bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further Experiments on the Production of Artificial Baits
Authors: Hughes Frank 
Published: May 2009

Since the publication of the last paper a number of experiments have been made in connection with the Bait question. The object aimed at was to obtain some material which would serve as a medium for the application of some or other of the extracts prepared by the methods given in the previous report. A number of common substances were tried without success. The majority were either not sufficiently porous, or, if possessing that qualification, they lacked that strength and toughness which is absolutely necessary in a bait which must lie in the water for some hours.It is this length of time which renders such materials as sponge, however fine, quite useless, since no extract, even if very much thickened, will remain in a piece of sponge more than a few minutes. Mr. Bateson in his report on this subject suggested the use of China clay; I tried a number of experiments with this, both dried and soft. In the latter case disintegration occurred at once, and the dried clay did not absorb sufficient extract to render it attractive; besides this, fish always reject any hard substance, even if it be made attractive with the smell of a favourite food. A somewhat promising material was obtained by boiling down skate skins until they were quite soft, and pressing them into blocks. The large amount of gelatine in these skins caused the fibres to adhere, forming a compact mass. This was somewhat porous and elastic, and took up a considerable amount of extract, but, like a number of other gelatine preparations, would not withstand the prolonged action of the water.
Monthly Reports on the Fishing in the Neighbourhood of Plymouth
Authors: Calderwood W. L. 
Published: May 2009

Iintroductory StatementIn these reports I shall not take into consideration the mMBIr methods of fishing which are practised in the locality, such, for instance, as eel spearing, mullet trapping, shrimp and prawn fishing, but shall confine myself to the most important branches, in which the beam trawl, drift and seine nets, and long lines are employed, and I shall also include crab and lobster fishing.With reference to the class of boats employed in this neighbourhood, the trawlers, compared to those of the North Sea, are not of large size. The average boat is about forty-three tons. They are usually rigged as ketches (dandy-rig), but the smaller ones sometimes as cutters. The dandy-rig is preferred because with it there is not the very large mainsail and heavy boom of the cutter, and also because, like the yawl, where the mizzen mast is stepped behind instead of before the stern-post, the vessel can be more easily brought under easy canvas in heavy weather. These vessels only carry four men and a boy as crew, and therefore the question of ease in handling becomes one of great importance. Steam trawling is not practised from Plymouth, nor do the sailing trawlers fish in the “fleeting” system common in the North Sea, where many boats belong to one company and remain on the fishing grounds it may be for weeks, while their fish is carried to market by special steamers.At Plymouth each trawler is worked independently, goes out to the fishing grounds east of the Eddystone, Mounts Bay, or Bristol Channel, and returns with its catch.
Notes and Memoranda
Authors: W. L. C.  
Published: May 2009

TheBulletin of the United States Fish Commission for 1889 contains a report upon a physical investigation of the waters off the southern coast of New England in the schooner Grampus during the summer of 1889, by Professor W. Libbey of Princeton College. This forms the first instalment of a series which promises to throw much light on the relations of temperature and salinity to the distribution of fishes and their food, and was itself directly suggested by researches upon the shad and the menhaden.The observations cover the area between lat. 39° N. and lat. 41° 10′ N., and long. 70° W. to long. 71° 30′ W., soundings being obtained as nearly as possible every 10′ along lines 10′ apart. At each station a very complete series of temperature observations was made, and samples were collected at surface, bottom, and in the deeper soundings at an intermediate point. The specific gravities of these samples were determined by means of a Kilgard salMBImeter.The temperature profiles along meridians of longitude are of great interest, extending as they do from near the coast over the edge of the continental plateau into deep water. The bathy-isothermal line of 50° F. shows a remarkable curvature off the continental platform, which the report says “would seem to point to a mechanical intrusion of cold water from the surface of the continental platform.” The conclusion is confirmed by the specific gravity observations; and the report goes on to say, “The existence of this body of warm water off the continental edge may offer an explanation of the richness of this particular spot in all forms of marine life, as shown by the successful dredging of the Albatross upon it.”
Breathing Movements inEntobdella Soleae(Trematoda, Monogenea) from the Skin of the Common Sole
Authors: Kearn G. C. 
Published: May 2009

An undulating movement of the body was observed inEntobdella soleae, a monogenean found on the blind surface of a mud-dwelling flat-fish,Solea solea, at Plymouth. The movement is described and shown to have a breathing function, the rate of undulation increasing with decreasing oxygen content of the ambient sea water and vice versa.The relationship between the movement and micro-habitat is discussed and the phenomenon is compared with breathing movements in other muddwelling animals.A similar movement was noted in three other skin-parasitic monogeneans:Acanthocotylesp. from Raiaclavata, Pseudocotyle squatinaefromSquatina squatinaandLeptocotyle minorfromScyliorhinus canicula.
The Effect of Environmental Factors on the Distribution of the Amphipod Pectenogammarus Planicrurus, with Particular Reference to Grain Size
Authors: Morgan Edward 
Published: May 2009

The distribution of Pectenogammarus planicrurus Reid around the British coast appears to be restricted to a few scattered areas. As far as is known it has only been recorded in three localities.The first of those is the ‘type locality’, described by Reid (1940), at Saltdean, Sussex. Here the upper region of the shore consists mainly of flint pebbles, the middle shore mainly of sand with patches of flint and chalk pebbles and the lower shore of boulders of chalk on a solid chalk base. Reid found it plentiful under stones near high water mark.In a brief survey of the south coast beaches, from Brighton, Sussex, to Deal, Kent, in the summer of 1965, P. planicrurus was found in large numbers on the chalk and flint beaches associated with the coastal outcropping of the chalks of the North and South Downs. By far the largest populations were found at Seaford, Sussex, where, unlike Saltdean, the pebbles and gravel extend down to low water and P. planicrurus was not restricted to the upper part of the beach as it was at Saltdean. It appears that the ‘type locality’ described by Reid (1940) does not give a true picture of the vertical range of distribution of the species.The second locality is at Port Erin, Isle of Man, where Jones (1948) observed P. planicrurus ‘under stones’ between H.W.N. and L.W.N. at Spaldrick on the north side of Port Erin Bay. Jones did not find this species in sufficient numbers to formulate a general idea of its habitat.
Notes on the Biology of Some Pogonophora
Authors: Southward A. J. , Southward E. C. 
Published: May 2009

Observations have been made on living pogonophores obtained from the continental slope to the south-west of the British Isles and from the continental shelf off the west coast of Ireland.The blood of five species examined contains haemoglobin in solution. The tube appears to be freely permeable to water, but less so to electrolytes and small molecules.The appearance and behaviour of living embryos is noted and the spermatozoon of one species figured. Possible feeding and other behaviour is discussed and it is concluded that the best line of future investigation lies with the shallow-water forms found in the Arctic Ocean.
The Role of Endogenous Rhythms in Vertical Migration
Authors: Harris John E. 
Published: May 2009

Photographic recording at hourly intervals of a group of animals contained in a small tank kept in continuous darkness has revealed a 24 h cycle of locomotor activity in Daphnia magna and in Calanus helgolandicA change in periodicity of the rhythm in Daphnia kept under continuous illumination suggests that the cycle is not determined by external stimuliThe phasing of the cycle differs in the two animals, but in both there is an increase in activity during the hours of darkness.In Calanus and possibly also in Daphnia, the cycle of activity is absent in the winter months.
The Fecundity of Icelandic Plaice
Authors: Bagenal T. B. 
Published: May 2009

This paper is one of a series on the fecundity of the plaice Pleuronectes platessa L. over a wide area of its geographical distribution and is concerned with the number of ripening eggs in the roes of female Icelandic plaice prior to spawning (see Bagenal, 1962, for references to other areas).Thirty-eight plaice were caught by the Icelandic research vessel ‘Maria Julia’ on 23 and 24 March 1961 in the Midnessjor area. They were measured and weighed and the otoliths were extracted. The ovaries were preserved in modified Gilson's fluid (Simpson, 1951). I am very grateful to Mr Jon Jonsson who kindly made all the arrangements and Mr Gunnar Joakimsson who prepared the material in Iceland. The fish were very ripe and a few had developed translucent eggs, but spawning had not begun. The subsampling and statistical treatment of the results were the same as before (Bagenal, 1962). The otoliths, after being kept dry, were very difficult to read.The Icelandic plaice are an isolated population, separated by deep water from the rest of Europe, and there are several spawning areas. currents move clockwise round Iceland and will carry the fertilized eggs and young larvae from Midnessjor and the S.W. coast spawning areas (Thomsen, 1948) to the good nursery grounds of Faxa Bay. Tåning (1929, 1948) has given accounts of the Faxa Bay plaice biology and suggests that ‘the eggs and tiny fry, which are found in the Bay in the spring months, seem mainly to come from the outside, for the greater part most probably from S.W. Iceland’. The eggs from the population offish considered in this paper, from Midnessjór, would drift into Faxa Bay which forms a good nursery ground.
Comparison of Several Methods of Determining Inorganic Phosphate in Sea Water
Authors: Jonesx P. G. W. , Spencer C. P. 
Published: May 2009

Five methods of estimating dissolved inorganic phosphate in sea water are compared. Membrane-filtered inshore water from the Menai Straits was used in the study.Wooster and Rakestraw's method gave higher results than Harvey's procedure. This was caused by some unidentified factor resulting in a non-sensitized reduction of molybdate in the former method.
Contributions to Marine Bionomics: II. The Function of Antero-lateral Denticulations of the Carapace in Sand-burrowing Crabs
Authors: Garstang Walter 
Published: May 2009

The antero-lateral margins of the carapace in many of the crabs of our own and of foreign coasts are beset with a row of teeth or spines, which vary in character and number in different species and genera. In the Oxyrhyncha (Spider-crabs) the whole surface of the carapace is generally studded with spines and stiff hairs of a peculiar character, but there is no general restriction of these processes of the carapace to the antero-lateral margins of the body. These crabs, moreover, do not adopt burrowing habits. Their armature of spines, tubercles, and hairs is employed, as is well known, for protective purposes: in some cases possibly as an actual defence against attack, in others (i.e., Eurynome aspera) as a means of protective resemblance to their surroundings; but in the great majority as mere pegs and hooks for the fixation of foreign bodies, such as algae, hydroids, polyzoa, and ascidians, for purposes of concealment and disguise.In the Catometopa (Land-crabs, etc.) the carapace is usually smooth over its whole surface. These animals often burrow in sand, but for the most part their burrows are permanent subterranean tunnels and chambers.In the Cyclometopa, however—the group which includes most of our commoner British crabs—the back of the carapace is generally smooth, while the antero-lateral margins are in most forms conspicuously serrated. Most of these animals inhabit sandy or gravelly areas, and show a marked propensity towards burrowing habits. Their burrows are never permanent channels or tunnels in the sand, but are mere temporary excavations, the sand, mud, or gravel being in actual contact with their bodies when imbedded.
The habits and feeding organs of Dentalium entalis
Authors: Morton J. E. 
Published: May 2009

The Scaphopoda or tusk-shells are the smallest and most uniform class of molluscs. They burrow in sand of medium to coarse shelly grade, and specialize on a diet of hard-shelled microbenthos, particularly Foraminifera. Dentalium entalis L. is the commonest West European species, and may become locally dominant. Le Danois (1948) has described a ‘Dentalietum’ in deeper water sandy ground at about 100 fathoms in the southern Celtic Sea. Stephen (1933) discusses the distribution of D. entalis in the northern North Sea, where it is largely restricted to the ‘Offshore zone’, the southern limit being marked by the 60 m line. Low salinity is probably responsible for its absence from the southern North Sea; and in general it seems limited more by hydrographic conditions than by the relative abundance of foraminiferan food. For example, in Stephen's Thyasira+ Foraminifera Zone, it is no more than sparsely present. Holme (1953) finds Dentalium entalis rare or absent near Plymouth, though it was relatively common at the Eddystone Grounds at the end of last century (Allen, 1899). It has today receded to the mouth of the Channel, in coarse deposits resulting from fairly strong scour, and Holme suspects it to be one of the list of species sensitive to recent hydrographic changes in the area.For the living material used in this study I am greatly indebted to Mr N. A. Holme, who collected it in deeper water in the Celtic Sea on a 1953 cruise of the R.R.S. ‘Discovery II’. With it were collected Chlamys opercularis, Caryophyllia and in places Astropecten irregularis; there were also many of the tusk-shaped serpulid tube worm Ditrupa arietina which as I found can impose a neat deception on the uncritical hunter for scaphopods.
Ecology of the genus Acanthochondria Oakley (Copepoda parasitica)
Authors: Kabata Z. 
Published: May 2009

Among the parasites of the branchial chamber of the flatfishes of the Eastern North Atlantic, those belonging to the genus Acanthochondria (fam. Chondracanthidae, tribe Cyclopiformes) occupy a conspicuous place. Both their relatively large size and their abundance, render them easily noticeable even to a casual observer, in spite of the protective nature of their environment. It is a reflexion on the state of our knowledge of marine parasites that, not withstanding their accessibility, very little is known about the animals of this genus.The genus Acanthochondria was erected by Oakley (Leigh-Sharpe and Oakley, 1927) for the chondracanthids, which until then were included in Chondracanthus Delaroche, 1811, and which differed from the other members of that genus in the absence of the cephalic barbs and the dorsal and ventral processes. They were also characteristic in their preference for the flatfish hosts.
The Larvæ of the Decapoda Macrura and Anomura of Plymouth
Authors: Webb Gladys E. 
Published: May 2009

The larvæ of the Decapod Macrura occur throughout the year in the tow-nettings taken in Plymouth Sound; while during the summer months they form an important and conspicuous feature of the coastal plankton.In only a few cases have their life-histories been fully worked out, owing probably to the difficulty of rearing the larvæ under artificial conditions; and the literature on the subject is consequently both scanty and scattered. It has therefore been suggested that a brief review of the larvæ already described, together with a few additional ones which have been identified during two years' examination of the Plymouth plankton, from 1917–1919, might be of some use to future investigators.The object of the present paper is to enable future workers to see at a glance how far these forms have been investigated, and especially to facilitate the identification of the living larvæ from the tow-nets.No attempt has been made to describe the appendages in detail, as such particulars can generally be found in the literature cited. A general outline drawing is given of the more important forms in their first larval stage, and a figure of the telson and uropods in the fourth or last larval stage is also shown.As the coloration of the larva is often of great assistance in identifying the living animal, it is here described rather fully, and, whenever possible, the drawings and the colour notes have been made from the living larva. In cases where no direct observations were available the colour descriptions are quoted from other authorities.
Intersexes in Gammarus Chevreuxi and Related Forms
Authors: Sexton E. W. , Huxley Julian S. 
Published: May 2009

Since 1912 extensive investigations have been carried on in the Laboratory of the Marine Biological Association at Plymouth on the genetics of Gammarus Chevreuxi Sexton, a brackish-water amphipod (Allen and Sexton '17 and '20, see also Sexton '13 and Sexton and Matthews '13).During the course of the work, numerous individuals have appeared showing abnormalities in sexual behaviour or structure. In view of the interest attaching to such forms, especially after the work of Goldschmidt ('20), Banta ('16), Sturtevant ('20) and others, it was deemed advisable to collate and publish the available data in spite of their some what fragmentary character.In normal circumstances, the males of Gammarus chevreuxi mate with the females some days (3 to 9 days) before fertilisation is due to take place. Unless the female is mated for the first time she will normally be carrying in her brood-pouch a brood of developing embryos. After hatching, the young are carried about 24 hours before extrusion, and during that time they come to the anterior end of the brood-pouch and feed on what the mother is eating. Finally they are extruded by a voluntary opening of the brood-pouch. Immediately afterwards the female moults, whereupon fertilisation occurs and a new batch of eggs is extruded into the pouch.The pair have by now separated, and remain separated usually until the embryos have gone through about half their development in the pouch.Cannibalism is of fairly frequent occurrence, the male eating the female immediately after she has moulted. It is extremely rare for the normal female to eat a male.
Line-Fishing on the Continental Slope III. Mid-Water Fishing with Vertical Lines
Authors: Forster G. R. 
Published: May 2009

INTRODUCTIONThe results of bottom line fishing have shown that significant catches can be made down to 3000 m depth at several positions on the continental slope off south-west England (Forster, 1968). But when hooks were lifted off the bottom either deliberately or accidentally very few fish were taken. The chances of catching bathypelagic fish in mid-water by baited hooks therefore seemed slender. In 1966 when thin white lines were tried, they were bitten through several times, always at about 1100 m depth. Trials with baited hooks set on thin wire lines in 1967 showed that the black scabbard fish Aphanopus carbo could be taken at this depth. In 1968 and 1970 during the course of short voyages on R.V. ‘Sarsia’ further vertical line hauls were made, taking Aphanopus regularly and also two species of deep-water squaloids.
Heterotrophic Utilization of Dissolved Organic Compounds in the Sea III. Measurement of the Oxidation Rates and Concentrations of Glucose and Amino Acids in Sea Water
Authors: Andrews P. , Williams P. J. Leb. 
Published: May 2009

INTRODUCTIONOne of the longstanding problems in marine biology has been to determine the quantitative importance of bacteria in the regeneration of the inorganic nutrients. There probably still is no entirely satisfactory way of studying this. It is currently believed that although a variety of marine organisms may utilize soluble organic compounds, bacteria dominate this activity. Thus, a measurement of the amount of soluble organic material oxidized will give a first approximation of bacterial activity. Such an estimate may have to be revised at a later date to allow for the activity of other micro-organisms.
On the Seasonal Abundance of Young Fish XII. the Years 1967, 1968, 1969 and 1970
Authors: Russell F. S. , Demir Necla 
Published: May 2009

Observations made with the 2 m ring-trawl off Plymouth during the years 1967,1968, 1969 and 1970 indicate that the increased abundance of young fish, excluding clupeids, reported for the year 1966 has been maintained.For the collections made in 1969 the species of clupeids, Arnoglossus, sand-eels and Callionymus have been separately identified.The year 1969 was characterized by the high numbers of post-larvae of Phrynorhontbus norvegicus. For the first time on record a post-larva of Sargus sargus was caught. Unusual abundance of post-larvae of the bass, Dicentrarchus labrax, was recorded for May 1970.
Hydrology of the Ythan Estuary With Reference to Distribution of Major Nutrients and Detritus
Authors: Leach J. H. 
Published: May 2009

INTRODUCTIONA long-term ecological study is being carried out in the Ythan Estuary in north-eastern Scotland. An understanding of the hydrology of the estuary is a prerequisite for future studies into energy relationships in lower trophic levels of the food web. Much of current research into the estuarine environment is concerned with large coastal-plain systems where physical and chemical characteristics are so different from those of shallow estuaries, such as the Ythan, that comparisons of environmental data are untenable. The present investigation reports information collected between October 1966 and September 1968 on major environmental factors and their effect on the distribution of nutrients and detritus in the ecosystem. Results of a concomitant study of algal productivity in a mudflat of the estuary are reported in Leach (1970).