bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal Changes in Population Density and Vertical Distribution of Harpacticoid Copepods on an Intertidal sand Beach
Authors: Harris Roger P.
Published: May 2009

An account has been given (Harris, 1972b) of the distribution of interstitial harpacticoid copepods on an intertidal transect at Whitsand Bay, E. Cornwall. The present work describes seasonal changes observed in the copepod species populations over a period of 2 years, from May 1968 to May 1970. Changes in population density and vertical distribution are described, and the relationship between these changes and the physical environment are discussed. A full account of the reproductive activity and lifecycles of the copepod species will be given later (Harris, 1972d). The only detailed accounts of seasonal cycles of individual intertidal harpacticoids are those of Lasker, Wells & Mclntyre (1970) for the sand-dwelling benthic copepod Asellopsis intermedia (T. Scott) and of Barnett (1968, 1970) for two species of Platychelipus Brady on an intertidal mudflat.
Reproductive Activity of the Interstitial Copepods of a Sandy Beach
Authors: Harris Roger P.
Published: May 2009

Information on the reproduction of interstitial harpacticoid copepods is mainly restricted to occasional references in the taxonomic literature to the presence of ovigerous females in collections. C. G. Rao (1967) provides the only account of the life-history of an exclusively interstitial species. The only detailed field study of seasonal reproductive cycles of harpacticoid copepods are of two species of Platychelipus Brady on a mudflat (Barnett, 1970), and of a sand-dwelling benthic copepod, Asellopsis intermedia (T. Scott) (Lasker, Wells & Mclntyre, 1970).
The Vertical Distributions and Diurnal Migrations of Calanoid Copepods Collected on the Sond Cruise, 1965 III. Systematic Account: Families Euchaetidae up to and Including the Metridiidae
Authors: Roe H. S. J.
Published: May 2009

This paper is the third of four dealing with the calanoid copepods taken with a modified Indian Ocean Standard Net (N113H) on the R.R.S. 'Discovery' SOND cruise of 1965. Details of the cruise are given by Currie, Boden & Kampa (1969) and the sampling methods used in the N113 H series are described by Foxton (1969) and by Angel (1969).
The Ionic Composition of the Lateral-Line Canal Fluid of Dogfish
Authors: Liddicoat Jennifer D. , Roberts B. L.
Published: May 2009

The sense organs of the lateral-line system of lower aquatic vertebrates are mechanoreceptors which respond to water movements. They are distributed over the body, usually in lines which form a definite pattern on the head and along each side of the trunk. In the Cyclostomes the sense organs project from the body surface ('free neuromasts'); in other aquatic vertebrates they are usually housed in canals which are sunk into the dermis and which open at regular intervals to the exterior, although in some teleosts and in all modern amphibia the canal system has been secondarily lost and the neuromasts are once again situated externally.
The Behaviour, Survival and Respiration of the CocklesCerastoderma EduleandC. Glaucumin Air
Authors: Boyden C. R.
Published: May 2009

Aspects of the physiology of the two cocklesCerastoderma edule(L.) andC. glaucum(Poiret) in air have been investigated. Both cockles exhibit bradycardia during exposure and are similarly tolerant of anoxic conditions, butC. edulesurvives longer in air thanC. glaucum. This is accounted for by the fact thatC. eduledisplays a behaviour pattern of valve movements upon emersion which allows air-breathing. Oxygen uptake rates of this cockle measured in air lie close to the lowest rates recorded in water, and are considered to approximate to a basal or quiescent level.C. glaucumdoes not air-breathe and is restricted to lowest shore levels. Values for ‘maximal’ levels of oxygen uptake in water have also been obtained together with estimates of metabolic scope for the cockle.
Chemical Survey of the Tamar Estuary I. Properties of the Waters
Authors: Butler E. I. , Tibbitts Susan
Published: May 2009

An initial report is presented on some chemical properties of the waters in the Tamar Estuary. The results are compared to those obtained in the Western Channel during the same period. Considerable differences are shown in the concentrations of inorganic nutrients but the dissolved organic nitrogen concentrations are relatively similar. Dissolved iron has been estimated both before and after the breakdown of organic compounds by photocombustion. The results show the build-up of humic substances and associated iron after heavy rain. When the concentration of suspended sediment in the water is high it can control the level of dissolved phosphorus by removing it from rich water and releasing phosphorus into poor waters.
Saprophytic and phagocytic isolates of the colourless heterotrophic dinoflagellateGyrodinium lebouriaeHerdman
Authors: Lee Robert Edward
Published: May 2009

Nutritionally, there are three basic types of Dinophyceae: (1) free-living photosynthetic autotrophs; (2) parasitic heterotrophs living on or in other organanisms and (3) free-living phagocytic or chemosynthetic heterotrophs. Representatives of the first type, the free-living photosynthetic autotrophic species, have been extensively investigated at the fine-structural level (for a review see Dodge, 1971). There are fewer species of the second type, the parasitic Dinophyceae, but many of these have been investigated in the electron microscope (Cachon & Cachon, 1966, 1970, 1971a,b; Cachonet al.1968; Soyer, 1969 c; Manier, Fize & Grizel, 1971; Siebert & West, 1974). The third type, the free-living heterotrophic Dinophyceae, probably comprises the greatest number of species in the class; as Kofoid & Swezy (1921) state ‘One cannot work with the marine unarmored Dinoflagellata for even a short time without being struck by the fact that the majority of the individuals observed show evidence of holozoic nutrition and that the number actually containing chromatophores is relatively small throughout the entire Dinoflagella’. While the free-living heterotrophic Dinophyceae comprise the largest proportion of the class they have been, by far, the most poorly studied at the fine structural level. Investigations on these organisms have been limited to a comprehensive study ofOxyrrhis marina(Dodge & Crawford, 1971a,b, 1974) plus studies on specific parts ofCryptothecodinium cohnii(Kubai & Ris, 1969; Pokorny & Gold, 1973) andNoctiluca miliaris(Afzelius, 1963; Soyer, 1968, 1969a,b; Zingmark, 1970).
Tidal residuals in the English Channel
Authors: Pingree R. D. , Maddock Linda
Published: May 2009

The amplitude and phase of tidal characteristics in the English Channel have been described both using numerical models (Grijalva, 1962; Hyacinthe & Kravtchenko, 1967) and a hydraulic model on a rotating table (Chabert d'Hières & le Provost, 1970). The aim behind the development of the numerical model described here is first to derive an accurate representation of the principal lunar semi-diurnal (M2) tide in the English Channel and then to use the currents generated by the tidal input to determine the tidal circulation patterns and residual flow through the English Channel. A test of the model must be its ability to reproduce the known clockwise eddy in Lyme Bay and the south-ward flow either side of Portland Bill. If these known tidal residuals can be reproduced then the model may help to elucidate residuals in other regions where the flow is unknown. In addition to deriving the mean tidal velocities, horizontal distributions for the mean squared and cubed values are calculated and the importance of these distributions in determining the nature of the bottom and the degree of stratification of the water column in summer is demonstrated.
An apparent specific dynamic action in Mytilus edulis L.
Authors: Bayne B. L. , Scullard C.
Published: May 2009

The results of experiments recorded by Bayne & Scullard (1977) confirmed earlier studies (Bayne, 1973) in describing a decline in the rate of oxygen uptake (Vo2) by Mytilus edulis during starvation, eventually reaching a steady-state value, called the standard rate of oxygen consumption. Earlier experiments had also shown that if such starved mussels were fed, oxygen uptake increased rapidly to a high level called the active rate of oxygen consumption (Thompson & Bayne, 1972; Bayne, Thompson & Widdows, 1973). Some of this increase in metabolic rate is undoubtedly due to an increased filtration rate that is stimulated by the presence of food (the ‘mechanical cost of feeding’ discussed by Bayne et al. 1976), and part is due to the ‘physiological costs of feeding’, which includes energy utilized in digestion and assimilation of the food, and energy that is lost during deamination and other catabolic processes that accompany digestion (Warren & Davis, 1967). Increases in metabolic rate associated with feeding have been called the specific dynamic action (SDA) of the ration (see Harper, 1971, for a discussion) or the apparent SDA (Beamish, 1974)5 and they have been related to aspects of protein metabolism (Krebs, 1964). This paper describes the results of some experiments designed to examine the relationships between SDA and ammonia excretion in Mytilus edulis L.
Distribution of water inArenicola marina(L.) equilibrated to diluted sea water
Authors: Freeman R. F. H. , Shuttleworth T. J.
Published: May 2009

It is our aim in this paper to answer three questions. All of them relate to the well-known ability of lugworms to act as isosmotic osmo-conformers over a wide range of salinities. When exposed to diluted sea water, the body fluids come into osmotic equilibrium with the lowered external concentration, and considerable amounts of water enter the body of the worm. There is no evidence of weight or volume regulation in dilute media, as assessed by a return of the body weight towards its original value. The processes of osmotic adaptation down to the lowest salinity limits for survival include, therefore, tolerance of a lowered osmotic concentration of the body fluids, and of the retention of increased amounts of water in the body. The evidence on which this view of osmotic adaptation in lugworms is based is reviewed by Oglesby (1969, 1973). Additional information onArenicola marinais provided by Freeman & Shuttleworth (1977).
The depth distributions and community organization of the planktonic cyclopoids (Crustacea: Copepoda) of the Cape Verde Islands Region
Authors: Boxshall G. A.
Published: May 2009

In November 1969 on ‘Discovery’ Cruise 30 a day and a night series of hauls were taken with the RMT 1 + 8 net system (Baker, Clarke & Harris, 1973) in the region of the Cape Verde Islands. The cyclopoid copepods from the two series have been examined and this account describes their depth distributions, vertical migration patterns and community organization. Some taxonomic observations on one family, the Oncaeidae, have already been published (Boxshall, 1977).
Stretch Receptor Organs in the Thorax of the Hermit Crab,Pagurus Bernhardus(L. 1758)
Authors: Pilgrim R.L.C.
Published: May 2009

Muscle receptor organs (MRO) are present in the abdomen in a wide variety of higher Crustacea (see review by Alexandrowicz, 1967), though most experimental work on these organs has been carried out on representatives of only the Astacura and Palinura, in which the anatomy is relatively uniform. In the very varied group Anomura, they have been reported from among the Galatheidea, Thalassinidea and Paguridea (Alexandrowicz 1952b; Pilgrim, 1960); in the latter paper, they were shown to have properties physio-logically similar to those of the Astacura and Palinura, with slowly- and fast-adapting components. Stretch sensitive organs also occur in the thorax of many forms, but are of two distinct types there. In the posterior thorax are MRO comparable with those of the abdomen, i.e. comprising receptor cell, specialized muscle and a complex innervation of excitatory and inhibitory nerves as well as sensory fibres. In the more anterior thorax are the relatively very simple N-cells, whose dendrites spread among the fibres of non-specialized muscle and which are not known to possess any accessory innervation (Alexandrowicz, 1952a).
Copepoda Monstrilloida From South-West Britain Including Six New Species
Authors: Isaac M. J.
Published: May 2009

The Monstrilloida form an aberrant group of Copepoda, distinguished by the complete lack, in the adults, of gut and mouth-parts. Sars (1921) divided the group into two sections, one being the Monstrilloida Cyclopimorpha, comprising a single family, now called the Thespesiopsyllidae (see Wilson, 1932), with two genera. The larvae of Thespesiopsyllus are gut parasites of ophiuroids (Bresciani & Liitzen, 1962). The second genus, Orientopsyllus, was described by Sewell (1949) from the Indian Ocean.

The second section, the Monstrilloida Genuina, comprises the single family Monstrillidae, various authors (Malaquin, 1901; Sars, 1921; Rose, 1933; Davis, 1949) differing in their division of this into genera. The present author regards the family as consisting of three genera, Monstrilla Dana, 1848, Thaumaleus Kroyer, 1846, and Monstrillopsis Sars, 1921, separated according to the criteria listed in Table 1.
The Food of Deep-Sea Copepods
Authors: Harding G. C. H.
Published: May 2009

The question of how organisms living below 1000 metres depth in the oceans obtain food in sufficient quantity to survive has lately received a lot of attention (Vinogradov, 1968; Sanders & Hessler, 1969; Fournier, 1972). The oldest and simplest theory, first advocated by Agassiz (1888), is that deep-sea organisms are nourished by a ‘rain’ of organic detritus from overlying surface waters. Detritus is defined to include all organic particles, living and dead, which sink passively. An alternate proposal by Riley (1951), Vinogradov (1962) and Wickstead (1962) is that the main supply of food for deep-sea plankton is conveyed from the euphotic zone by overlapping vertical migratory plankters.
A Redescription of the Dinoflagellate Gymnodinium Simplex with the Aid of Electron Microscopy
Authors: Dodge J. D.
Published: May 2009

In 1908 Lohmann described a small dinoflagellate which appeared to lack a sulcus and was therefore placed in a new genus – Protodinium. The type species, P. simplex (Text-fig, IA) was broadly ellipsoidal with broad rounded apices, circular in cross-section and about 1–5 times as long as broad. The girdle was poorly defined, but was more or less median in position. The nucleus was relatively large and centrally located and yellow leaf-life chloroplasts, four to many in number, were arranged in the periphery of the cell.
Ultrastructural Observations on Nanoplankton Collected from the Coast of Jugoslavia and the Bay of Algiers
Authors: Leadbeater B. S. C.
Published: May 2009

A large number of nanoplankton species originally found in the sea around Britain have now been collected from other northern temperate waters (see Leadbeater, 1972 c; Manton & Leadbeater, 1974). It was, therefore, of considerable interest to collect nano-plankton from warmer waters such as those of the Adriatic and Mediterranean. The larger plankton of both the Adriatic and Mediterranean has been the subject of investigation by a succession of scientists from many countries (for references see Tregouboff, 1952). Whilst many workers acknowledged the importance of the smaller plankton from these areas (e.g. Bernard, 1958; Lalami-Taleb, 1971) only a few have attempted to study and identify species belonging to this group. In this respect the meticulous work of Lohmann (1902a, 1911) and Schiller (19136, 19256) requires special mention. Lohmann (1902a), working on the phytoplankton from the coast of Sicily, first used the technique of pumping sea water through filter paper and in this way he was able to collect and identify many minute species for which he later suggested the name ‘ Nannoplankton’ (Lohmann, 1911). On a later excursion to the Atlantic Ocean, Lohmann (1911) found the gentle centrifugation of sea-water samples was a more satisfactory and less destructive way of concentrating small cells. Schiller's most important contribution concerns a phytoplankton study carried out as part of an international hydrobiological survey of the Adriatic Sea during the years 1911–14. Schiller's findings confirmed many of Lohmann's previous observations and added a further range of new species including many green flagellates (Schiller, 1913 6, 1925b).
Observations on the SilicoflagellateDictyocha SpeculumEhrenb. From The Firth of Clyde
Authors: Boney A. D.
Published: May 2009

Occasional reference to the sporadic appearances of silicoflagellates (commonlyDictyochaspp.) are to be found in a number of seasonal studies of phytoplankton in the coastal waters of the British Isles. The silicoflagellates are rarely described in any detail since they usually form a small component of the annual phytoplankton. The autumnal occurrence of silicoflagellates in the Firth of Clyde was briefly described by Marshall (1924) in an account of the food ofCalanus, and further seasonal observations on silicoflagellates in European coastal waters are to be found in the works of Margalef (1965), Nival (1965), Travers & Travers (1968) and Ignatiades (1970). Numerous studies on silicoflagellates have been concerned with their taxonomy, particularly the plasticity of form shown by their tubular siliceous skeletal structures and the many taxa (fossil and living) so far described. The confusion which has arisen through the differing views of palaeontologists studying fossil material, and botanists working with live populations and their seasonal abundances, has been highlighted recently in a culture study ofDictyocha fibula, in which skeletal variations in a single clone were matched with a number of other entities, fossil and living (Van Valkenburg & Norris, 1970).
A Summary of the Observations on the Occurrence of Planktonic Stages of Fish off Plymouth 1924–1972
Authors: Russell F. S.
Published: May 2009

Records of the occurrence of postlarval stages of teleostean fishes in the plankton off Plymouth have been kept for a period of nearly 50 years. During that period noteworthy changes in the abundance of postlarvae have taken place. While in the 1920s postlarvae were very abundant in the plankton, in the 1930s they became much fewer at about the time when the herring fishery declined. Somewhere around 1965 another change took place and post-larvae became once more very abundant. There was also a marked increase in the quantity of macroplankton, which like the young fish had become much reduced in quantity in the 1930s (Russell et al. 1971).
Axial Skeleton and Musculature in the Thorax of the Hermit Crab,Pagurus Bernhardus[Anomura:Paguridae]
Authors: Pilgrim R. L. C.
Published: May 2009

During an examination of the distribution and relationships of muscle receptor organs in the hermit crab,Pagurus bernhardus(Pilgrim, in preparation), it was found that not enough was known about the muscular anatomy of the animal for the experimental work to be described satisfactorily. This paper is therefore an account of the anatomy appropriate to a better understanding of the receptor organs. In the preparation of this account, it was necessary to examine the skeleton of the animal in great detail, since a knowledge of the relationships of especially the movable skeletal parts is basic for an understanding of the muscular system. The study also forms part of a series in which the comparative anatomy of the axial skeleto-muscular systems is examined in the Decapoda. This paper falls naturally into two parts, dealing respectively with the skeleton and the muscles. Although emphasis in this work is on the trunk anatomy of the last six segments of the thorax, it is necessary to extend observations beyond this region for certain interpretations.
Notes onGyptis CapensisandSosane Sulcata[Annelida:Polychaeta] From the Benthos off the South Coast of Cornwall
Authors: Gibbs P. E. , Probert K.
Published: May 2009

Studies of the distribution of china clay waste and its effects on the bottom communities off the south coast of Cornwall, initiated by Portmann (1970) and Howell & Shelton (1970), have been supplemented by further surveys, the results of which will appear in future papers by Shelton & Rolfe (in preparation) and Probert (in preparation). This paper describes two polychaete species which have been discovered in this area, namely the hesionidGyptis capensis(Day) and the ampharetidSosane sulcataMalmgren. From the zoogeographical viewpoint, the records of both species are of great interest: hitherto,G. capensiswas known only from southern Africa and the tropical West Pacific region, andS. sulcatafrom Scandinavia, West Scotland and the Mediterranean.
A New Type of Heart Mechanism in the Invertebrates
Authors: Heron A. C.
Published: May 2009

The tunicate heart has been extensively studied, with particular recent emphasis on the physiology of heart reversal (see Krijgsman (1956) and Kriebel (1968) for reviews). The salp heart, however, has received much less attention (Schultze, 1901; Nicolai, 1908), mainly because of the difficulty of maintaining this delicate marine animal in the laboratory. Thus the structure and function of the salp heart has been assumed to be similar to that of the sessile tunicates (Ihle, 1935; Berrill, 1950).
The Broods of British Mysidacea (Crustacea)
Authors: Mauchline J.
Published: May 2009

All species of the Mysidacea (Crustacea) lay their eggs into a marsupium, thus allowing direct counts of brood sizes to be made. The different forms of the young stages in the marsupium are closely similar in all species. The most detailed embryological studies are those of Manton (1928) on Hemimysis lamornae (Couch), Wagner (1896) and Needham (1937) on Neomysis integer (Leach), and Nair (1939) on the tropical species Mesopodopsis orientalis (W. M. Tattersall). Kinne (1955) describes and figures the general body forms of the different stages of development of the larvae in the marsupium of Neomysis integer; Vannini (1930) examines the larvae of Leptomysis lingvura (G. O. Sars), while Kane (1904) illustrates the most advanced larval stage of Mysis relicta Lovén. The larvae of several non-British species have been described -Boreomysis arctica (Kröyer) by Jepsen (1965), Mysidium columbiae (Zimmer) by Davis (1966) and Neomysis intermedia Czerniavsky by Murano (1964b).
Adaptation of the PolychaeteNereis Diversicolorto Manganese in Estuarine Sediments
Authors: Bryan G. W. , Hummerstone L. G.
Published: May 2009

In a previous paper (Bryan & Hummerstone, 1971) the average concentrations of copper, zinc, lead, manganese and iron in the polychaeteNereis diversicolorO. F. Müller from several estuaries draining the mineralized areas of South-West England were compared with concentrations in the sediments. Although high levels of copper and zinc were encountered in some sediments none contained high levels of manganese and, in the worms, concentrations of manganese were low and relatively constant. Other estuaries in the area have since been examined, but although thousands of μg/g of copper, zinc, lead and arsenic have been found in some sediments, concentrations of manganese exceeding 1000, μg/g have rarely been encountered. Manganese ores occur quite widely in South-West England but the scale of mining appears to have been small by comparison with that for more obvious contaminants of estuaries such as copper, lead and arsenic (Dines, 1956). However, it is thought that the field observations and experimental results described in this paper can be extrapolated to situations where much higher concentrations of manganese occur.
Scyphistoma Regeneration From Isolated Tentacles in Aurelia Aurita
Authors: Laurie-Lesh Georgia E. , Corriel R.
Published: May 2009

All animals do not display the same capacities for repairing injuries, i.e. they possess what may be termed different ‘regeneration potentials’. One parameter influencing the regeneration potential manifested by an organism is its developmental history, or ontogeny. Early in an animal's ontogeny many of its cells are still undergoing both structural and biochemical modifications. As the animal matures, its cells become increasingly differentiated, ultimately attaining a high degree of specialization (Hay, 1966; Balinsky, 1970).

Numerous studies support the contention that the younger an animal ontogenically, the greater is its regeneration potential. Investigations using amphibians have presented several cogent examples of this generalization (Balinsky, 1970). Analogous situations are also evident in the Cnidaria. In the hydrozoan, Hydra, the tentacles contain what are among the ontogenically ‘oldest’ cells in the organism (Tripp, 1928; Brien & Reniers-Decoen, 1949; Burnett, 1966; Campbell, 1967b). Unlike the remainder of the organism, these structures also reportedly possess no regeneration potential (Peebles, 1897; Kanaev, 1952).

Three explanations have been proposed to account for the absence of regeneration potential in isolated tentacles. Nussbaum (cited in Kanaev, 1952) suggested that the absence of interstitial cells in the tentacles precluded regeneration. However, other regions of the animal, when experimentally deprived of this cell type, retained their regenerative capacities (Brien, 1953; Diehl & Burnett, 1964).

A second explanation invoked the size of an isolated tentacle as a factor limiting regeneration. In disputing this suggestion, Peebles (1897) measured tentacle volume. Isolated Hydra grisea (Pallas) tentacles ranged from 0.01 to to 0.03 mm3, while the volume of the smallest body fragment capable of total regeneration was considerably smaller, 0.006 to 0.01 mm3. From these measurements she concluded that the size of isolated tentacles could not account for the inability to regenerate.
Studies on the Factors Affecting the Release of Organic Matter By Skeletonema Costatum (Greville) Cleve in Field Conditions
Authors: Ignatiades L.
Published: May 2009

At the present time only limited data about the release of organic matter by phyto-plankton in the marine environment are available (Antia, McAllister, Parsons, Stephens & Strickland, 1963; Fogg, Nalewajko & Watt, 1965; Hellebust, 1967; Jitts, 1967; Home, Fogg & Eagle, 1969; Anderson & Zeutschel, 1970; Thomas, 1971; Samuel, Shah & Fogg, 1971).
Studies on the Factors Affecting the Release of Organic Matter BySkeletonema Costatum(Greville) Cleve in Culture
Authors: Ignatiades L. , Fogg G. E.
Published: May 2009

A few studies on the excretion of organic matter by marine phytoplankton in culture have been reported (Guillard & Wangersky, 1958; Wangersky & Guillard, 1960; Stewart, 1963; Hellebust, 1965). Eppley & Sloan (1965) reported extensive excretion inSkeletonema costatum(Greville) Cleve cultures as they approached senescence and emphasized that excretion is inversely proportional to the physiological activity of cells. Hellebust (1965) demonstrated the release of high amounts (up to 38% of the carbon assimilated) of organic matter bySk. costatumcells exposed to low light intensities. It is apparent that more knowledge is needed in order to define the intra- and extracellular factors affecting the excretion.
A Preliminary Consideration of the Taxonomic Position of Palmaria Palmata (Linnaeus) Stackhouse = Rhodymenia Palmata (Linnaeus) Greville
Authors: Guiry M. D.
Published: May 2009

The life history and taxonomic position of Rhodymenia palmata (Linnaeus) Greville, one of the commonest red algae in the northern hemisphere, have been a source of considerable speculation. Carpogonial plants and carposporangial plants are unknown although tetrasporangial plants are common and spermatangial plants have been reported on numerous occasions. A parallel situation occurs in the genus Halosaccion Kützing for which carpogonial and carposporangial plants have never been recorded and spermatangial plants are well known only in the species Halosaccion ramentaceum (Linnaeus) J. G. Agardh. It is proposed in this paper to consider the relationship of Rhodymenia palmata to the other genera of the Rhodymeniaceae (Rhodymeniales) particularly Halosaccion and Leptosarca Gepp & Gepp.
A Resurvey of Colman's Intertidal Traverses at Wembury, South Devon
Authors: Boalch G. T. , Holme N. A. , Jephson N. A. , Sidwell J. M. C.
Published: May 2009

In 1930, Colman (1933) made a study of the zonation of common intertidal animals and plants on Blackstone or Church Reef, Wembury. Four lines were marked out across the reef, and three of these, which radiated from his so-called ‘Central Rock’, were resurveyed during the summer and autumn of 1973. Besides the authors, help was given in the 1973 survey by Mr P. G. Corbin, Dr P. E. Gibbs, Dr P. K. Probert, Dr A. J. Southward, Mr R. L. Barrett and Mr T. J. Perry. Mr G. A. W. Battin was responsible for surveying and levelling, and Mr D. Nicholson for the photography.
The Nature of Tissue Regeneration After Wounding in the Sea AnemoneCalliactis Parasitica(Couch)
Authors: Young Jane A. C.
Published: May 2009

Regeneration of ectoderm and mesogloea, and the interactions of these layers, in the sea anemoneCalliactis parasitica(Couch) have been studied by examining the healing of simple wounds. Studies included the part played by the mesogloeal cells, the origin and functions of which have been much debated.
The Distribution of Settled Larvae of the Bryozoans Alcyonidium Hirsutum (Fleming) and Alcyonidium Polyoum (Hassall) on Fucus Serratus L.
Authors: Hayward P. J. , Harvey Paul H.
Published: May 2009

The spatial settlement of marine invertebrate larvae is not a random process. The distribution of the adults of a particular species is influenced by the behavioural responses of the animal to a range of environmental stimuli which, in the case of many sessile invertebrates, result in the display of clear substrate selection. The role of habitat selection in determining the distribution of aquatic invertebrates has been the subject of a review by Meadows & Campbell (1972). The selection of algal substrata by the larvae of various intertidal species of Bryozoa has been demonstrated by Ryland (1959); among these, the ctenostomatous bryozoans Alcyonidium hirsutum and A. polyoum were shown to exhibit a strong preference for fronds of the alga Fucus serratus, an experi-mental result which accorded well with the distribution of the two species on the shore (Ryland, 1962).
Growth and Mortality of the BryozoanAlcyonidium Hirsutum(Fleming) onFucus Serr AtusL.
Authors: Hayward P. J. , Harvey Paul H.
Published: May 2009

As the processes by which epiphytic bryozoans become established in aggregations on intertidal algae become more clearly understood, it is necessary to consider some of the ecological consequences of non-random settlement. The adaptive significance of aggregation in epiphytic bryozoans has been discussed recently by Hayward & Ryland (1974), who also showed how the worst effects of overcrowding are mitigated. Acorn barnacles and spirorbine tubeworms have evolved a specific behavioural pattern which results in regular, spaced-out settlement within aggregations, thus allowing room for each individual to become established and begin growing. By contrast, epiphytic bryozoans do not exhibit this kind of behaviour (Harvey, Ryland & Hayward, in preparation). Al-though a minimum size is probably required before the colony is able to breed, the pattern of growth observed forAlcyonidium hirsutumshows that this can be achieved through lability of growth direction. The linear relationship found to exist between colony size and fecundity shows that no advantage is conferred by increased size; the smaller colony is as effective in reproduction as the larger. In the present paper two other ecological consequences of aggregated settlement are considered: mortality and size.
Studies on the Chromosomes of the ScallopPecten Maximus(L.) and Related Species
Authors: Beaumont A. R. , Gruffydd LL. D.
Published: May 2009

A number of species of the family Pectinidae (Lamellibranchia, Mollusca) are of considerable commercial importance in many parts of the world. Many of these are being reared in laboratories and hatcheries and this has made easier studies of cytogenetics using eggs and embryos, and ultimately will make studies of their genetics feasible. Recently, simple squash techniques have provided a fast and reliable method for obtaining chromosome numbers from eggs and embryos of several bivalves includingMercenariaspp. (Menzel & Menzel, 1965),Ostrea luridaandCrassostera gigas(Ahmed & Sparks, 1967),Mytilusspp. (Ahmed & Sparks, 1970), andCrassostreaspp. (Menzel, 1968). In 1967, Longwell, Stiles & Smith published the karyotype ofCrassostrea virginicaobtained from embryos which had been treated with colchicine.
Breeding Biology and Seasonal Population Changes ofJaera Nordmanni NordicaLemercier [Isopoda, Asellota]
Authors: Jones M. B.
Published: May 2009

Jaera nordmanni(Rathke) occurs abundantly beneath stones and algae in freshwater streams (McCartan & Slinn, 1953), brackish water pools (Naylor & Slinn, 1958), and estuaries (Naylor, Slinn & Spooner, 1961; Harvey, Jones & Naylor, 1973). The species is widely distributed and ranges from the Black and Mediterranean Seas south to the Azores, and north to the west coast of Scotland (Naylor, 1972). Three forms ofJ. nordmannihave been described (Lemercier, 1958, i960) of which onlyJaera nordmanni nordicaLemercier has been recorded in Britain (Naylor, 1972; Jones & Fordy, 1973). The two other forms,Jaera nordmanni nordmanniLemercier andJaera nordmanni massiliensisLemercier, have a more southerly distribution (Naylor, 1972), and can be separated fromJ. nordmanni nordicaby differences in male sex characters (Lemercier, 1958, 1960; Jones & Fordy, 1973). Apart from some eco-physiological work (Nayloret al.1961; Harveyet al.1973) and a recent study with a scanning electron microscope (Jones & Fordy, 1973), little is known of the biologyof J. nordmanni.The present paper reports on the breeding biology and seasonal population fluctuations ofJaera nordmanni nordica, and compares the results with a similar study on the members of theJaera albifronsLeach group of species (Jones & Naylor, 1971) which are closely related to and often in competition withJ. nordmanni.
Circeis Paguri, The Spirorbid Polychaete Associated with the Hermit-CrabEupagurus bernhardus
Authors: Ogily-Al S.M. , Jones-Knight E. W.
Published: May 2009

The genusCirceisSt-Joseph was based uponC. armoricanaSt-Joseph (1894), but Caullery & Mesnil (1897) suggested that the latter is a mere variety ofSpirorbis spirillum(L.), which Chamberlin (1919) therefore regarded as the type of the genus. These two species are indeed closely related to each other, but distinguished by the sculpturing of the collar setae (Knight-Jones, Knight-Jones & Al-Ogily, 1975). They belong to a genus which is very distinct fromSpirorbis, as was pointed out by Knight-Jones, Knight-Jones & Kawahara (1975), who regardedC. armoricanaas the type species.
Sound and Startle Responses in Herring Shoals
Authors: Blaxter J. H. S. , Gray J. A. B. , Denton E. J.
Published: May 2009

The behavioural experiments described in this paper were carried out to complement earlier physiological work on the acoustico-lateralis system of the clupeid fishes. Previous work, summarized by Blaxter, Denton & Gray (1981a), has shown that the sense organs of the clupeid utriculus are highly sensitive to alternating pressures. Since the utriculus signals the polarity and amplitude of each peak in a complex pressure wave form separately, independently of the rate of change of pressure over a range equivalent to a frequency band of 30–800 Hz, it is well suited to give information on brief noises. In the clupeids the lateral line is hydrodynamically connected with the ear and we have suggested that the signals arising from the inner ear and the neuromasts of the lateral line are used in conjunction to provide information about direction and range.
Patterns of Variation in The Prosome Length of Overwintering Stage V Copepodites of Calanus Finmarchicus in The Firth of Clyde
Authors: Grigg H. , Bardwell S. J. , Tyzack S.
Published: May 2009

In attributing variations in growth and metabolism within a population to environmental fluctuations, and in interpreting the biological response to environmental fluctuations, it is important to recognize the variations that are intrinsic to the population or species. Consequently, it is common practice in studies on the growth and metabolism of calanoid copepods to separate instars and, in the case of adults, males and females when analysing measurements. Although studies on calanoids, in particular species of Calanus and Euchaeta, have demonstrated the existence of pronounced sexual differences in parameters such as dry weight, biochemical composition and respiration rate (e.g. Comita, Marshall & Orr, 1966; Marshall, 1973; Bamstedt, 1975, 1979; Gatten et al. 1979, 1980), the possibility that similar differences might occur in pre-adult instars has not been examined, this despite the fact that in many species in this group it is possible to distinguish the sex of copepodites IV and V, the two instars preceding the adult.
Fish in Salps: the Association of Squaretails (Tetragonurus Spp.) With Pelagic Tunicates
Authors: Janssen John , Harbison G. R.
Published: May 2009

Stromateoids are fishes of the open ocean commonly found in association with gelatinous zooplankton (Mansueti, 1963; Haedrich, 1957). One genus, Tetragonurus, has been found inside the branchial chambers of salps (Emery, 1882; LoBianco, 1909) and cloacal chambers of pyrosomes (LoBianco, 1909; Fitch, 1949, 1951).
The Settlement ofSargassum MuticumPropagules in Stationary and Flowing Water
Authors: Norton Trevor A. , Fetter Richard
Published: May 2009

Waves and currents render the shallow sea a chaotic environment. Seaweeds broadcast into the water tiny dissemination phases whose powers of locomotion are at best puny in relation to the water forces that act upon them.
The Anatomy of Respiratory Structures in the Dorid Nudibranchs,Onchidoris BilamellataandArchidoris Pseudoargus, With Details Of The Epidermal Glands
Authors: Potts Geoffrey W.
Published: May 2009

The respiratory function of the naked body of sea slugs (Opisthobranchia) has long been recognized. The gross anatomy of the gills of dorid nudibranchs was first published by Hancock & Embleton (1852) and was later revised and corrected by Eliot in 1910 in his supplement to the Ray Society monograph by Alder & Hancock (1845–55). Herdman (1890) and Rao (1936) give histological details, but do not seriously add to the understanding of the function of dorid gills or their circulation system. While the gill ciliation of bivalves (Atkins, 1938) and prosobranchs (Yonge, 1947) has been thoroughly examined this is not so in dorid nudibranchs and only the ciliation of the notaspidPleurobranchus membranaceushas been described in any detail (Thompson & Slinn, 1959; Thompson, 1976) and the dorsal mantle of some dorids (Kress, 1981). Much of the general anatomy of opisthobranchs is reviewed by Hoffman (1939).
A New Bottom-Sampler
Authors: Holme N. A.
Published: May 2009

A bottom-sampler is described for use under open-sea conditions, particularly where the bottom is of sand or coarser material.

It takes a sample of 1/20m.2 area of semicircular cross-section and maximum depth 15 cm. There is probably little loss of material while hauling and no danger of the apparatus losing soil through being wedged open by shell fragments, etc. The instrument weighs over 45 kg. and is weighted to n o kg. in use.
Short-Period Fluctuations in the Numbers of Barnacle Larvae, With Notes on Comparisons between Pump and Net Plankton Hauls
Authors: Pyefinch K. A.
Published: May 2009

Records are given of the numbers of barnacle larvae obtained from samples of water pumped through a plankton net. Several series of hauls were made at intervals over the time of year when barnacle larvae are abundant.

The numbers of the cyprid larvae of Balanus balanoides in the surface waters show a diurnal variation, being markedly less during the hours of darkness. This conclusion may also apply to the cyprids of B. crenatus and Verruca stroemia, but the numbers of these larvae were too small to permit reliable conclusions to be drawn. There is some evidence that similar diurnal variations occur in larval stages other than the cyprid.
On the Larval Development of Elminius Modestus Darwin
Authors: Knight-Jones E. W. , Duncan Waugh G.
Published: May 2009

Nauplii of the first two stages were obtained from adult Elminius modestus and larvae of all stages, except the smallest, were obtained from the plankton over Essex oyster beds.

Over 200 nauplii of all sizes were measured. Their size distribution, plotted graphically, showed six peaks corresponding to six naupliar stages. The later stages were much more variable in size than the earlier stages.

The size limits and characteristics of each naupliar stage are given. Briefly, Stage I has the fronto-lateral horns pointing backwards. Stage II has the caudal spine much longer than the abdominal process. Stage III has the abdominal process about as long as the caudal spine, but has no carapace fold posteriorly. Stage IV has a carapace fold but no sign of the abdominal appendages. Stage V has the rudiments of these appendages showing indistinctly within the abdomen. In Stage VI the abdominal appendages are prominent.
The Occurrence of Unusual Species of Chaetognatha in Scottish Plankton Collections
Authors: Fraser J. H.
Published: May 2009

There are six species of Chaetognatha that are usually taken in Scottish plankton samples from the appropriate localities. These are

Sagitta setosaJ. Müller, from lower salinity water such as that found in the southern and central North Sea and the Irish Sea.

S. elegans elegansVerrill, from mixed oceanic and coastal water.

S. serratodentataKrohn, from surface and subsurface warm oceanic water of fairly high salinity.

S. maxima(Conant), from cold deep water.

Eukrohnia hamata(Möbius), from cold deep water.

Sagitta lyraKrohn, from warm deep water.

All are valuable indicator species (Meek, 1928; Russell, 1935, 1939; Fraser, 1937, 1939). Of these, the first five have occurred in somewhat varying numbers and distribution according to hydrographic conditions every year since at least 1935, except possibly during the period 1940–45 when no investigations were made.S. lyrahas been taken in most of these years, but was not found in 1935, 1936 or 1937. It was, perhaps, most abundant in 1948, and one specimen was taken in that year from the Moray Firth, though its presence there must be regarded as distinctly unusual.

Spadella cephaloptera(Busch) is widely distributed throughout the Scottish area as a bottom-living form and is therefore not included here as planktonic.

There are several other species which occur only occasionally in the Scottish plankton either as individual specimens or in small numbers in specialized localities: for convenience these may be termed unusual species. They are as follows.

Sagitta elegans arcticaAurivillius, which has occurred in several years in the Faroe-Shetland Channel associated with the community characterized byEukrohnia hamataandCalanus hyperboreus.
A Source of Error in the Absorptiometric Determination of Inorganic and Total Phosphorus in Sea Water
Authors: Armstrong F. A. J.
Published: May 2009

The results of phosphate determinations in sea water by the Deniges method, using red light, in an absorptiometer, may be in error if the stannous chloride reagent has low HC1 concentration, and contains stannic tin.

The error is in the reagent blank determination, and seems to be caused by colloidal stannic compounds which increase the opacity of the solution. In sea water the effect may be smaller or immeasurable so that results are over-corrected.

When the stannous chloride solution contains about 5% hydrochloric acid, reagent blank figures are low, and independent of stannic tin concentration. This acidity is recommended.
Measurements to Determine Extinction Coefficients and Temperature Gradients in the North Sea and English Channel
Authors: Gall M. H. W.
Published: May 2009

During a cruise in the southern North Sea and English Channel in 1948 a series of measurements on light penetration was secured.

The apparatus used has been described, and methods of handling it discussed. A description of the experiments for determining the transmission curve of the niters used in the photometers, has been included.

Of the systematic and random errors to which the photometer measurements were liable the most serious lay in not knowing the precise depth of the sea cell.

Extinction coefficients have been determined from the gradients of logarithmic transmission-ratio/depth graphs, and the results tabulated for each station.

Temperature gradients were never large, usually of the order of 0·02 degrees per metre, the temperature usually dropping with increased depth, frequently there was no gradient at all.
Notes on the Plymouth Marine Fauna Chironomidae (Insecta:Diptera)
Authors: Hall R. E.
Published: May 2009

The following records were obtained during a fortnight at the beginning of April 1949. The localities investigated were rocky shorepools below the Laboratory, and a small area at the upper tidal limit of Tamerton Lake. In addition to imagoes collected on the wing, larvae were reared from a mud sample taken from the stream bed just below the upper limit of tidal penetration. None of the Tamerton species are marine in the strict sense adopted by Edwards (1926), but those bred out are tolerant of brackish water and belong to the estuarine fauna.
The Breeding of Arenicola Ecaudata Johnston and A. Branchialis Aud. & Edw. at Plymouth
Authors: C Eve , Southward A. J.
Published: May 2009

The two ‘tail-less’ lugworms, Arenicola ecaudata Johnston and A.branchialis Audouin and Mime-Edwards (= A.grubii Claparede), live in gravel and under stones, unlike the 'tailed' species which are found mainly in sandy beaches. Both are local in distribution compared with the wide-spread caudate species. A. ecaudata is known to occur from Iceland to northern Spain, and thus has a rather more boreal distribution than A. branchialis which ranges from the west coast of Scotland to Morocco, the Mediterranean and the Black Sea. (Ashworth, 1912; Mclntosh, 1915; Fauvel, 1927; Rioja, 1935; WesenbergLundj 1951.) Neither species is known from the western side of the Atlantic.

Since the two species can often occur side by side and it appeared that they were adapted, not for life in different habitats, but for different temperature regimes, it was suggested to us by Prof. G. P. Wells, F.R.S., that an investigation of their breeding seasons at Plymouth might help in understanding their distribution and specific separation. It happened that we had already made some preliminary investigations in the Isle of Man, and we were therefore pleased to adopt Prof. Wells's suggestion.

Mature specimens of both species have been noted by previous workers. Ashworth (1912) found mature gametes in A. ecaudata at Port Erin in April and at Plymouth in August. Fauvel (1899) recorded mature worms at Cherbourg from March to October, while Hentschel (1930) believed spawning occurred at Plymouth in February-March and August-September.
Requirement for Thiamine Among Some Marine and Supra-Littoral Protista
Authors: Droop M. R.
Published: May 2009

The requirement for thiamine was examined in eleven marine protists of littoral, supra-littoral or neritic origin. Six were found to have an absolute requirement for the vitamin.

The thiamine-requiring Chrysophyta responded to the pyrimidine half of the vitamin, whereas the two thiamine-requiring Pyrrophyta responded to the thiazole half.

All the species requiring thiamine were auxotrophic with respect to at least one other factor (usually vitamin B12).

For half-maximal growth, species responding to pyrimidine required 100–300 mμg/1. pyrimidine or thiamine and species responding to thiazole 2000 mμg/1. thiazole or thiamine.