bluuebunny/crossref_metadata_2025 huggingface dataset:
Food Ingestion in the Estuarine TurtleMalaclemys Terrapin:Comparison With The Marine Leatherback TurtleDermochelys Coriacea
Authors: Bels V.L. , Davenport J. , Renous S.
Published: May 2009

This study sheds light on the evolution of aquatic and terrestrial feeding modes in vertebrates, using two aquatic turtles as models. The estuarine aquatic diamondback turtleMalademys terrapinhas a feeding mechanism that is similar to the basic feeding mechanism of terrestrial tetrapods (jaw gape cycles incorporate slow opening, fast opening, fast closing and slow closing phases). Strikes upon prey also involve neck extension and cycles of the forelimbs.Malademys terrapinmodulate their feeding behaviour and jaw action in relation to the nature of the prey item. Mussels are approached by walking on the substratum, and limb cycles are of small amplitude during the strike. Crabs, whether encountered in mid-water or on the substratum, are approached by swimming, and the strikes partly produced by vigorous upstrokes of the forelimbs, that occur simultaneously with neck extension. Crabs are dangerous prey, and the turtles often strike with the gape already at maximum, minimizing the time needed to bite a limb or other part of the crab. The tongue is not involved in food capture, but has a major role in food manipulation and transport prior to swallowing. Although transport cycles are similar to ingestion cycles, ingestion and transport are easily separable in the species.Malademys terrapinexhibit great distension of the throat during the strike, but this does not appear to generate adequate suction to aid capture of hard-shelled prey; it is suggested that throat distension reduces pressures in front of the advancing snout, thus preventing pressure waves displacing or alerting prey. The pelagic marine turtleDermodielys coriacea, which specializes in gelatinous prey, relies heavily on suction for ingestion, which overlaps considerably with transport.
Morphological Variation inFucus VesiculosusPopulations along Temperature and Salinity Gradients in Iceland.
Authors: Kalvas A. , Kautsky L.
Published: May 2009

Geographical morphological variations inFucus vesiculosuspopulations were studied along the coast of Iceland. Principal component analysis (PCA) based on 11 morphological characters clustered the 26 sampling sites into four different morphological types as follows: (1) a morphological type found along the S-SW-W coast; (2) an intermediate form comprising only two populations in the NW; (3) a type found along the N-NE-E-SE coast; and (4) a type found independent of geographical area, in estuaries and at sites influenced by large freshwater outflows. Populations influenced by low salinity had significantly (P≤ 0·001) shorter thalli, a shorter distance from the holdfast to the oldest dichotomy, smaller fronds, narrower stipes and midrib width compared to the morphology of all other more saline populations. No significant difference in frond width was found between the S-SW-W and the N-NE-E-SE populations. However, significant (P≤ 0·001) morphological differences between them were observed, the former having shorter thalli, a greater distance from the holdfast to the oldest dichotomy, narrower stipes and smaller midrib width compared to the latter.
First Record of the Cornich Blackfish Schedophilus Medusophagus (Pisces: Centrolophidae) Larvae from the Adriatic Sea
Authors: Dulčić Jakov
Published: May 2009

The capture of the cornich blackfish, Schedophilus medusophagus, larvae from the Adriatic Sea represents an easterly extension in range of this species, and the first larval record in Adriatic waters.

Schedophilus medusophagus Cocco, 1839, is a mesopelagic species from temperate waters of the north-eastern and north-western Atlantic and the western Mediterranean (Bini, 1968; Tortonese, 1975; Haedrich, 1986). The first record of this fish from the Adriatic Sea was reported in 1880 according to Ninni (1912). The second record was during the invasion of medusae Pelagia noctiluca (Malej, 1982; Rottini-Sandrini & Stravisi, 1982; Vučetić, 1982,1983) in Pelješac channel near the town of Korčula-island Koršula (central Adriatic) in 1982 (Onofri, 1986). Ten juvenile specimens, from 10·0 to 20·0cm total length (TL), were collected with medusae at 2m depth. This record Onofri (1986) connected with the ingression of inter-median waters (50–100 m) in the central Adriatic influenced the increase of salinity and temperature in 1982. Jardas (1996) noted that S. medusophagus is a very rare species in the Adriatic Sea.
The Organic Metabolism of Sea-water with Special Reference to the Ultimate Food Cycle in the Sea
Authors: Keys Ancel , Christensen E. H. , Krogh August
Published: May 2009

Studies are reported of the behaviour of stored sea-water with regard to oxygen, ammonia, and bacteria content in relation to the conditions of storage and to the effect of various filtration procedures.

When sea-water is sterilised by filtration and stored in the dark, the oxygen content remains constant or diminishes only by less than 0·07c.c. per litre in several hundred hours.

In non-sterile experiments there is always an oxygen consumption roughly parallel to a bacterial multiplication which begins very suddenly after collection of the water. These effects are greatest in “raw” water, less in paper-filtered water and least in water which is doubly filtered.
The Biology of Balanus balanoides. IV. Relation to Environmental Factors
Authors: Moore Hilary B.
Published: May 2009

1. Vertical traverses down the shore were worked at four localities in the Isle of Man, with varying degrees of wave-exposure, for which factor a coefficient is given.

2. The upper limit of distribution is high water neaps in a sheltered place, and up to high water of extreme spring tides at greater waveexposure. The lower limit similarly drops with increasing exposure.

3. Barnacles are largest and most abundant in a wave-exposed locality. The effect of wave-exposure may be reproduced by a current.

4. In sheltered localities the optimum level for growth, mean size, etc., is at low water for newly settled barnacles, but moves progressively up to high water as they grow older. In a very exposed situation, however, the optimum is always at low water.

5. In an exposed situation the gonads mature in their first year below about half-tide level, and in their second year above this level. With decreased wave-exposure the age of maturation rises, especially at high water until in a very sheltered place few barnacles mature at all.
On the Value of Certain Plankton Animals as Indicators of Water Movements in the English Channel and North Sea
Authors: Russell F. S.
Published: May 2009

The possibility that certain plankton organisms retained by a stramin net may prove of value as indicators in elucidating the water movements at the mouth of the English Channel is shown.

The water populated by Sagitta setosa is shown to be clearly demarked from that in which S. elegans lives, the latter living to the west of the Channel mouth south of Ireland. The water in which S. elegans lives has here been called “western” water.

It is shown that the planktonic indicators for “western” water are Sagitta elegans, Sagitta serratodentata, Aglantha rosea, Stephanomia bijuga, Clione limacina, Meganyctiphanes norvegica, Thysanoessa inermis, and Cosmetira pilosella (in spring and summer only). Sagitta setosa is regarded as an indicator of “Channel” water. Muggiæa, Salps, Doliolids, Liriope exigua and Euchœa hebes are regarded as indicators of “south-western” water.

The geographical distribution of S. setosa is discussed. It is shown that it is probably a neritic species mainly confined to the English Channel and North Sea.

S. setosa predominates off Plymouth when the easterly element in the Dover Straits current is suppressed and the flow of Atlantic water into the North Sea from the north is strong (Carruthers' Theory). The two Sagitta populations swing to and fro off Plymouth so that, with a strong flow of Atlantic water into the North Sea from the north, the S. elegans population is pushed westward to the mouth of the Channel and S. setosa occurs off Plymouth.

During the course of the five years, 1930 to 1934, an agreement has been found between the occurrence or absence of concentrations of the diatom Rhizosolenia styliformis in the southern North Sea and the variations in the composition of the Sagitta population off Plymouth In the years in which Ehizosolenia, an indicator of Atlantic water, was abundant in the southern North Sea S. setosa predominated off Plymouth; when Rhizosolenia was absent S. elegans predominated.

These diatom concentrations have been shown by Savage and Hardy t o have an apparent influence on the movements of the Herring which is reflected in the landings at Yarmouth and Lowestoft.
On Some Aspects of Digestion in Ciliary Feeding Animals
Authors: Yonge C. M.
Published: May 2009

This paper embodies various observations which were made from time to time while the author was a member of the staff of the Plymouth Laboratory. It also outlines certain generalisations based on the author’s previous published work and that of other recent workers in the field of comparative physiology of feeding and digestion.
Studies on Conditioned Responses in Fishes. Part III. Wave-length Discrimination in Blennius pholis L.
Authors: Bull Herbert O.
Published: May 2009

It has been shown (1, 2) that the capacity for building up visual conditioned responses is common to many types of fish when the unconditioned stimulus used as the basis for the “conditioning” is food. Preliminary work at Plymouth, using the fish Blennius gattorugine, showed that was possible that a knowledge of wave-length discrimination in that species might be acquired by the now familiar method of “conditioning” to an electric shock. This work was continued when I came to Cullercoats, and six specimens were used which were sent from Plymouth in 1929. All of these died within a short space of time during the succeeding winter months, owing to the intense cold. It was therefore necessary to restrict the investigation to Blennius pholis L., which is both plentiful and hardy at Cullercoats. Some progress had already been made and in Part II (2) it was intimated that an analysis would be made of the capacity for wavelength discrimination in Blennius pholis using an electric shock as the unconditioned stimulus. The present paper gives the results of that enquiry as far as it was taken.
Studies on Conditioned Responses in Fishes. Part V. On the Controlling Influence of Normal Behaviour Traits upon Capacity to Form Experimental Conditioned Motor Responses Under Certain Conditions.
Authors: Bull Herbert O.
Published: May 2009

Normal behaviour traits control the ability of fishes to form conditioned motor responses. This is shown by a series of experiments upon various species of fish in which it is found that Pleuronectids are found incapable of forming such responses for at least 200 associated presentations whilst other fishes have done so in less than 40. The bearing of the results on current theories of animal learning is briefly discussed.
Plankton production off Plymouth and the mouth of the English Channel in 1939
Authors: Mare Molly F.
Published: May 2009

A quantitative seasonal survey of the phytoplankton and small zooplankton has been made from the end of January to the end of August 1939, at a station, L4, with supplementary observations at a station off Rame Head, both near Plymouth. The results are compared with those of a fuller survey made in 1934.

The spring maximum in numbers of plant cells was late, not being reached until the middle of April.

The monthly means of the total numbers of animals caught were of the same order in the two years, but the numbers of copepods plus copepodites in 1939 were only two-thirds of those in 1934.
On the Biology of the Caprellidae. Growth and moulting of Pseudoprotella phasma Montagu
Authors: Harrison R. J.
Published: May 2009

The process of moulting in Pseudoprotella phasma is described. Sixteen instars have been found with a discontinuity in growth at the third stage. The instar lengths differ by a common ratio of 1·169 in the male and 1·148 in the female, the animals becoming differentiated at the twelfth stage. There are no secondary sexual characteristics except the brood pouch. The growing parts display simple positive allometry. The growth rates of the chelae and antennae alter after stage XII but remain the same in the third body segment. Changes in shape in the chelae, antennae and spinous armature are described.
The mantle cavity of some of the Erycinidae, Montacutidae and Galeommatidae with special reference to the ciliary mechanisms
Authors: Popham Mary Leyborne
Published: May 2009

The habitat, external appearance and habits of members of the Erycinidae, Montacutidae and Galeommatidae, three families included in the order Leptonacea, have been investigated and are described.

The ciliary currents of the gills, palps, visceral mass, foot and mantle are described in detail.

There is some reduction in the shell in this order. In Kellia, Lasaea, Montacuta and Mysella the shell is external and the adductor muscles are well developed. In Galeomma the shell and adductors are reduced, and in Devonia the shell is also partially covered by the mantle.

The foot is modified, and all members of this order progress on the flattened ventral surface of the foot which forms a creeping sole. The burrowing habit is lost.
The fecundity of the herring of the southern North Sea
Authors: Hickling C. F.
Published: May 2009

The number of eggs produced by the herrings of the East Anglian shoals increases with the length of the fish at a rate equal to the 3·465 power of the length, and with the age of the fish to the 0·66 power of the age. This fecundity is compared with that found in other races of herrings.

The number of eggs produced is closely correlated with the mean weight of the ovary, and it is found that the weight of the ovary increases with length at a rate equal to the fourth power of the length, and that a slightly higher rate applies to the testis.

The weight of the gutted fish, however, increases in relation to the length at a much slower rate, namely, as the 2·3 power of the length in the males, and the 1·5 power of the length in the females.
Nutrition of some marine microalgae with special reference to vitamin requirements and utilization of nitrogen and carbon sources
Authors: Turner M. F.
Published: May 2009

The status of our knowledge of the organic nutrition of algae has been summarized in tabular form from time to time. Albritton (1954) listed a mere 14 taxa of pigmented algae as having been examined from this point of view. Eight of the 14 were species ofEuglenaand only ‘Nitzschia dosterium' (=Phaeodactylum tricornutumBohlin) was marine. This paucity of information reflected in part the lack of suitable denned culture media as prerequisites of nutritional experiments. By the early 1960s this lack had been overcome to a large extent (see, for example, Provasoli, McLaughlin & Droop, 1957) and Thomas (1968) could list some 280 species, both freshwater and marine, on which nutritional work in terms of organic requirements had been undertaken. The vitamin requirements (or lack of them) of most of these species were known, but knowledge of their ability to grow in the dark on organic carbon sources and of their ability to utilize different nitrogen sources in the light was fragmentary. It still is, despite the fact that some of the gaps in Thomas's tables have been subsequently filled and the list of species has been extended.
A field study of settlement behaviour inBalanus balanoidesandElminius modestus(Cirripedia: Crustacea) in relation to competition between them
Authors: Barnett B. E. , Edwards S. C. , Crisp D. J.
Published: May 2009

There can be little doubt that competition for space, both inter- and intraspecific is a major factor in barnacle ecology. Southward & Crisp (1956) first pointed out the role of competition betweenBalanus balanoides(L.) andChthamalus stellatus(Poli) in south-west Britain which Connell (1959, 1961) later demonstrated experimentally. Crisp (1958) discussed competition between the indigenousB. balanoidesand the immigrantElminius modestusDarwin in the intertidal zone, and measurements of growth rates, using manipulated populations of these two species, indicated that inter- and intraspecific competition for space after settlement is intense (Crisp, 1964).
Seasonal variation in weight and biochemical composition of the tissues of the queen scallop,Chlamys opercularis, from the Clyde Sea area
Authors: Taylor A. C. , Venn T. J.
Published: May 2009

A number of studies exist on the seasonal cycles of body weight and tissue biochemistry of several species of bivalve from the Clyde Sea area (Ansell & Trevallion, 1967; Ansell, 1974,et seq), including two members of the Pectinidae, namelyChlamys septemradiata(Müller) (Ansell, 1974) andPecten maximusL. (Comely, 1974). Some comparative data are available forChlamys opercularis(L.) from Manx waters (Soemodihardjo, 1974) and forP. maximusfrom the north Irish Sea (Stanley, 1967).
Predation on chaetognaths by typhloscolecid polychaetes: one explanation for headless specimens
Authors: Feigenbaum David
Published: May 2009

The Phylum Chaetognatha consists of morphologically and biologically similar species and its relationship with other invertebrate groups is obscure (Hyman, 1959; Ghirardelli, 1968). The possibility of regenerative power has been investigated as one of the clues to the affinity of the phylum. Kulmatycki (1918) made cross-sectional and diagonal cuts through the body and tail fin of Spadella cephaloptera Busch and reported that this species could regenerate the whole caudal section including the body proper. Further support for regenerative ability came from Pierce (1951) who caught 26 specimens of Sagitta enflata Grassi and Sagitta helenae Ritter Zahony which appeared to be in the process of regenerating their heads (presumably lost to a large predator). He noted that the loss of this section of the body did not kill the animal. Both Kulmatycki and Pierce are cited in Hyman's (1959) important review of the phylum and headless chaetognaths have been referred to as animals with regenerating heads (e.g. Almeida Prado, 1968).
The export of phosphorus from Dartmoor catchments: a model to explain variations of phosphorus concentrations in streamwater
Authors: Rigler F. H.
Published: May 2009

Our knowledge of the export of solids and solutes by streams from different types of catchments has lagged behind that of water yield despite the fact that it is important in the prediction of erosion and landform development as well as the prediction of water quality. To remedy this shortcoming there has developed an increasing interest in export of various substances by small catchments. Gregory & Walling (1974) have described this trend as well as our growing awareness of the need to concern ourselves with the variation of fluvial processes as a function of landform, geology and land use. But because few studies of this sort have been completed in Great Britain, Gregory & Walling stressed the need to understand the controls on sediment and solute production, particularly in a variety of different landforms and geological formations.
Tidal flow around an island with a regularly sloping bottom topography
Authors: Pingree R. D. , Maddock Linda
Published: May 2009

A numerical model of the tides in the neighbourhood of Portland Bill (Pingree & Maddock, 1977; Maddock & Pingree, 1978) indicated that there was some asymmetry in the flood and ebb tidal patterns due to the effects of the Earth's rotation. Thus, in addition to the generation of vorticity due to the bottom frictional torque which becomes large in the high-velocity shoaling region near the promontory, vorticity is generated as columns of water with planetary vorticity are stretched or squashed as they move across water depth contours.

In order to examine the Portland Bill situation in more detail, a model was developed in plane polar coordinates (Pingree & Maddock, 1979). This model allowed the flow to be taken around the promontory without the numerical difficulties associated with corners in rectangular grid meshes and gives increased resolution near the headland where the major changes in tidal structure occur. The regular geometry of the polar model also allows the use of an idealized submarine topography and therefore changes in tidal flow due to imposed beach gradients can readily be examined.

The polar model has now been developed to derive the tidal flow around an idealised circular island surrounded by a uniformly sloping beach gradient. In the absence of effects due to the Earth's rotation the derived tidal structure and the associated patterns of residual flow possess twofold symmetry. In a rotating reference frame, however, some asymmetry in these flow patterns can be detected. In this paper some numerical results showing the hourly tidal streams around an island are derived.
The zonation of psammolittoral harpacticoid copepods around the Isle of Man
Authors: Moore Colin G.
Published: May 2009

The early qualitative works on the harpacticoid fauna of the British Isles by T. & A. Scott, Norman, Brady, Gurney and Thompson largely omitted the intertidal psammic biotopes. Nicholls (1935, 1939) did much to redress the situation, describing many new species of interstitial harpacticoids from the sandy shores of the Firth of Clyde. Although his studies were taxonomic, he supplied some useful information on the distribution of the species. Some ecological data is also to be found in subsequent works on the east coast of Ireland (Wells, 1963 a; O'Riordan, 1971), the Exe estuary (Wells, 1963 b) and the Isles of Scilly (Wells, 1961, 1970). The only detailed studies of interstitial harpacticoid zonation on British coasts are those of Harris (1972) for the lower shore at Whitsand Bay, Cornwall, and Mclntyre & Murison (1973) for Firemore Bay, Scotland.
Valve structure and growth in the chiton Lepidochitona cinereus (Polyplacophora: Ischnochitonidae)
Authors: Baxter J. M. , Jones A. M.
Published: May 2009

Valve structure was investigated using light and scanning electron microscopy and each valve was found to comprise four layers; periostracum (dorsal), tegmentum, articulamentum and hypostracum (ventral). The penetration of the valves by the aesthetes within channels is described and three distinct types of aesthete channels are identified, namely, multiple branch aesthete channels, slit ray aesthete channels and jugal sinus aesthete channels. The distribution of the different aesthete channels within the various valves is defined and their relationship with the valve external sculpturing is described. The process of valve growth by marginal increment is discussed in relation to the formation of the aesthetes.
The entraining effect of turbulence on the circa-tidal activity rhythm and its semi-lunar modulation in Eurydice pulchra
Authors: Hastings M. H.
Published: May 2009

Turbulence measurements taken at the water's edge at Derbyhaven beach, Isle of Man, indicated that maximum turbulence on any particular tide predictably occurred at the time of high water. However, long term monitoring failed to record any predictable semi-lunar modulation of the intensity of turbulence. Laboratory experiments showed that cycles of mechanical agitation applied for 2 h every 12 h for 4 days could entrain the endogenous circa-tidal activity rhythm of adult Eurydice pulchra. The effect was the same with shaking in constant light or constant darkness. However, when applied at different phases of an imposed L/D cycle, the synchronizer had a varying effect. The strongest entrainment occurred when shaking was phased to ‘midday’ and ‘midnight’ - a phase relationship paralleled by the high water of spring tides. Minimal synchronizer effect occurred when shaking was applied at ‘dawn’ and ‘evening’, the phase relationship of neap tide high water to the solar day. The varying response is suggested to be the origin of the semi-lunar modulation of activity seen in Eurydice pulchra.
Studies on bioluminescent marine amphipods
Authors: Herring Peter J.
Published: May 2009

The luminescence of a number of amphipods of the genera Scina, Parapronoe, Cyphocaris, Megalanceola, Thoriella and Chevreuxiella/Danaella is described. The flashes of Scina spp. are rapid, 80–300 ms in duration, and may be elicited repetitively by electrical stimuli. Cholinesterase inhibitors are potent inducers of luminescence both in whole animals and in isolated appendages. A characteristic postural response is usually associated with mechanically induced luminescence of the larger species of Scina. Cyphocaris and Chevreuxiella/Danaella species also respond to electrical stimuli but the luminous responses are of longer duration than those of Scina and are not stimulated by eserine sulphate. In Parapronoe luminescence can be most easily induced with dilute hydrogen peroxide and the photogenic cells are associated with a brown pigmented area restricting the light output to a ventral direction. Secretory luminescence has been observed only in Megalanceola.
Branchiostoma lanceolatum– A Freshwater Reject?
Authors: Binyon John
Published: May 2009

The ultrastructure and dimensions of the solenocytes ofBranchiostoma lanceolatumare reviewed briefly. The functional ability of these units is calculated upon theoretical grounds in a manner similar to that applied to flame cells. Their more delicate construction would suggest that Branchiostoma would have great difficulty in maintaining any significant osmotic pressure difference between the medium and its body fluids.
The Langerhans receptor of Oikopleura (Tunicata: Larvacea)
Authors: Bone Q. , Ryan K. P.
Published: May 2009

The bristle-bearing receptors on either side of the trunk in Oikopleura are connected to the caudal ganglion by the axons of central cells which form electrical synapses (gap junctions) at the bases of the receptor cells. The same axons also form similar synapses with epithelial cells adjacent to the receptors. Direct mechanical stimulation of the receptor processes evokes changes in the locomotor rhythm of the same kind as evoked by action potentials propagated in the epithelial cells. This remarkable arrangement is suggested to be a consequence of the reduced numbers of cells in larvaceans.
Description of a new species of Asterina (Asteroidea), with an account of its ecology
Authors: Emson R. H. , Crump R. G.
Published: May 2009

This paper describes a new asterinid starfish found first in southern Britain, but now
also known from the Mediterranean and the Adriatic. Detailed comparison is made between the new species and the closely related Asterina gibbosa in terms of morphology, reproductive biology and life-history. The new species is adapted for life on the upper parts of rocks and on perennial algae in intertidal rock pools; it is small in size, matures early, lays large eggs, broods its young and has a short life span.
Fate of biologically accumulated copper in growing and decomposing thalli Of two benthic red marine algae
Authors: Seeliger U. , Edwards P.
Published: May 2009

Two benthic Rhodophyta,Ceramium pedicellatwnandNeogardhiella baileyi, were cultured in the laboratory to investigate uptake and subsequent release of Cu by both living and decomposing thalli. Concentration factors of Cu in the thalli of 4540-6864 were obtained. Algae grown initially in copper-supplemented media were cultured for 7 days in organic free medium and the amounts of Cu associated with the dissolved inorganic and organic fractions were then determined.
Vitellogenesis and Formation of the Egg Chain inSpirorbis Borealis[Serpulidae]
Authors: King P. E. , Bailey Julie H. , Babbage P. C.
Published: May 2009

Vitellogenesis in S.borealisis described. The large protein yolk spheres consist of protein and lipoid. This comes by pinocytosis from outside the oöcyte and from the golgi within the oöcyte. This is discussed in relation to other animal oöcytes. Cortical granules are present at the periphery of the oöcyte and release their contents just before the egg leaves the coelom. When released the eggs have an envelope around them, and evidence is presented which suggests that it is formed from material produced by secretory cells around the exit hole and along the ciliated groove.
Larval Development ofCucumaria Elongata(Echinodermata: Holothuroidea)
Authors: Chia Fu-Shiang , Buchanan J. B.
Published: May 2009

Cucutnaria elongataDüben & Koren, collected from the Northumberland coast in January 1968, was induced to spawn in the laboratory by raising the temperature. At spawning, the animal waved its pharyngeal bulb back and forth while a thin string of gametes was discharged. The freshly spawned eggs, surrounded by a jelly coat, were at the end of the second meiotic division and the size varies from 250 to 350 μ in diameter. Oocytes in the ovarian tubules can be grouped into three stages according to their size and other morphological features. Insemination of artificially recovered eggs resulted in only a very low frequency of abnormal development up to 8-cell stage. However, over 90% fertilization was achieved by insemination of the naturally shed eggs and the development was normal. The cleavage was holoblastic and radial type. The larva hatched at post blastula stage and swam freely with its animal pole upward. A doliolaria stage with four ciliary bands and pentactula stage with five primary tentacles subsequently developed. The planktonic life at temperature 9–11 °C ended on the ninth day after fertilization. Pentactula, up to 4 months old, live underneath the mud where they are deposit feeders. The primary tentacles bearing mucus glands in the form of papillae are important in both locomotion and feeding. An outline of chronology from fertilization up to 5 months old is presented.
The Effect of Mytilicola Intestinalis on the Biochemical Composition of Mussels
Authors: Williams C. S.
Published: May 2009

The biochemical constituents of mussels both infected and free from the copepod parasite Mytilicola intestinalis Steuer have been determined over a period of 2 years. All the constituents except moisture content (i.e. lipid, protein, carbohydrate and ash) were determined from dried mussel flesh, and all showed seasonal variation, the changes of which were correlated to the breeding cycle of the mussel.
An Ecological Study on Laminaria Ochroleuca
Authors: John D. M.
Published: May 2009

The distribution of Laminaria ochroleuca along the south-west coast of England and the Isles of Stilly is brought up to date. The pattern of distribution is discussed with reference to certain factors controlling the ‘ performance’ and success of the species on the northernmost edge of its range. The performance of individuals of the species (measured as net stipe production) sampled from populations growing on the coast of south-west England is compared with populations from north-west Spain, where it is growing in the centre of its geographical range.

The degree of exposure to direct onshore wave action appears to govern the upper limit of its bathymetric range as well as its distribution along the south-west coast of England.

It was found possible to age this species using the method and precautions described by Kain for Laminaria hyperborea.

The stipe material sampled from the English populations had a higher ash content per gram dry weight and a higher calorific content per gram of organic material than that from the Spanish populations.

Individuals from the English population had a lower weight per unit length of stipe in all age-classes than those from Spain.

It is suggested that incident radiation may be a more important factor than temperature in controlling the northward limit of the species.
Distribution and Regional Variation of Argentina Sphyraena [Pisces: Isospondyli]
Authors: Halliday R. G.
Published: May 2009

The lesser argentine, Argentina sphyraena L., is a Mauretanian-Mediterranean-Boreal species extending from about 68° N. off the Norwegian coast to 25° N. off Spanish West Africa. It is most commonly caught on the offshore continental shelf in depths between 50 and 100 fm where average sea temperatures of 6° and 17°C are encountered at the northern and southern limits respectively of the species geographical range. Larger, older fish are taken in deeper water, and occurrences inshore and at depths less than 50 fm are usually associated with the presence of deep trenches over 50 fm.
The Vertical Distribution of Marine Macroplankton. XII. Some Observations on the Vertical Distribution of Calanus finmarchicus in Relation to Light Intensity.
Authors: Russell F. S.
Published: May 2009

1. Observations are given on the vertical distribution of adult Calanus finmarchicus in the daytime off Plymouth in July and August, 1931, as a result of collections made simultaneously with the photo-electric measurement of submarine illumination.

2. A series of nets, usually six, was towed simultaneously in such a manner that the depth of each net was known approximately.

3. The female Calanus in July preferred higher intensities of light than did the females in August; this change was coincident with a change in the Calanus population as shown by size measurements. A similar change in distribution and in population was shown by the males.

4. The females in July were living in intensities of 20,000 m.c. and more; but those in August were avoiding such high intensities. The males in July avoided intensities of 40,000 m.c. and over, while in August their upper limit was about 10,000 m.c.
On the Biology ofCalanus finmarchicus. Part IV. Seasonal Changes in the Weight and Chemical Composition in Loch Fyne
Authors: Orr A. P.
Published: May 2009

1. The dry weight of 100 male, female and Stage V Calanus in Loch Fyne fluctuated throughout the year. 100 Stage V Calanus in May weighed only about ⅓ of what they did in December. Male and female Calanus also fluctuated considerably in weight.

2. Stage V Calanus is usually largest and heaviest when it is most abundant. With male and female Calanus size and weight are related.

3. Stage V Calanus, in spite of being smaller than female Calanus, was from the beginning of June till the end of August considerably heavier (over 100%). When Stage V Calanus was at its lightest and smallest, it weighed less than female Calanus at the same time.

4. The weight of Stage V Calanus fell during the spring and did not increase again till after the end of the first breeding period.

5. The fat and protein content of Calanus depends chiefly on dry weight. The values obtained for fat content were considerably higher than those hitherto recorded for zooplankton and those of protein lower.

6. The ash content is about 3·6% and the chitin content about 3% of the dry weight.

7. Stage V Calanus accounted for by far the most important part of the total weight of the catch throughout the year.

8. The total food value of the Calanus in Loch Fyne probably varies very considerably from year to year.
The Determination of Phosphorus and Nitrogen in Plankton
Authors: Cooper L. H. N.
Published: May 2009

Phosphorus in plankton has been determined by digestion with sulphuric acid and perhydrol followed by colorimetric determination.

Nitrogen has been readily determined by the micro-Kjeldahl method of Parnas and Wagner.
On the Biology of Calanus finmarchicus. V. Seasonal Distribution, Size, Weight and Chemical Composition in Loch Striven in 1933, and their Relation to the Phytoplankton
Authors: Marshall S. M. , Nicholls A. G. , Orr A. P.
Published: May 2009

1. The seasonal changes in the population of Calanus in Loch Striven in 1933 have been investigated.

2. There were three main breeding periods. The first was in February and March, an unsuccessful beginning of the second in April, the true second brood in May to June, the third in July, and subsidiary broods in August and September.

3. Numbers were very low until April when the copepodites of the first brood caused a large increase; there was a second increase in May consisting mainly of the eggs of the second brood, and the maximum for the year came in July. The last and subsidiary broods provided the stock for the autumn and winter of 1933.
Notes on the Swimming Methods and Habits of Certain Crustacean Larvæ
Authors: Foxon G. E. H.
Published: May 2009

The swimming methods and habits of certain Decapod larvse have been observed. The first larva ofMunida bamfficawas chosen for special attention. Such a study shows the importance of (1) orientation, (2) the presence of a reversal mechanism.

Observations on other types show these factors to be of great importance and also show that there are a great variety of attitudes in which larvæ swim.

Points in the relation of the larvæ to their environment were next considered; orientation is again important here, but whereas in Munida larvæ a “resting” orientation is found no such attitude is seen in Brachyurous zoeas.
The Flow of Water Past the Seven Stones Lightvessel
Authors: Carruthers J. N.
Published: May 2009

A brief reference to the state of opinion concerning the water movements off S.W. England is made. Then a series of Drift Indicator records relating to 28 days of observation at 6 fathoms depth from the Seven Stones Lightvessel is presented and discussed. An overall flow of water towards the S.E. quadrant and of speed approaching 2 miles per day characterised the entire period. The residual current as worked out for the individual records, displayed considerable variation in speed and direction—setting as frequently towards the northern half of the compass as towards the southern, but more frequently towards the eastern half than towards the western half. There were pronounced changes in the wind speed and direction, and it appears as though the wind can drive the water at 6 fathoms depth towards a point to the right of its own direction, no matter from which of the four quadrants it blows.
Replacement of Potassium by Rubidium inNitzschia closterium
Authors: Stanbury F. A.
Published: May 2009

Variousattempts have been made to substitute certain elements for those acknowledged as essential for plant growth. Using plant material, sodium is the element usually chosen as a possible substitute for potassium, but results show that whilst sodium may be taken up in fairly considerable quantities this is only possible if small amounts of potassium be present as well. Total replacement appears to be impossible (11,13,15).
Factors affecting climbing in the coastal gastropod Hydrobia ulvae
Authors: Barnes R. S. K.
Published: May 2009

In a series of laboratory experiments designed to create conditions under which the dispersal and feeding hypotheses of climbing in Hydrobia ulvae would predict opposing results, significantly larger numbers of snails climbed (a) food-bearing sticks than non-food-bearing sticks, (b) in 100% sea water than in 41% sea water, and (c) in the dark than in the light. The first two of these results are in accordance with the hypothesis that climbing is not a distinct behavioural activity but is merely normal crawling/browsing behaviour carried out in a vertical plane; they are in disagreement with the hypothesis that climbing is undertaken in order to facilitate dispersal away from unfavourable conditions. The third result is neutral in respect of the two hypotheses, but is explicable in terms that activity during the night is advantageous because of lowered rates of vertebrate predation.
Squid mantle muscle
Authors: Bone Q. , Pulsford A. , Chubb A. D.
Published: May 2009

The mantles of the small squidAlloteuthis, the largerLoligo, and the cuttlefishSepiacontain an elaborate framework of connective tissue fibres running in different planes. Some of these fibres are apparently elastic. The circular muscle fibres which provide the power stroke in mantle contraction are of two types. Inner and outer mantle zones consist of well-vascularized mitochondria-rich fibres, whereas the central zone contains only mitochondria-poor fibres with a sparse vascular bed. Nerve terminals on the two fibre types are similar. The radial fibres opposing the circular fibres are of the same type as the central fibres, at least in the mid-region of the mantle. It is suggested that the central fibres are involved in escape jetting contractions, and that the fibres of the inner and outer zones are used during rhythmical respiratory contractions.
Ammonia excretion by Nassarius reticulatus and Buccinum undatum (Gastropoda: Prosobranchia) during starvation and after feeding
Authors: Crisp Mary , Gill Catherine W. , Thompson M. C.
Published: May 2009

The rate of excretion of ammonia by Nassarius decreases progressively during starvation. Both Nassarius and Buccinum exhibit a transient peak of ammonia excretion some 16–48 h after a meal. In Nassarius the length of the delay between feeding and maximum ammonia excretion depends on the duration of prior starvation.
Structure and function of the anal sacs ofBonellia viridis(Echiura: Bonelliidae)
Authors: Harris R. R , Jaccarini V.
Published: May 2009

The structure of the anal sacs of the echiuranBonellia viridisRolando was studied using SEM, TEM and light microscopy. The characteristic ciliated funnels which open into the coelom and connect it to the lumen of the sac were observed live by interference contrast light microscopy. Clearance of the extracellular marker inulin from the coelomic fluid (Vc= 9·6 ± 1·9 ml 100 g−1wet weight of animal day−1) indicated that a filtrate of coelomic fluid is produced by the ciliary activity of the funnels. The flow of this filtrate into the sacs is unidirectional. Comparison of the ionic composition and osmolality of the anal sac fluid with the coelomic fluid, and surrounding sea water, indicates that the filtrate passes unmodified by absorptive or secretory processes to the outside. Thus the sacs do not appear to have a clear iono- or osmoregulatory function. During osmotic uptake of water in low salinities the rate of clearance of inulin by the anal sacs did not increase, indicating that their role in volume regulation is insignificant. The reddish-brown granules in the epithelium and lumen of the organ (which give the sacs their characteristic colour) may be important excretory products, and the primary function of the sacs their elimination.
Zinc transport in the haemolymph ofCarcinus maenas(Crustacea: Decapoda)
Authors: Zatta Paolo
Published: May 2009

InCarcinus maenashaemolymph, zinc is almost entirely bound to the respiratory pigment, which is the copper-protein haemocyanin (Hc). Zinc ions are loosely bound, as indicated by the low value of the association constant (k= 1.7 × 105M-1at pH = 8.0). The number of binding sitesNis equal to 4 per minimal functional subunit (75000 Dalton). No co-operativity has been found between the different metal sites. Data reported in this paper support the hypothesis that haemocyanin can act as metal carrier in the haemolymph ofC. maenas.
Incubation and scissiparity in Sabellidae (Polychaeta)
Authors: Jones-Knight Phyllis , Bowden Nigel
Published: May 2009

Incubated embryos are here recorded from the Sabellinae Amphiglena mediterranea, Potamilla neglecta and Perkinsiana antarctica, and the Fabriciinae Fabricia sabella, Fabriciola chilensis, Oriopsis alata and Oriopsis ehlersi, but incubation has not been observed in most species of Sabellinae, nor in any Myxicolinae. Natural fission (as opposed to regeneration following damage or autotomy) is also rare in Sabellidae, but a Scilly Isles tube worm identified as Sabella variabilis Langerhans, multiplies by fission from the posterior end, like the Filograninae amongst serpulids.
Hydrodynamic aspects of particle capture byMytilus
Authors: Silvester N. R. , Sleigh M. A.
Published: May 2009

Available data on the size distribution of particles captured byMytilusindicates that a somewhat leaky, but non-sticky, filter with a minimum mesh size of a little over 1.0 μm is present. The side branches of the latero-frontal cirri have such a mesh and are positioned so as to filter water passing between the gill filaments. Information on the pressure distribution within the water circulation, and calculations of the pressure required to pass watet ihrough the latero-frontal filter at observed speeds, suggest that a little more than half the pressure generated by the lateral ciliary pump is required to overcome resistance in the latero-frontal filter and the remainder is required to circulate water in through the inhalant opening and out in an exhalant jet. The lateral cilia appear theoretically capable of generating sufficient power to produce the required pressures. Calculations indicate that although hydro-mechanical shear forces are unlikely to provide a significant contribution to particle capture, they may provide a means of keeping particles within the frontal current without a need for mucus, after filtration and transfer of particles to the frontal surface by the latero-frontal cirri.
Red pigment epithelium of fish eyes
Authors: Best A. C. G. , Nicol J. A. C.
Published: May 2009

The eyes of characins (Characidae), pike, pickerel (Esocidae) and wrasses (Labridae) have a red pigment epithelium. There is no melanin, the epithelial cells containing red particles (erythrosomes). These are tiny cylinders in the cell processes, and spherules in the cell bases. In characins and pike, the red cylinders participate in retinomotor activity. Cylinders are birefringent and act as waveguides; they transmit long wavelengths (> 550 nm). The red pigment has been extracted and purified. It appears to be the same in the three families. Ultraviolet, visible and infra-red spectra are presented.
Shell implosion depth and implosion morphologies in three species ofSepia(Cephalopoda) from the Mediterranean Sea
Authors: Ward Peter D. , Boletzky Sigurd Von
Published: May 2009

The maximum habitation depths of chambered cephalopods are dictated by the mechanical properties of the shell. All chambered cephalopods have a depth at which ambient pressure is sufficient to implode the gas-filled shell portions. Experiments on Sepia elegans D'Orbigny,S. officinalisLinne andS. orbignyanaFérussac from the Mediterranean Sea show these three species to have differing depth limits and modes of shell implosion. LargeS. officinalisimplode between 150 and 200 m, whereas newly hatched and advanced embryonic specimens implode between 50 and 100 m. The largerS. officinalisare occasionally caught at depths greater than the implosion depth of the juvenile shell parts. They apparently avoid implosion of the early shell portions by refilling these first-formed chambers with cameral liquid later in life. Implosion inS. officinalisgenerally resulted in the crushing of all or most of the septa in a band extending from the embryonic region to the anterior part of the shell. Implosion was generally accompanied by fatal rupture of underlying tissue into the implosion zones. Implosion ofS. orbignyanaoccurred between 550 and 600 m and was very different in form from that inS. officinalis, occurring mostly within the smooth zone of the last-formed several chambers, and rarely extending back into the siphuncular region (striae zone). Increasing depth caused episodic implosion of sequentially older chambers in the smooth zone. The shallower implosions were accompanied by little soft-tissue damage. Massive internal injury only occurred in the deepest implosions (700 m or greater). Implosion inS. elegansoccurred betw en 400 and 600 m. Too few specimens were available to allow generalizations about morphology of implosion in this species.