bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and morphology of the glochidium larva of Anodonta cygnea (Mollusca: Bivalvia)
Authors: Wood Elizabeth M. 
Published: August 2009

The development of the parasitic glochidium larva of Anodonta cygnea L. is outlined, with reference to earlier studies on unionid larvae, and a comparison is made between the mature glochidia of the three genera, Anodonta, Unio, and Margaritifera.The glochidium of Anodonta cygnea is anatomically and morphologically specialized in connection with its parasitic existence. The specialized structures are described, and their significance discussed.
A re‐examination of the subspecies of Red deer (Cervus elaphus) with particular reference to the stocks in Britain
Authors: Lowe V. P. W. , Gardiner A. S. 
Published: August 2009

In 1906, Lönnberg identified a native subspecies of Red deer Cervus elaphus scoticus L., in Britain after examining a sample of stags' skulls from Glenquoich (Inverness‐shire, Scotland). In north‐west England, it is commonly believed that “Red deer of indigenous stock have persisted in this area (Furness Fells, Lancashire, England) from time immemorial…” (Chard, 1966). Arrangements were made to introduce animals into a park within this area in 1970, which, in view of this local opinion, would have been the only Red deer within the district not of native origin. Therefore, it was thought desirable to examine all the stocks of wild or feral Red deer in Britain and to determine which, if any, of them could be considered native and thus deserving of special measures to ensure their survival.After examining samples of skulls, using multivariate analysis, it appeared that, within the limits of the material representing the various subspecies of the world, there was little support for the concept of subspeciation in Red deer. In Great Britain, however, there appeared to be two distinct forms of Red deer leading a free existence, one presumed to be native and the other to be of park derivation. Visually, the differences were indetectable and could be demonstrated only by discriminant analyses.
The Grapsidae and Ocypodidae (Decapoda: Brachyura) of Tanzania
Authors: Hartnoll R. G. 
Published: August 2009

Twenty‐nine species of the Grapsidae and 15 species of the Ocypodidae were collected from the littoral zone in the area around Dar es Salaam. Nine species of Grapsidae and three of Ocypodidae were new records for the East African area, bringing the total of recorded species for the region to 35 and 26 respectively. The distribution of these crabs indicates a very limited endemism in the western Indian Ocean, with the majority of species forming an attenuated extension of the abundant Indo/West Pacific brachyuran fauna.The habitat preference of each species is described. Within each subfamily there is a relative uniformity in general habitat preference, mode of life and manner of feeding. The species of each subfamily are then separated by substrate choice and preferred level on the shore. The greatest numbers of species occur in the most diverse habitats—the creek mangrove, the coastal mangrove and the reef flat.
The ultrastructure of the small granular, proteinaceous epidermal cells of some British lumbricids (Annelida) and a reassessment of the identity of the so‐called albumen cells
Authors: Richards K. Sylvia 
Published: August 2009

The ultrastructure of the small granular, proteinaceous cells of 11 species of lumbricid earthworm is described and no species differences were recorded. The cells are characterized by the presence of membrane‐bound, electron dense granules (0.6–0.7 urn in diameter) arising from polarized Golgi systems in close topographical relationship to the granular endoplasmic reticulum. Variations in electron density of the granules appear to be associated with maturation of the granules. The granules show a finely reticular substructure at high magnification. A less than fully mature stage of this cell type is described.The occurrence of the small granular cell type in the annelids is discussed, as is the possible function of its secretion.The confusions in the lumbricid literature concerning this cell type are discussed, and the much referred to figure of the ‘albumen’ cell type in English texts is shown not to be equivalent to the small granular, proteinaceous type referred to in this and a previous histochemical study.
Evidence for social difference in the flank organ secretion of Arvicola terrestris (Rodentia: Microtinae)
Authors: Stoddart D. Michael , Aplin R. T. , Wood M. J. 
Published: August 2009

Gas‐liquid chromatographic and mass spectroscopic analysis of secretion from the flank organs of Arvicola terrestris (L.) reveals a complex mixture of long chain esters, with the possible addition of some other substances and certainly cholesterol. Each g.l.c. peak consists of a series of isomers of the particular compound.By comparing the proportion of the total peak height contributed by individual peaks, it was possible to analyse chromatograms to identify differences in pattern of peak height proportion between the sexes, between adult and juvenile animals of each sex, between families and between populations. There is little obvious difference between the sexes but quite marked differences between adult and juvenile animals. Comparison of samples taken from a population in June, when density was low and the breeding season had just begun and September, when density was high and the breeding season was drawing to a close, showed marked differences—especially in females. Cholesterol is a very important constituent of female flank organ secretion in June but much less important in September. Families born in captivity show significant differences between chromatogram peak patterns. The occurrence of highly significant differences between populations suggests the presence of olfactory dialects. It is not known whether this is genetically or environmentally influenced.These observations indicate the range of difference in sebaceous output found in one species of rodent, and suggest that sexual condition and group affiliation is expressed in glandular secretion thought to be used for range demarcation.
Water usage and diet preferences of free ranging kangaroos, sheep and feral goats in the Australian arid zone during summer
Authors: Dawson Terence J. , Denny M. J. S. , Russell Eleanor M. , Ellis Beverley 
Published: August 2009

In much of the arid rangelands of Australia the common large mammalian herbivores are the native marsupials, the Red kangaroo (Megalein rufa) and the Euro (Mucropus robustus), and the introduced eutherian species, the domestic sheep (Ovis aries) and the feral goat (Capra hircus). In the north west of New South Wales a study was carried out to examine the patterns of water usage during summer of these species when they were free ranging in the same area. Drinking frequencies, water turnovers, electrolyte concentrations and diet preferences were determined and information obtained on movements and dispersal from watering points.The marsupials had a much lower water usage than either of the eutherians. The tritiated water turnover of the goats was three times and that of the sheep four times the value obtained for kangaroos. While much of the difference between the marsupials and eutherians appeared to be due to fundamental physiological differences the high water usage of sheep was in part related to the high intake of halophytic plants in their diet.The water turnovers of the Red kangaroos and Euros were not found to be different. Drinking studies and urine osmolalities suggested, however, that the open plains dwelling Red kangaroos had a higher water requirement than the hill inhabiting Euro.The principal components of the diets of the Red kangaroo were grasses; of the Euro, grasses and shrubs; of goats, trees and shrubs; of sheep, halophytic shrubs.
An investigation of the factors influencing mean cell volume in populations of the ciliate Colpidium campylum
Authors: Laybourn Johanna E. M. 
Published: August 2009

Variation in mean cell volume of the ciliate Colpidium campylum Stokes is described in relation to energy consumption, temperature and population density. Mean cell volume was unaffected by temperature and population density, while energy consumption had a marked effect. A linear relationship existed between mean cell volume and energy consumption up to an energy intake of 8000 μJ during 24 h by each individual present at the beginning of each experiment, above this level of energy intake mean cell volume maintained a maximum.SummaryWithin the temperature range 10°C‐20°C, temperature had no effect on the mean cell size of C. campylum. Population density also exerted no noticeable effect on mean cell volume. The quantity of energy consumed, however, had a marked effect. In experiments where less than 8000 μJ were consumed/individual/24 h, the mean cell volume decreased. Above this level of energy consumption mean cell volume maintained a constant level.The maximum values obtained for cell sizes were 160–190 × 103μm3 and the minimum values 40–100 × 103μm3. A response to decreased food concentration and hence decreased energy consumption was obtained within the 24 h experimental period, indicating a rapid response to changed environment by the ciliates.
The mechanics of hopping by kangaroos (Macropodidae)
Authors: Alexander R. McN. , Vernon Alexandra 
Published: August 2009

Force‐platform records and films of kangaroos and a wallaby hopping have been analysed to obtain data about the energetics of hopping and about the stresses which act in muscles, tendons and the tibia. The quantitative anatomical data required for the analysis have been obtained from X‐radiographs and dissections. It is shown that fluctuations of potential energy and external kinetic energy account for most of the energy cost of hopping; fluctuations of internal kinetic energy are relatively unimportant. Evidence is presented that large savings of energy are effected by elastic storage of energy in the gastrocnemius and plantaris tendons. The elastic mechanism is particularly effective at high speeds and seems to account for the observation of Dawson & Taylor (1973) that oxygen consumption is more or less constant over the whole range of hopping speeds. A mathematical model of hopping is presented. The stresses which occur in hopping are discussed.SummaryForce platform records and films have been made of kangaroos and a wallaby hopping.The maximum forces exerted on the ground were about six times body weight. The force exerted on the ground changes direction, throughout the period when the feet are on the ground, so that it is always more or less in line with the centre of mass. Consequently the animal decelerates a little and then accelerates again, during the contact phase.The fluctuations of potential energy which occur in each hop are slightly smaller at high speeds than at low ones. Fluctuations of external kinetic energy increase with speed and account for most of the energy cost of hopping at high speeds. Fluctuations of internal kinetic energy (due to acceleration and deceleration of the limbs) are relatively small. While the feet are on the ground the extensor muscles of the hip do positive work, those of the knee negative work and those of the ankle negative work followed by positive work. The energy cost of hopping is reduced substantially by elastic storage of energy in the Achilles tendon. In the case of a wallaby hopping at moderate speed the calculated saving was 40%. The maximum stresses developed in leg muscles, tendons and the tibia have been calculated and are discussed in relation to the known properties of muscle, tendon and bone. The trunk pitches as the animal hops because the two legs swing forwards and back simultaneously. Appropriate tail movements reduce, but do not eliminate, this effect. A mathematical theory of hopping is presented and used to investigate the merits of different hopping techniques.Dawson & Taylor's (1973) discovery that the rate of oxygen consumption of kangaroos decreases a little, as hopping speed increases, is probably to be explained by the increased role of elastic storage of energy at high speeds.
Studies on the effects of bait and sampling intensity on trapping and estimating Wood mice, Apodemus sylvaticus
Authors: Gurnell J. 
Published: August 2009

The effects of baiting a Longworth trap with whole oats and the density of traps on an area, or sampling intensity, on trapping and estimating Wood mice were studied on two neighbouring woodland plots in November 1971. Standard capture‐mark‐recapture (CMR) methods were used for two weeks followed by five nights of removal trapping.The presence of bait significantly increased the likelihood of capturing marked and unmarked animals. By increasing the sampling intensity a greater proportion of the population was sampled, although the number of animals captured per trap night decreased. These results have been related to the “effective” number of traps on an area.Observations on population structure, weather, movement and capturing marked and unmarked animals have been made. CMR population estimates closely resembled the cumulative number of individuals captured in each study and were for the main part lower than the estimates from the removal trapping carried out at the end of the studies.
Kinetics of smimming in some smooth‐bodied polychaetes
Authors: Clark R. B. , Hermans Colin O. 
Published: August 2009

The opheliids Amniotrypane and Armundiu have very small parapodia bearing few chaetae, and these are pressed back against the body when the animals swim; the archiannelid Polygordius lacks parapodia and chaetae. All three worms have smooth bodies and swim by retrograde sinusoidal movements in the same way as other long, narrow, smooth‐bodied animals, unlike nereidiform polychaetes in which the parapodial beat provides the driving force and the body undulations travelin the same direction as that of locomotion.The wavelength of the undulations is comparable to the body length of these smooth polychaetes and this generally results in pronounced yaw. The kinetics of swimming are similar to those observed in nematodes and the amphioxus, and these polychaetes have comparable structural and mechanical features. A thick cuticle containing a spiral fibre system and lacking circular body‐wall muscles is comparable to the situation in some nematodes, but in these polychaetes transverse muscles antagonize the longitudinal muscles and may allow adjustment of the internal hydrostatic pressure‐and hence the stiffness of the body‐as in the notochord of amphioxus which has similar swimming characteristics.Like amphioxus, these polychaetes leave and re‐enter the substratum in which they live. The small archiannelid Protodrilus has a similar muscular anatomy to that in Polygordius, but has a thin cuticle without spiral fibres. Prorodrilus has not with certainty been observed to swim.
Chemical composition of the body fluids andmuscle of the hagfish Myxine glutinosa and the rabbit‐fish Chimaera monstrosa
Authors: Robertson James D. 
Published: August 2009

Comprehensive analyses have been made of the plasma and parietal muscle of the marine cyclostome Myxine glutinosa and of the chimaeraoid Chimaera monstrosa, and the sum of some 17 constituents compared with the directly determined osmotic concentration of plasma. Both Myxine and Chimaera plasmas are isosmotic with sea water within 2%. Ions account for at least 96% of the total concentration of the plasma in Myxine and about 60% in Chimaera, but the blood of the latter contains 332 mM urea, compared with 3 mM in Myxine. In muscle a similar divergence exists, the urea concentrations per kilogram muscle water being practically the same as in the respective plasmas of the two species. The mean values in millimoles of the other nitrogenous constituents of muscle are for Myxine and Chimaera (figures for latter in brackets), trimethylamine oxide 87 (189), betaine 65 (38), creatine and creatinine 30 (37), amino acids 291 (43). Using osmotic coefficients the calculated osmotic concentration of muscle exceeds that of plasma in Myxine and possible reasons for this are discussed.Estimates of inulin space in Myxine muscle have enabled intracellular concentrations of ions to be calculated. Analysis of Myxine bile shows it to have much higher concentrations of sodium, calcium and magnesium, and much lower chloride, than plasma. The resulting large anion deficit is presumably made up chiefly by the bile salt myxinol disulphate.
Dual bioluminescent systems in the anglerfish genus Linophryne (Pisces: Ceratioidea)
Authors: Hansen Kjeld , Herring Peter J. 
Published: August 2009

Females of the anglerfish genus Linophryne bear barbels containing luminous organs, in addition to an escal light organ. Luminescence has been observed from the barbels of four species of Linophryne, and the morphology of the luminous organs investigated. The barbel light organs do not contain bacteria but complex paracrystalline photogenic granules. The esca contains luminous bacteria. The esca is ectodermal in origin whereas the barbel organs may be derived from the mesoderm.The possible significance of this unique dual system of luminous organs is discussed.
The House mice of the Faroe Islands: a study in microdifferentiation
Authors: Berry R. J. , Jakobson M. E. , Peters Josephine 
Published: August 2009

The House mice (Mus musculus L.) of the Faroe Islands (62°N, 7°W) are frequently quoted as examples of rapid evolution, because they seem to be clearly differentiated both from mice in other parts of the world, and between different islands within the Faroe group despite being introduced through human agency within the last millennium. They are also of interest in being among the most climatically stressed mice in the Northern Hemisphere.The present study is an attempt to determine the extent of differentiation between the populations on the six Faroe islands which harbour mice. It is based on size and organ weights, measurements on the mandibles and scapulae, non‐metrical variation of the skeleton, and allozymic frequencies at 22 loci. Distance statistics calculated for all five groups of data between samples from each island compared with every other, showed that all the populations were clearly distinct. However the distances calculated from the different data were disconcertingly heterogeneous. The most likely explanation is that the different characteristics scored each depend on a relatively small number of different genes.Taking all the results together, it seems most probable that mice first entered the Faroes via the main port of Torshavn and spread from there to Nols0y, Hestur and Sand0y, and from Sand0y to Fugloy and Mykines. The large inter‐island differences can be attributed primarily to “instant sub‐speciation” produced by each colonization depending on a probable small number of effective founders.
The cell kinetics of teleost fish epidermis: Epidermal mitotic activity in relation to wound healing at varying temperatures in plaice (Pleuronectes platessa)
Authors: Bullock Alistair M. , Marks Ronald , Roberts Ronald J. 
Published: August 2009

An autoradiographic study of experimental wounding of the skin of juvenile plaice was performed using tritiated thymidine (20 μCi per gram body weight) injected intraperitoneally, at water temperatures of 5, 10 and 15°C.Samples of lesion were taken at regular intervals up to 108 hours and autoradiographic preparations made. In addition wounds of less than 12 hours duration, unsuitable for autoradiography were examined and in vitro explant autoradiography studies on similar material used to support the findings for these short term lesions. Results showed that there was a very rapid migration of Malpighian cells into the defect which was not accompanied by any evidence, over the time‐scale of the study, of a mitotic burst. Adjacent normal skin was markedly reduced in thickness. Closure of these relatively small wounds was achieved within nine hours at 10°C and by 12 hours at 5°C. The thickness of the migrated epidermal cover was much thicker at 15°C than 5°C.Numbers of labelled cells were similar in migrating and peripheral epidermis and mucous cells appeared to be randomly distributed except in the periphery of advancing migrating cells, where thev were absent.
The diurnal rhythm and the processes of feeding and digestion in Tridacna crocea (BivaMa: Tridacnidae)
Authors: Morton Brian 
Published: August 2009

Tridacna crocea Lamarck 1819 possesses a diurnal rhythm of activity. During the daylight hours the hypertrophied siphonal tissues, containing zooxanthellae, are expanded and phasic adductions occur that pump fresh sea water into and filtered water and pseudofaeces out of the mantle cavity. During the night the shell valves become more apposed, the mantle folds are withdrawn and few phasic adductions occur. Such a pattern of activity is similar to that described for other sublittoral bivalves.With this cycle of activity and inactivity is correlated the process of extra‐cellular digestion of filtered food in the stomach. This is accomplished by the alternate, but incomplete, dissolution and subsequent reformation of the crystalline style. The style partially dissolves at night and reforms during the day. The digestive diverticula undergo a sequence of cytological changes related to the intra‐cellular digestion of filtered food, again related to the cycle of night and day and thus to feeding.During the night there is a transport and intra‐cellular digestion of zooxanthellae by amoebocytes from the mantle to the haemocoel surrounding the visceral mass. During the day digested zooxanthellae are transported to the digestive diverticula where they are discharged (together with the waste products of the intra‐cellular digestion of filtered food) into the tubule lumina and thus back into the stomach to be eventually voided via the anus.Recognizable zooxanthellae are also transported to the kidney, where they are taken up by the cells of the distal limb to form cellular globular concretions; these too are probably also eventually voided.The discharge of digested zooxanthellae via the digestive diverticula has resulted in modifications to the processes of tubule breakdown and reformation involving the digestive cells only. These unique modifications are described and compared with the structural changes seen in the digestive diverticula of other bivalves.It is concluded that the unusual functioning of the digestive diverticula is a direct consequence of the utilization by Tridacna of a secondary source of food without the concomitant evolution of special organs of digestion, as for example there has been in the Teredinidae feeding on filtered food and wood. Specific comparisons are made between the Tridacnidae and the Teredinidae and suggestions are made as to how zooxanthellae came to be used as food in these unusual bivalves.
The luminescence and photophores of euphausiid crustaceans
Authors: Herring P. J. , Locket N. A. 
Published: August 2009

Euphausiid shrimps bear light organs, two pairs in the thorax, and four similar single organs in the abdomen: A pair on the eyestalks differ in structure from these others, and are not considered further by us. In most species the size of the organs is related to that of the animal, but they are relatively smaller in deeper living species. In some species certain light organs are larger in males. The flashes of light emitted begin abruptly, remain steady for several seconds and die away slowly. Euphausiids flash in response to light, including that of another euphausiid, and to certain drugs, notably 5 hydroxytryptamine and certain analogues.The photophores contain a lantern where the light is generated, and three separate optical components which reflect and refract the light out of one pole of the organ. Our interpretation of the structures suggests that light generation is probably controlled by alteration of the blood flow through the lantern, and that this in turn is under nervous control.