bluuebunny/crossref_metadata_2025 huggingface dataset:
The Bottom Fauna of the English Channel
Authors: Holme N. A.
Published: May 2009

A survey has been made of the bottom fauna inca. 10–50 m along the south coast of England, using a modified anchor-dredge. Particular attention has been paid to the molluscs (both living and dead) and to the echinoderms, only larger or more conspicuous members of other groups being identified.

Within the Channel there are considerable variations in temperature and other hydrographic conditions, and these are discussed in relation to their possible role as limiting factors in distribution. The fauna and bottom deposits of the different areas covered in the survey are briefly described.

Distribution trends are classified as:

(1) Species generally distributed in the Channel. This is the largest group, and includes three species reaching their northern limits in British waters.

(2) Species confined to the western parts of the Channel.

(a) Western species. Four or five species common at Plymouth in the 1920's, but now absent or very rare. Small numbers are found today only off the south Cornish coast, and those which occur in the North Sea are restricted to the north-western areas. Apart from one species, these forms are not at their geographical limits in the English Channel, and their occurrence may be partly related to the presence of ‘western’, but not necessarilySagitta elegans, water.

(b) Cornubian species. These are near the northern end of their range, and occur quite commonly off the south Cornish coast, becoming progressively less common farther up-Channel. It is suggested that their distribution is related to an intolerance of the lower winter temperatures in the more eastern part of the Channel.
On the Biology of Calanus Finmarchicus XII. The Phosphorus Cycle: Excretion, Egg Production, Autolysis
Authors: Marshall S. M. , Orr P. , Conover R. J.
Published: May 2009

It is shown that equilibrium of 32P throughout the body of Calanus is reached only after a feeding period of about a week. The time required to liberate by excretion the amount of P present in a Calanus is about 20 days. Fed Calanus excrete at a higher rate than starved. The implications of excretion in feeding experiments using 32P is discussed.

There are large differences in the total P content of individual Calanus. Figures are given for ripe and unripe females, fat and lean Stage V, and eggs. A high percentage, up to 55% of the total P, may be lost by excretion during starvation.

A high proportion of the P in the food assimilated (up to 70%) may appear within a week as eggs laid.

Liberation of P from dead Calanus is very rapid and is almost complete in three days.

The relation of excretion and autolysis to the P cycle in the sea is discussed.
Further Observations on the Fine Structure of Chrysochromulina Minor and C. Kappa with Special Reference to the Pyrenoids
Authors: Manton I. , Leedale G. F.
Published: May 2009

Chrysochromulina minor and C. kappa have been re-investigated by means of electron microscopy of thin sections to add details of the microanatomy of pyrenoids and haptonemata, and by anoptral contrast light microscopy to study pyrenoids in living cells. In both species the pyrenoid is in the form of a diverticulum projecting from the centre of the inner face of a plastid and, in C. minor, strongly flexed to lie along it. In C. kappa the pyrenoid is commonly enveloped by the nucleus which may conceal it entirely from view in life. Some details of the behaviour of the surface membranes of plastids and pyrenoids in relation to that of the nucleus are given. The haptonema structure in both species is shown to be comparable to that of others in which this appendage is much longer, though an occasional variant with eight instead of seven central fibres or tubes has been encountered in C. kappa and is demonstrated. The presence of ‘peculiar’ Golgi structure is reported for both species and demonstrated for C. kappa. Some direct evidence indicating an internal origin of scales from vesicles is demonstrated in C. minor. Finally a summary is given of salient structural criteria for all the described species attributed to this genus from the marine plankton, the closest agreement as regards pyrenoid structure in the two species under investigation being with C. chiton.
Nervous Control of Stomach Movements in Dogfishes and Rays
Authors: Young J. Z.
Published: May 2009

The organization of the alimentary canal of fishes differs greatly between species of different dietary habit, but is not well understood. The vagus and sympathetic systems are very different in elasmobranchs and teleosts, but there has been little work on the corresponding physiology and pharmacology. The digestive system of elasmobranchs has unusual features connected with the fact that the absorbtive surface is provided by the spiral intestine (Fig. 1). This is a short fat tube whose surface is greatly increased by the presence of a coiled fold, the spiral valve. This arrangement provides a large area for absorbtion, neatly packed, but it leaves only a narrow lumen, so that no large particles can pass along the spiral intestine. Presumably it is in connexion with this condition that the stomach is divided into two parts. The cardiac division is a large sac into which the prey is received whole, its wall is very glandular and much breakdown of the food proceeds there (Hogben, 1967). The pyloric division is a narrower tube, leading from the hind end of the cardiac part to the pylorus.
Host Defence Reactions of the Shore Crab, Carcinus Maenas (L.): Clearance and Distribution of Injected Test Particles
Authors: Smith Valerie J. , Ratcliffe N. A.
Published: May 2009

It is well established that crustaceans can overcome infection and clear foreign material introduced into the circulation (Cornick & Stewart, 1968; Tyson & Jenkin, 1973; Stewart & Zwicker, 1974). In the absence of vertebrate-type specific acquired immunity, the non-specific activity mediated by the circulating blood cells appears to be of considerable importance in resistance to disease (Sindermann, 1971). Among the cellular defence mechanisms of the Crustacea, phagocytosis has received most attention and there is considerable evidence from in vitro studies that this process plays an important part in the removal of foreign particles from the blood (McKay & Jenkin, 1970a; Paterson & Stewart, 1974; Tyson & Jenkin, 1974; Paterson, Stewart & Zwicker, 1976; Smith & Ratcliffe, 1978). Such studies, however, may not always reflect the true in vivo condition, and there is a great need for correlated in vitro and in vivo investigations.
The Cultivation of Calanojdes Carinatus Krøyer (Copepoda: Calanoida) under Different Temperature and Food Conditions-with a Description of Eggs and Nauplii
Authors: Hirche Hans-Jürgen
Published: May 2009

According to its mouthparts Calanoides carinatus is a herbivorous filter-feeder (Mensah, 1974a; Schnack, 1978) that is often associated with phytoplankton blooms. The species has been reported from the three oceans and the Mediterranean (Vervoort, 1946). Interest in this copepod is increasing due to its apparent importance as a dominant link between phytoplankton and fish in upwelling areas. Its presence in surface waters is regarded as an indication for upwelled water (Bainbridge, 1972; Binet, 1973). Population dynamics and life-cycle have been studied best on the West African shelf (Mensah, 1974b; Binet & Suisse St Claire, 1975; Petit & Courties, 1976; Binet, 1977). Courties (1978) has recently given a comprehensive review of the literature on C. carinatus. In the above-mentioned studies, generation time usually is estimated by measuring successive peaks of larval stages and adults as well as using sex ratio and length distribution. In spite of its importance, C. carinatus has not yet been successfully reared in the labora-tory. Tomasini & Petit (1977) determined experimentally the developmental time of eggs and some copepodite stages, but could not obtain all stages. Schnack (1978) studied the feeding behaviour in feeding and assimilation experiments using various species of algae on board ship.
Cytology and Cytochemistry of the Pericardial Gland Cells of Mytilus Edulis and their Lysosomal Responses to Injected Horseradish Peroxidase and Anthracene
Authors: Moore Michael N. , Bubel Andreas , Lowe David M.
Published: May 2009

The functions and structure of the pericardial glands (Keber's organ) of bivalves were reviewed by White (1942). The cells of this gland have been considered to have an excretory role and Grobben (1887) suggested that the cells of the pericardial gland could be compared with the chloragogen cells of annelids.
Evidence for an Alternative Transport Route for the Use of Vitellogenesis in the Sea-StarAsterias Rubens(L.)
Authors: Broertjes J. J. S. , Posthuma G. , Breejen P. Den , Voogt P. A.
Published: May 2009

The inter-organ nutrient transport in echinoderms has presented an interesting but as yet unresolved problem for more than eighty years. During that time two systems have been proposed as candidates for the transporting medium or transport route, namely the coelomic fluid and the haemal system.
Distribution of Sodium, Potassium and Chloride in the Ophiuroid,Ophiocomina Nigra(Abildgaard)
Authors: Pagett Richard M.
Published: May 2009

Echinoderms are not generally considered to experience significant dilution of the surrounding medium in their usual marine habitats and so it is to be expected that, due to the absence of any obvious excretory organ, the ionic composition of the body fluid would be similar to that of the ambient sea water. In general this has been confirmed by previous workers for many species of echinoderm. Binyon (1966) lists the results of workers who have determined osmotic pressure and/or ionic concentrations in the perivisceral and/or ambulacral fluids of many echinoderms. With reference to the perivisceral fluid in asteroids there is usually a small excess of potassium (9–16%) which is maintained in the more euryhaline species and in those acclimatized to reduced salinity. Generally, the chloride content is similar to, or a little higher than, that in the surrounding sea water. In echinoids there is little difference in the potassium content and chloride concentrations with respect to sea water though there may be a small increase in the former ion. In the holothurians, there is little regulation of potassium ions. Such concentrations which have been determined for the chloride ion in this group are found to be a little higher than in sea water. The sodium concentration in the perivisceral fluids of echinoderms tends to be similar to, or slightly lower than, that in the surrounding sea water. However in the ambulacral fluids of the water vascular system it has been shown that the potassium concentration is 20–90% higher in some species of asteroids and echinoids (Robertson, 1949; Binyon, 1962,1966). The fluids of the water vascular system of echinoderms, analysed to date, have concentrations of sodium ions lower than in the ambient sea water. From the available evidence, there appears to be little difference between environmental and ambulacral chloride concentrations.
Surveying Stocks of Scallops (Pecten Maximus) and Queens (Chlamys Opercularis) with Underwater Television
Authors: Franklin A. , Pickett G. D. , Holme N. A. , Barrett R. L.
Published: May 2009

In England the fisheries for both scallops (Pecten maximus) and queens (Chlamys opercularis) expanded rapidly in the 1970s. Considerable research has been undertaken to develop an effective method of surveying stocks of these species in order to assess the impact of this greatly increased fishing effort on commercial populations. Visual photographic surveys seemed likely to provide the best means of assessing populations (Pickett & Franklin, 1975) and this paper outlines the preliminary results obtained from such a system - a towed sledge carrying both television and still cameras, developed at the Plymouth Laboratory.
The Spermatozoon of Actinia Equina L. Var. Mesembryanthemum
Authors: Larkman A. U. , Carter M. A.
Published: May 2009

Actinia equina var. mesembryanthemum, the beadlet anemone (Stephenson, 1935), is a very common and widely distributed littoral anthozoan, whose sexual reproduction shows several interesting characteristics. Adult sea anemones of both sexes brood planulae and more advanced developmental stages within the gastrovascular cavity, although earlier embryonic stages are rarely found brooded in this way. Chia & Rostron (1970) suggest that embryos are expelled from the parent female anemone at an early stage and pass through a free-living phase before re-entering anemones of either sex for brooding. However, recent work (Cain, 1974) suggests that juvenile anemones are genetically related to the adult anemones in which they are brooded, and also the distribution of genetic material during sexual reproduction appears to be abnormal (Carter & Thorp, 1979). In an attempt to achieve a better understanding of the unusual sexual reproduction of this species, an ultrastructural investigation of gametogenesis was undertaken. This paper describes the fine structure of the spermatozoon within the testis.
Toxicity of Heavy Metals to the Marine DiatomDitylum Brightwellii(West) Grunow: Correlation between Toxicity and Metal Speciation
Authors: Canterford G. S. , Canterford D. R.
Published: May 2009

The possibility of dissolved organic compounds acting as complexing or chelating agents in natural waters has received considerable attention in the last two to three decades. Stumm & Morgan (1970) have expressed doubts about the existence of humicmetal ion complexes in natural waters. Strickland (1972) has also stated that although the addition of chelating agents to sea water often improved the growth of phytoplankton, there was little evidence that the function of dissolved organic matter in oceans and lakes was to complex metals so as to increase or decrease their availability to phytoplankton. Strickland argued that even if all dissolved organic carbon were present as a compound of strong complexing ability it would not be able to compete for most metals with inorganic ligands such as chloride, sulphate and hydroxide. However, there is an increasing amount of data indicating that metals in natural waters may exist in chelated forms with dissolved organic matter (see, for example, Davey, Morgan & Erickson, 1973; Chau & Lum-Shue-Chan, 1974).
Formation and Regeneration of Abnormal Cells of the Marine DiatomDitylum Brightwellii(West) Grunow
Authors: Canterford G. S.
Published: May 2009

Heavy metals, as well as affecting the growth rate and photosynthesis of algae, have a considerable effect on the size and morphology of algal cells (see, for example, Erickson, 1972; Nuzzi, 1972; Davies, 1974; Kayser, 1976). Changes in the colour of algae in the presence of heavy metals have also been observed (Greenfield, 1942). At metal concentrations resulting in total growth inhibition of algae the cells, although abnormal, are not necessarily dead (see, for example, Nielsen & Kamp-Nielsen, 1970; Erickson, 1972; Nuzzi, 1972; Blankenship & Wilbur, 1975).

In heavy-metal toxicity studies withDitylum brightwellii(West) Grunow (Canterford & Canterford, 1979) it was observed that low concentrations of ethylenediaminetetraacetic acid (EDTA) and toxic concentrations of several heavy metals resulted in the formation of abnormal cells. In the present paper factors affecting the formation of abnormal cells are discussed. Experiments were carried out to establish whether or not these abnormal cells could be regenerated.
Structure and Proportions of the Spermaceti Organ in the Sperm Whale
Authors: Clarke Malcolm R.
Published: May 2009

The head of the sperm whale (Physeter macrocephalusL.), which is largely snout and the crest of the skull necessary to support it, may exceed a third of the total weight and a quarter of the length of the whale. This indicates the snout has an extremely important function but few theories regarding its function take into account the overall structure, whilst the detailed structure and proportions of the adult's snout have been almost totally neglected. Similarly, consideration of the thermal properties of the spermaceti oil, which is the most remarkable component and constitutes a large proportion of the head, have been neglected in studies of function.
Buoyancy Control as a Function of the Spermaceti Organ in the Sperm Whale
Authors: Clarke Malcolm R.
Published: May 2009

This paper will discuss the buoyancy of the sperm whale throughout its range and show that the whale probably has some control over its own buoyancy. Evidence will then be presented in support of the hypothesis that the whale can attain neutral buoyancy at depths greater than 200 m by control of the temperature of the spermaceti oil in its head. As a basis for this, papers describing the detailed structure and proportions of the whale (Clarke, 1978a) and some physical properties of spermaceti oil (Clarke, 1978b) have already been published.
Physiological Indices of Stress in Mytilus Edulis
Authors: Widdows J.
Published: May 2009

In nature, organisms are subjected to a variety of environmental factors acting together and they respond to the total resulting stimulus rather than to single environmental variables. In addition, the animal's response is not in terms of individual physiological rates but rather as a whole organism. Therefore an experimental approach to an animal's response to a complex environment could usefully include (a) multivariate experiments and (b) integration of individual physiological processes to provide a greater under-standing of the ‘whole organism’ response. In this paper, non-linear multiple regression equations and response surfaces are used to describe and illustrate the combined effects on the common mussel, Mytilus edulis L., of body size, ration and season on physio-logical integrations such as the scope for growth, growth efficiency and the oxygen: nitrogen ratio (reviewed by Bayne, 1975; Bayne, Widdows & Thompson, 1976). The data used to compute these physiological integrations are derived from a series of multivariate experiments described in a preceding paper (Widdows, 1978).
Growth and Fecundity in a Northumberland Population ofSpirorbis Spirorbis(Polychaeta: Serpulidae)
Authors: Daly John M.
Published: May 2009

So few data are available concerning polychaete fecundity that recent speculation about the relative advantages of different life-history ‘strategies’, and about the relative value of protected and unprotected larval development, has been almost completely abstract. The dangers of this approach have been clearly indicated by Stearns (1976) in his recent review. Until quantitative studies are made of the number and weight of gametes produced in relation to the weight of individuals for a range of species, there seems little basis for discussion of the problems mentioned above.
The Formation Of The Shambles And Other Banks By Tidal Stirring Of The Seas
Authors: Pingree R. D.
Published: May 2009

It is well known that if a beaker of water, to which a little sand has been previously added, is stirred, then the sand moves along the bottom and accumulates in the centre. The result is the same whether the beaker is stirred clockwise or anticlockwise. It is perhaps less obvious, but equally true, that if the beaker is placed on a rotating table, then stirring clockwise and anticlockwise produces different effects. Any stirring rate in the sense of rotation may produce a concentration of sand towards the centre (better effects may be observed with less dense material – tea leaves for example). However, if the stirring is against the rate of rotation, then it is necessary to exceed the rotation rate before sand will accumulate in the centre of the beaker. In an analogous manner, ‘spinup’ of the table produces dispersion of bottom material, whereas spin-down results in a concentration of material towards the centre of the beaker.
The Life History of the Cirratulid Worm, Cirriformia Tentaculata, on an Intertidal Mudflat
Authors: George J. D.
Published: May 2009

The seasonal fluctuation in numbers of C. tentaculata was investigated from
December 1959 until February 1962. The lowest numbers were recorded in April followed by a rapid increase in numbers during May. The magnitude of the increase varied from year to year, as also did the number of peaks that occurred during the summer months.

The worm was shown to have an extended breeding season from the end of March to September during which several spawning ‘bursts’ took place. Experiments suggest that some spawning may occur when the mudflat is inundated by the rising tide, although spawning was not observed in the field.

The population of C. tentaculata exhibited an annual cycle of growth which was influenced by the seasonal variation in temperature. Laboratory observations suggest that a temperature of about 20° C is optimal for the growth of young worms. The growth rate (8 mm/year) is slow compared with that of other polychaetes.

It is tentatively concluded from the field mortality data that between 10 and 16 % of animals survive to an age at which they are sexually mature; between 6 and 8 % of each generation reach an age of 15 months. Causes of mortality in the population are briefly discussed.
The Neurosecretory System of the Vena Cava In Cephalopoda I.Eledone Cirrosa
Authors: Alexandrowicz J. S.
Published: May 2009

Nerves known to supply the anterior part of the vena cava in Cephalopoda have been found to belong to a special system for which the term ‘neurosecretory system of the vena cava’ (NSV system for short) is proposed. InEledone cirrosathis system consists of neurons whose cell bodies are aggregated: (a) in the visceral lobe in a layer termed the NSV layer; (b) in the ganglionic trunks continuous with this layer and associated with nerves arising from the visceral lobe—there is on each side a ‘lateral NSV trunk’ accompanying the nervus infundibuli posterior, and a ‘medial NSV trunk’ accompanying the nervus visceralis. Each of these trunks in its further course separates from its nerve and runs far in the caudal direction diminishing in thickness and giving off sideshoots of irregular shape which end blindly in the loose connective tissue and show no connexions with any organ.

The NSV layer and trunks consist of unipolar nerve cells of small size and uniform appearance. Their very thin axons unite in bundles which form nerves running to the vena cava. The total number of neurons of the NSV system, approximately estimated, must be over two millions. The disposition of the elements of this system is peculiar in that the axons of the cells situated in the caudal prolongations of the ganglionic trunks must run far rostralwards until they reach the nerves to which they contribute.

The nerves entering the vein penetrate through its muscle coat and form a network under the endothelial lining of the vein; this continuous neuropile layer extends from the anterior end of the vein to the entrance of the vena hepatica; all this part of the vein has on its inside longitudinal ridges formed by the uneven thickness of the neuropile layer.
The Integumentary Mucous Secretions of the Ophiuroid Ophiocomina Nigra
Authors: Fontaine A. R.
Published: May 2009

The general histology of the integument of the ophiuroid Ophiocomina nigra is outlined. Two types of integumentary mucous glands are described in detail for the first time. The first is a multicellular gland, the basal end of which is located deep within the calcareous layer of the integument. The source of the secretion is a variable number of nuclei embedded in a common cytoplasmic mass filled with fine basiphil granules. These cells contributed their secretion to a duct which pursues a tortuous course through the integument. The ducts frequently branch and anastomose so that any one exit pore may extrude mucin derived from a number of separate, polynuclear sources. The structure so formed is, thus, a massive, multicellular gland. Histochemical studies demonstrate that the mucin is a highly sulphated acid mucopolysaccharide. The second type of mucus-secreting unit is a unicellular gland usually located superficially in the calcareous layer or sometimes restricted to the epidermis and distributed universally over the body. The secretion product of these cells is shown histochemically to be a simple acid mucopolysaccharide. The mucin secreted by the tube-foot glands is demonstrated also to be a highly sulphated acid mucopolysaccharide.

The function of these secretions has been investigated to some extent. The massive glands secrete only under conditions of alarm and it is suggested that this mucus serves as a defence against predation. The unicellular glands secrete in a periodic fashion correlated with the act of feeding. This secretion is probably utilized in a suspension-feeding mechanism.
The Chorioidal Tapeta of some Cartilaginous Fishes (Chondrichthyes)
Authors: Denton E. J. , Nicol J. A. C.
Published: May 2009

1. A study of the histology of the eyes of some cartilaginous fishes has been made with special reference to their reflecting tapeta.

2. The rate and way in which the pigment in the melanophores spreads over the reflecting cells of the tapetum ofSqualus acanthiaswhen it is lightadapted are described.

3. The reflecting plates in the tapeta are about parallel to the plane of the retina in the centre of the eye, but as we move towards the periphery they become more oblique, until near the ora they are almost perpendicular to the plane of the retina. It is shown that when we take account of the way in which the pupil limits the light which can reach the retina in all these situations the plates are arranged to be roughly perpendicular to the incident light. They reflect light either back through the pupil or on to the very black inside surface of the iris and do not scatter it to other parts of the eye.

4. The reflectivity of tapeta for various angles and various wave-lengths of light has been found by several different methods, and a new and simple way of measuring the reflectivity of natural tissues is described. For the blue and green lights which will be those reaching the eye in life the reflectivity is very high, over 80%, and so approaches that of a good metallic mirror.

5. The external segments of the retinal rods of cartilaginous fishes which have well-developed tapeta are only about half as long as those of other fish living in the same environment, and the retinal optical densities of photosensitive pigments in these fish are only about a half of those of fish without reflecting tapeta.
The Uptake of Radioactivity by Fish and Shellfish I. 134Caesium by Whole Animals
Authors: Morgan F.
Published: May 2009

The uptake of 134Cs by 36 species of marine and freshwater fish and shellfish has been measured, and for selected species has been shown to depend on a power of the weight. For plaice, lobster, and eel, over thousand-fold ranges of weight, the uptake varies according to ω0.78. The times taken to reach half-equilibrium concentrations vary according to a value between ω0.25 and ω0.29, e.g. for a 100-fold increase in weight there is a 3.5-fold increase in
half-value time.
Notes on the Distribution of Electric Rays (TorpedoSpp.) in Northern European Waters
Authors: Wheeler Alwyne , Heaume Valerie Du
Published: May 2009

The distribution of electric rays (Torpedospp.) in northern European waters is discussed.Torpedo nobilianais admitted as of regular occurrence; records of occurrence ofT. marmorataare given in detail. The status in these waters ofT. torpedois doubtful. A synoptic key is provided together with illustrations of the three species.
The Effect of Extracts ofFucus Serratusin Promoting the Settlement of Larvae ofSpirorbis Borealis[Polychaeta]
Authors: Williams G. B.
Published: May 2009

Free-swimming planktonic larvae of most species of sedentary marine invertebrates do not metamorphose in mid-water and settle at random, but possess considerable powers of delaying metamorphoses until a suitable substrate is encountered. Within recent years several workers have analysed the physical properties of a substrate to which larvae respond, particularly amongst those species which are restricted in their distribution in the littoral zone to the surfaces of other animals and plants. The serpulidSpirorbis borealisoccurs most abundantly onFucus serratus; experiments conducted in which surfaces treated with extracts ofF. serratuswere offered as alternatives to untreated surfaces illustrated that the larvae settle on these extract-treated surfaces in significantly greater numbers. It has been demonstrated that this response is to some chemical substance derived from the alga rather than to changes in physical properties of the surface such as increased thickness of the overlying film, or changes in the surface texture. Contact with this substance modifies the settlement behaviour from that observed amongst larvae settling on untreated surfaces. The photopositive behaviour is curtailed, and the duration of the crawling behaviour preceding settlement abbreviated. The precise mechanism by which the larvae respond to the active substance is as yet unknown, but observations have illustrated that it is dependent upon the larvae detecting the active substance as an adsorbed layer on the surface rather than a response to concentration gradients in solution. The significance of an innate ability to detect specific substrates by chemical structures characteristic of the surface in the speciation of the Spirorbinae has been discussed.
Aspects of the Biology of Laminaria Hyperborea III. Survival and Growth of Gametophytes
Authors: Kain Joanna M. , Jones N. S.
Published: May 2009

The lower limit of the Laminaria hyperborea (Gunn.) Foslie zone is probably not always determined only by lack of sufficient light, even when a suitable substratum is present (Kain, 1962). It also appears that the establishment stage is critical although growth conditions deteriorate with depth (Kain, 1963). It therefore seemed desirable to determine exactly what the light requirements of the various different early stages were, and relate these to what could be found out about the light penetration in the natural habitat. The effect of temperature on these stages is also of interest, in relation to the seasonal cycle as well as to the geographical distribution of the species. In this study two different techniques were used: culturing the gametophytes on cover-slips and also studying changes in oxygen concentration as measured by the Winkler method.

The gametophytes of the different members of the Laminariales show a similar general course of development. A zoospore from a fertile frond of a Laminaria plant loses its motility, rounds off, swells and produces a tube with another sphere at the end into which all the cell contents pass (Killian, 1911). This process can be carried through in the dark but further development depends on light (Schreiber, 1930). In this genus the gametophytes are dioecious (Sauvageau, 1918; Williams, 1921) and equal numbers of male and female plants are produced (Schreiber, 1930). The female gametophyte may become fertile before dividing further (Sauvageau, 1918), resulting in a single egg, or may form a luxuriant filamentous structure which may produce many oogonia over a period of time (Ikari, 1921; Myers, 1925; Schreiber, 1930).
Experimental Studies of Plankton Luminescence
Authors: Hardy A. C. , Kay R. H.
Published: May 2009

Experimental studies of plankton luminosity have been made with specially designed photomultiplier equipment; this records (on a Servograph Recorder) the flashes given off either by a sample of plankton or by individual animals placed in a container in a dark observation chamber. The apparatus is described.

Apart from preliminary laboratory records on the flashing of Beroë, Pleurobrachia and Pyrosoma, and record of the general luminosity in the sea at a depth of 62 m (made with an underwater version of the apparatus), the main work has been a laboratory study of the luminescence of dinoflagellates and of the euphausiacean Meganyctiphanes norvegica.

The dinoflagellate experiments showed the inhibiting effect of light, both natural and artificial, on luminescence, and the stimulating effect of mechanical disturbance which may override the former inhibition. A rise in temperature increased luminosity and cooling reduced it. A difference in the pattern of the luminosity of plankton samples containing dinoflagellates was shown by the introduction of actively swimming animals of different kinds. The dinoflagellates in the samples were mainly Peridinium depressum, Ceratium horridum and C. tripos var. balticum.

The Meganyctiphanes experiments showed a spontaneous flashing in seventeen out of twenty-seven tests and in one test the animals maintained such activity for the greater part of a 24 h period. In addition to their bright flashing, the photophores would at times keep up a dull glow for long periods (especially see the observations of F. Körte in the Appendix). Spontaneous flashing does not only occur in the breeding season as had been suggested by Mauchline (1960).
The Structure, Ciliation and Function of the Lip-Apparatus of Lima and Pecten [Lamellibranchia]
Authors: Gilmour T. H. J.
Published: May 2009

The structure and ciliation of the lip-apparatus of two species of Lima—L. hians (Gmelin) and L. excavata (Fab.)—and one species of Pecten—P. maximus (L.)—is described.

It is suggested that the lips of these three species of bivalves have been hypertrophied (and in one case partially fused) in order to retain particulate material being carried from the ctenidia to the mouth while at the same time allowing the escape of water currents, generated by the ciliary tracts of the ctenidia and palps, from the proximal oral grooves. Such water currents must emerge from between the lips of all bivalves but do not usually interfere with the passage of particulate material. In the Limidae and Pectinidae, these water currents have been intensified by the reduction of the anterior regions of the mantle cavity. Since this change in the proportions of the body can be correlated with the evolution of the monomyarian condition in the Anisomyaria,
it is postulated that the lips of all monomyarian Anisomyaria will be similarly hypertrophied.
The biology ofLaminaria hyperboreaX. The effect of depth on some populations
Authors: Kain Joanna M. , Jones N. S.
Published: May 2009

Some understanding of the mechanisms involved in the development and maintenance of forests ofLaminaria hyperborea(Gunn.) Fosl. can be gained from the analysis of populations under different conditions. The main variable is depth and unfortunately the available depth range of suitable substrata in the Isle of Man is limited. For this reason two visits were made to western Scotland and the Outer Hebrides, in 1970 and 1976. This paper, which is intended as the last in this series, reports on results obtained rom there and from certain sites in the Isle of Man.
External morphology of the choanoflagellateSalpingoeca gracilisJames-Clark
Authors: Thomsen Helge Abildhauge
Published: May 2009

In his search for evidence illustrating the botanical/zoological affinities of the sponges (Porifera), James-Clark (1867) studied a number of colourless flagellates. The genusSalpingoeca(Craspedophyceae, Christensen, 1962; cf. Chadefaud, 1960) was thus erected to comprise certain solitary, lorica-dwelling organisms, characterized by a single anterior flagellum encircled by a ‘filmy, membranous, colourless collar’ (James-Clark, 1867).

About fifty species (approximately twenty marine) are at present allocated to this genus, provided it is defined as e.g. by Norris (1965) and Bourrelly (1968) (i.e. includingLagenoecaKent andPachysoecaEllis).
Effect of size upon metal content of shellfish
Authors: Boyden C. R.
Published: May 2009

Studies of tissue metal concentrations in shellfish have progressed along two major lines: first, to record the range of concentrations within commercial species, a response to the need to identify potentially hazardous levels from a human nutritional standpoint; and second, to compare concentrations within a single species on a geographical basis as a framework for an environmental monitoring programme. Body size is a parameter which can influence tissue metal concentrations, and if significant variations due to size do occur, then clearly it is a factor which should be taken into consideration within these contexts.
A morphological staging system for the larval development of the herring, Clupea harengus L.
Authors: Doyle M. J.
Published: May 2009

It has been possible for some years to rear artificially-fertilized herring eggs through to metamorphosis making experimental studies on the larval phase of the life history practicable (Blaxter, 1968). However, a comprehensive larval staging system has not previously been published.
Tidal eddies and coastal discharge
Authors: Pingree R. D. , Maddock Linda
Published: May 2009

Radioactive wastes and sewage discharged into coastal waters may be largely dispersed by tidal streams. Before authorization for sea discharges can be granted by responsible authorities representing public interests, as much information as possible must be obtained on water movement in the chosen area. Comprehensive data on tidal conditions around the British Isles can be found from the Admiralty Tidal Stream Atlases (Hydrographic Department). The method by which these currents are measured is explained in the Admiralty Manual of Hydrographic Surveying (Hydrographic Department, 1948). Further, special surveys using sea surface drifters and current meters are usually necessary to provide additional information in the neighbourhood of a proposed release. The purpose of this note is to point out that further relevant information can be obtained using numerical models and that these results should also be taken into account when decisions have to be made.
The Distribution of Iron in the Waters of the Western English Channel
Authors: Cooper L. H. N.
Published: May 2009

With 2:2′-dipyridyl as reagent for reducible and total iron, determinations were made on samples from the western English Channel at midwinter 1946–47, at the time of the maximum of phosphate, and also in July 1936.

The midwinter results have been treated statistically and the errors of analysis assessed.

Unlike phosphate and nitrate, much of the inorganic iron occurs as particles of fair size, distributed at random in the water. In winter there is no statistically significant difference between the total iron content of samples drawn from 0·5,5,25 and 50 m. depth, the grand mean and standard deviation for the whole area being 0·25 ± o·11 mg.-atom/m.3. The reducible iron for the same depth range and area was 0·19 ± 0·14 mg.-atom/m.3. There appears to be about 0·06mg.-atom/m.3 of iron which is reasonably highly dispersed and not determinable until the water has been oxidized with bromine.

In the bottom layers of water, although the reducible fraction differs little from the overlying layers, the total iron shows a very much greater mean value and variance.

The very low content of total and reducible iron and of particulate ferric phosphate in bottom water at a position 49° 30′ N., 5° 00′ W. has been provisionally attributed to removal by a dense bed of suspension feeders, possibly the mollusc Pinna.

By a statistical examination of the analytical results it has been deduced that the particulate fraction in the upper 50 m. was distributed on an average amongst about 45 particles per litre, each containing about 0·24μg. Fe and with a diameter of about 160μ. This result has been compared with data on the distribution of iron in plankton organisms.

As a statistical average waters richer in phosphate were also richer in total iron, the atomic ratio Fe/P being about 0·57.

In July 1936 the ‘elegans’ water to the westward was much richer in both phosphate and total iron than the more eastern mixed water containing Sagitta setosa. The results agree well with the conclusions drawn from the cruises at midwinter 1946–47.

In 1933–34 concentration of iron was frequently observed in the surface layers; in 1946–47 it was not. In the earlier work the surface film was always cut and included in the sample, in the later it was not. The probable amount of a surface unimicellar film of electropositive unprotected ferric hydroxide has been calculated and agrees well with observation.

Particulate ferric phosphate was found to the extent of about 0·06 mg.- mols/m.3 This appears to increase towards the bottom.

The success of the work at Newlyn in January 1947 owes much to the willing co-operation of Capt. Creese and the crew of R.V. Sabella under very adverse weather conditions. To Mr P. G. Corbin grateful thanks are due for undertaking single-handed the supervision of all the scientific work at sea on stations never more than two hours apart for two or three days on end. The statistical development would not have been possible without the unstinted assistance of Mr G. M. Spooner.
Particulate Ammonia in Sea Water
Authors: Cooper L. H. N.
Published: May 2009

The hypothesis is proposed that inorganic ammonia may be adsorbed on particulate matter in the sea. The random distribution of such particulate ammonia would account for the frequent ‘contamination’ reported in ammonia analyses and for the finding of nitrifying bacteria associated only with particulate matter, but never with sea water itself.
Phosphate and Fisheries
Authors: Cooper L. H. N.
Published: May 2009

Landings of the spurdog, Squalus acanthias, at Mevagissey reflect the changes in phosphate at the neighbouring International Hydrographic Station Ei.

It is suggested that commercial landings of rays and skates ought to follow major changes in nutrient content of the overlying water with a time lag of some years. Fishery statistics for English Channel ports support this view. The dependence of the bottom in-fauna upon the fertility of the overlying water is also discussed.

Proposals to improve commercial fisheries by artificially fertilizing considerable areas of the open sea are critically examined. Such artificial enrichment is considered to be grossly uneconomic unless fishing becomes pisciculture in which weeding of unwanted algae and control of unwanted pests—competing predators and parasites—is undertaken.
The Estimation of Phosphate and of Total Phosphorus in Sea Waters
Authors: Harvey H. W.
Published: May 2009

A simple photoelectric meter is described which allows the molybdenum blue formed in sea water, due to the presence of phosphate, to be estimated within that due to ± 0·25 mg. phosphate-P per m.3.

The effects of concentration of acid, molybdate, reductant, temperature and suspended particles on the rate of formation, fading and amount of molybdenum blue, formed in sea waters containing phosphate are detailed.

Intramolecular changes taking place during storage of molybdate solutions, and while being mixed with acidified sea water, have been investigated.

The hydrolysis of organic phosphorus compounds in acidified sea water at 140° C , and the prevention of arsenate formation, are described.

Procedures, resulting from these investigations, for the estimation of phosphate, and of total phosphorus, are described.

The growth of bacteria and the physical adsorption of organic phosphorus compounds in solution on the walls of glass vessels used for storage of sea water have been investigated, and a method of prevention evolved.
Structure, Tadpole and Bud Formation in the Ascidian Archidistoma
Authors: Berrill N. J.
Published: May 2009

Archidistoma is a genus created for a species discovered and described briefly by Garstang in 1891 as A. aggregatum. It has been found at different times only in the Plymouth region, the original locality, attached to rock surfaces in a few feet of water. Recently, however, it has been found near Cape Hatteras on the eastern American coast (Van Name, 1945), suggesting either harbour to harbour transportation by ship bottom, or that its inconspicuous appearance has obscured a wide distribution.

This form is of considerable interest as it represents a type less specialized in zooid structure, nature of tadpole, and method of budding than any merosomatous ascidian except the diazonids. Diazonids are oviparous and have the simpler development and tadpole associated with small eggs, although there is a more elaborate branchial sac correlated with the relatively large size of the mature zooid.

Colony

The colony consists of a brownish tough matrix forming a thin encrustation on stones and shells, with individual zooids (a few millimetres long), partly embedded in the test but for the most part extending freely in clumps usually of three or four. Sand grains and round particles adhere to or become buried within the test, making this form the most inconspicuous of ascidians.

Structure of Zooid

The zooid is divisible into a thorax and a long slender abdomen (Fig. 1). There is no postabdomen, nor is there hypertrophy of the ventral test vessels, thereby segregating Archidistoma as a type from that of the synoicids (polyclinids) and the clavelinids respectively.
The Development, Morphology and Budding of the Ascidian Diazona
Authors: Berrill N. J.
Published: May 2009

Diazona is represented in European waters only by Diazona violacea Savigny. It is a compound ascidian forming massive colonies of spectacular size and appearance. In many ways it is the most interesting of all ascidians, for in its adult structure it straddles two commonly accepted orders and in itself is a strong argument against such a division; it is the only oviparous and small egged compound ascidian, two features undoubtedly primitive; and its manner of budding is the simplest and probably is the basic type for the group as a whole. Only fragmentary descriptions of the morphology and reproduction exist, and a more or less complete account of the various stages of the life cycle may be of some value. The family Diazonidae includes, in addition to Diazona itself, the genera Tylobranchion of subantarctic regions, and Rhopalea of Mediterranean and northern waters. In its entirety Diazona appears to link with such divergent forms as Ciona on the one hand and Archidistoma on the other. The fact that Diazona is obtained by dredging in relatively swift offshore waters and lives poorly in an aquarium probably accounts for the existing unsatisfactory state of knowledge of most of its phases. Most of what is known concerns asexual reproduction; and attention has been given, at various times, primarily to the process of regeneration, rather than bud formation, for example by Della Valle (1884), Caullery (1914), Oka (1906) under the name Aphanobranchion, and by Salfi (1926).

The material of the present account was collected at various times in the Plymouth area from the Mewstone and Eddystone grounds.
The Effect of Narcotics on the Endogenous Respiration and Succinate Oxidation in Oyster Muscle
Authors: Humphrey George Frederick
Published: May 2009

The action of the following compounds on homogenates of the adductor muscles ofSaxostrea commercialiswas studied: urethane, phenyl urethane, chloral hydrate, salicylic acid, morphine, caffeine, barbitone, benzoic acid, salicylamide and benzamide.

It was found that, except for 0·05 M urethane, the endogenous oxygen consumption was reduced by all these compounds when present in concentrations ranging from o·001 to 0·05M. The oxidation of succinic acid was partially inhibited by these substances.

These findings are discussed in relation to similar studies on other tissues.
Some new and little-known serpulid polychaetes from the continental slope
Authors: Southward Eve C.
Published: May 2009

Three new species, Paraserpula planorbis, Omphalopoma stellata and Spirorbis sarsiae, are described and three known species are redescribed. A list is given of the Serpulidae found between 100 and 1000 fm (approx.) and an appendix gives a key to genera of the sub-families Serpulinae and Filograninae