bluuebunny/crossref_metadata_2025 huggingface dataset:
Rhythmic activity of migrating juvenile American eels Anguilla rostrata
Authors: Wippelhauser Gail S. , McCleave James D.
Published: May 2009

Glass eels of the American eel Anguilla rostrata (Lesueur) utilize selective tidal stream transport, a series of semidiurnal vertical migrations in phase with the tide, to migrate up the Penobscot River estuary, Maine, U.S.A., in the spring. Glass eels, freshly collected during their migration, exhibited rhythmic activity with circatidal periodicities when tested in groups in the presence of a water current under constant conditions in the laboratory. Freshly collected groups of eels which had already completed their migration through tidal water did not exhibit circatidal activity rhythms under the same conditions. The activity rhythms of groups of eels freshly caught in tidal water appeared to be entrained by a 12.5 h cycle of water current reversals, but not by a 10.0 h cycle of current reversals. In other entrainment experiments water collected on flood and ebb tides was alternately added to the experimental tanks every 5.0 h. Under these conditions groups of eels freshly caught in tidal water did not display any rhythmic activity. Only 2 of 100 glass eels, freshly collected from tidal and non-tidal water, which were tested individually in static tanks, exhibited rhythmic activity. The activity rhythms would allow an eel to time its vertical migrations in the estuary despite varying environmental conditions.
Age determination in bass and assessment of growth and year-class strength
Authors: Kelley D. F.
Published: May 2009

Scale readings from 6269 bass caught in 1946–86 on various parts of the U.K. coast, with a few from the Channel Islands and France, have been analysed to determine U.K. growth patterns and assess the relative abundance of successive year-classes. In the U.K. growth was fastest on the south-east coast, slowest on the west coast. In the Channel Islands growth was initially slower than on the south-east coast but faster after maturity; though less fast than on the Biscay coast of France. Year-classes of exceptional abundance tended to grow more slowly than classes of normal abundance. There was evidence in each region of a slight long-term fall in growth rate. Best growth occurred in warm summers. The growth period commenced, and annulus formed, at dates ranging from early May for the youngest juveniles to mid July for adults; terminating in each case in October. Males grew rather more slowly than females and appeared less long-lived and less hardy, except on the south-east coast, where, exceptionally, samples were caught well offshore and included large, generally faster growing fish; this suggests a behavioural difference between the sexes rather than consistently slower growth in males. Explanations are offered for occasional fast growing fish, which occur mainly on the south-east coast and mainly with particular year-classes, notably 1966 and 1969. Problems of interpretation are considered and solutions offered.
The Effect of Eyestalk Removal, Wounding and Limb Loss Upon Moulting and Proecdysis in the Prawn Palaemon Elegans (Rathke)
Authors: Webster S. G.
Published: May 2009

Most current literature concerning moult control in crustaceans concludes that initiation of premoult is controlled by changes in the level of moult-inhibiting hormone (MIH) produced by the eyestalk neurosecretory organs. MIH is thought to act by repressing the secretory activity of the Y-organs, preventing increases in circulating ecdysteriod levels, necessary for moulting (see Kleinholz & Keller, 1979). This hypothesis is based upon the observation that eyestalk removal, by removing the source of MIH, leads to accelerated moulting (see Passano, 1960; Vernet-Cornubert, 1961; Sochasky, 1973, for reviews), and it survives despite many contrary reports indicating that moulting is unaffected by eyestalk removal (Sochasky, 1973). Perhaps the best known of the most contradictory data of this nature have been reported for Palaemon serratus for which Drach (1944, 1947), Panouse (1946, 1947) have shown that eyestalk removal generally accelerates moulting in this species. In contrast, Scheer & Scheer (1954) and Carlisle (1953) demonstrated no moult inhibition in this species following eyestalk removal.
Growth Inhibition and Recovery in Mussels (Mytilus Edulis) Exposed to Low Copper Concentrations
Authors: Redpath Keith J.
Published: May 2009

Studies concerned with the sub-lethal aspects of the toxicity of copper to the mussel have, in many cases, been compromised through the use of static experimental systems (see Davenport & Redpath (1984) for review). Manley, Gruffydd & Almada-Villela (1984), using a through flow system, reported a significant reduction in shell growth at a concentration of 10 μg I-1 added copper with recovery after metal addition had ceased. Strömgren (1982) investigated the effects of a series of concentrations of the metal (amongst others) on Mytilus, but there are discrepancies between his results and the work of others which have been fully discussed elsewhere by Davenport and Redpath.
The Biology of Fish of the Family Moridae in the Deep-Water of the Rockall Trough
Authors: Gordon J. D. M. , Duncan J. A. R.
Published: May 2009

The morid fishes are important members of the deep-water associations of fish on the continental slope of the Rockall Trough. Three species, Lepidion eques, Halargyreus johnsonii and Mora moro, are distributed between about 500 and 1250 m while Antimora rostrata has its centre of abundance between about 1750 and 2200 m. Aspects of their biology including changes in abundance and length composition with depth, reproduction and fecundity and age composition are described.

INTRODUCTION

In a trawling survey of the bottom-living fish of the Rockall Trough at depths from about 400 to 2900 m, 4 species of the family Moridae were sampled. Three species, Lepidion eques, Halargyreus johnsonii and Mora moro were distributed on the upper and mid slopes while a fourth species Antimora rostrata occurred on the lower slope and continental rise. Several different trawls were used to sample the fish populations of the slope and Gordon & Duncan (in the Press) have discussed the relative selectivity of each of these nets for sampling different species of fish. In many of the bathymetric zones fished morids were important both in terms of biomass and abundance. Some preliminary observations on aspects of the biology of Lepidion eques have been published (Gordon, 1979 a, b) and Mauchline & Gordon (1980, 1984) have described the diets of the morid fish from the Rockall Trough in some detail. In this paper other aspects of their biology will be described.
The Reproduction of the Lobster
Authors: Allen E. J.
Published: May 2009

Amongst the numerous subjects which have occupied the attention of the fishery authorities of the United States, that of the great decline in the productiveness of the lobster fishing industry has received much consideration, and several competent naturalists have, in consequence, devoted themselves to a scientific study of the habits and life-history of the American species. This species (Homarus Americanus) is so nearly allied to the European lobster (Homarus vulgaris), that the results arrived at for it, with regard to such questions as the time of year at which spawning takes place, the length of time during which the eggs are carried by the female attached to the under side of the abdomen, and the time of year at which the eggs are hatched, might be expected to apply, to some extent at least, to the latter. That this is so, appears to be abundantly proved by Dr. Ehrenbaum's study of the lobsters which frequent the shores of Heligoland, and certain observations which I have been able to make on lobsters taken in the neighbourhood of Plymouth during the last two years, in the course of my work on the nervous system of the embryo, also tend to confirm this view.
Observations and Experiments on Sex-Change in the European Oyster (O. edulis). Part II. On the Gonad of Egg-Spawning Individuals
Authors: Orton J. H. , Amirthalingam C.
Published: May 2009

Illustrations are given of successive stages of the gonadial products, of the European oyster (O. edulis) after the act of egg-spawning. Both, microscopic and fresh preparations are figured.
Note on the Condition of the Water in a Marine Aquarium
Authors: Atkins W. R. G.
Published: May 2009

Somewhere about 1914 D. J. Matthews maintained the sea-water in the Plymouth aquarium tanks at a pH value close to that of the outside sea-water by the addition of suitable quantities of sodium carbonate.
Notes on Shell-Depositions in Oysters: Note on the Chemical Composition of “Chalky” Deposits in Shells of O. edulis
Authors: Orton J. H. , Amirthalingam C. , Bull H. O.
Published: May 2009

The observations recorded form preliminary studies which it is hoped will be useful in special investigations on the physiology of shell-depositions in oysters. The distribution of chalky shell-deposits on the internal faces of the valves in young and old O. edulis and O. angulata has been studied, and its average distribution determined in shells of O. edulis of jnedium age from West Mersea and the Fal Estuary.

The distribution of this material in the shells of young O. edulis and in O. angulata is such that there can be little doubt that the function of the chalky deposit is to fill in rapidly grooves, hollows, and other spaces, which are inimical to efficient functioning in the changing needs of the individual.

In O. edulis of medium age large deposits occur regularly in the shell adjacent to the exhalent chamber and smaller ones on the border of the shell in the region of the inhalent chamber. The hypothesis is advanced that these regular deposits can be explained in the same way as those more easily understood by assuming that in a high percentage of shells of medium age, the contour of the shell in the region of the exhalent chamber and other parts is such that rapid extension and contraction of the mantle cannot be effected; deposition of chalky shell-material modifies this contour of the shell with certainty in some cases, but hypothetically in others, so that the mantle can be extended and retracted with a maximum of efficiency.
The Fæcal Pellets of the Trochidæ
Authors: Moore Hillary B.
Published: May 2009

FæecalPellets of the following species are described:—

Gibbula cineraria (Linn.).

G. umbilicalis (Da Costa).

G. tumida (Montagu).

G. magus (Linn.).

Cantharus (Jujubinus) clelandi (Wood).

Calliostoma zizyphinum (Linn.).
The Salinity of the Water Retained in the Muddy Foreshore of an Estuary
Authors: Alexander W. B. , Southgate B. A. , Bassindale R.
Published: May 2009

It has been shown by Eeid (1930) that the salinity of the water retained in a sandy foreshore at low tide may be considerably higher than that of a stream of brackish water flowing over it. A few similar observations have been made on the salinity of the water held in the muddy foreshore of the estuary of the River Tees.
An Experiment on Breeding Wild Pairs of Gammarus cheureuxi at a High Temperature, with an account of Two New Recessive Types of Red Eye
Authors: Spooner G. M.
Published: May 2009

On each of two former occasions when specimens of Gammarus chevreuxi Sexton have been brought from the wild into an incubator and kept at 21° C. or more, red-eyed recessive types have been reared among the F2 progeny (4, pp. 190 and 194). In November, 1930, an opportunity occurred for making further tests on this point. Twenty-three wild pairs, taken in Chelson Meadows on November 19, were placed on the following day in the incubator, the temperature of which at first averaged between 21° and 22° C, but was raised after a few days to an average of between 22° and 24° C. The young which were extruded from eggs laid in the wild were discarded. Those of subsequent broods were reared with a view to obtaining as many F2 families in each stock as would give a reasonable opportunity for segregating recessive characters to appear. The F2 young were examined for recognisable variations that might indicate the presence of a recessive character.
Testing The Validity of the Synthesis Ratio of Protein to Low Molecular Weight Metabolites as an Estimation of Phytoplankton Growth in the Field
Authors: De Madariaga I. , Fernandez E. , Serret P.
Published: May 2009

Cholorophyll a, primary production and the patterns of 14C assimilation into the major end-products of photosynthesis were determined for phytoplankton in the coastal waters off Plymouth, in order to study their physiological ecology during spring conditions. At the end of the study period, a diatom bloom occurred after the development of a slight thermocline. Throughout the pre-bloom period, the majority of the label was found in storage products, and phytoplankton growth was not nutrient-limited. During the development of the bloom, however, an increase in protein synthesis was found, which is interpreted as a result of an active phytoplankton growth. Both synthesis ratios for protein to storage products, i.e. lipid and polysaccharide, (P/L+S) and protein to low molecular weight metabolites (P/M), summarize the variations in the physiological state of phytoplankton during this study. Comparison of the P/M synthesis ratio and different estimations of phytoplankton growth rate shows the usefulness of this index for characterising natural populations.
Some Additions to the Sponge Fauna of Plymouth
Authors: Borley H. J. H.
Published: May 2009

In a small collection of sponges obtained during the winter of 1930–31 at Plymouth, six specimens were found which are of special interest. Four of these have proved to be new to the locality, the fifth was new to British waters, and the sixth was found to be a new species. Those species new t o the Plymouth area are Gellius angulatus (Bowerbank), Pachymatisma johnstoni Bowerbank, Eurypon clavatum (Bowerbank), and Halichondria firmus Bowerbank. The latter is the first example of the species to be recorded since it was first described forty years ago. The species new to the British waters is Reniera aquœductus Schmidt, and the new species Pseudaxinella alleni n.sp.
Preliminary Observations on the Early Stages of Scatella stagnalis Fal. (Ephydridae, Diptera)
Authors: Sen Purnendu
Published: May 2009

The insects, Scatella stagnalis, for the present study were collected from the Marine Biological Laboratory at Plymouth at the kind suggestion of Dr. Allen, F.R.S., the Director of the Laboratory, during my short stay there in the summer of 1929. So far as I can see, no work on the early stages of the genus Scatella is available. This led me to put on record the present account of the different pre-imaginal stages of the insect Scatella stagnalis in the following pages. I have described here only those stages that are exhibited in my hurried collection which may not be complete. A study of its complete biology would be of considerable interest; this, however, requires a constant watch of the species at the spot for a fairly long period.
Growth in Length during the Transition from Larva to Adolescent in the Pilchard and Sprat
Authors: Ford E.
Published: May 2009

Growth in length during the transition from larva to adolescent in the pilchard and sprat has been analysed, and simple straight-line equations deduced from observed data have been used to demonstrate how the different intervals along the dorsal and ventral surfaces of the body alter in length and proportion as development proceeds.

In the herring, pilchard, and sprat at least one of the body-intervals remains for all practical purposes unaltered in length during the transition. In the herring there are two such intervals, namely, (1) the distance from the back of the brain along the dorsal surface to the insertion of the first dorsal fin-ray, and (2) the distance from the insertion of the pelvic fins along the ventral surface to the anus. In the pilchard and sprat one of the above two remains stationary, but the other increases in length; in the pilchard the fixed interval is the distance from the back of the brain to the first dorsal fin-ray, and in the sprat it is the distance from the pelvics to the anus.

In the herring and pilchard the greater part of each unit of increase in the length of the body ventrally from the back of the head to the end of the caudal peduncle is added in front of the pelvic fins, whereas in the sprat this is added post-anally.
An underwater event recorder for use in behavioural research
Authors: Potts G. W. , Robinson S. G. , Edwards J. M.
Published: May 2009

An event/time recorder is described which is contained in a sealed waterproof case, with no external electrical connections and which uses novel methods for communicating control and data signals, and for charging the internal battery. The instrument is designed to be used underwater for recording behavioural and faunistic census information. On return to the laboratory the data can be retrieved, stored and processed using a microcomputer. The instrument is uncomplicated to use, completely waterproof, of a size that is easily carried and robust enough to withstand hard usage.
The Composition of Tidally Deposited Growth Lines in the Shell of the Edible Cockle,Cerastoderma Edule
Authors: Deith Margaret R.
Published: May 2009

The shells of marine invertebrates grow incrementally (Wilbur, 1972). When a section of shell is observed under the microscope, the increments are often visible, separated by fine lines (Fig. 1). Studies of these phenomena have focused chiefly on the periodicity of increment and growth-line formation, principally because of its geological or archaeological application as a ‘biological clock’ (e.g. Wells, 1963; Koike, 1973).
X-RAY Microanalysis of Selected Coelenterate Statoliths
Authors: Chapman David M.
Published: May 2009

When scanning electron microscopy became integrated with X-ray micro-analysis, it became an easy matter to localize an object and perform a semi-quantitative elemental analysis of atoms of atomic number 11 or higher using an energy dispersive spectrometer. This technique is used in the present study to determine the chemistry of the statoliths of eight hydromedusae, two scyphomedusae, one cubozoan and a ctenophore with respect to their comparative biomineralization and the relationship of the mineral to their taxonomy.
The Early Life History of The Sand Smelt (Atherina Presbyter)
Authors: Bamber R. N. , Henderson P. A. , Turnpenny A. W. H.
Published: May 2009

The sand smelt (Atherina presbyter Cuvier) is a small, pelagic inshore fish common on some coasts of Britain. The biology of the sand smelt population in Southampton Water, Hants., U.K., has been described in detail (Turnpenny, Bamber & Henderson, 1981), but individuals less than 3 months old were not found during the course of that study.
Settlement ofBalanus Balanoides: The Effect of Cyprid Antennular Secretion
Authors: Yule A. B. , Walker G.
Published: May 2009

In a recent paper we reported on the discovery of an adhesive antennular secretion used by exploring cyprids ofBalanus balanoides(L.) and hinted at its possible implication in settlement behaviour (Walker & Yule, 1984). This secretion is thought to be modified integumentary protein. Since the integumentary protein of adultB. balanoidesis widely accepted as a powerful stimulus to settlement (Knight-Jones, 1953; Crisp & Meadows, 1962, 1963; Larman, Gabbott & East, 1982), we devised settlement experiments in May 1984 to investigate whether cyprid antennular secretion acts in a similar manner. The outcome of these experiments withB. balanoidescyprids is presented here.
The Development of Startle Responses in Herring Larvae
Authors: Blaxter J. H. S. , Batty R. S.
Published: May 2009

In common with many teleosts, herring show marked ‘fast startle’ responses when subjected to sound stimuli from a vibrating source (Blaxter, Gray & Denton, 1981). These comprise a sharp C-shaped contortion of the body; the fish respond to transients of as little as half a cycle of sound with a latency of about 25 ms and the turn is usually away from the sound source. There is good evidence that the Mauthner cells are implicated in other species (see Eaton & Hackett, 1984) but this has not been established in the herring, although they are known to be present.
Studies of water movements and winds at various lightvessels II. At the Seven Stones Lightvessel near the Scilly Isles
Authors: Carruthers J. N. , Lawford A. L. , Veley V. F. C. , Gruning J. F.
Published: May 2009

A review is given of the results obtained from upwards of 600 days of current measuring at the Seven Stones lightvessel during 1939–41. From the plotted observations, an attempt is made to deduce the association between the total daily water movement, irrespective of direction, the residual daily water movement or current, and the mean local residual wind.

The average residual water movement over the whole period was 2½ m.p.d. towards east-south-east. Statements made by earlier authors regarding the water circulation in adjacent areas are examined, and reconciliations are suggested where they seem to conflict with this finding.

An endeavour is made to correlate the wind and water movement mathematically.
The biology of Asterias rubens L. II. Parasitization of the gonads by the ciliate Orchitophrya stellarum Cépède
Authors: Vevers H. G.
Published: May 2009

The parasitic astomatous holotrich ciliate, Orchitophrya stellarum Cépède, has been found in the testes of starfishes (Asterias rubens) in the Plymouth area. It was found only in starfishes from numerically rich and well-fed populations, which also showed large gonad growth. In such populations it occurred in up to 28% of the males during March-April 1947, and in lower percentages during the spring of the three following years. The parasite was never found in a geographically adjacent population containing smaller numbers of poorly fed starfishes. The parasite was found to be relatively more common in the testes of medium-sized starfishes than in those of large and small starfishes.

Presence of the parasite causes a complete breakdown of all the germinal tissue of the testes, so that most of the infected starfishes suffer complete castration. This involution of the testicular tissue has been studied, and photomicrographs are given which show a number of stages in the process.
The respiration of some planktonic copepods
Authors: Raymont J. E. G. , Gauld D. T.
Published: May 2009

The respiratory rates of four species of planktonic copepods were measured. In two of the species measurements were made with two copepodite stages, and with adult male and female specimens.

The rate for Calanus finmarchicus Stage V at 17°C. was found to be 0·52 μl./cop./hr., a figure which agreed with previous measurements.

For all the species and stages studied the respiratory rate was found to be closely proportional to the length to the power of 2·2.

The relevance of such measurements to conditions in the sea is briefly discussed.
Muscle receptor organs in the Paguridae
Authors: Alexandrowicz J. S.
Published: May 2009

In the dorsal wall of the abdomen in the Paguridae muscle receptor organs have been found similar to those in the Macrura. In each of the first to fifth abdominal segments there are two receptor units on each side. A receptor unit consists of a long thread-like muscle, and a nerve cell connected with this muscle and sending its axon towards the central nervous system. The muscles of each pair run close together in the layer of the dorsal (extensor) muscles, but are independent from the latter following a more or less different course.

The nerve cells in each pair of muscle receptor organs are of two types. One of them has several very long distal processes expanding over one of the muscles. The other cell has one stout distal process giving off numerous but very short branches forming with their subdivisions a dense tuft of fibres terminating in the second muscle. The axons of the cells associate with one of the branches of motor nerves supplying the dorsal muscles and pass along these branches into the main nerve trunks of the respective segments.

Each receptor organ is supplied by several nerve fibres coming from the central nervous system.
A Comparison of the Biology ofEchinus esculentusin different Habitats. Part III.
Authors: Moore Hilary B.
Published: May 2009

1. Gonad examinations were made on monthly samples ofEchinus esculentusfrom Plymouth in 1934, 1935, and 1936.

2. Spawning is from February–March to May, 50% spawning occurring at a temperature of 9.2–9–7° C. compared with 7.0—7.8° C. in the Isle of Man. There was a winter drop in gonad volume one year, but not the other.

3. The nature, distribution and source of the pigments in the shell are discussed, and it is shown that pigment is found in quantity in the intestine only in the summer and autumn.

4. The known facts with regard to the seasons of growth, spawning, etc., are brought together into a generalized diagram.
Method for determination of fat percentage in unicellular algae
Authors: Collyer Dorothy M.
Published: May 2009

The method, which is suitable for algae down to 2 μ in diameter, determines the weight of total fatty acids (however originally combined) and total unsaponifiable fat-soluble matter in fresh algal material containing 20–280 mg total dry matter. The chemical treatment is based on that of Belin (1926). Experience with variations of the method on several algal species is described. Preliminary Soxhlet extraction with 95% ethanol for 18 h removed virtually all the lipid from the algae, ready for purification and further analysis, in the cases of Chlorella marina, C. vulgaris and Scotiella sp. (Chlorophyceae), Tribonema aequale (Xanthophyceae), Isochrysis galbana (Chrysophyceae) and Phaeodactylum tricornutum (Bacillariophyceae). This extraction was not efficient, however, in the cases of two members of the Myxophyceae (Anabaena cylindrica and Microcoleus vaginatus) and one of the Rhodophyceae (Porphyridium cruentum). The fat metabolism of these two classes is known to differ from that of other classes, but a similar inefficiency in the case of Monodus subterraneus (Xanthophyceae) is unexplained. In such cases supplementary processes were necessary to achieve full extraction. The methods are described in detail.
The rapid response ofMyxicola infundibulum(Grübe)
Authors: Roberts M. B. V.
Published: May 2009

In Myxicola the rapid muscular response produced by direct stimulation of the nerve cord with a single shock is usually large and obeys a simple ‘all-or-nothing’ relationship to the intensity of stimulation. A single shock of sufficient strength evokes a single giant fibre impulse which produces an extensive contraction of the longitudinal muscle.

The magnitude of the summated contraction obtained by repetitive stimulation of the nerve cord is found to depend on the number and frequency of the shocks, thus providing the animal with a mechanism by which, theoretically, it could grade its escape response.
Feeding and respiration in the copepodTemora longicornis(Müller)
Authors: Berner Ågot
Published: May 2009

Laboratory experiments on feeding and respiration were carried out with the copepodTemora longicornisin the Clyde sea-area. In feeding experiments, a method using radiophosphorus as a tracer was employed. The filtering rate was very variable and is probably related to size. There seemed to be a seasonal variation in filtering rates. During the summer of 1961 weekly water samples were taken for estimation of the particulate carbohydrate in the sea. There was always enough food present forTemora. Respiration was measured by using a modified Winkler method. Oxygen consumption was related to surface area, and corrections in respiratory rates were made for the size differences in the animals used. Respiratory rates were very high at the beginning of an experiment, but after a sharp fall the rate became steady in about 30 h. An indication of seasonal variation in oxygen uptake was found.
Adaptations of two intertidal isopods I. Respiration and feeding in Naesa bidentata (Adams) (Sphaeromatidae)
Authors: Wieser Wolfgang
Published: May 2009

In freshly collected Naesa bidentata there exists a clear dependence of respiration rate, measured in sea water, on the tidal cycle, with the maximum occurring at high tide, the minimum at low tide. In specimens that had spent 1–2 days in the laboratory the tidal rhythmicity is less pronounced due to a lowering of the Qo2-values at high tide and at the beginning of experiments. This is interpreted as reflecting differences in nutrition between freshly collected and laboratory specimens.
The reactions of certain mysids to stimulation by light and gravity
Authors: Foxon G. E. H.
Published: May 2009

Light-adapted mysids as exemplified byHemimysis lamornaedisplay phototelotaxis which regularly alternates in sign from positive to negative andvice versa. This reaction may be disturbed by other activities such as feeding; it only takes place in horizontal illumination.

Dark-adapted mysids display negative geotaxis. When a light stimulus is given this geotaxis is reversed in sign irrespective of the direction of the incident light.

When the statocysts of the mysids are removed their responses are much more like those of planktonic creatures. In the light normal orientation is maintained by the “dorsal light reflex”, and in darkness by the “general position reflex”. In the darkness a feeble negative geotaxis is sometimes seen. In light, phototaxis is seen in both light-adapted and dark-adapted conditions; in the majority of cases it is negative but on occasion has been seen to be positive.
Change in inheritance in echinoid hybrids
Authors: Hörstadius Sven
Published: May 2009

In 1932 crosses were made at Plymouth between Psammechinus miliaris ♀, both Z-type (from the shore) and S-type (from Eddystone), and Echinus esculentus ♂. The larvae from the S eggs differed in size and shape from those from the Z eggs (cf. Figs. 1,2 with 3–6). None of the hybrid plutei possessed the green pigment of P. miliaris, nor the posterior epaulettes of E. esculentus. Some of the larvae (Figs. 3, 4) had a posterior pedicellaria, like E. esculentus, in others this organ was missing (Figs. 1, 2, 5, 6). Some of these plutei were preserved, others went through metamorphosis. Healthy larvae of these combinations (00+ and 000) have not hitherto been described. The results are compared with those of previous authors (see table, p. 100). Some possible causes of change of inheritance in different years are discussed.
Jaera hopeana, an intertidal isopod new to the British fauna
Authors: Haahtela I. , Naylor E.
Published: May 2009

A long-established population of Jaera hopeana living ectocommensally upon Sphaeroma serratum is described from Wembury. This is a new record for the British fauna and is the northernmost record of a species which is found predominantly in the Mediterranean and Black Sea.
Studies on Marine Flagellates
Authors: Parke Mary
Published: May 2009

Six marine flagellates, used as food in the rearing of the larvae ofOstrea edulisL., are described.

One belongs to the Chlorophyceae,Pyramimonas grossiin.sp. (Polyblepharidaceae); four belong to the Chrysophyceae,Chromulina pleiadesn.sp. (Chromulinaceae),Isochrysis galbanan.g., n.sp.,Dicrateria inornatan.g., n.sp.,D. gilvan.g., n.sp. (Isochrysidaceae); and one belongs to the Cryptophyceae,Hemiselmis rufescensn.g., n.sp. (Nephroselmidaceae).

A form of reproduction in a palmelloid phase, not previously described, is recorded for the Isochrysidaceae.
Regeneration in the polychæt Chætopterus variopedatus
Authors: Berrill N. J.
Published: May 2009

1. Regeneration from different levels in the polychæt worm Chætopterus variopedatus has been studied.

2. Regeneration can occur posteriorly from any segment, but anteriorly only from segment XIV forwards.

3. Where regeneration occurs at all, given sufficient time, it will be complete, i.e. the original segments occupy in the new worm the relative position they originally occupied in the old worm.
The Ascidian Fauna of the Plymouth Area
Authors: Berrill N. J.
Published: May 2009

The nomenclature followed is that used by Hartmeyer (9), in which account will be found identificattion keys and complete lists of the synonymous species, only the commoner of which are given below. That his conclusions in this respect are open to question has already been pointed out (see Journ. Mar. Biol. Assoc., Vol. XV, p. 159).

For a description with figure of a species the reference number is placed after the name.
The Rapid Estimation of the Copper Content of Sea-water
Authors: Atkins W. R. G.
Published: May 2009

1. The copper content of sea and river waters can be rapidly determined using the sodium diethyl-dithiocarbamate method followed by extraction with chloroform.

2. This solvent takes up only traces of the natural colouring matters found in waters, but blank estimations should be made with some river waters and occasionally with sea-waters on account of the presence of plankton.

3. Carbon tetrachloride can be used instead of chloroform as solvent, it extracts less per unit volume, but the volume recovered is larger, the resultant yield being identical. Amyl alcohol extracts more than chloroform, but the volume recovered is smaller, the resultant yield being about 0-8 times that of the others. The alcohol takes up more colouring matter from river water, does not separate as readily as the others, and floats, whereas they, more conveniently, sink. For work in hot climates its higher boiling-point may be an advantage.

4. In fresh water iron salts in large excess might cause error; this can be checked by the electro-deposition method.
An Account of the Herring Investigations Conducted at Plymouth during the Years from 1924 to 1933
Authors: Ford E.
Published: May 2009

The Plymouth Laboratory is well situated for the study of the herring, and its commercial fishery, and since the winter of 1924–25, advantage has been taken of the varied facilities for research thus afforded. From time to time reports have been published in the Journal of the Marine Biological Association as a series, entitled: “Herring Investigations at Plymouth” and these have dealt with many seemingly distinct subjects of study, including experiments with larvæ from laboratory-fertilised eggs; studies of growth, migration and structure of young and old fish; and accounts of the commercial operations during the winter drift-fishery at Plymouth. It has now been considered advisable to bring together the several results in one paper, in an endeavour to show their essential bearing upon the problems of the practical fishery.
The Plymouth Laboratory of the Marine Biological Association of the United Kingdom
Authors: Russell F. S.
Published: May 2009

In The Times of 31 March 1884, it was announced that a meeting would be held that day in the rooms of the Royal Society for founding a society having for its purpose ‘the establishment and maintenance of a well-equipped laboratory at a suitable point on the English coast, similar to, if not quite so extensive as, Dr Dohrn's Zoological Station at Naples’ (M.B.A., 1887a). With Prof. T. H. Huxley in the chair a gathering of distinguished gentlemen gave reasons why such a laboratory should be built. All stressed what its value would be from the purely scientific viewpoint, and all were agreed that both by fundamental research and by more direct investigations on our food fishes, knowledge of economic import would be gained. The last speaker, Mr George J. Romanes, said that there was one function of the proposed laboratory which had not received the attention it appeared to deserve; he meant the investigation of invertebrate physiology. ‘In the invertebrate forms of life’, he said, ‘we saw life in its simplest shape, and in the shape which best admitted of observation and experiment, with the view of throwing light upon most of the great questions relating to the processes of life’ (M.B.A., 1887b).
The suspended matter of sea water
Authors: Armstrong F. A. J. , Atkins W. R. G.
Published: May 2009

Sea water collected at Station E1, surface, between June 1948, and November 1949, contained suspended matter from 2·77 to 0·45 g./m.3 (or parts per million) dried and ignited. A few determinations of insoluble organic matter gave 1·77 to 1·15 parts per million dry weight at 100° C. The ignited residue contained from 55 to 17% silica, 28 to 3 of ferric oxide, 20 to under 1 of alumina and 70 (or excluding one high value 29) to 9 calcium carbonate. There was nothing in the records for temperature or salinity to suggest that the water mass had changed during the period of sampling.

The analyses reveal an unsuspectedly large amount of iron, compared with that found in solution. The ignited residue is rich in silicate, judging from the silica alumina ratio, but it is quite doubtful whether the additional supply of silicate available for diatoms is at all adequate to balance their requirements calculated on a phosphate utilization basis. It seems more probable that a considerable amount of the phosphate is available for non-siliceous phytoplankton.
Advances in the physiology of peripheral nerve
Authors: Hill D. K.
Published: May 2009

The last 20 years have seen many advances in our knowledge of the mechanisms responsible for the transmission of impulses in peripheral nerve fibres. This has come about largely through researches on the nerves of marine invertebrates. Much of the work has been done at Plymouth. The purpose of this article is to give some of the reasons why certain features of these nerves, which distinguish them from the nerves of vertebrates, should make them so desirable for experimental work.
Nomograms for chlorophyll determinations
Authors: Battin G. A. W.
Published: May 2009

Nomograms are presented for solving the equations relating the concentrations of chlorophylls a, b and c to sample volume and the extinctions of acetone extracts at three wave-lengths.
The ratio of kappa- to lambda-carrageenan in nuclear phases of the rhodophycean algae, chondrus crispus and Gigartina stellata
Authors: Chen L. C-M. , McLachlan J. , Neish A. C. , Shacklock P. F.
Published: May 2009

The ratio of the concentrations of κ- to λ-carrageenan is shown to be related to the nuclear phase in Chondrus crispus both in culture and in nature. This ratio is low in tetrasporic plants and relatively high in the gametophytes. It was found to vary somewhat amongst samples analysed, but was always less than unity in tetrasporophytes and greater than unity in gametophytic plants. The κ/λ ratio in Gigartina stellata was high in gametophytes as in C. crispus; the tetrasporophytic phase of this species is unknown. It is suggested that the commercial quality of carrageenan can be correlated with the biological status of the harvested plants.
The association of amphipods in the shallow-water sand habitat of Strangford Lough, Co. Down
Authors: Fincham A. A.
Published: May 2009

Ten stations were sampled in the shallow-water sand habitat of Strangford Lough using a naturalist's dredge. Sediment samples were analysed to determine median diameter (ranging from 1·13 to 3·23 ø), Phi quartile deviation (ranging from 0·17 to 0·65 ø) and Phi quartile skewness (ranging from –0·11 to –0·04 ø).

Twenty-two species of amphipod belonging to thirteen families were identified; ten species were new records for Strangford Lough and the Family Phoxocephalidae was recorded for the first time. The average number of species per station was nine and average abundance was 660 amphipods per station. The most frequently occurring species was the caprellid Phtisica marina (present in 90% of the samples); the overall dominant species was the corophiid Corophium crassicorne representing 52% of all specimens recorded.
The occurrence and seasonal variation of trace metals in the scallopspecten maximus(L.) andchlamys opercularis(L.)
Authors: Bryan G. W.
Published: May 2009

A comparison has been made between the concentrations of eleven trace metals in the tissues of two species of scallops,Pecten maximus(L.) andChlamys opercularis(L.), collected from the same area of the English Channel. Although there was considerable variation between individual animals, the mean concentrations of Ag, Co, Cr, Cu, Mn, Ni, Pb and Zn were higher in the whole body ofChlamysthan inPectenbut concentrations of Al, Cd and Fe were lower. In both species, seasonal changes in the concentrations of Co, Cu, Fe, Mn, Ni, Pb and Zn were observed and, in general, the highest values were found in the autumn and winter months. These changes may be related to food supply, since concentrations were generally highest when phytoplankton productivity was low and tended to fall in the spring as productivity increased rapidly to its annual peak. Despite problems arising from individual and seasonal variation, the kidneys and digestive gland of scallops appear to have potential as biological indicators of trace metals.

The results obtained forPectenandChlamysare compared with those in the literature for species from the family Pectinidae.
The calls of gadoid fish
Authors: Hawkins A. D. , Rasmussen Knud Just
Published: May 2009

Of nine northern European species of the Gadidae examined in the aquarium, or in cages in the sea, four produced sounds. The vocal species were the haddock,Melanogrammus aeglefinus(L.); the cod,Gadus morhuaL.; the lythe,Pollachius pollachius(L.); and the tadpole-fish,Raniceps raninns(L.). The main differences between the calls of the vocal species lay in their temporal structure, all the calls being divisible into brief pulses of low frequency sound, repeated at different rates and in different groupings. Calls with this structure yielded spectra with a series of spaced harmonics, the frequency spacing depending upon the pulse repetition rate.

Sixteen additional species were dissected, and seven of these showed well developed muscles attached to the swimbladder, similar to those found in the four vocal species. The remaining nine species, together with the five non-vocal species examined in the aquarium, lacked the muscles.

The behavioural significance of the calls and the operation of the sound producing mechanism are discussed.
Jet propulsion of the calycophoran siphonophoresChelophyesandAbylopsis
Authors: Bone Q. , Trueman E. R.
Published: May 2009

Jet propulsion in the small siphonophoresChelophyesandAbylopsiswas investigated by measuring chamber pressures and thrust exerted in tethered nectophores, and by cinephotography of free swimming colonies. Although of similar design, the two siphon-ophores swim at different speeds, and with very different chamber pressures in the locomotor nectophores. Estimates of drag incurred during swimming, and of the cost of the process in the two forms are discussed.
Oxygen binding of erythrocruorin and coelomic cell haemoglobin from the terebellid polychaeteNeoamphitrite figulusrelated to some environmental factors
Authors: Wells Rufus M. G. , Warren Lynda M.
Published: May 2009

Measurements of pH, oxygen content, O2-combining capacity, and haemoglobin concentration were made for the vascular blood of the burrowing polychaeteNeoamphitrite figulusin order to assess the role of its two respiratory pigments in respiration. The oxygen equilibrium curve of the erythrocruorin (extracellular haemoglobin) in the vessels was sigmoidal, having an n50value of 1·5 and a low affinity for oxygen as determined by the P50which was 26 mmHg at pH 7·31 and 18 °C. O2-binding by the erythrocruorin is sensitive to changes in pH (Δ log P50/Δ log pH = –0·24 to –0·29). The coelomic cell haemoglobin has a hyperbolic equilibrium curve (n50= 1·0) and a high affinity for oxygen (P50= 4·5 mmHg) independent of pH, suggesting an oxygen transfer system from the erythrocruorin to the coelomic cells.
A Comment on Gracilaria verrucosa (Huds.) Papenf. (Rhodophyta: Gigartinales)
Authors: Bird C. J. , van der Meer J. P. , McLachlan J.
Published: May 2009

The life histories of Gracilaria verrucosa from England and from Vancouver Island, Canada, were completed in culture. Although representatives of the two populations were morphologically and anatomically indistinguishable, their chromosome numbers differed markedly, being n = 32 for British material and n = 24 for western Canadian plants. It is propounded that the Vancouver Island plants are not authentic G. verrucosa and, moreover, that this name may have been applied erroneously in other reports of the species from localities distant from the British Isles (type locality).
The taxonomic relationship of Parathemisto gaudichaudi (Guerin) and P. gracilipes (Norman), with a key to the genus Parathemisto
Authors: Sheader M. , Evans F.
Published: May 2009

The results of morphometric and developmental studies made to elucidate the relationship between Parathemisto gaudichaudi (Guerin) and P. gracilipes (Norman) show them to be one and the same species. Apparent differences are due to differences in the size of specimens at maturity, and to the degree of development of the bispinosa-compressa condition. P. gaudichaudi takes precedence over P. gracilipes.

The species is highly variable, existing in two extreme forms, the bispinosa form and the compressa form, together with all possible intermediates. The full range of the bispinosa-compressa condition is not expressed until a body-length of 10 mm is reached. Specimens are capable of changing towards either extreme at moults, but the factors causing the change are unknown.

A key to the genus Parathemisto Boeck is included.
The feeding preferences ofAeolidia papillosa(L.) (Mollusca, Nudibranchia)
Authors: Edmunds M. , Potts G. W. , Swinfen R. C. , Waters V. L.
Published: May 2009

A clear preference for the actinian anemonesActinia equina, Anemonia sulcataandAnthopleura elegantissimawas demonstrated, while the acontian anemones andCorynactis viridisranked low in the order of preference. The significance of acontia as defensive structures in anemones is discussed briefly. No differences in food preference were found between eolids collected from Plymouth and Millport; and BritishAeolidiabehaved in the same way towards Californian anemones as did CalifornianAeolidia.

The eolids varied in their tendency to bite different species of anemone, but the performance of each individual eolid was similar in different experiments. It is possible that the individual variations may account for conflicting reports in the literature.
Migrations and Growth of the Thornback Ray (Raia clavata L.)
Authors: Steven G. A.
Published: May 2009

Although workers in several European countries (England, Germany, Russia, Scotland) are stated (5) to be carrying out marking experiments on rays or skates, the writer is not aware of any recently published account of the results of any of these researches. Fulton (4, p. 191), however, records that in the years round about 1890 he marked 71 thornback rays (R. clavata) and 23 specimens of grey skate (R. batis) in Scottish waters. Two of the thornbacks and one skate were subsequently recovered. Of the former, one—about 36·5 cm. in width on marking—remained at liberty for about three months before being recaptured and had travelled about 13 miles from the place where it had been set free. The other—35 cm. in width—remained at liberty for 278 days and travelled about six miles. The single skate, recaptured after only 10 days, had in that time changed its position by 10 miles. No records of size increments are given.