Published: May 2009

At the junction between the scyphistoma's scyphopharynx-filament complex and its endoderm is a narrow zone of simple columnar cells. These cells can transform into amoebocytes which collect together and work their way to the aboral end of the polyp, where they secrete a cuticular encasement, thus forming the podocyst.

Light and electron microscopy, as well as histochemistry, show the podocyst to be a lamellated tanned chitin-protein complex covering the protoplasmic contents, which have a nucleated outer clear cytoplasmic layer and a yolky central zone which may be liquefied in places.