bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Hypothesis of Mitogenetic Radiation
Authors: Choucroun Nine 
Published: May 2009

1. The observed “action at a distance” undoubtedly exists.2. This action cannot be ascribed to a radiation, nor more generally to an action “through the wall” of the receptacles.3. This action must then be exercised “across the surface” of the wall of the receptacles by a mechanism which remains to be explained. This seems, however, to be of great interest in view of the apparently very small mass of the substance concerned in the action.4. The action of something material is rendered probable from the fact that the eggs develop very abnormally in sea-water previously exposed to the active culture.5. Although these experiments have only been carried out upon sea-urchin eggs, their conclusions may be valid in the case of the very numerous experiments concerning mitogenetic radiation.
Some New Eye-Colour Changes in Gammarus cheureuxi Sexton. Part I
Authors: Sexton E. W. , Clark A. R. , Spooner G. M. 
Published: May 2009

1. In a large number of experiments with Gammarus chevreuxi when the animals were kept under similar conditions at temperatures ranging from 20° to 28° C., twenty instances occurred in which red-eyed mutations appeared independently and simultaneously. The most important of these (Mutant Stock V) is described in detail in this paper.2. The Red eyes which have arisen in this Stock V and in the four previous Stocks, I to IV, have proved to be all genetically distinct from one another.3. There are at leadt two different classes of “red-eye,” the one simple, the other with intermediate stages. Mutant Stock V, here described, represents the second type. Differences in the method of origin of the two classes have been pointed out.4. The inheritance of the red-eyedness of the second class—namely, that in which intermediate stages and various colour changes occur—is of a complicated kind. For an interpretation in terms of Mendelian genes, even if allowance is made for an extent of variation in members of one particular genotype, clearly several of them are involved. Further, there must be considerable interplay of one kind or another among the different genes.5. Although so many different colour shades have appeared in Mutant Stock V, all can be interpreted in terms of varying concentrations of two pigments—the black and the red. Dilute black pigment with little or no red gives a purple eye.
Algal-induced dislodgement as a cause of bivalve mortality on some Scottish beaches
Authors: Ansell A. D. , Robb L. , Powell H. T. 
Published: May 2009

During July 1984, large numbers of the sandy beach bivalve Donax vittatus (da Costa) were found either stranded in the intertidal, or washing to and fro in the surf on beaches at Dornoch, on the east coast of Scotland. The affected bivalves all carried large growths of several species of algae. The normal burrowing and recovery responses of the bivalves were unable to overcome the increased drag resulting from these epizoic algal colonies so that wave action caused dislodgement from the sand and eventually, stranding and death from dehydration. The resulting mortality affected mainly older individuals in the population; younger individuals had very small or no attached algae and were not dislodged.The algal growths were complex and showed three stages in their development: primary settlements formed generally short tufts or mats attached to the posterior tip of die shell; secondary ‘dominant’ species were also attached to die shell but formed larger growths; tertiary species were attached as epiphytes to the primary and secondary growths. At least eight species of algae were involved. Juvenile mussels (Mytilus edulis L.) were also present in many cases attached to the weed, adding further to die drag.During 1985, at Dornoch, secondary and tertiary algal species developed progressively from overwintering primary settlements, but the size of die algal colonies which developed was generally smaller dian in 1984 and diere was apparently little dislodgement and mortality.Donax vittatus populations on other beaches in die Moray Firdi, and on most other Scottish beaches examined, had fewer individuals with attached algae, and diose affected carried only relatively small colonies which did not prevent normal burrowing. Complex algal colonies, showing even greater species diversity than those of Dornoch were, however, found on D. vittatus on beaches in South Harris, Outer Hebrides, during September 1984.
Evidence for selective mortality inChlamys varia(L.) transplant experiments
Authors: Gosling E. M. , Burnell G. M. 
Published: May 2009

Two hundredChlamys varia(L.) from Roskeeda Bay (W. Ireland) and Lough Hyne (S. Ireland) were collected and labelled in December 1979. One hundred individuals from the L. Hyne sample were then transferred to Roskeeda; similarly, 100 Roskeeda scallops were transferred to L. Hyne. At each site 100 indigenous scallops were held as controls.After a period of approximately 1 year, survivors at each site were scored at 13 enzyme/protein loci using starch gel electrophoresis. Significant genetic differences were observed at thePgmandLaploci between native L. Hyne and native Roskeeda scallops. These differences persisted between surviving Roskeeda scallops (92% of the original sample) transferred to L. Hyne. However, after one year L. Hyne scallops transferred to Roskeeda (61% of original sample) did not differ significantly from indigenous Roskeeda scallops. Possible reasons for the observed selective mortality at this site are discussed.
Observation on the life history and functional morphology ofCerithiopsis tubercularis(Montagu) andTriphora perversa(L.)
Authors: Fretter Vera 
Published: May 2009

Cerithiopsis tubercularisandTriphora perversafeed on siliceous sponges: a long proboscis is thrust through an osculum of the sponge, or into breaks in the surface, to reach the softer parts. These are loosened by jaws, entangled in saliva and swept into the buccal cavity by the radula.The formation of a long introvert, which must be withdrawn through the narrow space in the nerve ring and narrow enough to go through an osculum, has brought about (i) a lengthening of the mid-oesophagus inCerithiopsis, with a narrowing of its diameter, and a spreading of the oesophageal glands along its length, (ii) inTriphora, a reduction of the ventral glandular part of the mid-oesophagus, its stripping from the food channel and a displacement of the salivary ducts so that they open into the glandular part of the oesophagus. InTriphorathere is a dorsal gland of unknown function on the posterior oesophagus.The stomach in both species is a simple ciliated sac: the oesophagus opens anteriorly and ventrally, and the intestine originates above this opening; there are two ducts from the digestive gland.The pallial region of the male and female genital duct is open; and there is no penis. It is suggested that the open condition of the duct and the absence of a penis in the mesogastropods is correlated with a long, narrow mantle cavity which contains a relatively large ctenidium.
Observations on the spawning behaviour ofSaccoglossus horstiBrambell & Goodhart, and of other Enteropneusta
Authors: Burdon-Jones C. 
Published: May 2009

The genital products ofSaccoglossus horstiare discharged within the burrows and expelled after the tide has ebbed. They are not retained in the burrows for any length of time.Fertilization occurs mainly in the overlying surface water, or during the flood.An ‘epidemic’ spawning was observed on three occasions in the field.A rise of temperature to about 160° C. is regarded as the essential factor primarily responsible for initiating the spawning.The females were observed to spawn before the males. Some reciprocal inducement might have occurred.The breeding season in the Solent area is mainly confined to the months of May, June and July, and is seemingly dependent on climatic and tidal conditions during these months.The spawning behaviour of other species of the Enteropneusta is discussed.
Spontaneous activity patterns in animal behaviour: the irrigation of the burrow in the polychaetesChaetopterus variopedatusRenier andNereis diversicolorO. F. Müller
Authors: Wells G. P. , Dales R. Phillips 
Published: May 2009

Simple methods for recording the water currents, which many polychaetes drive through their tubes, are described. The circulation may be either open (the worm having access to large amounts of well-aerated sea water) or closed (in which case the worm can circulate a small volume only, and there is no oxygenacion or removal of excretory products).When on open circulation, bothChaetopterus variopedatusandNereis diversicoloroften trace quite regularly cyclical patterns for hours at a stretch. Each species has several possible patterns, and may change from one to another without evident external cause. The tracings of each species differ from those of the other, and also from those ofArenicola marina, which were described elsewhere.
The grazing rate of planktonic copepods
Authors: Gauld D. T. 
Published: May 2009

The filtering rate of four species of marine planktonic copepods was measured by estimating the rate at which they consumed cultures of Chlamydomonas.The filtering rate was independent of the concentration of the food organism and it is concluded that the copepods were acting as filter feeders.The filtering rates were much greater than those reported by Fuller & Clarke (1936) and Fuller (1937), but agreed with those reported by Harvey (1937).Some evidence was obtained that grazing was restricted to some only of the 24 hr., most probably to the hours of darkness.The filtering rates were approximately proportional to the square of the linear dimensions of the copepod.The purely mechanical selection suggested by Fuller (1937) to account for differences in filtering rates obtained with different species of diatoms cannot account for all the differences which have been observed.It is probable that the copepods could obtain sufficient particulate food in the sea by filtering a daily volume of water corresponding to the filtering rates found.
Notes on the growth and biology of the prawn Pandalus bonnieri Caullery
Authors: Pike R. B. 
Published: May 2009

Pandalus bonnieri is a dioecious species and no protandrous hermaphrodites have been seen.The breeding season and incubation period for P. bonnieri are described.The number of eggs laid increases with the size of the female. At 16 mm. carapace length the number of eggs is c. 1000 and at 24 mm. carapace length the number of eggs is c. 4000. The number for a single mm. size group varies roughly by ±10%.Both male and female P. bonnieri become sexually mature at about 18 months, and in the Clyde seldom live beyond 3 years of age.The colour of the eggs in P. bonnieri is sage green, in P. borealis blue green, in P. montagui light emerald green and in P. propinquus fawn.Juvenile P. bonnieri can be separated into males and females by the shape of the pleopods within 4–6 months of hatching.
The response mechanism in ascidians
Authors: Hoyle Graham 
Published: May 2009

A method is described for investigating the reactions and spontaneous activity of two species of ascidian,Phallusia mammillataandAscidiella aspersa, which does not disturb the animals unduly. The method can be used for obtaining graphic records of the so-called ‘reflexes’ of ascidians.If due attention is paid to certain factors which affect the state ofthe animals, they can be made to respond to electrical stimuli applied to the outside of the test in a way which can be observed repeatedly in the same animal, in other animals of the same species and in at least two genera of ascidian.Electrical stimuli applied to the test affect the excitable system of the whole animal in an all-or-nothing manner.Response to graded electrical stimulation reveals a facilitation mechanism which gives enormous enhancement to the size and speed of response to the second of a close pair of effective stimuli. It is suggested that this mechanism is responsible for the production of the rapid squirt of the large sedentary ascidians.A possible cause of the very rapid fatigue of ascidians to all kinds of stimulation is fatigue of the facilitation mechanism following a period of stimulation.A parallel is drawn between the responses ofMetridiumand the responses ofPhallusiaandAscidiella. The responses have some common features and the response mechanism appears to serve a similar purpose in the life of the animals.
Effects of A Toxic Bloom ofChrysochromulina Polylepison the Common Dog-Whelk,Nucella Lapilluson the Swedish West Coast
Authors: Robertson Annika 
Published: May 2009

A massive toxic bloom ofChrysochromulina polylepisoccurred along the Swedish west coast in May and June 1988 with severe effects on most biota in shallow marine habitats. In the present study, the effects on the common dog-whelk,Nucella lapilluswas investigated in the archipelago at the mouth of the Gullmar Fjord.Mortality varied throughout the archipelago, with extinction of populations in the inner parts and survivors found only on the outermost islands. Even on these sites, mortality could be as high as 98­99%. Extensive samples of survivors and dead animals were divided into five age groups dependent on size and wear of the shell. The cohort consisting of 3­4 year old individuals suffered the lowest mortality, while mortality was almost total in younger and older cohorts. In each age group, except the oldest, survivors were significantly larger than the dead.The number of egg capsules laid per female in 1988 seemed normal, but about half of the capsules were empty. The number of young per capsule was significantly lower in 1988 compared to 1989, but the young were significantly bigger.
Influence of Temperature on embryonic and larval development inNecora puber(Brachyura, Portunidae)
Authors: Valdes L. , Alvarez-Ossorio M. T. , Gonzalez-Gurriaran E. 
Published: May 2009

The influence of temperature on the duration of the embryonic and larval development inNecora puber(L., 1767) was studied. Nine different temperatures were used for the eggs and seven for the larvae, in both cases ranging from 2 to 35°C. The temperature range where visible development was obtained was between 4 and 31°C, with the lowest lethal temperature (temperature at which the eggs did not show any sign of development and development did not resume when the eggs were placed at 15°C) being between 2 and 4°C and the highest lethal temperature between 31 and 35°C for both eggs and larvae.Temperature was found to be inversely related to developmental time. The incubation period (D) fluctuated between 76 days at 10°C and 17·6 days at 25°C, with an increase in the rate of development (100/D) from 1·13 to 5·55 between these two temperatures. The larval period varied between 48·5 days at 15°C and 28 days at 25°C with rates of development of 2·08 and 3·57 respectively. The adjustment equations used show that temperature has a greater accelerating effect on eggs than on larvae. A simple potential equation, D=aT, describes the relationship between temperature and developmental time better than the Belehrádek equation, D=a(T-t).Acording to the fitted equations developmental time from spawning to the first postlarval stage is completed in 91–105 days at temperatures of 13–15°C which is very close to our experimental data. The model proposed also fits most of the data from the available literature even those for other species such asLiocarcinus holsatus(Fabricius, 1798) andCarcinus maenas(L., 1758), which suggests that a similar response of developmental timevstemperature could be expected from other related Portunidae.
Effect of Encrusting Bryozoans on the Physiology of Their Algal Substratum
Authors: Muñoz Jorge , Cancino Juan M. , Molina MarÍa X. 
Published: May 2009

Traditionally, colonies of encrusting epiphytic bryozoans have been regarded as biotic factors reducing photosynthetic performance in benthic algae. In this study we determined under laboratory conditions the effects of Membranipora tuberculata on the photosynthetic efficiency of the rhodophyte Gelidium rex.Encrusting bryozoans reduce to 44% the incident light reaching the algal thallus. However, concentrations of chlorophyll a and other accessory pigments are significantly higher in encrusted than in non-encrusted thalli. Consequently, photosynthetic efficiency is almost identical in both types of thalli. Although non-encrusted thalli showed a higher photosynthetic V due to higher levels of light reaching the algae, encrusted thalli exhibited a compensatory effect at low photon flux density and reached a similar P value. The detrimental effect of M. tuberculata on photosynthesis could be partially compensated by CO released from bryozoan cells, as G. rex preferred CO over HCO3 as a source of photosynthetic inorganic carbon. These results suggest that physiological interaction between bryozoans and algae, involving the interchange of metabolic substances, are likely to be important.
The taxonomy of monogenean gill parasites fromScyliorhinus caniculaandRaia clavataat Plymouth
Authors: Coupland Anne C. 
Published: May 2009

The monogenean gill parasites fromScyliorhinus caniculaandS. stellarisat Plymouth have been found to be identical; their proper taxonomic designation isHexabothrium appendiculatum(Kuhn, 1829) Nordmann, 1832.H. canicula(Cerfontaine, 1899) Price, 1942 is a synonym ofH. appendiculatum.The hexabothriid collected fromRaia clavataat Plymouth has been identified asRajonchocotyle emarginata(Olsson, 1876) Sproston, 1946, andR. clavataBracey (in Sproston, 1946) has been shown to be synonymous with it.
On the effects of some carcinogenic hydrocarbons on the growth of sporelings of marine red algae
Authors: Boney A. D. , Corner E. D. S. 
Published: May 2009

Low concentrations of various carcinogenic polycyclic aromatic hydrocarbons cause a considerable increase in cell production when applied to sporelings of certain marine red algae.Whereas low concentrations of carcinogenic derivatives of benzanthracene stimulate cell production, similar concentrations of structurally related non-carcinogens inhibit it.The applicability of the method as a rapid screening test for carcinogens is discussed.
The morphology and larval behaviour of a new species ofSpirorbis(Serpulidae)
Authors: Gee J. M , Knight-Jones E. W. 
Published: May 2009

Spirorbis rupestrissp.nov. has a sinistrally coiled, unridged tube and is distinguished fromS. borealisDaudin only by colour, small morphological details and striking differences in larval behaviour. Though the larvae are capable of swimming, they do not usually do so, but crawl about and soon attach themselves to rock surfaces near the tubes of their parents, particularly when stimulated by the presence of the coralline algaLithophyllum incrustans. They will not settle onFucus serratus.S. rupestrisis found typically on rock surfaces in well-illuminated places throughout the lower half of the shore, generally associated withLithophyllum. It is abundant on the shores of south-west Britain, except where there is scouring by wave-borne particles.
The sexuality and spawning of Manx Pectinids
Authors: Reddiah Kosaraju 
Published: May 2009

The results of a comparative study of the breeding biology of the Manx pectinids with special reference to Chlamys varia, C. distorta, C. tigerina, C. striata and C. furtiva are presented.It is shown that C. varia and C. distorta are protandric hermaphrodites with separate sexual phases similar to those of oysters, and evidence is presented on the possibility of sex reversal. The other species, C. tigerina, C. striata and C. furtiva, are truly dioecious, possessing at no stage germ cells of both sexes in the same gonad and as most individuals produce only one brood, the possibility of sex reversal is excluded.C. distorta has two large-scale or peak spawning periods, once in summer and for the second time in autumn, although some spawning occurs as a rule in most months of the year. The breeding behaviour of this species is intermittent and therefore the breeding period is prolonged.C. varia has two mass spawnings in a year, once in June and for the second time during September and October and the breeding period is not markedly different from that observed in French waters. Spawning is usually completed within a short period. C. tigerina and C. striata spawn only once annually in June and August respectively and most individuals have only one breeding cycle during their life time. C. furtiva however, may have two spawnings in a year, but the material available was inadequate to confirm this.
The Saltash Tuck-Net Fishery and the Ecology of some Estuarine Fishes
Authors: Hartley P. H. T. 
Published: May 2009

The Saltash tuck-net is used in the estuaries of the Tamar and Lynher for seine netting on soft mud. The fishery is carried on during autumn and winter, from open boats with crews of two men.Hauls were made with a tuck-net in every month between November 1935 and December 1937.The fish population of the estuaries is essentially marine: its composition changes from month to month with the arrival from, or departure to, the sea of different species of fish. With the exceptions of salmon (Salmo salar), sea trout (Salmo trutta) and some of the Gobiidae, all the fishes of the estuaries go down to the sea to spawn.
The ecology of the Tamar Estuary IV. The distribution of the fauna and flora on buoys
Authors: Milne A. 
Published: May 2009

Buoys differ from the intertidal area in that they are constantly immersed near the surface of the water and the slope and texture of their surface is constant. The horizontal and vertical distribution of the macrofauna and macroflora on a series of buoys stretching from the open sea up the Tamar estuary is given.There are differences in estuarine penetration even among species belonging to the same genus. Distribution is likely to be affected by the time of laying the buoys and the period in the water. But the six buoys farthest from the sea were laid down and lifted at approximately the same time. For these, at least thirty species were available for colonization, but little more than half that number was found even on the most seaward; and the number decreased up-river.
On the faunas inhabiting intertidal seaweeds
Authors: Colman John 
Published: May 2009

This paper gives an account of a survey of the invertebrate populations (omitting Protozoa) of eight species of seaweeds on Church Reef, Wembury Bay, extending over the entire intertidal range.Above high-water neaps the faunas are poor, except for that in Lichina pygmaea which is the richest in individuals on the shore.Between high-water neaps and low-water springs the most numerous groups are copepods, acarines, young littorinids and (in Ascophyllum only) ostracods.In the holdfasts of Laminaria digitata polychaetes are very abundant and make up the majority of the population.The intertidal faunas are compared with those in the soil on land, and prove to be far more abundant. Even the most plentiful group in the soil, the insects, is rarely as numerous as it is in Ascophyllum around mean sea-level.Altogether 177 species are recorded, of which 35 are not in the Plymouth Marine Fauna (1931).
A preliminary study of the ecology of a mud-flat
Authors: Rees Colin B. 
Published: May 2009

Ten stations, from high water to low water, were investigated along a mud-flat in the Bristol Channel.The mud was analysed for water content and grade. The values suggested, with other observations, that the stations were distributed over two different areas.Quantitative analysis of both macrofauna and microfauna revealed a dense mud population.The operative ecological factors, including the food cycle, are defined.