bluuebunny/crossref_metadata_2025 huggingface dataset:
Notes on Some Copepoda from Plymouth
Authors: Gurney Robert
Published: May 2009

When examining the gills of a lobster for specimens of Nicothoe large numbers of copepods were found which, colourless and slender in form, had the sluggish and rather aimless movements which one would expect from a commensal removed from its natural habitat. It was somewhat of a surprise to find that they all belonged to a species already described —Tisbe elongata A. Scott. Scott obtained a few specimens from mud collected on mussel beds between Heysham and Morecambe. It appears, then, that we have here a species which is capable of free life, but its abundance, in all stages of growth, in the gill chamber of a lobster, proves that it is also to be considered a semi-parasite.
The Larval Development of Ophelia Bicornis Savigny
Authors: Wilson Douglas P.
Published: May 2009

Fertilizations of Ophelia bicornis Savigny were made and the larvae reared. This is the first time the larval development of any member of the family Opheliidae has been described.

The trochosphere is small and somewhat yolky; it has a broad prototroch, a narrow telotroch, a strong apical tuft and a long anal cilium.

Annulation is accompanied by the appearance of parapodial lobes and bristles. When the first pair of bristles of the third setiger protrude the larva is ready to metamorphose. It has two, sometimes three eyes.

The larva in its later stages can adhere strongly to solid objects, such as sand grains, by a secretion from the four anal papillae and the parapodial lobes. This is interpreted as an adaptive aid to settlement on sand banks swept by strong currents.

At metamorphosis the larval external cilia are lost and the bristles rapidly elongate, especially those of the third setiger.

Some of the larval bristles are slightly winged. So far only capillary bristles have been known in the Opheliidae.

It is pointed out that a development such as that of Ophelia is more typical of polychaetes as a whole than are the developments of certain species commonly used as text-book types.
The Genera Apomatus and Protula (Polychaeta, Serpulidae)
Authors: Hanson Jean
Published: May 2009

It is suggested that the genera Apomatus and Protula should be revised to reflect the close similarity between P. tubularia and the two species of Apomatus, and the dissimilarity of Protula intestinum. It is further suggested that the presence or absence of an operculum is not a sufficiently important character for distinguishing Apomatus from Protula, or Filograna from Salmanica; and therefore that these two pairs of genera should be fused into two genera.
The Structure and Life History of Some Minute Prosobranchs of Rock Pools:Skeneopsis Planorbis(Fabricius),Omalogyra Atomus(Philippi),Rissoella Diaphana(Alder) andRissoella Opalina(Jeffreys)
Authors: Fretter Vera
Published: May 2009

The external features ofSkeneopsis planorbis(Fabricius) are described and compared with those ofOmalogyra atomus(Philippi),Rissoella diaphana(Alder) andR. opalina(Jeffreys).

The foot has a large posterior mucous gland (Figs. 1 and 4,Pm; PI. IV, figs. 1 and 2,Al,Pl), its secretion forming a thread on which the mollusc can climb from one level to another.

Correlated with their small size are modifications of the pallial organs.Skeneopsis, the largest and least specialized, has a bipectinate osphradium, but the gill is reduced to nine filaments; the anus lies well within the mantle cavity. In the other genera osphradium and ctenidium are lost, though the latter may be represented inRissoellaby a small tract of ciliated epithelium. In the absence of a ctenidium the animals depend entirely upon pallial respiration and the stream of water through the mantle cavity is maintained by other means: from the anus strips of ciliated epithelium pass forward to the mouth of the mantle cavity, causing a strong exhalant stream and carrying away the faecal pellets. There is a compensating inhalant flow. The kidney (PI. IV, figs. 1 and 2, K), with its rich vascular supply, has migrated into the tissues of the mantle, increasing its respiratory efficiency.
Studies on British Laminariaceae. I. Growth in Laminaria Saccharina (L.) Lamour
Authors: Parke Mary
Published: May 2009

The production, longevity, growth, regeneration and reproduction of Laminaria saccharina (L.) Lamour. on the Devon and Argyll coasts are described.

Bathymetric zone and habitat control the fertility and longevity of the gametophyte and consequently the production of the sporophyte. Sporophytes develop at the higher levels during the winter, early spring, late summer and autumn, and at the lower levels during spring, summer and autumn.

Longevity of the sporophyte depends on season of germination, bathymetric zone and habitat. Winter sporophytes rarely persist to maturity. Spring sporophytes form the bulk of all L. saccharina populations except on very sheltered coasts in the sublittoral zone where summer sporophytes may be equally numerous. On the British coast the life-span of a L. saccharina sporophyte does not exceed 3 years.
Lumbricillus Reynoldsoni n.sp., an Enchytraeid from the Beaches of North Wales
Authors: Backland Helge O.
Published: May 2009

Dr T. B. Reynoldson of the Department of Zoology, University College of North Wales, Bangor, found some large enchytraeids on the shores of the Menai Straits. He suspected that it was an undescribed, or at least a rare and interesting species, and kindly sent six specimens to me for further study. I find that the specimens are indeed to be ascribed to a new species, which is here named Lumbricillus reynoldsoni, in recognition of the finder's prominent work on the ecology of Lumbricillus lineatus Mull, and Enchytraeus albidus Henle.
The anatomy of the body wall and appendages inArenicola marinaL.,Arenicola claparediiLevinsen andArenicola EcaudataJohnston
Authors: Wells G. P.
Published: May 2009

Worms for dissection, or for museum preservation, should be prepared by the magnesium-formalin method, of which two modifications are given in the text.

The body ofArenicolais differentiated into: (a) an achaetous ‘head’, comprising the prostomium and a small number (probably two) of subsequent segments, (b) a ‘trunk’, composed of a number, varying somewhat with the species, of chaetigerous segments, and (c) a ‘tail’, which may or may not be chaetigerous according to the species. The method of subdividing the body according to the distribution of the gills, so often met with in the literature, is misleading because it conceals the very fundamental differentiation between ‘head’ and ‘trunk’.

The main layers of the body wall are described. There are grounds for supposing that the circular muscle layer plays a greater part than the longitudinal in the maintenance of a postural fluid pressure in active worms.
The seasonal variation in weight and chemical composition of the common British Laminariaceae
Authors: Black W. A. P.
Published: May 2009

The seasonal variations in the total ash, crude proteins, mannitol, laminarin and alginic acid contents are given for monthly samples of the Laminariaceae,L. cloustoni, L. digitataandL. saccharinafrom November 1946 to October 1948, samples ofL. digitataandL. saccharinahaving been taken at different localities to determine the effect, if any, of the degree of exposure on the chemical composition.

The results agree favourably with those of the first 2 years examined and indicate that, with only a few exceptions, results might be reproducible in the corresponding season of any year, and it should be possible, therefore, to predict the approximate composition in subsequent years.

As before, the marked seasonal variations in chemical constitution occur in the fronds, where the bulk, if not all, of the photosynthesis occurs. The stipes undergo some variation parallel to that in the fronds, but within narrower limits, while laminarin is absent throughout the year.
A note on the barnacle larvae of the Clyde Sea Area as sampled by the Hardy Continuous Plankton Recorder
Authors: Barnes H.
Published: May 2009

A series of results is presented on the barnacle larvae population of an area of the Firth of Clyde, over a 15-day period in the spring taken by means of a modified Hardy Plankton Recorder.

The records and observations on barnacle settlement indicate that the larval population was considerably greater than usual.

The total larval population showed no great fluctuations from day to day, and on a given day the composition of the population over a wide area was often reasonably constant.

Evidence is presented that there is no great depletion of the population between Nauplius III and cyprid stages. It is suggested that the depletion previously reported may be due in part to the method of sampling or to the conditions at the time of sampling.

During the time when the evidence indicates no depletion of population there was a heavy diatom outburst, which in this instance did not appear to interfere with the larval development.

Data are given on the density of settlement.
Ophiopsila annulosa (M. Sars) in the Plymouth area
Authors: Vevers H. G.
Published: May 2009

Norman (1905) gave a short account of the distribution of the ophiuroid, Ophiopsila annulosa, having dredged it himself from Birterbuy Bay, Ireland, in 1874, and from outside Dartmouth Harbour in 1904. He also obtained specimens in 1903 from the Plymouth Laboratory; these had been dredged in 12–25 fathoms on Mewstone Ledge and Stoke Point Grounds, near Plymouth, and were recorded as not uncommon in the red sandstone, especially in old Pholadidea crypts. Mortensen (1927) expressed some doubt as to Norman's identification of the Irish specimens; he noted that the Plymouth specimens had been found in exactly the same locality and habitat as the smaller and commoner species, Ophiopsila aranea, and considered that the presence of the larger species in British waters could not be definitely settled until new records were to hand. O. annulosa was not recorded in the Plymouth Marine Fauna (Mar. Biol. Assoc, 1931) and no specimens have been found in the reference museum at the Laboratory.
The Occurrence of the smooth sand-eel, Gymnammodytes Semisquamatus (Jourdain), in the Plymouth area, with notes on G. cicerelus (Rafinesque), and G. capensis (Barnard)
Authors: Corbin P. G.
Published: May 2009

Gymnammodytes semisquatnatus, the North Atlantic smooth sand-eel, has a continuous distribution from southern Norway to the southern Atlantic coast-line of Spain. Its occurrence in the Irish Sea and in the Plymouth area are new records. In the latter area it is an off-shore species, apparently concentrating in shell gravel in winter for spawning. It has a mean vertebral number of slightly over 68 (Plymouth and Scottish specimens). A small sample of the Mediterranean species, G. cicerelus, gives a mean of just over 66, while the South African species, G. capensis, which is indistinguishable from G. semisquamatus by external non-metameric characters, has a much lower mean of 58·5.
On the production of living matter in the sea off Plymouth
Authors: Harvey H. W.
Published: May 2009

A study, now in progress, of the phosphorus cycle in the sea off Plymouth required some knowledge of the amount of plants and of several ecological groups of animals. There were no existing data except for zooplankton and the larger net-caught phytoplankton.

From information supplied by friends and colleagues, it was possible to make tentative estimates of the average biomass of other groups of animals occurring below unit area of the sea.
The bottom fauna of Great West Bay
Authors: Holme N. A.
Published: May 2009

An account is given of the bottom-fauna of Great West Bay from samples taken in 1948 with a new sampler. Comparison is made with a similar survey made by Mr E. Ford with the Petersen grab in 1923.

The deposits contain a fair proportion of mud, and the ‘EcVg’ communities denned by Ford dominate the area. Within the Bay are found fairly dense beds of Turritella communis, Lutraria sp., Callianassa subterranea and Spisula solida.

No marked changes in the fauna seem to have occurred since the earner survey. The fauna is briefly compared with that of the Plymouth area.
Bionomics of the poor-cod (Gadus minutusL.) in the Plymouth area
Authors: Menon M. Devidas
Published: May 2009

The volumetric and qualitative analysis of the food ofGadus minutushas been discussed. The post-larvae feed entirely on copepods, mostlyPseudocalanus elongatus. The O-group feeds on copepods, small decapods, amphipods, polychaetes and isopods. The adolescent and adult groups feed on larger decapods likeProcessa canaliculata, Galatheaspp. andPortunusspp., fish, polychaetes and amphipods.

The age and rate of growth ofG. minutushave been computed from a study of the supra-occipital crest. These age determinations have been correlated with the age determined by scales, otoliths and size-analysis. Back-calculations have been made by graphical method and by using the Lea-Dahl formula. The differences between the back-calculated lengths and actual observed lengths are negligible.
Amphipoda
Authors: Spooner G. M.
Published: May 2009

The marine Amphipoda of the Plymouth area, as a group, were last given attention in the middle 1930's by Crawford (1936,1937). Renewed investigation after the lapse of 15 years has indicated that knowledge of species present was by no means complete, or that some changes have occurred in the interval, or both. In a recent survey of the amphipod fauna of the Isle of Man, Jones (1948) found no indication of the existence of undescribed species, nor even of known species previously unrecorded from Britain. The experience at Plymouth has been quite the reverse.
A new deep-sea ray from the Bay of Biscay
Authors: Forster G. R.
Published: May 2009

A new species of Breviraja is described from a pair of fish caught by line at nearly 2500 m depth in the Bay of Biscay. Distinctive characters include: the sparse distribution of denticles and spines, small number of teeth, position and size of the orbits, and very pale dorsal surface.
The growth of Haliotis tuberculata: results of tagging experiments in Guernsey 1963–65
Authors: Forster G. R.
Published: May 2009

A tagging investigation on the ormer (Haliotis tuberculata L.) has been carried out for the Guernsey States Sea Fisheries Committee. Cementing plastic discs to the shell has proved a satisfactory technique since substantial numbers of 40—50% were recovered after 1 and 2 years in the open sea off the west coast of Guernsey. From the increase in shell size of the recovered specimens the mean growth rate has been shown to be about 15 mm of shell length per year up to a shell size of 50 mm, and thereafter decreasing until at 100 mm length growth is negligible. The growth parameters K and L∞ have been calculated. Annual rings were frequently, though not invariably, found on the shell. From the frequencies of the shell-ring lengths in the smaller ormers estimates of the shell size reached 1 and 2 years after settlement have been made. A single annual ring was also found with the majority of the larger shells (> 50 mm), though when growth did not exceed 4 mm in a year the rings were not included owing to the difficulty of separating annual rings from possible disturbance rings caused by the process of tagging. The position of the annual ring varied, being closer to the outer edge of the shell with increasing size. Measurements of the length increase from one annual ring to the next indicated rates of growth closely comparable to those obtained from tagging measurements. Damage to the shells by the boring sponge Cliona lobata Hancock is very widespread, particularly in the larger ormers living below the tide marks.
Studies on a sublittoral population of Aplysia punctata
Authors: Carefoot T. H.
Published: May 2009

The size-frequency distributions of monthly collections of Aplysia punctata from a sublittoral population in Trearddur Bay, Anglesey, made during the period from July 1964 to October 1965, indicate that the animals live for one year and that the major recruitment to the population occurs in the autumn. The Aplysia in this area are restricted mainly to sublittoral beds of the red alga, Plocamium coccineum, and the majority of animals feed, copulate and deposit spawn on this seaweed. The animals spawn from May, when the sea temperature reaches a minimum of about 9–9·5° C, until about October, with a maximum output of spawn in the late summer when the animals are fully grown. Aplysia in Trearddur Bay do not migrate inshore; instead, they probably colonize the intertidal region after being accidentally washed inshore from the sublittoral habitat. Intertidal and shallow-water Aplysia are larger than those from deeper water possibly because of the greater abundance of food. Similarly, it is thought that Aplysia found in the intertidal zone are brown and olive-green because they eat a particular alga or combination of algae present in this habitat.
The distribution ofEurydice[Crustacea: Isopoda] in British waters, includingE. affinisnew to Britain
Authors: Jones D. A. , Naylor E.
Published: May 2009

Of the seven British species ofEurydicetwo are intertidal, three range successively from the immediate sublittoral to the edge of the continental shelf, and two predominate at the edge of and beyond the shelf. Most species have been recorded from the benthos and from surface plankton.E. affinisis recorded for the first time in Britain, amongE. pulchrain intertidal sand in the Bristol Channel.
Changes in the bottom fauna of Weymouth Bay and Poole Bay following the severe winter of 1962–63
Authors: Holme N. A.
Published: May 2009

Anchor-dredge samples of the benthos in Weymouth Bay and Poole Bay were taken after the severe 1962–63 winter to ascertain what changes in the fauna had occurred. The same station positions as had been previously sampled in 1958 and 1959 were re-sampled in 1963–64 and the results from each Bay compared.

Most species had survived the previous winter, when sea temperatures had probably been at 3° or below for about a month, but populations of the bivalve molluscs Venus verrucosa and Venerupis rhomboides, previously common in the area, had suffered severe mortalities, none being taken in the 1963–64 samples. The brittle star Acrocnida brachiata had also disappeared from the samples, and many other invertebrates appeared to have declined in numbers. Two cold-water species, Spisula elliptica and Buccinum undatum, showed if anything a slight increase, perhaps reflecting colder sea temperatures over the past few years. Crepidula fornicata also showed an increase in numbers.

Mortalities were not necessarily of species close to the limits of their range, some of the latter having survived with no noticeable decline in numbers.
A study of glycogen and lactate in the myotomal muscles and liver of the Coalfish (Gadus virensL.) during sustained swimming
Authors: Johnston I. A. , Goldspink G.
Published: May 2009

The locomotor roles of the myotomal muscles of fish are dependent on swimming speed. The mean maximum sustained swimming speed for coalfish (Gadus virensL.) during a 6-h period in an experimental exercise chamber was determined using a fixedvelocity technique and found to be 4 bodylengths/s. Biochemical measurements were made on the concentration of glycogen and lactate in the red muscle and white muscle at a series of known swimming speeds. Evidence is provided that red muscle alone is used at speeds below 2 bodylengths/s. The fall in concentration of red muscle glycogen was directly proportional to increased swimming speed. At speeds in excess of 2 bodylengths/s a statistically significant increase in lactate concentration occurred in the white muscle fibres. A reduction in glycogen content of the white muscle was also noted at speeds at and above the estimated mean sustained swimming speed. These results are discussed in the light of the current ideas pertaining to the division of labour between myotomal muscles in fish.
Physiological changes inMytilus edulisL. induced by temperature and nutritive stress
Authors: Bayne B. L.
Published: May 2009

Three levels of oxygen consumption rate are identified, viz. standard, routine and active. Animals fed above the maintenance energy requirement adjust their oxygen consumption rate to a routine level. Animals fed below the maintenance requirement reduce their oxygen consumption rate to a standard level within 35–40 days. The routine rate is seasonally variable, with high values in the winter and low values in the summer. The standard rate also varies seasonally. The exponent that relates routine oxygen consumption to body size varies from a high value in the summer to a lower value in the winter.
Fine structure of the secretory epithelium in the hypobranchial gland of the prosobranch gastropod mollusc Buccinum undatum L
Authors: Hunt S.
Published: May 2009

The secretory epithelium in the hypobranchial gland of Buccinum undatum L. consists of a single layer of elongated cells resting upon a basement membrane which overlies layers of connective tissue and muscle. Three principal types of cell are present. Two of these participate in the actual production of the mucinous secretion while the third is a ciliated cell. The ciliated cells also bear numerous microvilli and contain abundant microtubules and microfilaments. Neuronal contacts with the ciliated cells can be detected.

The secretion product of the gland is a loose association of acid mucopolysaccharide and glycoprotein and the cells secreting these two materials can be clearly identified. Those secreting acid mucopolysaccharide have been called acid mucin cells while those secreting glycoprotein have been called goblet cells because of their resemblance to intestinal goblet cells. The acid mucin cells are large and distended with an amorphous mass of electron luscent material. This material is strongly metachromatic in the light microscope when stained with toluidine blue. Newly secreted acid mucopolysaccharide is contained within membrane-bound vacuoles where it exhibits a whorl-like or lammelar form. This latter fine structure is lost as the vacuoles coalesce filling the cell. The goblet cells are smaller and contain discrete globular, membrane-bound, packets of electron dense material. These do not stain metachromatically. Both types of cell release their contents by rupture of the cell membrane at the epithelial surface.
On the genus Golfingia (Sipuncula) in the Plymouth area with a description of a new species
Authors: Gibbs P. E.
Published: May 2009

A new species of the genus Golfingia (phylum Sipuncula), belonging to the subgenus Phascoloides Fisher, is described from the Plymouth area.

Studies of the local populations of G. (Golfingia) elongata have shown the species to vary considerably in some important taxonomic characters, in particular, the number of retractor muscles: over 13% have only two or three retractors instead of four.

Notes on, and a key to, the species of Golfingia found around the British Isles are given.
The histology and histochemistry of the pedal glandular system of two limpets,Patella vulgataandAcmaea tessulata(Gastropoda: Prosobranchia)
Authors: Grenon J.-F. , Walker G.
Published: May 2009

Patella vulgatapossesses nine different pedal glands, six of which pour their secretions on to the sole. Proteins secreted by the marginal gland into the marginal groove are used for locomotion, especially when the limpet moves off following a period of adhesion. Another protein-secreting subepithelial gland, sparsely present throughout the foot, is also believed to be used in locomotion. A third gland type is present in the epithelium of the sole. The secretion of these epithelial mucocytes which is a weakly acidic muco-polysaccharide (MPS) is likely to have a locomotory function. Three other sole glands secrete highly viscous acidic MPS. Their secretions are likely to have an adhesive function. The three other glands present in the foot are contained within the side-wall. Of these, two are believed to secrete mucus to protect the animal against desiccation during emersion; and the other, present only in youngP. vulgata, pours its acidic MPS secretion into the epipodial streak. This secretion consolidates debris before it is cleared from the pallial cavity; in adult animals, muscular contractions of the foot are powerful enough to clear debris without the help of the epipodial gland.

InAcmaea tessulatathe six glands present open out on to the sole and correspond in position, composition and function to the six glands of the sole ofP. vulgata. There are no glands within the side-wall.
Osmotic balance and respiration in the hermit crab, Pagurus bernhardus, exposed to fluctuating salinities
Authors: Shumway Sandra E.
Published: May 2009

Specimens of Pagurus bernhardus (with and without shells) were exposed to both gradual (sinusoidal) and abrupt (square-wave) salinity fluctuations and changes in haemolymph osmolality, tissue water content and oxygen consumption monitored. Oxygen consumption was also monitored under steady-state conditions; under these conditions there was no significant difference between the rate of oxygen consumption by animals with shells and animals without shells. Oxygen consumption was found to vary with body weight according to the equation O2 consumption = 0·292 W0·668. During exposure to fluctuating salinities the crabs with shells were seen to increase loco-motory activity when the external medium declined to approximately 75% sea water. Haemolymph osmolality values followed the same pattern of change as the external medium; the haemolymph of crabs without shells became significantly more dilute during exposure to low salinity than did that of crabs with shells. P. bernhardus showed significant increases and decreases in hydration level as salinities fell and rose respectively. Crabs with shells showed a marked temporary increase in oxygen consumption when the external medium declined to approximately 75% sea water; crabs without shells showed no such response. The importance of the shell as a means of protection against dilute media is discussed.
The feeding behaviour of the featherstar Antedon bifida (Echinodermata: Crinoidea)
Authors: La Touche Robert W.
Published: May 2009

The ecology and feeding behaviour of Antedon bifida bifida (Pennant) were studied in situ at five sites on the east and west coasts of Ireland. These encompassed a range of different habitats and hydrographic conditions, including currents of varying intensity, oscillations due to wave action, and multidirectional water movements.

Unlike other comatulids hitherto studied, this species was found to be relatively unspecialized in its choice of habitat and to display great flexibility of movement in its arms and pinnules which enable it to adapt to and feed in each of the different types of water movements described. Neither diurnal nor tidal feeding rhythms were observed, the animals being found to feed almost continuously. The relatively unspecialized nature of this species is discussed in relation to the almost cosmopolitan distribution of the genus Antedon.
The lipids of six species of shark
Authors: Craik J. C. A.
Published: May 2009

The compositions of the lipids of egg yolk, blood plasma and liver ofScyliorhinus caniculafrom the Irish Sea were examined by column chromatography and by various other methods. Considerable differences in composition were found between these three tissues. Phospholipid and triacylglycerols were the major components of lipids of yolk and liver respectively. Cholesterol, free fatty acid and phospholipid were present in all three tissues. Squalene and alkyldiacylglycerols were present only in traces, if at all. In this paucity or absence of squalene, this population differs from MediterraneanS. canicula. The compositions of the lipids of the livers of six shark species (Scyliorhinus canicula, Scyliorhinus stellaris, Squatina squatina, Galeorhinus galeus, Mustelus asteriasandSqualus acanthias) were compared by thin-layer chromatography. In all cases, triacylglycerols were the major components, while hydrocarbons were not detected by this method in any of the species. Alkyldiacylglycerols were present as a major component only inSqualus. Qualitatively, the other five species showed only minor differences from each other; these five species are largely confined to shallow coastal waters. The results follow previous work in showing that low-density lipids, such as squalene and alkyldiacylglycerols, are major components of hepatic lipid in shark species from deeper waters, although not necessarily from great depths. An attempt is made to explain the prevalence of such lipids in pelagic sharks in evolutionary terms. It is suggested that they may serve as an analogue of the swimbladder of teleosts.
Investigation of a nutrient-growth model using a continuous culture of natural phytoplankton
Authors: Jones K. J. , Tett P. , Wallis A. C. , Wood B. J. B.
Published: May 2009

Phytoplankton from Loch Creran, Argyll was maintained in continuous culture for 41 days. During most of this time the mixture of species retained the diversity and dominance pattern typical of summer phytoplankton in the loch, notwithstanding the manipulation of algal nutrient status to bring about phosphorus control of growth. Results suggest that most detritus was washed out early in the experiment.

The aim of the experiment was to test the applicability to natural multispecies phytoplankton of part of Droop's (1974, 1975) model of nutrient-limited algal growth. ‘Quasi-steady states’ with respect to concentration of chlorophyll, particulate carbon (PC), particulate phosphorus (PP) and particulate nitrogen (PN), wereobserved at two levels of input of dissolved inorganic phosphorus. At other times the algal phosphorus quota (estimated from the ratio of PP to PC) varied from about 0·002 to 0·015 atoms P per atom C. Specific growth rate was estimated from the rate of increase of PC. During part of the experiment, growth rate was linearly related to reciprocal phosphorus quota, thus confirming the applicability of the model.
Cyclonic eddies and cross-frontal mixing
Authors: Pingree R. D.
Published: May 2009

An examination of infra-red satellite images of the North-West European continental shelf suggests that cross-frontal mixing takes the form of cyclonic eddies. These are about 20–40 kmin scale and persist for a few days. It is suggested that the dynamics of cyclonic eddies willbe important in the development of frontal phytoplankton blooms.
Some factors affecting the respiration of intertidal Asterina gibbosa (Echinodermata: Asteroidea)
Authors: Murphy Christine T. , Jones M. B.
Published: May 2009

In Britain, the cushion star Asterina gibbosa Pennant 1897 (Echinodermata, Asteroidea) is confined to the west coast, where it occurs on rocky shores, often sympatrically with the closely related Asterina phylactica Emson & Crump 1979 (Crump & Emson, 1983; Emson & Crump, 1984). The vertical distribution of A. gibbosa extends from about 100 m depth, into the intertidal; however, littoral cushion stars occupy rock pools and relatively damp habitats such as gulley walls, crevices, overhangs and the underside of boulders, generally on the lower shore (Emson, 1979). On shores with rock pools, cushion stars may extend their upper limits of vertical distribution but not beyond the mean high-water neap-tide level (Crump & Emson, 1978). Absence of A. gibbosa from higher shore levels has been related to intolerance to desiccation and high temperature, inadequate food supply, and complex behavioural responses to gravity and light (Crozier, 1935; Emson, 1979; Crump & Emson, 1983). Prior to the present study, it has not been possible to discuss the influence of respiratory requirements on the vertical distribution of this species.
Behavioural responses of the copepodsCalanus helgolandicusandTemora longicornisto dinoflagellate diets
Authors: Gill Catherine W. , Harris Roger P.
Published: May 2009

Activity patterns of the first maxillae ofCalanus helgolandicusandTemora longicornis, restrained in a flow-through system, were investigated using a micro-impedance electrode technique. Copepods were exposed to four dinoflagellate species of similar cell size with filtered sea water and the diatomThalassiosira weissfloggias controls. In short-term transition experiments the beat frequency of the maxilla changed rapidly with the introduction and removal of cells from the surrounding medium. Similarly the introduction of cell-free algal homogenate, filtered through a 0·2µm membrane, produced elevated beat frequencies, evidence consistent with chemosensory food detection. During 24 h exposure experiments frequencies forCalanuson all dinoflagellate diets were lower than for the diatom, and in the case ofScrippsiella trochoideadid not differ significantly from the seawater controls. InTemora, frequencies when feeding on dinoflagellates, exceptProrocentrum micans, were lower than on the diatom. WithScrippsiella trochoideaandGonyaulax tamarensisbeat frequencies were the same as those for the sea-water controls. Significant depression of frequency below that observed in filtered sea water was shown for both copepods when presented with the bloom-forming,Gyrodinium aureolum. Differences in beat frequency in response to dinoflagellate diets are mirrored by other aspects of feeding activity, gut contents, egg production and mortality.
M-‘midget’ cells and moult cycle inPenaeus semisulcatus(Crustacea: Decapoda)
Authors: Al-Mohanna S. Y. , Nott J. A.
Published: May 2009

Within the hepatopancreas of the shrimpPenaeus semisulcatusthe functional develop ment and subsequent decay of M-‘midget’ cells is described and linked with the moult cycle. During the feeding stages the frequency of M-cells increases and they each form a large dense vacuole which contains proteinaceous material. Precursors for this material are probably derived from the haemolymph as the cells have no direct contact with the lumen of the gland. During the non-feeding stages before and after ecdysis the contents of the vacuole are progressively removed, probably to the haemolymph. Finally the cells die before the animals recommence feeding.
On the population biology of the common shrimp Crangon crangon (L.) (Crustacea: Caridea) in the Severn Estuary and Bristol Channel
Authors: Henderson P. A. , Holmes R. H. A.
Published: May 2009

A 5-year study of the population biology of the common shrimp Crangon crangon (L.) in the Bristol Channel is reported. Samples were collected from three commercial fishermen and from the filter screens of five power stations taking water from the estuary.

The Severn Estuary and Bristol Channel were found to contain a single shrimp population which undertook regular seasonal migrations in order to avoid low salinities and to reproduce. Previous studies had assumed that the regions held separate populations which migrated to avoid low winter temperatures.
Studies on benzo[a]pyrene mono-oxygenase in the shore crabCarcinus maenas
Authors: O'Hara S. C. M. , Corner E. D. S. , Forsberg T. E. V. , Moore M. N.
Published: May 2009

A cytochrome P-450-dependent benzo[a]pyrene mono-oxygenase enzyme system (BPM) has been identified and partially characterized in males of the shore crabCarcinus maenas(L.). Apparent Kmvalues obtained at 30 °C using microsomal preparations from the antennary glands of animals collected during summer were in the range 1.61–2.11µM. The cytochrome P-450 content was 0·022 nmol/mg microsomal protein when BPM activity in the same preparation was 0·085 nmol/mg protein/min.
Growth and development of Pseudocalanus elongatus and Calanus sp. in the laboratory
Authors: Thompson Brenda M.
Published: May 2009

Laboratory experiments to determine the stage durations of Pseudocalanus elongatus (Boeck) and Calanus sp. have been described. The duration of all the nauplius and copepodid stages at temperatures ranging from 4° to 15 CC is given for both species. The effect of temperature on the development rate of copepod eggs has also been determined at these temperatures. The effects of food supply and temperature on the distribution, abundance and development rate of different species of copepods are discussed.
The larval development of three species ofMagelona(Polychaeta) from localities near Plymouth
Authors: Wilson Douglas P.
Published: May 2009

Fertilizations ofMagelona filiformis, M. alleni, andM. mirabiliswere made in the laboratory and the resulting larvae reared through the earliest stages. Later stages of all three species were obtained from the plankton and induced to metamorphose in the laboratory. The long larval tentacles derive from the prototroch and associated tissues. Adult tentacles appear during later pelagic life as thickenings at the bases of the larval tentacles; the latter, together with the long provisional bristles, are discarded at metamorphosis. The early larvae ofM. alleniare considerably larger than equivalent stages of the other two species. The early larvae ofM. mirabilisare peculiar in that at first the larval tentacle of the left side is a mere stump while that of the right side is relatively large; in the other two species both tentacles are of equal length. Larvae of the three species are readily identifiable by characters described in the text.
Effects of variations in light intensity on life processes of the planktonic foraminifer Globigerinoides sacculifer in laboratory culture
Authors: Caron David A. , Bé Allan W. H. , Anderson O. Roger
Published: May 2009

The planktonic foraminifer Globigerinoides sacculifer (Brady) was cultured under two different light intensities and in continuous darkness. High light intensity (HLI = 400–500 μeinsteins/m2/s) resulted in a longer lifespan, a greater number of chambers formed, and a larger final shell size compared with individuals cultured under low light intensity (LLI = 20–50 μeinsteins/m2/s) or in continuous darkness. Shell growth rates were unaffected by increasing light intensity, but gametogenesis was delayed. Continuous darkness induced a rapid onset of gametogenesis in organisms with shell lengths larger than 250 μm. Feeding frequency had a greater effect on growth and reproduction than light intensity under conditions of LLI and HLI, but continuous darkness had an overriding effect on growth and reproduction owing to the rapid onset of gametogenesis which terminated the life of the mother cell. Our previous data indicated that the longevity of G. sacculifer was dependent on feeding frequency, and that G. sacculifer cultured under LLI had a lifespan of approximately 2–4 weeks. Present results suggest that the lifespan can vary from a minimum of 8 days for organisms fed daily in continuous darkness to a maximum of 54 days for organisms fed once every 7 days and maintained in HLI. It is concluded that individual G. sacculifer attain a shell size greater than 600 μm only if they maintain their position in the euphotic zone. Prolonged existence below the euphotic zone would result in premature death or gametogenesis following stunted shell growth.
Settlement ofElminius modestuscyprids in contact with adult barnacles in the field
Authors: Hui E. , Moyse J.
Published: May 2009

Elminius modestuscyprids settle readily in contact with adult barnacles in the field, and do not discriminate between conspecific and alien adults. This settlement strategy is contrasted with that previously shown to be employed byBalanus balanoides.
Caryophyllia sarsiaen.sp. and other recent deep-waterCaryophyllia(Scleractina) previously referred to little-known fossil species (C. arcuata, C. cylindracea)
Authors: Zibrowius H.
Published: May 2009

Three deep-water species of the north-eastern Atlantic have been studied:Caryophyllia abyssorumDuncan, 1873, C.calveriDuncan, 1873,C. sarsiaen.sp. Of these onlyC. abyssorumhas not been found in the Mediterranean. In the north-eastern Atlantic these species appear characteristic of somewhat different depths, but occasionally can be found together. Obtained by early deep-sea expeditions (“Porcupine” cruise of 1870, cruises of Prince Albert I of Monaco), all three species have been previously confused and assigned, chiefly, to the little-known fossil speciesC. arcuataandC. cylindracea. In order to show the world-wide confusion aboutC. arcuata, some other records, from Cape Verde Islands to Japan through Antarctica, are quoted.
Golfingia margaritacea (Sipuncula) in British waters
Authors: Gibbs P. E.
Published: May 2009

Specimens of Golfingia margaritacea (Sars) (Sipuncula) from the south coast of Devon and Cornwall and from Raasay, West Scotland, are described and discussed in relation to the taxonomy and zoogeography of the species.
SOND Cruise 1965: Further factor analyses of the plankton data
Authors: Angel M. V. , Fasham M. J. R.
Published: May 2009

Factor analyses have been carried out on the total data for 134 planktonic forms sampled during the 1965 SOND cruise by R.R.S. ‘Discovery’. Species assemblages are largely consistent with the intragroup analyses carried out previously (Angel & Fasham, 1973). Factor score plots for the separate day and night series confirm the rather limited number of categories of vertical distribution patterns that occur despite the occurrence of vertical migration. The analysis of the combined day and night data confirms the rather limited number of patterns of vertical migratory behaviour. Size spectra of euphausiids in some of the assemblages associated with each category suggest that there may be resource partitioning. The trophic relationships within the assemblages appear to be structured and are discussed in the light of the limited knowledge of the feeding behaviour of many of the species involved. Diurnal vertical migration behaviour in planktonic species appears to be limited to the top 700 m.
The colouration and its behavioural significance in the corkwing wrasse,Crenilabrus melops
Authors: Potts G. W.
Published: May 2009

The colour patterns of the corkwing wrasseCrenilabrus melopsand the functional significance of these patterns has been described. The resting colours of the fish are described for juveniles, mature males and mature females. These colour patterns assist in making the fish less conspicuous in their natural environment. Agonist behaviour is characterized by the development of a series of vertical bars on the body together with ritualized lateral and frontal displays in aggressive, and a head-up submissive posture in fright situations. Most aggressive behaviour is associated with the territorial activity of the mature male. Courtship and spawning activities involve a complex series of visual signals that synchronize the roles played by the male and female. The differences in colouration between juvenile and mature fish and the changes any individual can display have wrongly lead earlier authors to splitC. melopsinto different species or varieties.
Two new species of cranchiid cephalopod from the North Atlantic, Uranoteuthis bilucifer n.gen., n.sp. and Galiteuthis triluminosa n.sp
Authors: Lu C. C. , Clarke M. R.
Published: May 2009

Two new species of cranchiid cephalopod are described. These were both collected by opening-closing midwater trawls (RMTs) when vertical series were fished in the North Atlantic from R.R.S. ‘Discovery’.
Biochemical changes during growth of the spat of the oyster,Ostrea edulisL.
Authors: Holland D. L. , Hannant P. J.
Published: May 2009

The biochemical composition of three batches ofOstrea edulisL. spat was determined during post-settlement growth. The spat were from spatfalls in January, March and June. For the first few months after settlement the neutral lipid (triglyceride) content was greater than the glycogen content. However, in three- to five-month-old spat the glycogen content became greater than that of neutral lipid.
Report on the Surface Collections made by Mr. W. T. Grenfell in the North Sea and West of Scotland
Authors: Bourne Gilbert C.
Published: May 2009

Mr. Wilfrid Grenfell, the Superintendent of the Mission to Deep Sea Fishermen, has most kindly arranged to carry on a series of observations on the pelagic fauna and the fishes of the seas traversed by the Mission boats in the course of their work. The following report gives an account of the pelagic fauna collected in the North Sea during the early spring, and in the west of Scotland and Kinsale Harbour during the summer. The collections were preserved in picro-sulphuric acid and spirit, and were forwarded to Plymouth for examination. Owing to pressure of work, and to my leaving Plymouth somewhat unexpectedly, I have not been able to make a thorough investigation of all the collections, but have worked out the Copepoda with care, and have confined myself to short notes on the other species.
Seals (Halichoerus grypus) of Cornwall Coasts.
Authors: Steven G. A.
Published: May 2009

It has long been known that there is a considerable seal population on the North Cornwall coast. But precise information concerning the species present, the density of the population, and the positions of the rookeries has been almost entirely lacking. In order to obtain data on these points, a detailed survey of the North Cornwall coast was carried out during the fortnight August 7th-20th (1935) inclusive.
The Occurrence, Ecology and Life History of Tigriopus fulvus (Fischer)
Authors: Fraser James H.
Published: May 2009

The peculiar and exacting environment of Tigriopus fulvus is discussed and a census of Tigriopus from a series of pools in the Isle of Man is given.

Experiments have been made determining the resistance of Tigriopus to desiccation and its revival in favourable circumstances.

The life history has been worked out, times taken in development noted, and the various stages compared and contrasted with those described by Guiglia.

Sex can be determined at the fourth copepodid stage. Females are normally fertilised as fifth copepodids, but the males are not functional until the adult stage. A single female may produce several egg sacs giving rise to living nauplii from a single fertilisation.

There is no evidence for parthenogenesis.
The Seasonal Abundance of the Pelagic Young of Teleostean Fishes in the Plymouth Area. Part III. The Year 1935, with a Note on the Conditions as Shown by the Occurrence of Plankton Indicators
Authors: Russell F. S.
Published: May 2009

Records are given on the abundance of the pelagic young of teleostean fishes off Plymouth as shown by half-hour oblique hauls with the 2-metre stramin ring-trawl.

In comparison with similar observations made since 1924 the year 1935 has been the poorest yet recorded.

A parallel between the quantity of phosphate in the water at the beginning of the year and the abundance of young fish is further confirmed. In January, 1935, the winter maximum phosphate value was the lowest yet recorded.
An Investigation of the Seaweeds within a Marked Zone of the Shore at Aberystwyth, during the Year 1933–34
Authors: Lewis Edith A.
Published: May 2009

The following piece of research has been undertaken at the suggestion of the Conway Fisheries Eesearch Station of the Ministry of Agriculture and Fisheries.

For some years experiments have been in progress at Conway in connection with oyster breeding. During the oyster season, from May to August, when the tanks of the Kesearch Station are not being used for mussel cleansing, cultural work on the oyster (Ostrea edulis) has been carried out. One of the greatest difficulties is the feeding of the larvae in the free swimming state and this problem affects both tank culture and culture on a smaller scale. In some years a settlement of spat has taken place, but it is not known what conditions made that phenomenon possible. It has been suggested that the available food supply might be of importance, since both detritus on the one hand, and seaweed spores and gametes on the other, have been regarded as constituting the food of larvae (Martin, 1923). As nothing over 10μ can be ingested by the larvae, there is a limit to the spores and gametes which may be used.