bluuebunny/crossref_metadata_2025_split huggingface dataset:
The taxonomy of some little-known Sipuncula from the north-east Atlantic region including new records
Authors: Gibbs P. E. 
Published: May 2009

INTRODUCTIONEarly investigations of the deep-sea fauna of the north-east Atlantic region resulted in many new Sipuncula species being described, notably by such workers as Koren & Danielssen (1877), Théel (1905), Sluiter (1900, 1912) and Southern (1913). Many of these species were erected from single, or few, specimens and some are still known only from the original records.This paper examines the status of certain species, mostly the seemingly-rare golfingiids described by Sluiter and Southern (see Table 1), the types of which were deposited in the collections of the Irish National Museum, Dublin (INMD) and the Musée Océanographique, Monaco-Ville (MOMV), and presents some new observations and records. The names of taxa follow the classification of Cutler & Gibbs (1985); Nephasoma Pergament and Apionsoma Sluiter, formerly considered as subgenera of Golfingia Lankester, are now elevated to generic rank.
Growth of juvenile Haliotis tuberculata (Mollusca: Gastropoda) in their natural environment
Authors: Clavier Jacques , Richard Olivier 
Published: May 2009

INTRODUCTIONThe ormer (Haliotis tuberculata L.) occurs in some abundance off the north coast of Brittany and the Channel Islands. On the French coast, exploitation of this species is not legally authorised except in the intertidal zone and the sublittoral stocks have for some years aroused the interest of local fishermen. Studies have therefore been initiated to investigate the exploitation potential of this new resource, and different aspects of the biology and ecology of the ormer have been examined so as to make use of models of population dynamics. Thus, a study of growth merits particular attention.
The Foraminifera of the Exe Estuary
Authors: Worth R. H. 
Published: May 2009

Samples of sand were taken, either from the shore immediately above low water of spring tides, or from the bottom in a few inches of water.With one exception no samples were dredged. The localities were few: Polesands; the north or estuarine shore of the Warren west of Salthouse Lake; the banks of the Salthouse Lake; a low-water stream on the Warren; near Lympstone; and (the dredged sample) within Exmouth Docks.
Biological Cycle of Podocoryna Exigua (Cnidaria: Hydrozoa) from a Sandy Bottom of the Ligurian Sea
Authors: Cerrano Carlo , Bavestrello Giorgio , Puce Stefania , Sarà Michele 
Published: May 2009

The genus Podocoryna is characterized by species living on shells usually inhabited by hermit crabs; but the mutual benefits of this association are not well understood.This study, besides describing the biological cycle of the hydroid Podocoryna exigua, brings new information on the relationship between hydroid and the hermit crab Diogenes pugilator, especially concerning their trophic strategies.The hydroid shows a seasonal cycle with a minimum density during summer and an increase during autumn and winter, reaching the highest value in spring. The production of medusae is almost constant during all seasons. The dwelling behaviour of the hermit crab affects a particular sedimentivorous strategy of the polyps while a clepto-commensalistic strategy is adopted by the hermit crab towards the hydroid. Laboratory experiments show that the presence/absence of the hermit crab in the shell and also the seawater temperature strongly influence the number of spines, particularly structures developing from polyps. In addition, free-living polyps in the sediments may represent a strategy to colonize free shells.
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.
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.
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.
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.
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.
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.INTRODUCTIONIt 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.
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.
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.
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.
Re-investigation of Polyoeca dichotoma and Acanthoeca spectabilis (Acanthoecidae: Choanoflagellida)
Authors: Hara Shigemitsu , Takahashif Eiji 
Published: May 2009

Light and electron microscopical reinvestigation of Polyoeca dichotoma Kent revealed that Acanthoecopsis spiculifera Norris, the type species of the genus, is a synonym for Polyoeca dichotoma. Since this step invalidates the use of the name Acanthoecopsis, a new genus Acanthocorbis was established for the three species formerly included in Acanthoecopsis.The three dimensional arrangement of costal strips forming the loricae of Polyoeca dichotoma and Acanthoeca spectabilis Ellis were examined by scanning electron microscopy. The arrangement of costal strips were similar in both species. The longitudinal costal strips and those forming the spines were arranged outside the supplementary costae and those of the transverse bonds.
Sarcotaces sp., a Parasitic Copepod Infection in two Deep-Sea Fishes, Lepidion Eques and Coelorhynchus Occa
Authors: Bullock A. M. , Phillips S. E. , Gordon J. D. M. , Roberts R. J. 
Published: May 2009

This paper describes the incidence and pathology of a copepod parasite (Sarcotaces sp.) in two species of deep-sea bottom-living fish. The fish Lepidion eques (Moridae) and Coelorynchus occa (Macrouridae) are common on the continental slope to the west of the British Isles at depths from about 400 to 1300 m and 700 and 2000 m respectively.In both species the parasite was located beneath the skin. In L. eques it was found primarily on the head, whereas in C. occa it was present on the mid to lower flank, often close to the anal vent. Excision of the parasite from the host tissue showed it to consist of a pyriform sac filled with inky black fluid. Detailed histological investigations revealed the parasite wall to be a highly complex structure. Within the gut fluid shown to be of haematogenous origin, numerous copepod nauplii were often observed.
Light and life on RRS ‘Discovery’
Authors: Herring Peter J. , Partridge Julian C. 
Published: May 2009

Research ships are much more numerous on the high seas in the 1990s than they were in the 1950s. At that time the United Kingdom was fortunate in that it had a purpose-built research vessel, RRS 'Discovery II' (see inside back cover), the successor to Scott's 'Discovery' (which was itself granted the title Royal Research Ship in 1923, see inside front cover). 'Discovery II's prime objectives had originally been oceanographic research in the Antarctic relevant to the whaling industry, to which end she had completed six two-year Antarctic commissions. In the 1950s she was being operated by the National Institute of Oceanography and was working extensively in the North Atlantic, covering the gamut of marine physics, chemistry, biology and geology, including participation in the research programme of the International Geophysical Year. However, by 1959 she was 30 years old, and both scientific space and stability had become limiting. Increasingly stringent Ministry of Trade requirements were also making successive refits less and less cost-effective. In April of that year the first brief outline for a replacement vessel was prepared, and six months later discussions between naval architects and the National Oceanographic Council (represented by Dr H.F.P. Herdman) produced an outline draft specification for the new ship. Further discussions with the Admiralty finally resulted, in June 1961, in an order being placed for a new vessel, at an estimated cost of £800K (Deacon, 1967).The new ship, the RRS 'Discovery', was launched in July 1962 and commissioned on 17 December, 10 m shorter than her originally conceived length but at a contained final cost of £802K.
A note on the elongated eye of the octopus Vitreledonella richardi
Authors: Land Michael F. 
Published: May 2009

The elongated eye of Vitreledonella richardi is described from two specimens caught at 200 m in the North Atlantic. It is shown that the cylindrical shape, with the lens placed centrally, results in a reduced field of view in the horizontal plane. It is argued that the unusual shape is an adaptation which minimises the silhouette of the eye as seen from below, and is part of the animal's camouflage strategy.IntroductionThe majority of fish and cephalopods have two hemispherical eyes, each of which has a field covering roughly the 180° on one side of the animal (Walls, 1942; Packard, 1972). The commonest exceptions to this rule are animals with so-called ‘telescopic’ eyes, found in many species of deepsea fish (e.g. Benthalbella, Argyropelecus, Opisthoproctus, Scopelarchus, see Marshall, 1954; Locket, 1977) and some cephalopods (Amphitretus, see Chun, 1915; Histioteuthis sp., see Young, 1975a). These eyes are tubular, with the lens at the open end of the tube, and a retina with a reduced field of view at the other. The eyes usually point upwards, and it is generally agreed that their shape is determined by the need to concentrate sensitivity and resolution into the rather narrow field above the animal where the residual daylight is still adequate for visual detection. It is 200 times darker in the downward direction (Denton, 1990), and so there must be some depth at which upward vision works, but downward vision does not. These are not the only kind of tubular eyes, however. In some cephalopods, but not to my knowledge in any fish, there are eyes of tubular appearance but with the lens not at the end, but in the centre of the tube (Figure 1).