bluuebunny/crossref_metadata_2025_split huggingface dataset:
On Some Small Ianthina Janthina (L.) Stranded on the Isles of Scilly, 1957
Authors: Wilson Douglas P. 
Published: May 2009

In an earlier paper (Wilson & Wilson, 1956) there was described a large-scale stranding, on the shores of Cornwall and Devon in 1954, of the pelagic gastropod Ianthina janthina (L.). Most of the shells then collected were broken, but thirty-six were entire and measurements of these showed that, in spite of considerable variation in the proportion of width to height, the width is proportionately greater in young than in old shells. None of the 1954 shells was less than half an inch high, the majority being considerably higher. Two shells stranded at Sennen several years before, and the figure of one in a paper by Fowler (1947, as I. planispirata Adams & Reeve) were the only specimens less than half-an-inch high available for comparison with the larger ones. The measurements of these agreed with the general conclusion that as the shell grows it becomes proportionately less wide. In the past these variations in shell shape have been responsible for the erection of a number of different species. In order to establish the conclusion firmly it was desirable to examine a collection of young shells.On 31 March 1957 Mrs M. Hicks wrote from St Agnes, Isles of Scilly, to say that on that day her husband had found eight small Ianthina, six of which had stranded alive on the afternoon's tide, the other two, one of them alive, earlier. Subsequently more were collected. On 8 April Miss Deborah Hicks (age 9) picked up about 130, some of them living, some apparently not.
The Modes of Action of Toxic Agents III. Mercuric Chloride and N-Amylmercuric Chloride on Crustaceans
Authors: Corner E. D. S. , Rigler F. H. 
Published: May 2009

Experiments have been carried out with 203Hg-labelled n-amylmercuric chloride (n-C5H11HgCl) and mercuric chloride (HgCl2) to study the modes of action of these compounds as poisons to some crustaceans.Differences between the susceptibilities of Artemia salina and Elminius modestus to the poisons do not reflect differences between the quantities of these compounds which the animals can tolerate in their tissues, but are directly related to the rates at which the poisons are accumulated. Thus, experiments with either species have shown that Hg is taken up at approximately the same rate from equitoxic solutions of the two poisons; and the rates at which Hg is accumulated by the two species from equitoxic solutions of either poison are of the same order.Experiments with reduced glutathione have given results consistent with the view that most of the Hg taken up by either species penetrates into the tissues of the test animals and does not act simply by becoming attached to their surfaces.Direct evidence of the penetration of Hg compounds into a crustacean has
been obtained from experiments with Leander serratus. Considerable amounts of Hg have been detected in the antennary glands.
Observations on Cochlodesma Praetenue (Pulteney) [Eulamellibranchia]
Authors: Allen J. A. 
Published: May 2009

Cochlodesma praetenue is well adapted for a sedentary life in sheltered conditions in soft substrata at low-water mark to a depth of 60 fathoms.The habits, morphology and ciliary feeding and cleansing mechanisms are described and compared with those of members of the related families Thraciidae, Pandoridae and Lyonsiidae.The complex ligament is described. The mantle edges are extensively fused. The detailed structure of the siphons is described and related to their function of laying down mucus-lined inhalant and exhalant tubes.The morphology and ciliary currents of the stomach show modifications similar to those previously described for Pandora. These modifications involve the extent of the major typhlosole and the replacement of an intestinal groove by lateral rejection grooves.Analysis of three large samples shows that Cochlodesma from the Northumberland coast live for a maximum of 5 years. These animals become mature in their third year, spawning in early November.
The Behaviour of Littorina Littorea (L.) Under Natural Conditions and its Relation to Position on the Shore
Authors: Newell G. E. 
Published: May 2009

On the flat shore at Whitstable the population of common winkles is distributed appreciably at random over a variety of substrata ranging from wooden groynes, through shingle to muddy sand, between tidal levels corresponding to H.W.N.-E.L.W.S. but with a maximum density near M.T.L., although aggregations tend to occur in wetter situations and where planking joins vertical groyne posts.Observations on winkles marked with a dab of paint of distinctive colour
show that they tend to remain in approximately the same position for many weeks.For most of each tidal period winkles remain settled in situations such as stones or groynes, which provide good holding ground, but as the tide recedes or the incoming tide reaches them, they become activated to crawl, feeding meanwhile. These feeding migrations are recorded in the sand by roughly U-shaped tracks and can be seen under favourable circumstances as similar tracks in the vertical plane for winkles on groynes. By such excursions the animals are enabled to move, feed and return to approximately the place from which they started and this serves to explain how they maintain their station on the shore.When settled on vertical surfaces, winkles always orientate with the head uppermost, when the foot may be withdrawn and the animal become attached by a film of dried mucus.When crawling the eyes are exposed and the tentacles bend to test the substratum, but only that part of the tentacle distal to the eye bends so that the optical axis of the eye maintains a constant angle to the body axis.
Sabellaria Colonies At Duckpool, North Cornwall, 1961–1970
Authors: Wilson Douglas P. 
Published: May 2009

Between May 1961 and November 1970 almost monthly visits were made to Duckpool, an exposed shore on the north coast of Cornwall, where Sabellaria alveolata (L.) is the dominant organism on low-level rocks uncovered only by spring tides. Massive colonies several feet across and up to some 2 ft thick, formed mainly of shell particles cemented together by the worms, as well as many smaller colonies and single tubes, here reach their maximum development in south-west England.Selected sites and colonies were photographed and some measured at frequent intervals over long periods of time. comparative studies of long series of colour transparencies examined closely with a binocular microscope have proved invaluable in elucidating the manner and rate of growth of varied types of colonies, their lengths of life and the manner of their ultimate destruction. Detailed histories of these selected colonies are given in this paper and reveal much that was previously unknown or only guessed.A short spawning period every year in July initiates each new generation. Experimental work, already published, had shown that individuals develop at different rates, the final stage with ability to settle being reached at any time from 6 weeks to 6 or more months, and when reached the ability can be retained for some weeks. This accords with observations on the shore, where settlement takes place in any month between late August and the following early May, or rarely June. The intensity of settlement varies enormously from year to year, there being none in some years, with slight or moderate or heavy settlements in others.
The biology of Nicothoë astaci Audouin and Milne Edwards
Authors: Mason James 
Published: May 2009

Nicothoë astaci is a choniostomatid copepod (Gurney, 1929) parasitic on the gills of the lobster, Homarus vulgaris Milne Edwards. In view of the possible effect of Nicothoë on the lobster, which is of considerable commercial importance in Scotland, a programme of work was instituted on the biology of the parasite.Nicothoë attaches itself by means of its suctorial mouth to a gill filament of the lobster, and the wall of the filament is pierced by the sharp, styliform mandibles. The host's blood is sucked by means of a muscular gullet leading to the stomach. Nicothoë often occurs in groups, especially near the bases of the gills. The adult parasite is incapable of any movement except a slight lateral displacement of the abdomen and, once attached, probably remains in the same position throughout its life. Little is known of the life cycle, and all individuals so far definitely recognized have been females.
The larval and post-larval stages of Gymnammodytes semisquamatus (Jourdain)
Authors: Cameron Jane 
Published: May 2009

In the course of investigations (1955–8) into the Ammodytidae of the south of the Isle of Man, five species of sand eel were identified: Gymnammodytes semisquamatus (Jourdain, 1879), the Smooth Sand Eel; Ammodytes lanceolatus Lesauvage, 1825, the Greater Sand Eel; A. immaculatus Corbin, 1950; A. tobianus Linnaeus, 1758 ( = A. lancea Cuvier), the Lesser Sand Eel; A. marinus Raitt, 1934.Five different types of post-larvae were obtained and investigated. Four of these were the post-larvae of the above four Ammodytes species and the fifth type proved to be Gymnammodytes semisquamatus.
Experiments on some effects of certain environmental factors on Gracilaria verrucosa (Hudson) Papenfuss
Authors: Jones W. Eifion 
Published: May 2009

At an early stage of an autecological study of Gracilaria verrucosa (Hudson) Papenfuss it seemed possible that the best growth of the plants occurred in places, such as the Achill Sound and the Church Island Channel in the Menai Straits, where, in the absence of heavy wave action, strong currents flowed over the plants. Experiments were carried out, in the sea, to investigate the effect of currents on the growth rate; the apparatus used and described here would probably be suitable for the investigation of current effects on other sedentary marine organisms.These experiments also led to some observations on the effects of illumination on the pigmentation and growth rate of the plants which were supplemented by laboratory experiments. High intensity illumination in the laboratory also demonstrated positive phototropism in the plant.
Comparison between three Methods of measuring underwater illumination in coastal waters
Authors: Cooper L. H. N. 
Published: May 2009

SUMMARYThree methods of determining extinction coefficients of light in sea water have been compared: (a) on water samples contained in a Pulfrich photometer, (b) from brightness profiles determined by aerial photographic survey, and (c) by photoelectric underwater measurements. The ratios of extinction coefficients for green and red light as determined in 1945 by the Pulfrich photometer and by the brightness profile method are given in Table 3, columns 9 and 10. For green light the ratio is about i-8 and for red light 1-3.The departure from unity is attributed to the geometry within a confined tube and, within the Pulfrich measuring assembly, of light rays scattered forward by particles present in sea-water samples. In the following year, 1946, comparisons were made between the Pulfrich method and the submarine photometric method of Atkins and Poole. The discrepancies were variable and even larger, the ratios averaging 3-8 for green light and 2-0 for red light.The brightness profile and submarine photometric methods have not been directly compared, but, by comparing the two sets of determinations against the Pulfrich photometer, it would seem that extinction coefficients determined with the brightness profile method are about 2-2 times those determined by the submarine photometer in green light and about 15 times in red light.
The behaviour of polydora ciliata (Johnst.). Tube-building and burrowing
Authors: Dorsett D. A. 
Published: May 2009

SUMMARYPolydora ciliata is a spionid polychaete found below mid-tidal level burrowing in a variety of rocks all of which contain calcium carbonate. It can also penetrate some non-calcareous materials such as rotten wood. It excavates a U-shaped burrow which it lines with a tube composed of mucoprotein and sand grains. This tube has a smooth inner lining of mucoprotein. Both food and tube-building material is collected by the palps and it is suggested that discrimination is made chiefly on size of the particle. Selection is made between the limits of 003-0-05 mm, the smaller particles passing down the gut whilst the larger are used in construction of the tube. A particle selection mechanism is suggested. The function of the segmental mucus glands is to provide the inner lining of the tube.The problem of chemical penetration of rocks by animals is discussed. P. ciliata uses both mechanical and chemical methods. No acid has been identified, and the use of a sequestering or chelating agent linked with the biochemistry of mucus is suggested.
The ultra-violet absorption of sea water
Authors: Armstrong F. A. J. , Boalch G. T. 
Published: May 2009

SUMMARYMeasurements of the ultra-violet absorption spectra between 200 and 400 mix, have been made with a spectrophotometer. At short wave-lengths natural sea water has double the absorbancy of artificial sea water. The difference in samples from shallow depths is ascribed to organic material, of which part may be the Gelbstoff of Kalle. Regional variations have been found, coastal waters having higher U.V. absorptions. A small seasonal effect with an increase in absorbancy in summer in the English Channel has been seen. In deep Atlantic water increased absorption below 235 m/x may be due to its high nitrate concentration. At longer wave-lengths absorbancies were less than in surface waters. Measurements of U.V. absorption may supplement other physical methods of characterizing water masses.
Observations onEcheneibothrium maculatum(Cestoda: Tetraphyllidea)
Authors: Williams H. Harford 
Published: May 2009

SUMMARYForty-five specimens ofRaia montaguiFowler were recently examined for their cestode parasites and twenty-seven of these containedEcheneibothrium maculatumWoodland, 1927, a species which has not been found in any other elasmobranch. In addition to its well-marked specificity to this host there is an indication thatE. maculatumprefers to attach itself to a particular region of the intestine. The cestode was not recognized as a valid species by Baylis (1948) and is included as a synonym ofE. dubiumVan Beneden 1858 in the Plymouth Fauna List (Marine Biological Association, 1957), but Williams (1958a) and Euzet (1959) were not in agreement with these views. For this and other reasons a re-investigation ofE. maculatumwas undertaken.Materials And MethodsThe specimens ofRaia montaguiwere trawled off Plymouth by R. V. ‘Sula’ during August and September, 1958 and 1959. The rays were kept alive in the large sea-water tanks outside the laboratory and were examined for their cestode parasites as soon as possible, usually within a period of 24 h. This was found to be necessary because elasmobranchs kept alive under these conditions, presumably without food, have shown a strong tendency to lose their intestinal parasites. It is hoped to discuss this phenomenon more fully elsewhere.The intestines of some of the fishes were removed from the freshly killed hosts and opened with scissors following the course indicated by the arrowed broken lines in Text-figure 2. Having been opened in this manner they could be quickly examined as a flat piece of tissue for their cestode parasites (Text-fig. 3).
On the failure of the Plymouth herring fishery
Authors: Cushing D. H. 
Published: May 2009

SUMMARYAn hypothesis has been erected to account for the failure of the Plymouth herring fishery and the associated biological events in the early thirties. It was found that the quantity of winter phosphorus was inversely related to the quantity of pilchard eggs 6 months earlier and directly to the quantity of herring recruits a year earlier. It is thought that the differences in quantities of winter phosphorus have represented differences in numbers of 6-month-old pilchard larvae; the winter phosphorus provides the link between herring recruitment and numbers of pilchard eggs, suggesting that there has been competition between the herring and pilchard stocks, in their juvenile stages. Thus it is suggested that the Plymouth herring fishery failed in competition with the pilchard stock and that the other biological events which took place in the early thirties were a consequence of this postulated competitive change.
Persistent, vertical-migration rhythms in benthic microflora: I. The effect of light and temperature on the rhythmic behaviour of Euglena obtusa
Authors: Palmer John D. , Round Frank E. 
Published: May 2009

During daytime low tides on the River Avon at Bristol, England, the exposed river banks become a deep green colour owing to the presence of enormous numbers of Euglena obtusa which emerge out of the black mud. Cell densities on the surface surpass 105 cells/cm2. Before the tide returns to cover the area, the cells re-burrow back into the mud and remain there during high tide and throughout the night.The cells can be prevented from emerging on to the surface mud at low tide by artificially darkening the area with an opaque covering just as the tide recedes. Cells which are already on the surface can be made to re-burrow by similarly placing them in darkness.The vertical-migration rhythm will persist in the laboratory in constant illumi-nation, constant temperature, and away from the influence of the tide, for nearly one month. In these conditions the rhythm is diurnal, rather than tidal. The rhythm will not persist in constant darkness.Because of the excessive turbidity of Avon water, each high tide imposes a period of darkness on the surface mud. It is thought that these dark periods transform the fundamental diurnal rhythm into one of tidal frequency.Various intensities of constant illumination alter the form and amplitude of the rhythm, but not the period. The stable nature of the period, under different light intensities, is thought to be due to a unique, self-stabilizing feature inherent in this type of rhythm.The rhythm is inhibited at 2° C. Between 5° and 15° C, the period of the rhythm is virtually unaltered; it remains approximately 24 h in length.
Polarization of light reflected from the silvery exterior of the bleak,Alburnus alburnus
Authors: Denton E. J. , Nicol J. A. C. 
Published: May 2009

A method is described for measuring, for various angles of incidence, the polarization produced by reflexions from natural surfaces.This method was tested by measurements on matallic surfaces of known properties and then used to study reflexions from the silvery gill cover of the bleakAlburnus alburnus(L.).Althouth the reflecting surfaces of the gill cover are crystals of a dielectric guanine, there is no polarizing angle, and the reflecting properties of the gill cover resemble those of a sputtered aluminium mirrorThe biological significance of these results is briefly discussed.
Reflexion of light by external surfaces of the herring, Clupea harengus
Authors: Denton E. J. , Nicol J. A. C. 
Published: May 2009

The orientations of the reflecting layers in the external surfaces of the herring have been found both by light-measurements on the fresh fish and by histological studies on preserved specimens.The reflecting platelets which lie under the scales are orientated, with respect to the surface of the fish, in a similar way to the platelets found in the bleak and described earlier by Demon & Nicol (1965). However, on the curved dorsum of the fish, although the reflecting platelets are much more perpendicular to the sea surface than the scales on which they lie, these platelets are still inclined some 20° to the perpendicular. It is shown that, in this region, the fish reflects the fraction of the light striking the platelets which is sufficient to match the background against which the fish is seen. The platelets on the curved dorsum have the property of reflecting green light well if it falls obliquely on them but reflecting it poorly when it strikes them at angles close to normal incidence. On the broad flank of the herring the scales have reflecting platelets under most of their surfaces, and the individual scale has several distinctly coloured regions. When we look at any particular region of the flank of an intact fish we are always looking at several overlapping layers differing greatly from one another in their spectral reflecting properties.It is the combination of the reflexions of several layers which gives the very bright silvery reflexions of the intact fish. A system of overlapping scales of this kind is needed even to reflect one waveband of light well over a wide range of angles of incidence.
A comparison of plant production estimates using14C and phosphate data
Authors: Steele John H. 
Published: May 2009

Organic production in the sea can be measured by studying the changes in phosphate throughout the water column. Results obtained by this method are compared with estimates of carbon uptake using 14C made on the Fladen Ground during 1955 and 1956. There is good general agreement between the two methods but some differences in the vertical distribution.The results are also used to calculate filtering rates of phytoplankton and sinking rates of zooplankton, and to compare observed and predicted vertical distributions of chlorophyll.
On a new species of scyphomedusa,Atolla vanhoffenin.sp.
Authors: Russell F. S. 
Published: May 2009

In 1902 Ernst Vanhöffen drew attention to the occurrence of eight dark pigment spots inAtollawhich he thought might be excretory organs.It is shown that these spots are a specific character occurring only in some specimens, and medusae with this character have been namedAtolla vanhöffenin.sp. This species can now be distinguished fromA. wyvilleiby other characters.
The biology of a commensal copepod,Ascidicola roseaThorell, in the ascidianCorella parallelogramma(Müller)
Authors: Gotto R. V. 
Published: May 2009

A study has been made of the feeding activities and reproductive behaviour of the copepodAscidicola roseawithin one of its ascidian hosts,Corella parallelogramma.Ascidicola roseafeeds on particles which it removes from the food string as the latter is passing through the oesophagus of the host. When active feeding is not taking place, the copepod remains quiescent in the oesophageal bend. An inverted position within the oesophagus is sometimes adopted; this is generally associated with a meagre development of the food string. Certain peculiar structural features—notably the spinous pad on the penultimate segment and the long endopodal setae—are considered to be adaptations which assist the copepod while clinging to the food string.The eggs ofA. roseaare deposited in the ascidian's stomach and the nauplii pass through the host's alimentary canal still enveloped by the inner egg membrane. On reaching the anus, hatching takes place and the nauplii are expelled from the atrial siphon. There are four naupliar and two copepodid stages. Free-swimming life lasts for about 6 days.
The adaptations of Lasaea rubra (Montagu), a small intertidal lamellibranch
Authors: Morton J. E. , Boney A. D. , Corner E. D. S. 
Published: May 2009

A study has been made of the ecology of the small intertidal lamellibranch Lasaea rubra at various tidal levels at Plymouth and Wembury. In addition, experiments have been carried out to investigate physiological and behavioural differences arising from varying amounts of submersion at different tidal levels, and the following findings have been made.During the first hour after their submersion by sea water, L. rubra from high up the shore filter at a rate approximately twice that of animals which live lower down. After 2 h, however, both sets of animals filter at the same rate.High-level animals respond significantly faster to wetting by splash and can tolerate a considerable range of salinity. They also respire at a rate approximately twice that of low-level animals. Respiration, however, is not detectable when the animal is not immersed in sea water.