bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioluminescence of the oceanic apogonid fishesHowella brodieiandFlorenciella lugubris
Authors: Herring Peter J. 
Published: May 2009

The pyloric caeca and posterior intestine ofHowella brodieiare bioluminescent, and are associated with internal reflective tissues. The bioluminescence is not bacterial in origin. Unlike that of several shallow water apogonids, it does not depend uponVargulaluciferin.Florenciella lugubrishas bioluminescent oesophageal diverticula and is able to eject a pulse of luminescent material from beneath the operculum.The luminescence of the two species is compared with that of other perciform fishes.IntroductionThe perciform family Apogonidae (cardinal fishes) contains several bioluminescent coastal species in the Indopacific generaSiphamia, Rhabdamia, Archamia, andApogon. Their oceanic relatives are less well known and their systematic position is still a matter of some conjecture.Howellahas been assigned to the Apogonidae but has also been included in the Moronidae (Tortonese, 1986), and, more recently, in the Percichthyidae (Post & Quéro, 1991). Some authors have followed Mead & De Falla (1965) in assigning the oceanic apogonid-like fishes to the family Cheilodipteridae(e.g.Fedoryako, 1976), in recognition of the fact that they ‘are so different from their coastal relatives that comparison is pointless’ (Mead & De Falla, 1965).Bioluminescence has not been described in detail in any of the oceanic species. Mayer (1974) reported that one of the pyloric caeca inEpigonus macropswas separated from the others and associated with reflective structures. This strongly suggested that it was bioluminescent, based on comparisons with known luminescent shallow water perciforms, such as species ofPempherisandParapriacanthus.Mead & De Falla (1965) described a ventral reflective strip inRosenblattia robustawhich, by analogy with similar appearances in luminous neritic species, they considered a possible indication of bioluminescence.
The life history and reproductive biology ofOdostomia eulimoides(Gastropoda: Opisthobranchia) on the south coast of Ireland
Authors: McFadden Y. M. T. , Myers A. A. 
Published: May 2009

Populations ofOdostomia eulimoidesHartley were sampled from mussel beds on an exposed rocky shore at Preghane Point on the south coast of Ireland from April 1984 to October 1985 and from sublittoral farmed mussels at Bantry Bay on the south west coast of Ireland from March to October 1986.At Preghane PointO. eulimoideshad a area-annual life cycle with summer-autumn recruitment. Peak recruitment occurred from May to July in 1984 and from July to September in 1985. This aphasic recruitment was explained by the lower mean adult shell height recorded from April to June 1985 than in these same months in 1984.
The effect of feeding levels on the fecundity of plaice (Pleuronectes platessa)
Authors: Horwood J. W. , Walker M. Greer , Witthames P. 
Published: May 2009

Previous field studies have recorded yearly variations in fecundity of 40–60% in similar sized plaice, and an experiment was conducted to investigate whether these changes could be generated, in the laboratory, by feeding plaice different levels of ration. One group of plaice was fed at a rate of about 2–2.3% of wet body weight per day, and a second group was fed initially 0.5% and later 1.8% per day. The experiment lasted for a period of 406 days.Of those fed on the lower ration, 39% produced no granular oocytes, whereas all fish on the higher ration produced granular oocytes. A comparison between the two groups, of those which did produce granular oocytes, found that the better-fed fish had 59% more granular oocytes, but the differences were less pronounced for the smaller, mature fish. Numbers of resting oocytes are also recorded.The results suggest that food level can significantly affect fecundity, and also revealed a new mechanism for regulation of fecundity in the plaice. The lack of granular oocytes was not due to atresia, but to an early decision not to proceed with gonad development; whether this is of practical significance for the population of plaice in the wild is not yet established.
On the structure of the inshore fish community of England and Wales
Authors: Henderson P. A. 
Published: May 2009

Records of fish captures on power station intake screens were used to analyse the structure of the English and Welsh inshore fish community. The study was undertaken as part of a programme to predict fish captures at future power station sites. It was found that 118 of the 122 fish species known to live inshore were recorded from the screens of 12 coastal power stations. The maximum number of species at one site was about 80, achieved at fully marine localities along the English Channel coast. This number declined with increasing latitude and decreasing salinity.Fish subdivide their use of the inshore habitat both spatially and temporally and the proportion of species complement within the major subdivisions of the habitat was remarkably similar at all sites. On average, 28 species were present simultaneously and these would include 4 pelagic, 8 demersal and 16 benthic species.
The Lobster Fishing of one Boat in Plymouth District, from May 1st to September 29th, 1890
Authors: W. L. C.  
Published: May 2009

The data for this paper were again supplied by Mr. Roach, and have all been reduced to tabular form. I shall here state only the general results.The total number of lobsters taken was 1753. Of these 1226 were males and 527 females, i. e. 699 more males than females.
The Head Kidney of Teleostean Fishes
Authors: Calderwood W. L. 
Published: May 2009

Until the year 1881, when Balfour wrote on the subject, the pronephros was generally believed to be a functional kidney, not only in the larval condition, but also in those adult forms described as possessing the organ.Balfour, in his more detailed paper, published later, states that in the fishes examined—pike, eel, smelt, and angler—although the pronephros had all the appearance, externally, of a true functional kidney, no uriniferous tubules were present, and that a minute examination only disclosed a degenerate trabecular tissue which he describes as lymphatic.The angler (Lophius), it may be observed, is generally considered to possess only a head kidney. This organ Balfour found to be in a perfectly functional condition, but he declines to believe that it is a persistent head kidney, and argues from the highly modified structure of the fish that the organ in question is in reality the mesonephros. shifted forward from its normal position. He also maintains that in adult Ganoids the head kidney has no longer a renal function. His general conclusion, therefore, is, that since the pronephros was only supposed to persist in Ganoids and Teloosteans, it must be now considered as non-existent except in the embryonic or larval conditions.
Seasonal changes in condition factors and in the C:N ratio of the foot of the ormer, Haliotis tuberculata
Authors: Hayashi Ikuo 
Published: May 2009

The annual cycle of some physiological conditions in the ormer, Haliotis tuberculata L. was studied by the C:N ratios of foot tissue which were convertible to the glycogen contents, and the coefficients of fatness calculated from two formulae. The former method showed the seasonal change inrelation to the reproductive cycle indicating the foot tissue as a nutritive storage reservoir for spawning, and the latter gave no clear seasonal fluctuation, except a drop of the value shortly afterspawning.Comparison of ormer populations representing local sites in Guernsey was made by the two methods during the periods of gonad maturation, spawning and pre-spawning (May-October), and the shell forms were analysed by measuring three dimensions of shells, namely, shell length, width and height. The results revealed some changes in physiological conditions between different localities and seasons even within Guernsey. The shell forms also appeared to differ at each site probably as a reflexion of physical and biological conditions surrounding them. The relation of the results obtained by all the methods was discussed to give a more generalized account on physiological conditions of the ormer for its reproduction.
On the development of the olfactory and the gustatory organs of the Dover sole,Solea solea,during metamorphosis
Authors: Appelbaum S. , Adron J. W. , George S. G. , Mackie A. M. , Pirie B. J. S. 
Published: May 2009

The development of the olfactory system, taste and sensory buds of the Dover sole (Solea soled) during metamorphosis has been studied by light and electron microscopy and preliminary correlations with changes in feeding behaviour have been made.INTRODUCTIONDuring metamorphosis, the feeding behaviour of the Dover sole changes considerably. In the early larval phase, the fish swim pelagically, feeding on plankton using their visual sense, while the metamorphosed fish become more active at night, finding food by means of their chemical senses (for a review of the literature, see de Groot, 1971). However, previous observations have shown that sole are capable of feeding in the dark from the very early hatching stage (Blaxter, 1969) and also that at the time of first feeding, the majority of the larvae remain close to the bottom where they appear to ingest particles (Rosenthal, 1966; Fluchter, 1966).
The resistance to dislodgement ofSargassum muticumgermlings under defined hydrodynamic conditions
Authors: Norton Trevor A. 
Published: May 2009

The attachment capabilities of a brown seaweed,Sargassum muticum(Yendo) Fensholt were investigated in the laboratory on both smooth and rough substrata and in surging water motion reaching flow velocities of 57 cm s and 90 cm s.Newly released zygotes have no means of adhesion until they develop rhizoids, which can adhere on contact with the substratum. Attachment tenacity, as measured by the germling's ability to withstand dislodgement at a given velocity of water flow, is slight at first, but increases with time. This is not simply a function of time spent in residence on the substratum, for germlings cultured suspension stick very quickly and tenaciously when allowed to settle. Tenacity of adhesion seems to be a reflexion of the amount of mucopolysaccharide adhesive present. This increases gradually during the first few days of the germling's life, regardless of whether it is attached or not.Once secure attachment is achieved it is not weakened even by the death of the germling. A film of bacteria and micro algae on the surface of the substratum is not a requirement for germling adhesion, but its presence enhances the tenacity of adhesion.Smooth substrata are the least favourable for germling survival in flowing water. On rough substrata the ‘peaks’ of the microtopography and surfaces facing into the current are much less favourable than the troughs between the ‘peaks’, or surfaces in the lee of ‘peaks’. Germling survival increases with increasing substratum roughness up to an optimum rugosity at which the mean depth of the depressions on the surface is 420 μm, and the vast majority are deeper than the height of the germlings.
Effect of growth rate on the physiological rates of a chemostat-grown rotifer Encentrum linnhei
Authors: Scott J. M. 
Published: May 2009

The physiological rates of a normally omnivorous marine rotifer, Encentrum linnhei, were measured under the steady-state chemostat conditions in which the physiological state of the food-algae was kept constant whilst the rotifer growth rate was changed to preset levels. The specific clearance rate ranged between 50 and 100 μl/μg rotifer C/day (1.5–3.0 μ/rot/day) and varied hyperbolically with growth rate, a similar curve was obtained with the specific ingestion rate which varied between 1–2 μg C/μg rot C/day. A mean respiration rate of 0.45 μg C/μg rot C/day was obtained from oxygen consumption measurements. About 60‰ of ingested energy was found to be egested as paniculate matter and 9–4 °0 dissipated as heat, the latter comparing with a theoretical figure of 4–5‰.From rates, transfer efficiencies were obtained giving a mean net growth efficiency (K2) of 38‰ and a mean overall growth efficiency (K1 of 15‰. A curvilinear increase of Kl with growth rate contrasts with linear and hyperbolic responses found with brachionid rotifers.
On the Genus Phascolion (Sipuncula) with Particular Reference to the North-East Atlantic Species
Authors: Gibbs P. E. 
Published: May 2009

Members of the genus Phascolion Théel are probably the most familiar of sipunculans because most species inhabit the empty shells of molluscs and other similar structures and are therefore easily collected in dredge samples. Although the genus is represented in most seas and depths, few species have been investigated in detail and much of our knowledge is based on studies of the widespread Atlantic species P. strombi (see Åkesson, 1958; Hylleberg, 1975; Kristensen, 1970; Wesenberg-Lund, 1929). P. strombi is known to be remarkably plastic in many of its characters, particularly external, to the extent that Gerould (1913) was able to distinguish seven varieties in the western Atlantic region alone. Much of the variation in the size and colour of P. strombi, and in the form of the skin papillae, especially those generally termed ‘holdfasts’ or ‘adhesive papillae’, may be attributable to the size and type of shelter that is inhabited but experimental evidence is lacking. It follows that a similar degree of external plasticity to that recognised in P. strombi must be assumed for most, if not all, Phascolion, presently totalling around 45 species. Many Phascolion species have been erected on single or just a few specimens showing only slight differences of dubious systematic significance.Taxonomically, the genus is very difficult and no satisfactory key to the species has yet been devised. As a first step, there is a need for definitions of subgenera, preferably based on internal characters which are not subject to environmental influences. To this end, the retractor systems of the north-east Atlantic species described below have been studied and compared with the type specimens of species from other areas.
Notes on the Biology of Certain Lamellibranchs on the Scottish Coast
Authors: Stephen A. C. 
Published: May 2009

1. The observations were made on the Hunterston Sands, Ayrshire, opposite the Cumbrae.2. Small cockles appear on the ground about the beginning of August. This points to the breeding season being in summer and not spring, as is usually stated.3. By the end of the first autumn some few of the spat are as much as 10 mm. in length, but most are under 6 mm. The winter ring is faint and easily overlooked.4. The first of the several well-defined rings is therefore not the first but the second winter ring.
Some Observations on Schooling in Fish
Authors: Spooner G. M. 
Published: May 2009

1. Among schooling fish, the younger stages of the bass (Morone labrax) provide an instance in which the schooling habit, though strong, is not stereotyped into fixed forms of behaviour.2. Observations were made on individual fish in connection with their attraction for one another, a special point being made of observing their behaviour in front of a mirror.3. The data so obtained are summarised in the light of their bearing on the problems of school formation.
On the Colorimetric Determination of pH in Sea-Water
Authors: Gómez Ibáñez O. 
Published: May 2009

1. It is not always feasible to determine pH on board ship, owing to bad light and other conditions, although it may be possible to collect water samples.2. By preserving the water samples on collection with mercuric chloride solution (four drops per 100 c.c. of water) and by taking care to leave only a small air-space in the bottles it is possible to keep the water practically unchanged for many days.3. Test tubes containing such water (10 c.c.) plus 0·02% cresol red (0·5 c.c.) have been-kept unchanged for three weeks at 12–14° C. and for two days at 33° C, whereas unpreserved water showed a drop in pH of 0·05 unit in one day at 12° C.4. McClendon buffer solutions may also be preserved by mercuric chloride, but in this case a small correction must be applied since complex formation leads to a removal of effective buffer salts from the solution and a small decrease in pH.
Observation and Experiments on Sex-Change in the European Oyster (O. edulis.): Part I. The Change from Female to Male
Authors: Orton J. H. 
Published: May 2009

The gonads of 1,121 oysters have been examined at various periods from a few hours to twelve months after the individuals had spawned as females; the material for the research was obtained by collection and experiment. In 702 individuals taken with young in the mantle cavity the gonad shows a progressive development of maleness in its primary sexual characters; within a mean period of 2¼ hours after spawning eggs, the gonad was found in 50 per cent of cases with only young spermmasses developing, followed at later periods by a progressive ripening of the sperm-masses, until in individuals carrying shelled and black-coloured larvae 77 per cent contained abundant ripe sperm-masses as well as advanced developing sperm-masses.In 444 individuals examined at various periods after extruding their larvæ, the development of sperm was found to continue for about a month after egg-spawning, and to abate in about the second month. In from 2 to 3 months after egg-spawning sperm-development is completed and the male phase begins to wane, and a small percentage of individuals may become female or actively female-functioning again. In 12 months after the last egg-spawning a significant number of individuals become once more functional females.The varieties of mixed sexes found in O. edulis are denned and their frequencies shown by an analysis of samples—from two widely separated beds—examined at the beginning of the breeding season in 1926. Experiments on the rate of growth of sperm-masses and on determining of age at different stages of development in embryos and larvæ are given.
The Influence of Plankton on the Phosphate Content of Stored Sea-Water
Authors: Gill Robert 
Published: May 2009

1. The alteration in soluble phosphate content of untreated sea-water during storage is governed by the conditions of storage—a strong light, favourable to growth, produces a decrease, while darkness, unfavourable to growth, produces an increase.2. Samples from the surface layers of the sea give greater increases on storage in the dark than samples from deeper water, the extent of the increase being conditioned by the number and quantity of planktonic organisms included in the water sample.
On the Biology of Sagitta. The Breeding and Growth of Sagitta elegans Verrill in the Plymouth Area, 1930–1931
Authors: Russell F. S. 
Published: May 2009

1. A study of the adult population of Sagitta elegans Verrill has been made in the waters off Plymouth by weekly collections with the 2-metre stramin ring-trawl hauled obliquely in the daylight.2. Measurements of large samples and a study of the state of development of the gonads has shown that there were apparently four, if not live, broods of S. elegans produced in the year.3. These successive broods were apparently spawning in April-May, June-July, and September, 1930, and February, 1931.4. In the offspring of the September spawning population no gonads were developed during October and November. The male organs started to ripen in December, and the ovaries in January, but the brood did not appear to be fully mature until February.
On the Biology of Sagitta. II. The Breeding and Growth of Sagitta setosa J. Müller in the Plymouth Area, 1930–31, with a Comparison with that of S. elegans Verrill
Authors: Russell F. S. 
Published: May 2009

1. A study of the adult population of Sagitta setosa J. Müller has been made in the waters off Plymouth by weekly collections with the 2-metre stramin ring-trawl hauled obliquely in the daylight.2. Measurements of samples and a study of the state of development of the gonads has shown that there were apparently at least six broods of S. setosa during the period September, 1930, to August, 1931, inclusive.3. The successive broods were apparently spawning in September and October, 1930, and February, April-May, June, and July-August, 1931.
The Copper Content of Sea-water
Authors: Atkins W. R. G. 
Published: May 2009

1. On comparing the potassium ethyl xanthate and the sodium diethyldithio-carbamate methods for estimating copper the latter was found to be preferable because (a) It is at least twice as delicate, (b) The reagent is absolutely colourless, (c) In very dilute solution ferric iron causes little or no disturbance.2. Estimation of copper may be carried out by electro-deposition from one litre of sea-water at about 90-100° C. for three hours at 2.0 volts with subsequent re-solution and colorimetric estimation using the carbamate method.3. In agreement with the spectroscopic determinations of Dieulafait in 1879, it was found that sea-water contains about 10 mg. per cubic metre of copper.
Degeneration and Loss of the Eye in the Amphipod Gammarus cheureuxi Sexton. Part I
Authors: Sexton E. W. 
Published: May 2009

A description has been given of a mating which produced a great range of eye-irregularity in the offspring. Not only were the size, shape, and pigmentation affected, but the eye-structure itself, many cases occurring in which one eye or even both eyes were missing at birth.This experiment adds another proof to the statement that the farther removed from the normal an animal is, the lower its viability. The mortality was much higher amongst the abnormals, and breeding experiments with the survivors were exceedingly difficult on account of the trouble experienced not only in rearing them to maturity, but in finding suitable mates. The cannibalism of the males of this stock made it almost impossible to use them, and small, not too vigorous, males had to be sought in the Albino No-white strain.In three of the One-eyes, i.e. those in which one eye was present at birth, and no trace of a second could be seen (even with a high power), a very imperfect second eye developed later, after several moults had taken place. An example, CN.220c, is illustrated in Text-fig. 5 (List, p. 384).
The Larvæ of the Plymouth Galatheidæ. I. Munida banffica, Galathea strigosa and Galathea dispersa
Authors: Lebour Marie V. 
Published: May 2009

In the Plymouth district there are five or six species belonging to the Galatheidse, one Munida, and four or five Galathea. The species occurring are the following :—Munida banffica (Pennant).Galathea strigosa L.Galathea dispersa Kinahan.Galathea nexa Embledon.Galathea squamifera Leach.Galathea intermedia Lilljeborg.
Muds of the Clyde Sea Area. II. Bacterial Content
Authors: Lloyd Blodwen 
Published: May 2009

1. The bacterial content of mud deposits in the Clyde Sea Area has been investigated.2. The number of bacteria is found to decrease from the surface downwards.3. The numbers fluctuate very much in the top mud layers, and there is some evidence of bacterial zonation.4. In the deeper mud layers the bacterial content for any given station is fairly constant.5. The predominant organisms were found to be water bacteria of the Achromobacter and Chromobacterium type, and large spore-forming bacilli similar to common soil bacteria.6. The factors affecting the bacterial content of the muds are discussed.
The Vertical Distribution of Marine Macroplankton. XI. Further Observations on Diurnal Changes
Authors: Russell F. S. 
Published: May 2009

1. Details are given of the results of a series of hauls with the 2-metre stramin ring-trawl fished at six different depths in daylight, at dusk, in the dark, at dawn and again in daylight on June 3rd–4th, 1926.2. A comparison is given of the results obtained on the four nights July 15–16th, 1924; June 17–18–19th, 1925, and June 3rd–4th, 1926.3. The importance is stressed of the effects on the type of behaviour shown by any animal produced by the depth at which it is living in the daylight and the speed at which it can swim upwards.