bluuebunny/crossref_metadata_2025 huggingface dataset:
Nearshore zonation of benthic fauna, especially Nematoda, in Loch Etive
Authors: Warwick R. M. , Gage J. D.
Published: May 2009

The marked pattern of vertical zonation in the nearshore distributions of benthic fauna in sea-lochs seems to be controlled by the degree of fluctuation and extent of depression in salinity (Gage, 1974). The different vertical patterns in the abundances of species can be related to their known tolerances to reduced and fluctuating salinity. An overall faunal discontinuity seems to occur at a depth which roughly corresponds to the maximum depth to which markedly brackish conditions are experienced.
Vertical distribution of cephalopods at 11°N, 20°W in the North Atlantic
Authors: Lu C. C. , Clarke M. R.
Published: May 2009

This is one of a series of four papers dealing with vertical distribution of cephalopods in the North Eastern Atlantic at six stations near 20° W and at about 10° intervals from 60°N to 11° N (Clarke & Lu, 1974, 1975 a; Lu & Clarke, 1975). The present study is based upon a series of hauls made at discrete horizons between o and 2000 m with opening-closing nets during both daylight and darkness. The collections were made for the ecological programme of the National Institute of Oceanography, Wormley, Surrey, England (now part of the Institute of Oceanographic Sciences).
An apparatus to supply water of fluctuating salinity and its use in a study of the salinity tolerances of larvae of the scallop Pecten maximus L.
Authors: Davenport J. , Gruffydd D. , Beaumont A. R.
Published: May 2009

Salinity is a major limiting factor in littoral and estuarine environments and the salinity encountered in such habitats fluctuates with tide, season and weather. Despite this variable situation, most investigations of salinity tolerance and osmoregulation have involved laboratory experiments at steady salinities. The literature devoted to such investigations is extensive, and has been reviewed on several occasions, notably by Krogh (1939), Potts & Parry (1964) and Kinne (1971).
An analysis of the growth bands and ridges of barnacle shell plates
Authors: Bourget Edwin , Crisp Dennis J.
Published: May 2009

Periodic structures indicating discontinuous growth of shell wall plates have been observed in thin sections of shell and on the outer surface of shell plates of many species of operculate (Bourget, 1975). When sectioned and etched the shell plates appear to be composed of successive thin layers of shell material, each layer consisting of a few rows of fine crystals. Where two layers are adjoined, a dark line, marking the junction of two incremental zones, is clearly visible. The thin layers of shell have been termed growth bands whereas the junction of adjoining layers will be referred to as the growth line.
The ultrastructure and histochemistry of the larval cement of Ostrea edulis L.
Authors: Cranfield H. J.
Published: May 2009

The larval cement of Ostrea edulis is formed from material secreted by the settling larva from two types of pedal gland (Cranfield, 1973b). Light microscope observations suggested that there were fibrous regions in this cement. The histochemistry and ultrastructure of the cement were therefore examined to establish the nature of this fibrous structure and to determine the part each of the two secretions might play in its formation.
The accumulation of radioactive caesium in crabs
Authors: Bryan G. W.
Published: May 2009

The accumulation of 134Cs and 42K from artificial sea water has been followed in crabs of the following species, viz. Carcinus maenas, Portunus puber, P. depurator, Polybius henslowi, Cancer pagurus and Corystes. cassivelaunm. In all cases 134Cs is taken up far more slowly than 42K but at equilibrium a higher concentration factor is attained by 134Cs. In Carcinus a value of about 8 is found for 134Cs and about 4 for 42K. Uptake of 134Cs in Carcinus is not affected by feeding on inactive food over a period of 1000 h. The relationship between the rates of uptake of the two isotopes is not the same in the different species and it is concluded that it would not be possible to predict with any accuracy rates of uptake for 134Cs in other species of crabs from the results of short 42K experiments.

Uptake of 134Cs was followed in the blood and tissues of Carcinus and Cancer, and muscle is the principal limiting factor in the attainment of equilibrium by whole animals. Uptake of 42K by tissues has also been followed and in all species nearly all the inactive K appears to be readily exchangeable. At equilibrium in all species plasma/sea water and tissue/plasma 134Cs ratios nearly always exceed those for inactive K. The tissue/plasma 134Cs ratios in Carcinus are about twice those for K and the significance of this has been discussed.

Loss of both isotopes in whole Carcinus is a slower process than uptake.Isotope accumulation takes place mainly across the body surface in unfed animals, but uptake of 134Cs from food is very rapid and complete and would considerably enhance the attainment of equilibrium in a natural environment.

Selective excretion of 134Cs relative to K has been found in Carcinus, Cancer and Portunus puber.
Studies on the biology of limpets IV. The breeding of patella depress a pennant on the north Cornish coast
Authors: Orton J. H. , Southward A. J.
Published: May 2009

The breeding of Patella depressa was studied at Trevone, North Cornwall, for 4 years. Gonads were examined and assessed by methods described in a previous report on P. vulgata.

In contrast to the common Limpet, P. depressa is a summer breeder in Cornwall. Gonad development begins in the spring and is complete by June or July. Spawning coincides with maximum air temperatures in July, August or early September. The autumn and winter period is passed with gonads in recognizable post-spawning and spent stages, and only a small proportion of completely resting neuter gonads is found in the early spring.

Mass spawning takes place, and gametes are voided rapidly. No definite spawning stimulus can be shown, but, as with P. vulgata, there may be some relation between onset of spawning and the occurrence of wave action on the shore.

The differences in breeding behaviour of P. depressa and P. vulgata reinforce the other differences between them and throw some doubt on the concept of super-species in Patella.
Photomechanical changes in the eyes of fishes I. Retinomotor changes in Solea solea
Authors: Nicol J. A. C.
Published: May 2009

In the common sole Solea solea retinomotor changes take place. The retinal pigment usually expands in the light and cones shorten; reverse changes take place in darkness.
Notes on the mode of life of the Tellinidae (Lamellibranchia)
Authors: Holme N. A.
Published: May 2009

Evidence from animals dug up on the shore, from observations on burrowing, or from shell shape indicates that the following species normally lie below the surface with their right valve uppermost: Tellina squalida, T. tenuis, T. fabula, T. donacina, and Arcopagia crassa. Information on the habits of the remaining Tellinidae has not been obtained.

Animals placed on the surface of the soil with the left side up turn themselves over as they burrow. In Arcopagia the shell is turned over beyond the vertical before the animal enters the substratum, but in the remaining species studied the shell is gradually turned over so that it disappears below the surface almost vertically and subsequently completes the turning movement beneath the surface.

The disposition of the siphons of Arcopagia may differ somewhat from that of T. tenuis as described by Yonge, and there is a need for further observation on the siphons of the other species.
Shell form in Venerupis rhomboides
Authors: Holme N. A.
Published: May 2009

Two forms of Venerupis rhomboides occur in Plymouth waters. A more slender form, corresponding to that described by Pennant, occurs in the Eddystone shell gravel, and a more robust form, corresponding to the Venus sarniensis of Turton, occurs at the mouth of the River Yealm. The two forms differ in ratios of shell height, width and lunule width relative to shell length. A population with intermediate ratios is found at 6-5 m in Plymouth Sound.

Plots of height/length ratios of these and another intermediate sample on probability paper did not indicate that the intermediate populations were composed of mixtures of the two extreme forms, and it was provisionally concluded that these were all variants of a single species.

If the height/length ratios of series of samples from different localities are plotted against depth of water on a logarithmic scale, an inverse relationship, approaching a straight line, is obtained. Regression lines for median ratios in the 3-4 and 4-5 cm length groups have been plotted separately, as there is some change in proportion with increasing length. These show a highly significant negative correlation between shell ratios and depth.

From the regression lines it has been possible to obtain an estimate of the depth inhabited by even quite small samples of shells. Depth estimations have been made for eight samples, consisting mainly of dead shells. Six samples lay within the expected limits, and discrepancies in the other two samples are attributed to transport along the sea floor.

The possible causes of the differences in shell ratios are discussed. Previous work suggests that shell ratios may be affected by different rates of growth. Soil grade, temperature, food supply, and light penetration are considered unlikely causes of the observed differences in shell ratios, and it is suggested that the pattern of growth may be affected by pressure.

The Appendix contains a key to British species of Venerupis.
The effect of salinity upon the boring activity and survival of Limnoria (Isopoda)
Authors: Eltringham S. K.
Published: May 2009

The effect of salinity upon the wood-boring activity of Limnoria was investigated experimentally. Boring decreased linearly with salinity and ceased altogether below io%o. The limiting salinity varied inversely with the temperature, being 12%0 at 17-6 C and 15 %0 at 14-9 C (average temperatures). The boring activity was intensive in its early stages but after about 5 weeks fell to a lower constant rate.

Survival experiments suggested that the low salinity was the direct cause of the reduced boring activity. The only lethal salinity found during the period of the experiments (65 days) was 6%0 which proved fatal in about 15-20 days. The next higher salinity tested was i2%0. No reduction in survival was found in concentrated salinities up to a value of 48 %0, the highest salinity examined.
Observations on the British species of Jaera (Isopoda:Asellota)
Authors: Naylor E. , Slinn D. J. , Spooner G. M.
Published: May 2009

of winter phosphorus have represented differences in numbers of 6-month-old pilchard larvae; the winter phosphorus provides the link between herring recruitment and numbers of pilchard eggs, suggesting that there has been competition between the herring and pilchard stocks, in their juvenile stages. Thus it is suggested that the Plymouth herring fishery failed in competition with the pilchard stock and that the other biological events which took place in the early thirties were a consequence of this postulated competitive change.
Thecal fine-structure in the dinoflagellate genera Prorocentrum and Exuviaella
Authors: Dodge John D.
Published: May 2009

The structure of the thecae, as seen in the electron microscope, are described for two species of Prorocentrum and five of Exuviaella. For the first time it is possible to distinguish between true pores and the spines and thin areas of wall which have previously been described as pores or poroids. Several distinct features such as the spines covering the valves, the ridged valve margin and special flagella pore structures which are found in only two of the Exuviaella species suggest that it may be necessary to create a new genus.
Chitin in pogonophore tubes
Authors: Blackwell J. , Parker K. D. , Rudall K. M.
Published: May 2009

The chitin from pogonophore tubes is shown to be essentially the same as that from the pen of the squid Loligo and is classified as β-chitin (as are the known chitins in annelids). However, certain important differences in detail are seen when comparing X-ray diffraction photographs and infra-red absorption spectra of the chitin from the two sources. These matters are of interest in defining the systematic position of the Pogonophora as well as in reaching an understanding of the functions of the protective tube.
Further extensions to the known range of the Northern Rockling, Ciliata septentrionalis
Authors: Wheeler Alwyne
Published: May 2009

The known distribution of the Northern Rockling, Ciliata septentrionalis (Collett, 1875) is discussed and several additional occurrences reported. These greatly extend the range of the species. Notes on the biological background of the fish are provided, as are synoptic descriptions of it and its relative C. mustela.
An aid to the detailed examination of salps [Tunicata: Salpidae]
Authors: Foxton P.
Published: May 2009

A method is described for staining the musculature of preserved salps with Rose Bengale and reforming their natural shape by injecting the body cavity with molten agar. Compared with normal preserved material, specimens prepared in this way are easy to handle, more lifelike in appearance and the detailed arrangement of their musculature is clearly differentiated in three dimensions.
Direct measurements on the orientation of the reflecting surfaces in the tapetum of Squalus acanthias, and some observations on the tapetum of Acipenser sturio
Authors: Denton E. J. , Nicol J. A. C.
Published: May 2009

Direct observations on the reflecting layers in the tapetum of the spur dog Squalus acanthias confirm the orientations of the tapetal reflecting cells which were previously found histologically (Denton & Nicol, 1964). Surface views of the tapetum show the outlines of the exposed surface of the tapetal plates as ‘polygons’. The long axes of these polygons are parallel with the plane of the tissue on which they lie and the polygons are only inclined to this plane across their short axes. The angle to which they are inclined increases as we move towards the periphery of the eye.
Extracellular carbohydrate liberation in the flagellatesIsochrysis galbanaandPrymnesium parvum
Authors: Marker A. F. H.
Published: May 2009

The production of extracellular carbohydrate has been studied inIsochrysis galbanaandPrymnesium parvumin axenic culture. Increased extracellular production of carbohydrate occurred at reduced and increased salinity, low light intensity and under conditions of nitrogen starvation inIsochrysis, and in some cases appeared to be associated with the sedimentation of the cells from stagnant culture. Extracellular carbohydrate production was found to be greatest during the early and later stages in growth and dropped to a minimum during the mid-growth phase. Experiments indicated that the cells were not being damaged during harvesting of the cultures. A close similarity was found between the monosaccharide components of the intra- and extracellular carbohydrate after acid hydrolysis; both contained glucose, galactose, arabinose, xylose and ribose. It is suggested that the production of most of the extracellular carbohydrate is due to the passive release of organic matter from dead or dying cells.
On the attenuation of light in the sea
Authors: Burt Wayne V.
Published: May 2009

Recently Jones & Wills (1956) have related the attenuation of light in the sea and in estuarine waters to the concentration of suspended solid matter. The attenuation was measured with an in situ hydrophotometer with a beam acceptance angle of approximately 3.20°. The concentration of suspended materials was determined by filtering in the case of natural samples or by adding known weights of kaolin or mud to tap water. In the discussion of their data and methods they have made application of the difFraction theory for opaque particles relatively large compared to the wave-length of light.
Notes on oxygen sampling on the Fladen Ground
Authors: Steele John H.
Published: May 2009

A comparison is made of oxygen and phosphate data from the Fladen Ground. It is found that the conversion factor for oxygen:phosphorus given by Sverdrup et al. (1942) does not agree with the changes below the euphotic zone and an alternative factor is calculated. Problems concerning surface exchange and production are also discussed.
Luminescence in polynoids II. Different modes of response in the elytra
Authors: Nicol J. A. C.
Published: May 2009

Elytra of polynoids show two kinds of luminescent responses, viz. a quick flash (duration ca. 100 msec) and prolonged glow (duration 0·25–10 sec). Quick flashes are produced by nervous excitation; prolonged glow responses accompany or follow fast repetitive flashing, or are elicited by strong electrical stimuli. Anaesthetized isolated elytra still give the prolonged glow response when electrically stimulated. Facilitation is also evident in consecutive glow responses. From these various observations it is concluded that the prolonged glow response can be produced by fast repetitive nervous excitation or by direct electrical excitation of the photocytes. The occurrence of facilitation in glow responses of anaesthetized elytra raises the problem whether the same phenomenon in consecutive normal flashes may be due to intracellular changes taking place within the photocytes.
Luminescence in polynoids III. Propagation of excitation through the nerve cord
Authors: Nicol J. A. C.
Published: May 2009

Luminescent polynoids emit light from their elytra. These structures are arranged in two longitudinal rows covering most or all of the dorsal surface of the worm. Light emission is evoked by stimulation and appears as a single flash or series of flashes (Nicol, 1953, 1957).

When a polynoid is subjected to tactile stimulation, scales anterior and posterior to the stimulated region emit flashes. The response is a reflex, the excitatory pathways of which involve peripheral receptors, nerve cord, and a peripheral ganglion in each elytrum on the efferent side of the arc (Bonhomme, 1942; Nicol, 1954).
On the hormonal inhibition of moulting in decapod Crustacea II. The terminal anecdysis in crabs
Authors: Carlisle D. B.
Published: May 2009

In many if not most species of crabs (but not quite all) there is a limit to growth, when no more moulting or ecdysis is possible in normal circumstances. This condition of permanent anecdysis is known as the terminal anecdysis. In the spider crab Maia squinado, the last moult is the moult of puberty, when the animal finally attains sexual maturity, and this moult has different biometrical characteristics from the others. In Carcinus maenas, in contrast, the moult of puberty takes place when the animal is quite small and may be succeeded by about ten further moults before the terminal anecdysis begins.

The immediate cause of the cessation of moulting in Maia squinado is shown to be the degeneration of the Y-organ, which secretes a moult-promoting hormone. In the absence of this gland and its secretion moulting can no longer continue. In Carcinus the Y-organ does not degenerate after the final ecdysis and the cause of the cessation of moulting is to be sought in the excessive production by the X-organ-sinus gland complex of the moultinhibiting hormone. This effectively prevents moulting from proceeding Removal of the X-organ-sinus gland complex in Carcinus allows ecdysis to continue, so that giant crabs can be produced in the laboratory by this means, and at the same time the life-span may be increased. The operation has no such effect on Maia. In either species injection of Y-organ extracts produces transiently the first signs of an approaching moult, in the form of a heightened blood-calcium level. In Carcinus repeated injection led to eventual ecdysis. The presence of the Y-organ is shown to be necessary for removal of the X-organ-sinus gland complex to stimulate moulting in Carcinus.

Two separate methods of producing terminal anecdysis exist in crabs, both involving the hormones which normally regulate the moult cycle, but no reason is known for the existence of the phenomenon.
Some quantitative aspects of feeding in sabellid and serpulid fan worms
Authors: Dales R. Phillips
Published: May 2009

The rate of filtering has been examined in a series of sabellids and serpulids of widely different size, using suspensions of colloidal graphite and algal cultures. The filtering rates have been expressed as individual rates, as the volume strained per unit fresh weight, and per unit weight of the crown. It may be concluded that the smaller fan worms filter at a relatively higher rate than the larger. This is achieved partly by the relatively larger crown. Free swimming algae escape through the crown; only inert particles down to 1–2 μA are retained, implying that fan worms depend on suspended detritus alone. The filtering rates are briefly compared with those of Chaetopterus and some other filter-feeding invertebrates.
The Distribution and significance of organically bound iodine in the ascidianCiona intestinalisLinnaeus
Authors: Barrington E. J. W.
Published: May 2009

Some features of the organization of the endostyle ofCiona intestinalisare described. Autoradiographs show that bound iodine is present in a limited area of the epithelium (zone 7), where it is associated with characteristic secretory inclusions which are found only in this zone. These are regarded as providing the molecular basis for the iodination process, and are termed 'thyroidal granules', since they resemble in certain properties the similarly named granules of the endostyle of the ammocoete; it is concluded that they are homologous with these and, through them, with thyroid colloid. Their existence provides evidence that the iodination process is a product of biochemical specialization, and implies that it results in the formation of an hormonal secretion. It is concluded from the distribution of bound iodine over the pharyngeal epithelium and in the food cords that this iodinated secretion is carried in the latter into the intestine. Bound iodine is also present in the cuticle of the test; it is suggested that this may differ from the situation in the endostyle in being a consequence of the iodination of a skeletal protein secretion such as is known to occur in many invertebrates. Prior immersion of the animals in thiouracil solution largely eliminates bound radio-iodine from all of the sites mentioned, although a little may sometimes be detectable in the food cords and cuticle. The results are discussed in the light of recent work onAmphioxusand the ammocoete larva, and attention is drawn to their bearing on current views on the relationship between vertebrates and protochordates.
A new quantitative plankton net
Authors: Currie R. I. , Foxton P.
Published: May 2009

The apparatus described in this paper was constructed for the purpose of sampling the zooplankton standing crop in the ocean in a quantitative manner.

A meter is described, which will record both the depth and amount of water which a net filters as it is hauled vertically through the water. The meter records on a smoked glass cylinder.

The meter is mounted in a brass drum which is positioned in front of the silk filtering section of the net. In front of the meter a long canvas sleeve carries the throttling rope which closes the net by the Nansen method.

Calibration of the meter for depth is done by using reversing thermometers and lowering to a series of suitable depths. Flow calibration is easily accomplished in the field by towing the canvas sleeve and meter without the silk net.

The method of smoking the glass cylinders and taking photographic records of them is described.

From the records it is possible to study the complete behaviour of the net below water—what depth range it has fished, how much clogging occurred, the depth of closure, etc
Notes onMytilus galloprovincialisLamarck in Great Britain
Authors: Hepper B. T.
Published: May 2009

Mytilus galloprovincialisLmk. is recorded as dominating the mussel population on the north coast of Devon and the north and south-west coasts of Cornwall from Instow to the Lizard. It was also found less frequently on the coast of South Wales from Angle to Cardiff and on the south coast of Cornwall from the Lizard to Plymouth.

The chief distinguishing features ofM. galloprovincialisfrom Cornwall are summarized, in comparison withM. edulisL.

M. galloprovincialisis apparently intolerant of estuarine conditions, but otherwise appears to be ecologically similar toM. edulis.

M. galloprovincialisis not resistant to infection byMytilicola intestinalis, but appears to be less affected by the parasite than isMytilus edulis.

The synonymy of the species is briefly discussed and it is concluded that, although earlier workers tended to confuseM. ungulatusL. (recorded also asM. ungulataandM. angulata) withM. galloprovincialisLmk., the two types are distinct.M. ungulatusis a name of doubtful validity applied by Linnaeus to a distorted form ofM. edulis.
The growth of Scrobicularia plana (da costa) in the Gwendraeth estuary
Authors: Green J.
Published: May 2009

Populations of Scrobicularia plana with densities up to 1025 per m2 are found in the Gwendraeth Estuary.

In a region where the population density was about 500 per m2 it was found that some specimens lived for 16‐18 years and reached a length of 54 mm. An approximate growth curve is given.

There is very little successful settlement of spat in the sampling area; less than 2% of the shells were under 10 mm in length in July 1955. This low figure is attributed to the feeding activities of the dense adult population making the area difficult to settle in.
The feeding mechanism and structure of the gut ofOwenia fusiformisdelle Chiaje
Authors: Dales R. Phillips
Published: May 2009

Oweniamay feed either by ciliary means or by swallowing sand and detritus. The gut consists of three main parts, a fore-gut or stomach which is secretory, a non-secretory mid-gut region which is absorptive, and a hind-gut which is non-secretory, non-absorptive and serves to elaborate and store the faecal pellets. The mid-gut contains coproporphyrin III and also phaeophorbide-6, to which the green colour is due. The green pigment in the epidermis is also phaeophorbide-ft, but phaeophorbide-a is apparently absent from the body.
Preliminary observations on the role of the coelomic cells in food storage and transport in certain polychaetes
Authors: Dales R. Phillips
Published: May 2009

Determinations of the concentration of fat and glycogen in the body wall, in different parts of the gut and in the coelomic cells are described inAmphitriteandArenicola. It is suggested that the trephocyte system constitutes a store of fat and glycogen derived from a primary store in the absorptive parts of the gut itself. InArenicolaandNereissurplus fat is removed from the gut itself through the blood or directly by amoebocytes; the fat deposited in the epidermis and the glycogen in the peritoneum. In these worms the coelomic trephocytes are solely concerned with the maturation of the gametes. No relationship can be established between these cells and the chloragocytes. InAmphitriteandTerebellafat is stored also in the coelomic trephocytes which may derive their contents directly from the gut or from the body wall. Glycogen is stored in the trephocytes inAmphitrite, and inArenicolain the peritoneum. Thus while large amounts of fat and glycogen are found in the trephocytes inAmphitrite, the total amount present in the body is no more than inArenicolawhich lacks a well-developed trephocyte system, and in this species a larger proportion of fat and glycogen is found in the body wall.
Comparative evaluation of certain organic and inorganic sources of nitrogen for phototrophic growth of marine microalgae
Authors: Antia N. J. , Berland B. R. , Bonin D. J. , Maestrini S. Y.
Published: May 2009

Twenty-six species of marine planktonic algae, belonging to 8 taxonomic divisions, were tested tinder axenic-culture conditions for their capacity to grow, under cool-white light, on nitrate, nitrite, ammonium, urea, glycine, D-glucosamine or hypoxanthine as sole nitrogen source. The culture medium was composed of Mediterranean oligotrophic sea water enriched with phosphate, silicate, trace-metal ions and vitamins, and buffered at pH 7.5–80. Each nitrogen compound was tested at a fixed concentration of 500 μg-at. N per litre.
The nutrient status of algal cells in batch culture
Authors: Droop M. R.
Published: May 2009

In a recent publication in this Journal I presented a set of seven equations effecting to describe from a single set of constants any chemostat steady state of the flagellateMonochrysis lutheriin terms of phosphorus and vitamin B12without prejudice as to which was rate limiting, given only the input concentrations of the two nutrients and the dilution rate of the chemostat (Droop, 1974, equations 23–29). There was nothing inherent in this description to prevent its application to transient situations, and I felt that at least it should apply to the transitional phase of a batch culture. The aim of this paper, which is a continuation of the previous one, is to find out whether this is so and whether in fact the model can be adapted to describe the complete history of a batch culture, because if it can its value to predictive models for phytoplankton would be greatly enhanced.
The biology of Laminaria hyperborea VII. Reproduction of the sporophyte
Authors: Kain Joanna M. , Jones N. S.
Published: May 2009

There are two critical stages in the life history of Laminaria hyperborea (Gunn.) Fosl. The first is the attachment of the zoospores (meiospores) to suitable rock surfaces and the second is the successful fusion of gametes. The second clearly partly depends on the first which is in turn affected by the efficiency of zoospore production by the sporophyte and the time of year that this takes place. Because of lack of information on these aspects the present study of reproduction in the sporophyte was undertaken.
The transfer of65Zn and 59Fe along a Fucus serratus (L.)→ Littorina obtusata (L.) food chain
Authors: Young M. L.
Published: May 2009

In marine organisms the fresh-weight concentrations of the trace metals zinc and iron are 102–105 times the concentrations in sea water. Study of the transfer of these metals along marine food chains is of interest because of the possibility of their being pollutants of the marine environment. Also65Zn and 65Fe are released to the marine environment and have been found, in many instances, to be the predominant radionuclides in food chains leading to man (Lowman, Palumbo & South, 1957; Lowman, 1960; Osterberg, Pearcy & Curl, 1964; Preston, 1967). The transfer of these metals along marine food chains is thus of interest also in the context of human radiation exposure.
Comparisons of several methods of determining inorganic phosphate in oceanic sea water
Authors: Jones P. G. W.
Published: May 2009

Arsenate was found to interfere with both of Murphy & Riley's methods of estimating phosphate in sea water. The magnitude of interference showed day-to-day variations.

Five methods of estimating dissolved inorganic phosphate in sea water were compared in the northern North Atlantic. Differences observed between the methods were related to those found in similar earlier investigations in inshore waters by Jones & Spencer.
Notes on an escallop (Pecten maximus) population in Holyhead harbour
Authors: Baird R. H.
Published: May 2009

The sampling of a discrete unfished population of escallops at Holyhead by diving showed that there was no influx into the area of escallops at any age or size, other than by spat settlement. The success or otherwise of the spat settlement, which was very variable, determined the age- and size-distribution of the population. Evidence is adduced that normal dredge sampling gear is very selective or, if it is made unselective, becomes too laborious to use because of the low densities of escallops. In a commercially fished population the failure to catch the smaller escallops by the sampling dredges, combined with the fishing off of the larger ones, makes the age-distribution of the population appear always to be dominated by the 2- or 3-year-old escallops. The great variability of the success of year-classes is masked by this sampling selection combined with the effects of commercial fishing.
The component fatty acids of some sea-weed fats
Authors: Chuecas L. , Riley J. P.
Published: May 2009

The component acids of the fats of the following marine algae have been investigated by gas-liquid chromatography:Rhodymenia palmata, Laurencia pinnatifida, Laminaria digitata, L. saccharina, Fucus vesiculosus, F. serratus, Pelvetia canaliculata, Ascophyllum nodosum. The principal saturated acids are palmitic and myristic acids, some contain ca. 2–5% of stearic acid; traces of C8 and C10 saturated acids are present, but C12 (and in all but one) C 20saturated acids are absent. The major unsaturated acids are octadecenoic and octadecadienoic acids (probably oleic and linoleic acids), but some species also contain appreciable amounts (up to 12%) of hexadecenoic acid. All the oils contain significant amounts of an eicosatetraenoic acid (probably arachidonic acid) and in some eicosatrienoic and/or eicosapentaenoic acids are also present in small quantities. Two acids of unknown constitution (possibly branched chain acids) are also present in minor amounts. No C22 unsaturated acids could be detected.

INTRODUCTION

Very little is known about the component fatty acids of marine algae. Lovern (1936) examined the fatty acids from the fats of Fucus vesiculosus, Laminaria digitata and Rhodymenia palmata using lead salt crystallization and fractional distillation techniques (Table 2). With these methods, however, it was not possible to separate individual unsaturated acids having the same number of carbon atoms from one another. The mean unsaturation values of these fractions were therefore evaluated from their iodine values and expressed as the number of hydrogen atoms necessary to convert the fraction to the corresponding fully saturated state; thus ( — 4–0H) indicates an average unsaturation corresponding with two double bonds.
Emergence rhythms and tidal migrations in the brown shrimpCrangon crangon(L.)
Authors: Adhub-Al A. H. Y. , Naylor E.
Published: May 2009

The brown shrimpCrangon crangon(L.) is a burrowing caridean decapod, inhabiting sandy, sandy-mud and muddy substrata down to 90 m, but occurring mainly in shallow water and between tidemarks (Lloyd & Yonge, 1947; Allen, 1966b). The species also exhibits seasonal inshore and offshore migrations, reportedly in relation to salinity, temperature and availability of food (Ehrenbaum, 1890; Havinga, 1929, 1930; Meyer, 1935; Broekema, 1941, Academy Thesis, Groningen; Lloyd & Yonge, 1947; Allen, 1966a, b; Tiews, 1970). In addition Hartsuyker (1966) reported up and downshore migrations on each tidal rise and fall in the Wadden Sea. In contrast, Havinga (1929) stated that the species rests quietly buried in the substratum by day and feeds at night, and nocturnal emergence was confirmed by Lloyd & Yonge (1947) in aquarium observations. However the latter authors found no difference between field catches during day and night tides in the Bristol Channel and Severn Estuary. Tiews (1970) reported greatest activity at dusk and thatC. crangoncontinued to swim during the night even after feeding. So far there is therefore evidence of nocturnal and tidal rhythms of emergence inC. crangonwhich deserves further experimental investigation.
Digenetic trematodes in cephalopods
Authors: Overstreet Robin M. , Hochberg F. G.
Published: May 2009

Cephalopod molluscs have attracted little attention as potential hosts for digenetic trematodes. Though none appears to serve as a first intermediate host, many do act as second intermediate, paratenic, or final hosts. Hence, they probably play a more important role in the life history and dissemination of Digenea in the marine environment than is generally recognized.
Calcium accumulation and secretion in the serpulid polychaete Spirorbis spirorbis L. at settlement
Authors: Nott J. A. , Parkes K. R.
Published: May 2009

When the free-swimming larva of the polychaete tubeworm Spirorbis spirorbis settles permanently on a suitable substratum, it forms a thin, mucous, anchoring tube, which covers only the posterior half of the body. Within 3 h the worm has built a comparatively thick, calcareous tube onto the anterior end of the initial, mucous tube, which later becomes a compressed and folded remnant (Nott, 1973). The volume of calcareous material forming the tube cannot be stored within the body of the larva before settlement and must, therefore, be taken up rapidly from sea water or ingested material.
The structure of stretch receptor endings in the fin muscles of rays
Authors: Bone Q. , Chubb A. D.
Published: May 2009

The muscles of the paired fins of rays have long been known to possess large sensory endings of a special type, first described inTorpedoby Poloumordwinoff (1898) and Cavalie (1902), and subsequently re-examined by Barets (1956). They consist of many parallel beaded nerve fibres, derived from a large myelinated parent axon, lying between the muscle fibres of the fins. That they respond to stretch (as was inferred from their structure and position) was shown by Fessard & Sand (1937). Since these are the only sensory endings known in any fish which are stretch receptors lying amongst muscle fibres (neuromuscular spindles are absent from fishes), more information about their structure and relationships with the muscle fibres of the fins is desirable. In this note, we describe the ultra-structure of this simple type of stretch receptor, and the type of muscle fibre with which it is associated.
Combined effects of cadmium and salinity on development and survival of flounder eggs
Authors: Westernhagen H. Von , Dethlefsen V.
Published: May 2009

Like most heavy metals, cadmium is only found in minute amounts in natural sea water. Krauskopf (1956) stated that cadmium concentration of normal sea water ranges from 0.032 to 0.075 PPb (μg/l−1) while Goldberg (1965) gave a somewhat higher value of 0.11 ppb. Cadmium concentrations determined by Preston (1973) for the North-East Atlantic Ocean range from <0.01 to 0.41 ppb, and similar values have been found by Windom & Smith (1972) in the West- and Chester & Stoner (1974) in the South Atlantic Ocean (0.04–0.17 ppb).
Rare Species of Mysidacea [Crustacea] From the West Coast of Scotland
Authors: Mauchline J.
Published: May 2009

Information on the population structure and breeding of the following species is presented: Siriella armata (Milne-Edwards), 5. clausii G. O. Sars, S.jaltensis (Czerniavsky),Gastrosaccus spinifer (Goës), Anchialina agilis (G. O. Sars),Psendomma affine G. O. Sars and Hemimysis latnornae (Couch). There is no previously published information on the biology of these species in British waters except notes on 5. armata and A. agilis. Notes on the occurrence of the following species on the west coast of Scotland are also given: Siriella norvegica G. O. Sars, Gastrosaccus sanctus (van Beneden), G. normani G. O. Sars, Leptomysis mediterranea G. O. Sars, Mesopodopsis slabberi (van Beneden), Heteromysis formosa S. I. Smith and Acanthomysis longicornis (Milne-Edwards).
Seasonal Occurrence of Mysids [Crustacea] and Evidence of Social Behaviour
Authors: Mauchline J.
Published: May 2009

The seasonal maxima of occurrence of 23 species of mysids are examined; the numbers caught of a further four species were too small to draw any conclusions from. The evidence suggests that all species, except possibly two, aggregate; not enough information is available on Acanthomysis longicornis and Heteromysis fortnosa. The types of aggregations formed, whether population swarms or breeding aggregations, are unknown in 10 species. There is evidence of shoal and/or swarmformation in 12 species and of breeding aggregations in 7 species. All species known to form swarms live in shallow water; Leptomysis gracilis is the only species living in deep water that shows evidence of swarm formation. All other deep-water species aggregate, some for the purposes of breeding. Negative phototropism of individuals is suggested as a mechanism initiating aggregation of species in the bottom of deep-water basins. Reaction of one individual to another individual or groupof individuals (social behaviour) is considered necessary to intensify the initial degrees of aggregation and to maintain the integrity of shoals or breeding aggregations once formed. Parallels are drawn between aggregations of mysids and those of euphausiids.
Movements of Atlantic Cod (Gadus Morhua) Within the Spring Thermocline in Trinity Bay, Newfoundland
Authors: Wroblewski J.S. , Goddard Sally V. , Smedbol R. Kent , Bailey Wade L.
Published: May 2009

Using depth-telemetering, sonic tags orally inserted into the stomachs of Gadus morhua (Pisces: Gadiformes) found over-wintering in Trinity Bay, Newfoundland, the movements of individual fish were observed as surface waters warmed in early spring. Physiological measurements (antifreeze protein levels in the blood) indicate that many cold-adapted, bay cod change their thermal regime at this time. Fish acclimatized to subzero water temperatures enter the newly-formed thermocline and become available to a cod trap fishery. Most sonically-tagged fish resided in 0–1°C waters along the shoreline. Tracking data confirmed indications from declining antifreeze protein levels that cold-adapted cod, having moved into shallow waters in early spring, do not return to deeper, subzero-temperature waters for any appreciable time. At night some cod swam pelagically near the surface. Fish moved at times in the same direction as the tidal current, but ground speeds were several times greater than current velocities. Nocturnal pelagic swimming was also observed during the summer when temperatures within the thermocline exceeded 10°C.
Reproductive Biology of the Black Dogfish,Centroscyllium Fabricii, Collected From Waters off Western Greenland
Authors: Yano Kazunari
Published: May 2009

The reproductive biology of 1124 male (165–760 mm TL) and 1476 female (175–898 mm TL) black dogfish,Centroscyllium fabricii, was examined. The sharks were caught off western Greenland with bottom otter trawls. Size at maturity was about 550 mm TL in males and 650 mm TL in females. Ovarian ova did not continue to develop during gestation. The sex ratio of embryos was 1:1. Litter size ranged from 4 to 40, with a mean of 16–4. The total number of mature ova, fertilized ova, or embryos tended to increase with size of the females. Development of black dogfish embryos is dependent solely on yolk reserves. Near-term embryos (152–192 mm TL) had completely absorbed their external yolk sacs. The smallest free-living specimens collected in this study were 165 mm TL for males and 175 mm TL for females. The black dogfish does not seem to have a well-defined breeding season. This species displayed a well-defined pattern of depth segregation by size. The sex ratios in five shallow depth strata (500–599, 600–699, 700–799,800–899, and 900–999 m) were 1:1, but those of three deeper depth strata (1000–1099,1100–1199, and 1200–1299 m) contained a significantly greater number of females than males. Four abnormal hermaphrodites possessed gonads containing both testicular and ovarian tis-sues. Two specimens had normal female reproductive organs (e.g. ovaries, oviducts, nidamental glands, and uteri) as well as claspers.
A Mark-Recapture Experiment on Queen Scallops, Aequ1Pecten Opercularis, on a North Irish Sea Fishing Ground
Authors: Allison E.H. , Brand A.R.
Published: May 2009

A single-season mark-recapture experiment was carried out on queen scallops, Aequipecten opercularis (L.) (Bivalvia: Pectinidae) to assess the suitability of the technique for estimating population sizes and mortality rates of exploited populations. Tag-loss and tagging-induced mortality were 7.7% and 11.9% respectively. Non-reporting was negligible.

In a single fishing season (June-December 1989) 25.4% of releases were recaptured alive. Mean density of commercial-sized queens was estimated as 0.47 m−2 over the fishing ground. Instantaneous rates of total (Z), fishing (F) and-natural (M) mortality, calculated from the monthly decline of recaptures during the fishing season, were 0.;41,0.21 and 0.20 per month respectively. The calculated M is very high but includes non-yield or indirect fishing mortality. Analysis of the age-frequency distribution of queens from an adjacent, largely unexploited, area indicated an M of only 0.036 per month (0.43 y−1). There was some indication of an increase in M in older year classes, associated with senescence.

The mark-recapture methodology used here is suitable for this species, but single-release experiments place too much reliance on commercial catch-statistics.
Apatite Particles in the Test Wall of the Large Agglutinated ForaminiferBathysiphon Major(Protista)
Authors: Gooday A. J. , Nott J.A. , Davis S. , Mann S.
Published: May 2009

In the North Atlantic, the tubular agglutinated foraminiferBathysiphon majoroccurs at bathyal depths off the coasts of North Carolina and north-west Africa. Apart from its large size (up to almost 10 cm long), the most distinctive feature of this species is the appearance of the test wall which has a sooty black outer layer, about 20μm thick, overlying a much thicker layer, pure white in colour and consisting of sponge spicules and small quartz grains. The black layer is composed of irregularly shaped, plate-like particles, 1–25 (xm in size. The nature and composition of these particles has been studied using light and electron microscopy, x-ray microanalysis, electron diffraction analysis and infrared spectroscopy. The particles contain calcium and phosphorous and have electron diffraction patterns and infrared spectra consistent with a hydroxyapatite composition. Minor amounts of iron are probably responsible for their black colour. We believe that this represents the first report of apatite-like (phosphorite) particles occurring in the test of an agglutinated foraminifer. The particles are most likely to originate as phosphorite grains which are agglutinated by the foraminifer, although the possibility of authigenic precipitation cannot be eliminated. The function of the outer black layer is unknown.
Random Amplified Polymorphic Dna (Rapd) and Intraspecific Variation in Oerstedia Dorsalis (Hoplonemertea, Nemertea)
Authors: Sundberg Per , Andersson Susanne
Published: May 2009

INTRODUCTION

The littoral/sublittoral hoplonemertean (phylum Nemertea) species Oerstedia dorsalis (Abildgaard, 1806) is described as polymorphic in external characters (Örsted, 1844; Burger, 1895; Brunberg, 1964). Sundberg (1984) grouped specimens in three classes based on external morphology and asked, using multivariate morphometrics, if there was a consistent correlation between external and internal characters. Such a correlation would have indicated a restricted gene flow between the externally different morphs, and thus the possibility of a group of species instead of one, polymorphic, species.

One of the forms in Sundberg (1984) appeared to be different from the other two morphs but the morphometric analysis was inconclusive. Later, Sundberg & Janson (1988) established by enzyme electrophoresis that this form was genetically different and it was later described as Oerstedia striata (Sundberg, 1988). A problem both in Sundberg (1984), and Sundberg & Janson (1988) was that one of the groupings (class ‘C’ in both studies) of specimens subsumed a number of morphs, all speckled or dotted but to varying degrees. These morphs may in fact represent different species, which would have been concealed in the electrophoretic and morphometric analysis as merely increased intraspecific variation. One of the ‘C’ morphs in Sundberg (1984) and Sundberg & Janson (1988) is light brown with numerous small dark brown/black dorsal spots. Based on one specimen from Anglesey, North Wales, Gibson (1988) described Oerstedia (Paroerstedia) nigrimaculata which is externally similar to this variety. Envall & Sundberg (1993) could not find any differences in internal characters between the type specimen of O. nigrimaculata and the brown form of O. dorsalis but hesitated to conclude that O. nigrimaculata is a variety of O. dorsalis.