bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal Changes in The Phytoplankton During the Year 1951–52 As Indicated by Spectrophotometric Chlorophyll Estimations
Authors: Atkins W. R. G. , Jenkins Pamela G.
Published: May 2009

Chlorophyll from the phytoplankton at station Ei was examined from September 1951 till August 1952, from o to 50 m. The minimum was in June, i-8 mg./m.3, and the maximum 342 in March, both surface samples. The maximum 50 m. sample contained 18-4 mg./m.3 in April. The winter minima were 4-6 and 43, surface and bottom, in November. Converted to water column (70 m.) values, over iog./m.2 is obtained for the wet weight of phytoplankton for September and March, the April maximum and the June minimum being 132 and 015 g./m.2. A comparison with the production obtained from phosphate analyses suggests that the phytoplankton crop each month is rapidly devoured.

Exact proportionality was found between concentration and absorption in a chlorophyll band up to 40 mg./l. and a moderate error up to 80 mg./l. The spectral absorption curves have been given for pure cultures of phytoplankton and for cells filtered out of sea water. The chlorophyll in such extracts, made with 80% acetone, is stable when kept in total darkness.

The collodion disks containing suspended clay arid the algal cells may show a surprising variation in their colour intensity, from dark grey to a very faint tint, even though obtained from sea water about 20 miles from land and over 70 m. in depth. The surface may be far darker than 5, 10 or 15 m. samples.

The botanical composition of the water was studied by allowing the algae to multiply in diffuse light after enriching the water chemically. Eight species of Chlorophyceae, and one species each of the Chrysophyceae and Dinophyceae were recorded. Of the Cryptophyceae one winter sample from 50 m. gave a nearly pure growth of Hemiselmis rufescens Parke. The diatoms Melostra borreri, Nitzschia closterium and Navicula sp. occurred commonly.
Observations on Nucula Turgida Marshall and N. Moorei Winckworth
Authors: Allen J. A.
Published: May 2009

In the course of a study of the British Nuculidae the specific characters of a large number of specimens of N. turgida and N. moorei were re-examined. It was found that no distinction could be made between the two.

Examination of variation in shell colour showed that it was not possible to differentiate into two distinct types. There was a continuous graded seiies from a dark purple-grey in which the basic yellow colour was almost completely masked, through a series with decreasing numbers of purple-grey radiations, to shells in which the markings could not be differentiated as rays, and finally to shells without purple coloration. The purple-grey colour is not necessarily laid down continuously, and it does not develop until the end of the second year. As the shells get older an increasing percentage of them become coloured.

Although the two types of faecal pellets described by Moore were found they could not be associated with the radiate and non-radiate shell types. The five grooved faeces that he claimed were typical of the radiate variety, were found in only three of the fifty-six specimens examined. Only one of them was from a definitely radiate shell.

Shell measurements and growth rates were studied, and no feature was found on which two forms could be separated. Samples show that reproduction takes place at the same time in the rayed and unrayed shells.

As the name N. nitida Sowerby is preoccupied it is suggested that the name N. turgida Marshall should now be used with N. moorei a synonym of it.
Observations in the Skin Pigment and Amoebocytes, and the Occurrence of Phenolases in the Coelomic Fluid ofHolothuria ForskaliDelle Chiaje
Authors: Norman Millott
Published: May 2009

The black body-wall pigment of Holothuria forskali shows the characteristics of melanin.

From histological evidence it appears that the pigment is formed in association with the amoebocytes of the coelomic fluid, which eliminate the pigment in the body wall.

The amoebocytes contain a phenolase system, distinct from the cytochromecytochrome oxidase system, with the properties of tyrosinase.

The relation of these findings to those of a preceding and more complete investigation into melanogenesis in Diadema is discussed.
On Rearing the Hydroids of Certain Medusae, with an Account of the Methods Used
Authors: Rees W.J. , Russell F.S.
Published: May 2009

The development of the hydroid of Amphinema dinema (Peron & Lesueur) has been followed in the laboratory until the production of young medusae and the hydroid identified as Perigonimus serpens Allman.

The hydroid of Amphinema rugosum (Mayer) is described for the first time. It is very similar to P. serpens but more robust.

The hydroid has been reared from Rathkea octopunctata (Sars); it is very minute and the hydranths possess a single whorl of long filiform tentacles/

A small Cuspidella hydroid was reared from Mitrocomella brownei (Kramp).

Certain points in the synonymy of these species are discussed. An account of the methods of rearing used is also given.
On the Size-Changes of Diatoms and their Oceanographic Significance
Authors: Garstang Walter
Published: May 2009

Wimpenny's measurements of Rhizosolenia styliformis (this Journal, Vol. xxi, pp. 29-60,1936) are used to discuss the value of population curves of this species as indicators of water movements and mixture in the North Sea. His alleged correlation between average size and temperature is shown in this case to be untenable. On the coastal banks during 1933 there was a steady increase of size accompanying normal regeneration (bimodal curves), but this was complete by November, and in 1934, with fuller seasonal sampling, the size steadily diminished (all curves unimodal). The population phases on the Dogger and coastal banks were markedly divergent in 1933, but almost identical and intermixed in 1934, indicating a northern (“Atlantic”) influx in 1933 and its absence in 1934. Off the southern edge of the Dogger in the autumn of 1932 a bimodal and unimodal population were variously mixed, the former showing relations to the coastal population of the following spring, the latter probably marking the intrusive northern element which persisted into 1933.
On the Ratio of Nitrogen to Phosphorus in the Sea
Authors: Cooper L. H. N.
Published: May 2009

Data are presented confirming the belief of Harvey and of Redfield that, in broad outline, the ratio of nitrate-nitrogen and of phosphate-phosphorus in the sea and of nitrogen and phosphorus in marine plankton lies within fairly narrow limits. The ratio approaches twenty to one when expressed in terms of milligram-atoms or nine to one by weight. There are however deviations from this broad generalization, but they do not provide a reason for discarding the concept but rather suggest close examination of the causes of the variations.
The Nitrogen Cycle in the Sea
Authors: Cooper L. H. N.
Published: May 2009

The nitrogen cycle in the sea is reviewed as a whole in accordance with the scheme set out in Fig. 1. This summary includes only original matter, since the survey of other work does not admit of further condensation. The metabolism has been discussed of the following sources of nitrogen available to plants in sea water: mono, di and trimethylamine, trimethylamine oxide, urea, amino-acids, ammonia, hyponitrite, nitrite and nitrate. The methylamines will interfere in analyses of ammonia by distillation. Thermodynamic methods have been extensively used. The equilibrium between urea and ammonium cyanate at sea-water concentrations favours the cyanate. In sea water containing 28 mg. ammonia N per cu. m., the equilibrium mixture will contain fifteen times as much cyanate as urea. Hydrolysis of urea is probably purely chemical.
Note on Colloidal Ferric Hydroxide in Sea Water
Authors: Harvey H. W.
Published: May 2009

Colloidal ferric hydroxide flocculates in sea water, the less rapidly the greater the dilution. When formed in the presence of very small quantities of various emulsoids, it does not flocculate on adding to sea water or flocculates less rapidly.
The Influence of the Substratum on the Metamorphosis of Notomastus Larvae
Authors: Wilson Douglas P.
Published: May 2009

The question is raised how pelagic larvae of marine bottom animals reach a type of substratum suitable for adult life. Attention is drawn, to a few forms in which it is not entirely due to chance, since their larvae have been shown to exercise some degree of choice of the soil on which they will settle, and to be capable of preserving the ability to metamorphose for several days at least. These powers, if found to be fairly general in marine bottom animals, would have important bearings on distribution problems. There is supporting evidence from the investigations of Notomastus latericeus Sars here described. The adult is found in mud or muddy sand. Experiments showed that larvae of this species if provided with mud or sand generally metamorphose several days before those kept in clean glass vessels or with clean shell gravel. Mud perhaps induces slightly more rapid settling than sand. After metamorphosis the growth and health of the young worms is generally much better in mud or sand than in gravel or clean glass vessels.
The Metallic Constituents of Marine Gastropods
Authors: McCance R. A. , Shackleton L. R. B.
Published: May 2009

The sodium, potassium, calcium, iron and copper have been determined in sixteen marine gastropods, and the results are briefly discussed. A noteworthy finding is the large amount of potassium, calcium and (or) magnesium which may be present in these animals. Lacuna vincta for example may contain over I-I % of potassium, Archidoris britannica 1-58 % of magnesium per 100 g. of live weight
The Chemical Composition and the Acid Base Balance of Archidoris Britannica
Authors: McCance R. A. , Masters M.
Published: May 2009

The body of Archidoris britannica contains very high concentrations of calcium and magnesium which appear to be combined mostly with CO3 and fluoride. The bulk of these materials are in solid deposits throughout the submucous tissue. Sodium chloride and potassium phosphate account for most of the residual mineral matter.

The mucus secreted by the body has an inorganic composition resembling sea water.

The visceral mass contains only one-tenth as much calcium and magnesium as the body. The predominating bases are potassium and sodium and the acid radicles are essentially chlorides and phosphates.
Variations in the Chemical Composition of Herring
Authors: Lovern John Arnold , Wood Henry
Published: May 2009

A study has been made of the seasonal and other variations in the contents of fat, water and total solids (other than fat) of the flesh of herring. The herring studied were mainly from Scottish and Shetland waters.

Various races of herring, differing anatomically and with different spawning seasons, are considered separately.For each, the observed changes in chemical composition are considered in relation to the season of the year and the feeding and spawning cycles of the fish.

During May and June there is a rapid rise in the fat content of herring (demonstrated for some races and inferred for the rest). This is correlated with a period of intensive feeding. After the attainment of maximal values in July there is a fall to minimal values in April. The rapidity of the fall depends on the spawning season, a relatively high fat content being maintained until spawning takes place. During spawning there is a rapid fall in the fat content, due, in part at least, to cessation of feeding.
Note on the Technique of Making Bacteria-Free Cultures of Marine Diatoms
Authors: Chu S. P.
Published: May 2009

There is a great demand for algal cultures in studying morphology, cytology, ecology, cellular pathology and physiology, identification of species, and biotic interaction, and also in feeding small animals in culture for various studies. It is hoped that the following note may be of some use to those who want to start making pure cultures of marine phytoplankton organisms.
The Estimation in Sea-Water Solutions of Micro-Quantities of Mercury in the Presence of Copper by Means of Dithizone
Authors: Barnes H.
Published: May 2009

1. A brief survey is given of the methods for the estimation of mercury by means of dithizone.

2. The precautions necessary in mercury estimations are outlined and the stability of dithizone in chloroform solutions shown to be satisfactory.

3. Data are presented on the rate of extraction of copper, from sea-water solutions, at low pH values with chloroform and carbon tetrachloride solutions of the reagent. Using the former solvent the rate of extraction of copper is shown to be slow, while mercury is rapidly extracted under the same conditions.

4. The use of potassium cobalticyanide in combination with a chloroform solution of dithizone has enabled a method to be developed which eliminates interference of copper in mercury estimations; with the procedure given, mercury in concentrations of 1 to 55µg/l. may be determined in the presence of copper concentrations up to 69 mg./l.

5. Copper may be determined in the same solution subsequent to the mercury estimation by the use of sodium diethyldithiocarbamate, after the solution has been made alkaline with ammonium hydroxide.
On the Habits ofTurritella CommunisRisso
Authors: Yonge C. M.
Published: May 2009

Tumtella communisis a highly specialized burrower in gravelly mud. Once buried, it moves little in correlation with its apparently exclusively ciliary feeding habit. An inhalant depression in the mud is made by lateral movements of the foot. There is a unique exhalant siphon constituted by two overlapping folds, and through this water and faecal pellets are expelled without disturbing the surrounding mud.
Haddock on the Porcupine Bank, September 1944
Authors: Hickling C. F.
Published: May 2009

1. It is suggested that the population of haddock (Gadus aeglefinus L.) on the Porcupine Bank is largely a self-contained stock.

2. This stock had complete immunity from trawling from December 1940, to September 1944.

3. In 1939 and 1940 there was an abundance of small haddock in this stock, due to the good brood of 1938. In 1944, this brood was still very abundant, and was then joined by the good brood of 1942.

4. These two good broods, growing up immune from fishing mortality, caused the Porcupine Bank to carry, in 1944, the densest stock of haddock ever experienced there.

5. The average number of sclerites in the first zone of the scales of these fish is the highest recorded in any region. It is still high in the second zone, but in the later zones falls below that found in the scales of haddock from other regions.

6. The growth rate was faster, in the first four years of life, than even that of Iceland and Faroe haddock, but in the later years it fell behind these, though still superior to the growth rate of the North Sea haddock.

7. The expectation that this greatly increased stock of haddock, due to the war-time cessation of fishing, would show a slowing in its rate of growth, due to intensified competition for the available food, is not supported by the facts.
The Herring Fisheries at Milford Haven
Authors: Hickling C. F.
Published: May 2009

1. There are three herring fisheries carried on from Milford Haven, namely, a winter drift-net fishery, a spring drift-net fishery, and a trawl fishery in the summer and autumn. These fisheries provide herrings nearly all the year round.

2. There is evidence that the three fisheries are based on the same stock of herrings, and the annual migrations of these herrings, are deduced from statistical data.

3. There is a correlation between the results of the winter drift-net fishery and the following summer and autumn trawl fishery, so that it is possible to make an estimate of the prospects of the important trawled herring fishery some months in advance.

4. There is no evidence that the catches in any one season fluctuate with the moon's phases, but it is found that, in seasons when the moon was full in the last fourteen days of September, the result of the trawl herring fishery has almost always been poor.
Sabella Pavonina Savigny Var. Bicoronata Hornell and the Genus Spirographis Viviani (Polychaeta, Sabellidae)
Authors: Ewer D. W.
Published: May 2009

A variety of Sabella pavonina Sav. described by Hornell as bicoronata has been found at Plymouth. It is characterized by the unequal development of the two sides of the branchial crown. The characters by which Sabella pavonina, its variety bicoronata and Spirographis spallanzanii may be distinguished are described. It is concluded that the genus Spirographis is not valid and that its species should be referred to the genus Sabella which is redefined.
Permeability and Properties of the Membranes Surrounding the Developing Egg Of Homarus Vulgaris
Authors: Yonge C. M.
Published: May 2009

Subjection to a variety of fluids confirms the presence of two non-living membranes roundv the developing eggs of Homarus. It also reveals that the outer membrane has the restricted permeability of cuticle and the inner membrane the free permeability of chitin.

The inner, chitinous membrane bursts when the egg contents swell; the outer membrane stretches, up to 50 % above its initial diameter, when the internal osmotic pressure rises. It also has considerable elasticity.

These properties of the outer membrane enable it to withstand the pressure to which the developing eggs are subjected and also to stretch during the development of the embryo, hence they have,considerable biological significance.The inner, chitinous membrane, which does not stretch, is probably ruptured and absorbed during development.
The Plymouth Offshore Medusa Fauna
Authors: Russell F. S.
Published: May 2009

The composition of the medusa fauna in offshore waters off Plymouth is reviewed. A table is given showing the months in which the different species have been recorded and those months in which they are most abundant. A preliminary list has been drawn up attempting to discriminate between those species which are regularly indigenous off Plymouth and those which are brought from elsewhere by water movements. The results of weekly hauls with the 2 m. stramin ringtrawl during the years 1930-7 inclusive are given. The years 1935, 1936 and 1937 have been noteworthy for the paucity of all species of medusae. Observations on the structure and biology of certain species of medusae are recorded.
On the Seasonal Abundance of Young Fish. V. the Year 1937
Authors: Russell F. S.
Published: May 2009

The present report continues the observations on the seasonal abundance of the pelagic young of teleostean fish in the plankton off Plymouth(Russell, 1937) and gives the results for the year 1937. These results are published in the same form as in previous reports. The dates on which collections were made with the 2-metre stramin ringtrawl are given in Table I and the monthly average catches of the young fish per half-hour haul in Table II. In Fig. 1 is given the curve for the average catches for each fortnight of all young fish, excluding clupeids, and superimposed upon this the corresponding curve for the average catches over the period 1930–1934 inclusive.
The Ecology of the Tamar Estuary II. Under-Water Illumination
Authors: Cooper L. H. N. , Milne A.
Published: May 2009

The Zeiss Pulfrich photometer, with its eight spectral niters covering narrow spectral bands within the visible spectrum, has been used to investigate the penetration of light into an estuary under winter and summer conditions.

Throughout the visible spectrum, extinction coefficients in Hamoaze are always higher, in winter often very much higher, than in the English Channel. In marked contrast to the open sea, red light penetrates as well or better than green, and blue is cut down most rapidly
Turbonilla elegantissima (Montagu), a parasitic opisthobranch
Authors: Fretter Vera
Published: May 2009

Turbonilla elegantissima (Montagu), though one of the larger and more familiar members of the family Pyramidellidae, is known only by the shell and the appearance of the animal when crawling. Forbes & Hanley (1853) and Jeffreys (1867) state that it is common around the British Isles, and that its foreign distribution is from Tromsö to the Mediterranean. In the fauna list of the Marine Biological Association (1931) it is recorded as T. lactea (L.) ‘occasionally under stones, particularly where there is a certain amount of silt’ from low water to a depth of 10 fathoms, and, in the Salcombe estuary, ‘very common on the Zostera south of Pilworthy Pt., (Allen & Todd, 1900)’. Actually this opisthobranch has its own extremely specialized habitat, as do, apparently, all other members of its family (Fretter & Graham, 1949): like them it is an ectoparasite, restricted to the vicinity of its host. Specimens have been collected from the laminarian zone along the south coast of Devon and Cornwall, the largest number from Church Reef, Wembury, where silt and sand around boulders and between shale ledges provide suitable niches for such sedentary worms as Audouinia tentaculata and Amphitrite gracilis. When covered by the tide the tentacles of these polychaetes extend through the silt and sand and spread over the surface of the rocks for a considerable distance, and it is in the vicinity of these tentacles that Turbonilla lurks to suck liquids from them by means of a long proboscis (Fig. 1). Audouinia and Amphitrite were also recorded at Pilworthy Pt., but their association with Turbonilla was then unknown.
Studies in the biology of Talitridae (Crustacea, Amphipoda): effects of atmospheric humidity
Authors: Williamson D. I.
Published: May 2009

Although the high-water Talitridae are normally terrestrial they show little structural modification compared with aquatic amphipods. They have no obvious adaptations to limit water-loss, and their branchial method of respiration is typically aquatic. It was to be expected, therefore, that the evaporating power of the air would play a considerable part in limiting their habitats and determining their habits. The following experiments were made to try and assess the importance of this factor.
Observations on the structure and life history of Autolytus prolifer (O. F. Müller)
Authors: Dales R. Phillips
Published: May 2009

All the specimens of Autolytus prolifer (O. F. Müller) described here were gathered from colonies of the hydroid Obelia flabellata Hincks, growing on pebbles in a shallow creek in the intertidal zone of the Chalkwell mud flats, on the north side of the Thames estuary. The syllid was found to be very plentiful on this hydroid, living in semi-transparent tubes attached to the stem, but was not found elsewhere.

The specimens agree well with previous descriptions of Autolytus prolifer in the number and arrangement of the pharyngeal teeth, and in the chaetae; but some of the other anatomical features show similarities with other species of Autolytus Grube.
On Gammarus zaddachi oceanicus Segerstrale
Authors: Spooner G. M.
Published: May 2009

In a survey of the British species of Gammarus inhabiting estuarine waters (Spooner, 1947), it was found necessary to divide G. zaddachi Sexton into two well-marked morphological forms, with different salinity optima, which in fact behave as distinct species. They were, however, on account of their similarity in important structural features, retained as a single species and named G. z. zaddachi and G. z. salinus respectively. At the time little could be said about a third subspecies, essentially marine in its distribution (but ranging into brackish water), which Segerstråle (1947) independently described as G. z. oceanicus.
OnCallionymus reticulatusC. & V. and its distribution in European seas
Authors: Chang Hsiao-Wei
Published: May 2009

In the course of a study of the age and growth of the Common Dragonet,Callionymus lyraL., a number of specimens of another species ofCallionymushave been collected off Plymouth, differing from bothC. lyraL. andC. maculatusRafinesque, the only two dragonets previously recorded from the Plymouth area (Mar. Biol. Assoc., 1931), and, indeed, from northern European seas (Andersson, 1942; Day, 1880–84; Duncker, Ehrenbaum, Kyle, Mohr & Schnakenbeck, 1929; Jenkins, 1925; Mohr (in Joubin, 1929–38); Le Danois, 1913; Norman, 1935; Otterstrøm, 1912; Poll, 1947; Redeke, 1941; Sænundsson, 1949; Smitt, 1892–95).
A re-examination of Calanus collected off Plymouth
Authors: Russell F. S.
Published: May 2009

Rees (1949) has established significant biological differences between the two forms of the copepod Calanus finmarchicus, namely finmarchicus and helgolandicus. It is therefore necessary that in future research on the behaviour of Calanus the two forms should be distinguished.

I have myself published observations on the vertical distribution of Calanus and on the seasonal changes in size of individuals of the populations of this copepod off Plymouth. In order to know whether my results have been vitiated by the presence of the two forms in the collections, I have re-examined representative samples of adult females, using the fifth leg as the distinguishing character. The collections in question were those made in 1926 which formed the subject of a paper on seasonal changes in vertical distribution and in the sizes of individuals of different generations (Russell, 1928); and those made in 1931 and recorded in my paper on the vertical distribution of Calanus in relation to light intensity (Russell, 1934).
Lymphocystis tumours in the red mullet (Mullus surmuletus L.)
Authors: Alexandrawicz J. S.
Published: May 2009

A specimen of the red mullet (Mullus surmuletus L.), caught in Plymouth waters in October 1949, was found to have tumours projecting externally on the pectoral fins. They were spherical or elliptical in shape, the largest being 20 mm. long. On the suggestion of Mr G. A. Steven some of these outgrowths were cut out and given to the writer for microscopic examination.

When examined fresh they appear to consist of small, spherical, cyst-like bodies of various diameters, but there was no obvious clue as to their nature. After fixing in Bouin and sectioning, they are seen to be composed of cells of various sizes (PI. I, figs. 1–4). It can be seen that these cells lie close to one another, leaving only a little space for the embedding connective tissue which is characterized by the abundance of its own small cells. The blood vessels met with in this tissue contain fish erythrocytes. The whole is covered by stratified squamous epithelium (PI. I, fig. 2).
Notes on Leander squilla L.
Authors: Forster G. R.
Published: May 2009

After the monograph on Leander squilla by Höglund (1943) in Sweden, any further work might seem repetitive; however, at Plymouth some differences in the biology of this species have been noticed, as might be expected from the different climates. It has been thought worth while to record these additional notes on the age and growth, together with records of the food.

De Man (1915) has separated the Scandinavian population as the forma typica from those of Holland, France and Britain, which he grouped into the variety intermedia, the only distinctive character being the length of the carpus of the second leg relative (either longer or shorter) to that of the chela. It is not known whether the two forms intergrade.
The growth-rate of juvenile Asterias rubens L.
Authors: Barnes H. , Powell H. T.
Published: May 2009

The general biology of the common starfish, Asterias rubens L., has recently been studied by Vevers (1949), whose investigations included observations on the growth-rate of this species. His material was collected in the Plymouth area largely by means of an otter trawl, supplemented by a few Agassiz and dredge hauls, and there are therefore few records in his data of the growth-rate of juvenile A. rubens under natural conditions. Vevers also made observations on the growth-rate of individuals kept in laboratory tanks, but again the results apply mainly to fairly large animals. The only other direct observations on growth-rate appear to be those of Bull (1934), who dealt with three small individuals kept in aquarium tanks, while Orton & Fraser (1930) give measurements made on a natural population taken, after one year's growth, from a buoy.
Observations onSphenia binghamiTurton
Authors: Yonge C. M.
Published: May 2009

The family Myidae is represented in British seas by the two large and well-known species,Mya arenariaL. andM. truncataL., which burrow deeply into muddy sand and into stiff mud or clay respectively, and by the much smallerSphenia binghamiTurton. Interest in members of this family of Eulamellibranchia was aroused during 1949 when studying two species which are common along the coast of California, namelyPlatyodon cancellatus(Conrad) andCryptomya californica(Conrad). These differ most interestingly in habitat. The former bores into soft rocks between tide marks, and the latter, although practically devoid of siphons, burrows deep in the mud of tidal estuaries, always in association with burrows made by various large invertebrates. The species most usually involved isCallianassa californiensis, a large anomuran prawn (McGinitie, 1935). The almost sessile siphons open into the sides of the burrows. Accounts of both species have been prepared for publication in California.
Studies onChaetopterus variopedatus(Renier). II. Nervous control of light production
Authors: Nicol J. A. Colin
Published: May 2009

The production or emission of light is under nervous control in many marine animals that have a differentiated nervous system. The nature of this control is a field of neuro-effector physiology that has been little explored, but one which could advance considerably our knowledge of the behaviour and functioning of luminescent marine animals. Nervous control of luminescence is achieved in diverse ways in different animals, namely, by squeezing forth a pre-formed secretion through muscular contraction, as appears to take place inCypridina; by exposing a continuously luminescent organ through rotation or by movement of shutters, as in the teleostsPhotoblepharonandAnomalops; by initiating cellular changes that lead to intracellular luminescence, for example in the photophores of the shrimpAcanthephyra debilis; and by directly activating light gland cells to secrete. The last method is a special example of nervous regulation of glandular secretion, and is the process occurring in the polychaeteChaetopterus(Dahlgren, 1916; Harvey, 1920, 1940).
Processes of enrichment of surface water with nutrients due to strong winds blowing on to a continental slope
Authors: Cooper L. H. N.
Published: May 2009

Biological and physical evidence suggests that the area south-west of Ireland is one of loss from the Celtic Sea. In winter the shelf water there may cascade to 400 m. or even deeper (Cooper & Vaux, 1949). All the evidence suggests that new water enters the Celtic Sea and English Channel over the continental slope between Ushant and the Sole submarine promontory 250 miles to the west. No evidence exists that the Atlantic surface waters are ever rich enough to account for the enrichment of the English Channel observed in the nineteen-twenties. Although the existence then of sufficiently rich oceanic surface water cannot be excluded, it is much more probable that the enrichment was brought about by some form of upwelling. The cause of this is thought to be composite. Only a few times in a century may the component phenomena work together to produce the maximum effect. Each component needs separate study.
The physical and chemical oceanography of the waters bathing the continental slope of the Celtic Sea
Authors: Cooper L. H. N.
Published: May 2009

Knowledge of the hydrography of the English Channel and Celtic Sea is needed as a background for the life histories of the mackerel, pilchard and herring and, indeed, of every organism living within range of the Plymouth Laboratory. Such knowledge can never be fully attained until we know more of the exchanges with the deep Atlantic Ocean which take place 200–300 miles to the south-west and west over the continental slope. Moreover, at the slope we shall need to know not only what waters move in and out but what move up and down. Long ago Storrow (1925), and no doubt others, saw clearly some of the problems here to be discussed, but they were unable to bring factual evidence to bear. A critical reconstruction of the considerable but fragmentary observations in the neighbourhood of the continental slope of the Celtic Sea will be presented here and supplemented by observations made in 1950 with the generous co-operation of the vessels of the National Institute of Oceanography (Discovery Committee) and in 1948 by H.M. Surveying Ship Dalrymple. Though many of the conclusions remain tentative, it should now be easier to design observational work at sea to test specific hypotheses at the right time and place by the methods of experimental oceanography. The numerical results in 1950 will be published by the Conseil International pour l'Exploration de la Mer.
Classified List of Publications. Volumes XVI to XXIX of the Journal of the Marine Biological Association and other Publications Recording the Results of Researches Carried out at the Plymouth Laboratory from 1928 to 1950
Authors: F. S. R.
Published: May 2009

It is now 25 years since I produced the ‘List of Publications’ in Volume XV of this Journal, which brought the earlier 1913 list up to date.

Much has been published since then and there is an evident need for a supplementary list. Accordingly, Mr N. A. Holme has prepared the following classified list of the contents of Volumes XVI to XXIX of the Journal of the Marine Biological Association and of other pubhcations recording the results of researches carried out at the Plymouth laboratory from 1928–1950.
Spectral composition of the light of the Lantern-fish,Myctophum punctatum
Authors: Nicol J. A. C.
Published: May 2009

Relative spectral emission curves are available for the lights of many invertebrate animals, but none exists for fish. It seems likely that many bony fish use their photophores to signal to one another. Information about the spectral composition of fish luminescence is desirable to permit comparisons with the spectral sensitivities of fish eyes, to enable calculations to be made of luminous intensities, and to allow estimates to be made of the rate of attenuation of such lights in sea water. To further these ends, measurements were made of the spectral composition of the luminescence of the lantern-fish,Myctophum punctatum.
A check-list of British Marine Halacaridae (Acari), with notes on two species of the sub-family Rhombognathinae
Authors: Green J.
Published: May 2009

Mites of the family Halacaridae are abundant on the sea shore, and in the sea down to considerable depths. Their identification is not an easy matter; there is no one account which can be used to identify all the British species, and the use of any one of the general accounts of European species, such as André (1946) or Viets (1936), by itself might easily lead to misidentification.

The purpose of the present list is to record the species which have so far been found around the British Isles, and to indicate sources of reliable descriptions of each species. A list of the British species of this family was given in a general list of British Acari by Turk (1953), and this has provided the starting point for the present list; no reference to occurrence in Britain before Turk's list is given, apart from one by Halbert (1920) which was left out by Turk. Twelve of the thirty-six species in the present list were not recorded by Turk. One species, Halacarus zosterae (Fab.), recorded by Turk has been omitted because the original description is quite inadequate to decide even which genus the creature should belong to. Eight species are known from British fresh water; these have not been included in the present list.
Defensive adaptations in opisthobranchs
Authors: Thompson T. E.
Published: May 2009

This is the third and concluding part of an investigation into defensive mechanisms in some British gastropods. The first part (Thompson & Slinn, 1959) dealt with a single species of opisthobranch,Pleurobranchus membranaceus, which proved able to secrete a strong acid if disturbed. The second part (Thompson, 1960 a) recorded further instances of acid secretion. The present paper describes the remainder of my work on opisthobranchs.
On the biology of Calanus finamarchicus XI. Observations on vertical migration especially in female Calanus
Authors: Marshall S. M. , Orr A. P.
Published: May 2009

A number of different factors have been shown to affect the vertical migration of the zooplankton, among them changes in light intensity, temperature, salinity and the presence of food (see Russell, 1927; Hardy & Paton, 1947; Cushing, 1951; Bainbridge, 1953; Harris, 1953; Moore, 1958; Banse, 1959). The object of the present study was to find out whether in female Calanus there was any relation between vertical migration and the degree of ripeness.

When Calanus were taken by tow-nettings near the laboratory it was noticed that the percentage of adult females in the ripe condition was generally greater in hauls made close to the surface than in those from deep water. For example in the spring of 1953 a series of hauls was made near the surface in Fairlie Channel where the maximum depth is about 40 m, and at 60–80 m off Garroch Head a few miles away where the depth is 115 m. Throughout the period of examination there was a much higher percentage of ripe females in the shallow than in the deep hauls (Table 1, Fig. 1). The deep hauls show the progressive ripening of the females during the spring reaching a peak in percentage ripe which coincides with the spring diatom increase in the middle of March. It also coincides with the maximum number of eggs produced by laying females. In shallow water the sequence is not so obvious because of the high percentage of ripe females at the surface most of the time.
Some theorems and procedures in shallow-water oceanography applied to the Celtic Sea
Authors: Cooper L. H. N.
Published: May 2009

Twenty years ago the Plymouth Laboratory investigated the spawning of mackerel and pilchard in the Celtic Sea. The physical background for their work, which the late Dr G. A. Steven and Mr P. G. Corbin sought, could not be provided since waters with similar temperatures and salinities evidently had very different physical and biological histories.
The fecundity of plaice from the south and west coasts of Ireland
Authors: Bagenal T. B.
Published: May 2009

This paper is the fifth in a series dealing with the fecundity of flatfish (Bagenal, 1957a, b; 1958, i960), and is concerned with the numbers of eggs in, the roes of ripening female plaice Pleuronectes platessa L. caught off the south and west coasts of Ireland during November and December 1958. The fish were obtained from Wexford, Ballycotton, Schull, Dingle, Galway and Killybegs (Fig. 1).
The motile (Crystallolithus hyalinus Gaarder & Markali) and non-motile phases in the life history of Coccolithus pelagicus (Wallich) Schiller
Authors: Parke Mary , Adams Irene
Published: May 2009

A new coccolithophorid, Crystallolitkus hyalinus, was described with the help of electron micrographs by Gaarder & Markali in 1956 from preserved material in which the cells lacked the appendages. From temporary cultures set up from our September 1957 sea-water samples a coccolithophorid was isolated which appeared, under the light microscope, very similar to this newly described coccolithophorid but which possessed, as does the genus Chrysochromulina, a coning haptonema in addition to the two flagella. Electron micrographs, taken for us by Prof. I. Manton, have shown that the holococcoliths from our organism are identical in structure with those from the Crystallolithus hyalinus (cf. PL I, and Gaarder and Markali, 1956, pi. I).
Further observations on small green flagellates with special reference to possible relatives of Chromulina pusilla Butcher
Authors: Manton I. , Parke M.
Published: May 2009

The observations to be recorded here have been carried out primarily for the purpose of clarifying the taxonomic position and naming of the small organism previously known as Chromulina pusilla Butcher. This had been shown (Manton, 1959a) to possess the pigments and fine structure appropriate to a position in or near the Chlorophyceae but quite inappropriate to a position within the Chrysophyceae to which the genus Chromulina properly belongs. Before selecting a new generic name, it was highly desirable to make some comparative electron microscopical observations on authentically named material of appropriate kinds since the fallibility of the light microscope for study of organisms of this order of size (1–3µ) had been all too clearly exposed. A search was therefore made for a representative or representatives of the only genus of green flagellates known to us from the literature to possess a single posteriorly directed flagellum, namely Pedinomonas.
Studies on Marine Algae of the British Isles:Ceramium shuttleworthianum(Kütz.) Silva
Authors: Dixon Peter S.
Published: May 2009

The species was first distinguished by Carmichael, asCeramium acanthonotum,in his unpublishedAlgae Appinensis,the manuscript of which is now preserved at the Herbarium of the Royal Botanic Gardens, Kew. Harvey (in Hooker, 1833), in publishing Carmichael's description, regarded the species merely as a variety ofC. ciliatum.Agardh (1844) raised the variety to specific status, and it is asC. acanthonotumthat the species has been known generally. Kiitzing (1841),1in a revision of the genusCeramium,had described the entity independently asAcanthoceras shuttleworthianum;the specific epithetshuttleworthianumhas priority overacanthonotum[see Article 60 of the International Code of Botanical Nomenclature (Lanjouw, 1956)]. The priority of the epithetshuttleworthianumwas indicated, independently, by both Silva (1959) and Dixon (1959); of the two publications, that by Silva is the earlier.
A muscle receptor organ in Eledone cirrhosa
Authors: Alexandrowicz J. S.
Published: May 2009

Nerve cells evidently of a sensory nature have been found in Eledone cirrhosa on the inside of the mantle in a limited area near the stellate ganglion. The cells, whose number on each side of the body is no less than 50, are in close association with a special thin layer of muscles, and obviously must have a proprioceptive function. The whole complex can therefore be regarded as a muscle receptor which from its situation may be termed the substellar organ.

The muscular component of this organ consists of fibres arranged in very flat bundles which, anastomosing with one another, form a plexiform layer situated under the stellate ganglion and the stellar nerves. It may be called substellar muscle plexus (ss-plexus for short). The area occupied by it, which is roughly semicircular in shape, extends to the points where the stellar nerves penetrate the muscles or a little beyond these points (Text-fig. 1). The ss-plexus, although situated close to thecompact muscle of the mantle, does not appear to have anatomical relation with the latter; it has, however, direct connexions with strands of muscle fibres reaching theplexus from two directions. The fibres coming from the medianside belong to the muscle attaching the mantle to the visceral sac in which runs the pallial nerve (or mantle connective). This muscle, called lateral pallial adductor (see Tippmar, 1913) istwisted in such a way that its bundles coming from the anterior region of the visceral sac insert into the mantle behind the stellate ganglion, and those originating posteriorly insert in front of it.
On the biology of Crangon allmani Kinahan in Northumberland Waters
Authors: Allen J. A.
Published: May 2009

Since November 1954, the natant epifauna in depths greater than 20 fm. off the Northumberland coast has been sampled at a number of stations with the object of obtaining information on its constitution and fluctuations. The survey has been limited to those species caught with a net of f in. mesh. Seasonal and yearly fluctuations in this fauna must have a considerable effect on the inshore fisheries, for these animals form an important part of the food of marketable fish, yet, this fauna has never beensubject to a detailed analysis over a number of years.

Samples have been taken as regularly as weather and other laboratory commitments have allowed. In practice this has been of the order of one sample each month, butat times sampling has been more frequent than this (Table 8). Although sampling is being continued, the material collected so far gives much information on the epifaunaas a whole and the biology of the constituent natant Crustacea and Mollusca.
The identity of the ascidians Styela mammiculata Carlisle and S. clava Herdman
Authors: Millar R. H.
Published: May 2009

Carlisle (1954) described Styela mammiculata, a new species of stalked ascidian from the Plymouth area, and suggested that it had been brought into British waters, probably with oysters. Its recent discovery on other parts of the south coast of England (Houghton & Millar, 1960) supports the idea that it is an introduced species which is now spreading through a favourable environment. It is well, therefore, to consider whether this may not be a species known from another part of the world. Tokioka (1955) examined one of Carlisle's specimens and suggested that it fell within the range of variation of S. clava Herdman. As many specimens of S.mammiculata are now available, a more extensive comparison has been made and is reported in this paper.
Studies on luminescence. On the subocular light-organs of stomiatoid fishes
Authors: Nicol J. A. C.
Published: May 2009

Many stomiatoid fishes possess a peculiar light-organ below and behind the eye, as well as other kinds of photophores. This light-organ, of diagnostic importance, is termed the subocular, postocular or cheek-organ. Stomiatoid fishes, suborder Stomiatoidei, form a suborder of the Isospondyli. Subocularorgans are found in the following groups:
Amphibdellid (monogenean) parasites of electric rays (Torpedinidae)
Authors: Llewellyn J.
Published: May 2009

Electric rays (Torpedinidae) are known to harbour on their gills certain monogenean parasites (Amphibdella spp. and Amphibdelloides spp.) whose taxonomy is in a very confused state. Muchof this confusion has centred around a single morphological feature: a ‘transverse bar’ has been variously held to be present or absent from the adhesive apparatus, or sometimes two such bars have been stated to be present. Among those who have regarded the trans-verse bar as having taxonomic importance, Price (1937) recognized two genera of amphibdellids distinguishable by the presence or absence of the bar, but Palombi (1949) and Bychowsky (1957) believe that the bar may be present in young specimens but absent or inconspicuous in older specimens. No-one has investigated the function of thistransverse bar, or, indeed, any functional aspect of the adhesive apparatus. Again little attention has been paid in taxonomy to the genitalia or host specificity, or, in spite of a record of an amphibdellid from the heart of its host, to micro-habitat.
The effects of salinity on the developing eggs and larvae of the herring
Authors: Holliday F. G. T. , Blaxter J. H. S.
Published: May 2009

The herring(Clupea harengusL.) deposits its eggs in the coastal waters around the North Atlantic Ocean, North Sea, and Baltic Sea. The salinity on the spawning grounds may vary from about 35%0to 5%0. For instance, Brandhorst (1959) reports that successful spawning tookplace in the Kiel Canal in salinities down to 5%0, and Ford (1929) records that ripe herring have been found in the Tamar estuary. In a series of experiments Ford found that the eggs of herring could be successfully fertilized and incubated even in a salinity of 4·8%0. McMynn & Hoar (1953) investigated the effect of salinity on the development of the Pacific herringC.pallasiiand found it had a wide tolerance, the lower level being somewhere between o and 6‰