bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Indian Ocean giant tortoise Testudo gigantea on Aldabra
Authors: Gaymer R. 
Published: August 2009

The Indian Ocean giant tortoise survives on Aldabra, an atoll north‐west of Madagascar. The Bristol Seychelles Expedition estimated the total numbers as 33,000 during visits in 1964 and 1965. Growth and movements were recorded during marking experiments. The growth rate with size is plotted, the time scale being derived from the number of rings on the shields of the shell; and the growth curve is compared with that for captive tortoises.Variation in many characters of supposed taxonomic value is explained as the influence of environmental factors on the normal growth pattern, and of non‐adaptive differences expressed during adult life. The present separation of north and south Aldabra, and Seychelles forms is not supported.An explanation is suggested for the uniformity of shape among tortoises.Observations were made on the feeding, diurnal movements and mortality of tortoises on Aldabra.
The external morphology and life history of the pseudoscorpion Microcreagris cambridgei
Authors: Gabbutt Peter D. , Vachon Max 
Published: August 2009

A study of the five British pseudoscorpions, belonging to the family Neobisiidae, is completed by the present work on the external morphology of Microcreagris cambridgei (L. Koch) with special reference to chaetotaxy. It is concluded that M. cambridgei is more nearly related to Roncus lubricus L. Koch than either is to the genus Neobisium as represented by N. muscorum (Leach), N. carpenteri (Kew) and N. maritimum (Leach). The presence of a galea on the movable finger of the chelicera of M. cambridgei is discussed in relation to its significance as a subfamilial characteristic.Limited quantitative sampling and a Tullgren funnel extraction technique reveal that one generation is produced each year. The breeding season is short, the protonymphs are free‐living and deuto‐ and tritonymphs overwinter to mature the following summer. It is possible that adults breed for at least two years.Le présent travail termine l'étude des modifications morphologiques que subissent les espèces de Pseudoscorpions britanniques, appartenant à la famille des Neobisiidae, au cours du développement post‐embryonnaire qui comporte 4 stades: protonŷmphe, deutonymphe, tritonymphe et adulte. Les résultats obtenus confirment et complètent ce qui a été signale pour: Neobisium muscorum, Neobisium carpenteri, Neobisium maritimum et Roncus lubricus. Les variations numériques de la chaetotaxie, de la trichobothriotaxie ne cachent pas l'existence des stades mais, au contraire, permettent leur distinction avec plus de facilityé. On constate, au cours du développement que si certains caractères (soies fiagellaires, soies coxales, trichobothries etc.) se somplètent à chaque stade, d'autres s'arrětent, se stabilisent (soies céphalothoraciques, soies chélicériennes par exemple) à un stade donné et leur nombre, leur position, ne changent plus.La comparaison des formules chaetotaxiques et des diverses structures montre que Microcreagris cambridgei est plus proche des Roncus que des Neobisium. La présence d'une galéa au doigt mobile des chélicères est discutée en tant que caractère sous‐familial.L'étude de la densité des populations de nymphes et d'adultes est faite par prélévements, régulièrement accomplis au cours de plusieurs années en plusieurs stations. On peut admettre l'existence d'une seule génération annuelle et de chevauchements possibles de générations.
The cuticle of the Aplacophora and its evolutionary significance in the Mollusca
Authors: Beedham G. E. , Trueman E. R. 
Published: August 2009

The cuticle of Proneomenia consists of a mucoid matrix containing calcareous spicules and is secreted by the mantle epithelium at the base of the ventral (pedal) groove and over the general body surface. Histochemical examination shows the matrix to be composed of a glycoprotein complex with high acid mucopolysaccharide and low protein contents in which tanning plays little part in stabilization.The cuticle of the Aplacophora is tentatively equated with an early mucoid stage in the evolution of the molluscan shell and it is suggested that secretion of additional protein, followed by hardening by quinone‐tanning, are necessary further stages before a calcified shell evolves. The aplacophoran cuticle is compared with that of Acanthochitona (Polyplacophora) and, although they are similar in many respects, the latter has in addition a discrete inner cuticular layer whichmay act as a semi‐conducting membrane in the deposition of the calcareous plates. The spicules are similar in both groups, each being secreted within a thin cup‐like membrane which exhibits somewhat similar properties to the inner cuticle.
The larva of Oculotrema hippopotami (Monogenea: Polystomatidae)
Authors: Thurston June P. 
Published: August 2009

Oculotrema hippopotami Stunkard parasitizes the eye of the hippopotamus and is the only monogenean known from a mammalian host. Eggs from the uterus of O. hippopotami hatch in water in about 30 days at 24 to 26°C. The ciliated larva resembles the larvae of other polystomatid monogeneans, apart from the absence of hamuli and the unequal lengths of the two intestinal caeca.Up to 62 eggs are stored within the uterus of the mature worm. They are not expelled when the worm is transferred from the eye of the hippopotamus to a tube of water. Development starts when the eggs are placed in fresh‐water. There is no development in saline, and no evidence to suggest that larvae develop in situ around the eye, although very small worms have been collected from this site.
Oösorption in Nasonia vitripennis (Hymenoptera: Pteromalidae)
Authors: King P. E. , Richards J. G. 
Published: August 2009

The process of oösorption is described. Leucine amino peptidase and esterase produced by the follicle cells remove the chorion and vitelline membrane. The oölemma grows into the oöcyte and islands of degeneration are formed. The follicle is the entity of oösorption and is isolated from adjoining follicles.Under conditions of host deprivation oösorption begins earlier in older individuals than younger ones whose fat body is still large before egg production reaches its peak. The time of onset may be correlated with the reduction in the size of the fat body following the peak of egg production. This suggestion is supported by the reduced longevity of starved older individuals compared with younger ones.Age has no effect on the rate of oösorption.
Oviduct development and its relation to other aspects of reproduction in domesticated canaries
Authors: Hutchison Rosemary E. , Hlnde R. A. , Bendon B. 
Published: August 2009

The histology and development of the oviduct of unpaired female canaries during the natural breeding season were examined. The histology resembles that of the fowl. The tubular glands develop by invagination of the epithelial cells, and albumen granules subsequently form in their cytoplasm. The epithelium differentiates into ciliated columnar cells and goblet cells. The histology of the magnum is uniform along its length at all stages of development.Oviduct development is closely correlated with that of the ovary. In its early stages there appears to be little correlation between oviduct development and that of the brood patch or of nest‐building. The formation of albumen coincides with the enlargement of one ovarian follicle more than the rest, the completion of defeathering, and intensive nest‐building behaviour.
Numbers of flying fish observed during three voyages across the Indian Ocean
Authors: Plomley N. J. B. 
Published: August 2009

Variation in density of flying fish along a transect across the Indian Ocean between Fre‐mantle and Cape Gardafui, has been studied by counting, during three voyages on freighters, the flights induced by the passage of the ship. Two regions of maximum density were found, one in the region of 7°N., 58°E. and the other in the region of 5°S., 75°E. The causes of variation in the distribution are discussed briefly.The influence of some environmental factors on the flight of fish disturbed by the passage of a ship has been examined, and it has been concluded that wind force and direction, water temperature, and the components of weather, have little influence upon the choice of flight as a means to escape the disturbance. On the other hand, the bearing of the sun in relation to the direction of movement of the fish through the water before taking to flight has a considerable effect, fish being less likely to take to flight when their escape path is directed towards the sun than when it is directed away from the sun.
Temporal relations of brood patch development, nest‐building and egg‐laying in domesticated canaries
Authors: White Sheila J. , Hinde R. A. 
Published: August 2009

Relationships were assessed between brood patch development, nest‐building and egg‐laying in 20 female canaries in the natural breeding season. Twelve of these were unpaired; eight were provided with males after two months of being kept singly. The later laying of some females was due to their more protracted development rather than to their later start. The completion of brood patch defeathering, a certain stage of its vascularity, and the start of intensive nest‐building occurred within a few days of each other whatever the date of egg‐laying. Differences from an earlier study of paired females which had only limited access to nest material can be understood in terms of the known effects of the male and the nest‐cup on reproductive development.All birds showed a period of intensive nest‐building beginning about eight days before egg‐laying, with a peak about three days before. In those females in which the period of intensive building lasted for more than eight days, there was an earlier peak about seven days previously. This, and also the building behaviour of many females even earlier in the season, are in harmony with the view that reproductive development is not progressive, but intermittent.
Some new Heliconius pupae: their taxonomic and evolutionary significance in relation to mimicry (Lepidoptera, Nymphalidae)*
Authors: Turner John R. G. 
Published: August 2009

Pupae thought to belong to the butterflies Heliconius burneyi, H. tales, H. aoede, H. xanthocles and H. clysonymus are briefly described.Division of the genus according to morphology, especially of the pupae, shows that the Mullerian mimicry shown by some species, for instance, the “red‐and‐yellow”H. melpomene, H. erato, H. burneyi and H. aoede and the “blue‐and‐yellow”H. wallacei and H. sara, results not simply from failure to diverge but from convergent evolution of the patterns. There is some evidence that the larvae have evolved Mullerian mimicry.The pupa of H. doris is dimorphic for a striking morphological character—the presence
Competition and extinction: the mice of Foula, with notes on those of Fair Isle and St Kilda
Authors: Berry R. J. , Tricker B. J. K. 
Published: August 2009

House mice (Mus rnusculus muralis) on St Kilda became extinct within about 18 months of the human population leaving the island in 1930. Although it was argued at the time that they died out because they were unable to find enough food, house mice flourish on a number of uninhabited islands and it seems more probable that they could not successfully compete with the Long‐tailed field mouse (Apodemus sylvaticus) in the absence of man.A study of the distribution and diet of both house and field mice on the Shetland islands of Foula and Fair Isle shows that the house mouse populations tend to be centred on human dwellings, although both species were found apparently living together on Foula away from habitation. The natural history of the two species is reviewed, and it is concluded that the breeding of the house mouse is the most probable characteristic to be upset by disturbance, and that the disappearance of man on St Kilda allowed Apodemus to enter a habitat previously occupied almost exclusively by Mus.
Peristaltic waves of tubicolous worms and the problem of irrigation in Sabella pavonina
Authors: Mettaw C. 
Published: August 2009

A simple scheme is presented to illustrate four possible kinds of locomotory peristalsis in worm‐like animals. The application of this scheme to real animals is discussed. Peristaltic waves may be of constriction or dilatation. A continuous body cavity enables the worm to regulate both speed and direction of travel by controlling the relative tonus of its body wall muscles. Thus peristaltic waves can be used to pump water without causing locomotion. Sabella irrigates its tube by peristaltic swellings but the coelom and intestine are sub‐divided by entire septa. Anatomical and morphological features which allow the shortest, widest segments forming a “piston” to slide down the tube and the narrower elongated segments to grip its walls are considered. In this way the construction of the typical body segment is given a functional explanation.The functions of septa in annelids are discussed.
A study of the egg shells of the Gaviiformes, Procellariiformes, Podicipitiformes and Pelecaniformes
Authors: Tyler C. 
Published: August 2009

Egg shells of the Gaviiformes, Procellariiformes, Podicipitiformes and Pelecaniformes have been studied using general inspection, chemical analysis, histological and plastic embedding techniques.In all four orders there is a true shell consisting of large crystals having their origin at the surface of the membrane. In the Gaviiformes and Procellariiformes, the true shell is then covered with a cuticle, while in the Podicipitiformes and Pelecaniformes (except for the Phaethontidae) there is a calcareous cover over the true shell. Histological studies showed no major difference in the organic matrix of the true shell as between the four orders.Pore channels are all single and, in those egg shells which have a cover, these channels do not penetrate the cover. Considerable pigmentation is present in the Gaviiformes egg shells and also in the Phaethontidae, and pigment spots occur not only on the surface but also in the body of the shell. Studies of the apparent density of the true shells and the covers showed interesting differences.The taxonomic aspect of the results is discussed.
The incidence of the Pea crab, Pinnotheres pisum in the two types of Mytilus (Mollusca: Bivalvia) from Padstow, south‐west England
Authors: Seed R. 
Published: August 2009

Significant differences in the infection of M. edulis and the “Padstow type” mussel with P. pisum are recorded, and some possible explanations for these differences are discussed.Both types of Mytilus from the mid and lower regions of the mussel bed showed heavier infections than mussels higher on the shore. Even so, the differences between the two types were still maintained.A relationship exists between crab and mussel size, larger crabs being found only in larger hosts. The smallest mussel found to be infected with Pinnotheres measured 3·35 cm in length.Infection in M. edulis was found to increase with increased size of host, the largest occurring mussels having from 80 to 100% infection. Larger mussels occurred in greater numbers in the low shore. It is assumed that infection in the “Padstow type” would show a similar relationship if sufficient recordings had been available.The presence of the crab causes gill damage, and infected mussels show considerably lower tissue weights and slightly greater shell weights than uninfected mussels of similar size.The presence of the crab does not appear to influence the reproductive capacity of the mussel.
The stimulus to egg‐laying in the Bengalese finch
Authors: Slater Peter J. B. 
Published: August 2009

The effects of mate and nesting facilities on the occurrence of egg‐laying were examined in the Bengalese finch.Egg‐laying is unusual in isolated females and those kept in large groups. It is more common in monosexual pairs, and its incidence in them is not markedly altered by whether males can be heard or not. Females in heterosexual pairs usually lay within three weeks of pairing. A similar lag was found in pairs separated by bars, pointing to copulation being unnecessary.Carrying of nest material to the nest box is mainly done by males. It is unusual in isolated birds, but occurs in monosexual and heterosexual pairs, and in pairs separated by bars.Egg‐laying is delayed in the absence of hay for nest building. A delay was also found in pairs separated by bars, when only the male was given nest material: this indicates that personal experience by the female is important. Heterosexual pairs deprived of nest boxes, but given nest material, were not recorded as laying.It is concluded that egg‐laying is stimulated by mate and nest material in a complex fashion. The various stimuli these provide interact to a greater or lesser degree to give the physiological and behavioural changes observed.
The biology and ecology of the fishes of a small tropical stream
Authors: Welcomme R. L. 
Published: August 2009

Many small species of fish are found in the stream/swamp systems that flow into Lake Victoria. One such system, in Uganda, was inhabited permanently by only one species, although others ran into the stream when it was flooded in the rainy seasons. Other fishes were confined to the lower reaches near the mouth, but never moved far upstream.Studies on the biology of these fishes indicate that reproductive behaviour is generally confined to the rains in all species, the cyprinids using the system especially for breeding purposes at these times. Factors other than sexual state, such as feeding habits, vary little between fish from the river and those from the lake.Experiments show that there is a change in the sexual state of the females of one species during the journey upriver, indicating the importance of this activity in the life cycle of the migratory fish.The young of the cyprinids first appear in the up‐river swamps. Here they grow, migrating to the river and moving downstream to enter the lake after periods of time that are characteristic for each species. This distinctiveness in timing was also found for the other fishes that inhabit the system, and it suggests that downstream migration is controlled by changes in the physiological state of the fish with age.
The snapping strength of the egg shells of various orders of birds
Authors: Tyler C. 
Published: August 2009

A study of the snapping strength (S) of egg shells and its relationship to the square of the thickness (T2) has been made on seven orders of birds and also in respect of a few shells of ratite birds, domestic fowl and guinea fowl.There are considerable differences in strength between the egg shells of different orders of birds and when shells are snapped outwards the egg shells of Sphenisciformes are almost twice as strong as those of Podicipitiformes for a given thickness. The shells of the guinea fowl are very strong and those of the domestic fowl weak compared with the seven orders when they are snapped inwards.Comparisons of the strength of shells with and without the outside chalky cover, which occurs on the egg shells of Sphenisciformes, Pelecaniformes and Podicipitiformes, show very variable relationships, while comparisons of inward and outward snapping strength indicate that in some orders the difference is great but that in others it is negligible.The presence or absence of a cover on the shell could not explain any difference in snapping strength, nevertheless, a few tests on Pelecanus shells using impact strength showed that then the cover adds considerably to the strength. No other shell characteristics could explain the differences in snapping strength.
The natural control of a population of Tawny owls (Strix aluco)
Authors: Southern H. N. 
Published: August 2009

A long‐term study was made (1947‐59) of the numbers and breeding success of the Tawny owl (Strix aluco L.) in a woodland habitat near Oxford. Parallel studies were made of the numbers and distribution of the owl's two main prey species, the Wood mouse (Apodemus sylvaticus (L.)) and the Bank vole (Clethrionomys glareolus (Schr.)).The life‐cycles of all these three interrelated species were worked out and special attention was paid to the habit of strict territoriality of the owl (on the evidence of vocalizations and of the recovery, from the regurgitated pellets of the owl, of marking rings placed on the rodents) and to the sequence of losses which occurred during the breeding of the owl. The owls' vocal defence of their territories enabled an accurate census to be made of the adult population each spring and the fact that the fledged young remained for a long time in their parents' territories made it possible to count the number of young produced each year. Investigation of the breeding habits of the owls showed that the number of fledged young produced fell far short of what was possible: some pairs of owls refrained from breeding at all, others laid eggs but failed to hatch them, yet others hatched young but failed to rear them to fledging. By and large this degree of reproductive “failure” was associated with the numbers and availability of rodent prey. At an exceptionally low density of prey no owls even attempted to breed; as densities increased, correspondingly greater numbers of fledged young were produced up to a ceiling where no more young were produced however much higher the level of abundance of the rodents rose.In spite of these wide variations in the numbers of prey and in the numbers of fledged young produced, the population of adult owls remained notably stable, increasing from a low level of 17 pairs in 1947, owing to the emergency mortality of an exceptionally hard winter, to about 30 pairs in 1955, after which the population remained stationary until the end of the study in 1959.It is clear that this stability is maintained by those young which fail to find a territory either starving or moving outside the study area, which in most cases amounts to the same thing. Thus regulation of the population studied was due to territorial intolerance acting to produce subsequent mortality, though it is not certain that this applies over a larger area.
Some observations on the histology of the ovary and RNA synthesis in the ovarian tissues of the starfish, Henrida sanguinolenta
Authors: Chia Fu‐Shiang 
Published: August 2009

The general histology of the ovary and the cellular morphology of oöcytes in Henricia sanguinolenta (Muller) Bell is described.The single nucleolus in the germinal vesicle begins to multiply when the oöcyte is 90 μm in diameter, either by fragmentation or by budding and it reaches several hundred in number in a full grown oöcyte of 1200 μm in diameter. At no time during the oöcyte growth is RNA synthesis in the nucleolus or any other parts of the oöcyte detected by autoradiographic techniques. However, follicle cells and coelomocytes in the ovary are actively synthesizing RNA during this period.The inactivity of RNA synthesis in oöcytes is discussed.