bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors influencing the breeding of the rabbit flea (Spilopsyllus cuniculi): A spring‐time accelerator and a kairomone in nestling rabbit urine with notes on Cediopsylla simplex, another “hormone bound” species
Authors: Rothschild Miriam , Ford Bob 
Published: August 2009

Accelerated impregnation and maturation of the rabbit flea coincides with the spring peak litter‐size of the rabbit, but its breeding performance falls off before that of the domestic host. A kairomone nestling factor, which boosts copulation, impregnation and development of fleas feeding on the newborn young, is also present in relatively feeble amounts in baby rabbit urine. This urine boosts pairing of matured (=“primed”) fleas united in tubes away from a host, but impregnation is increased only if fleas are feeding on newborn young while exposed to the urine.Undeveloped fleas matured on the pregnant doe require a transfer to another host before they will pair, whereas fleas matured on the nestlings copulate without a transfer. A variable time‐lag between transfer and copulation of fleas, dependent on the “priming” qualities of the preparatory host, suggests that a chemical intermediary is involved.If the antennae of the females are coated with vaseline, the maturation of these fleas is delayed feeding on nestlings, but not on the prepartum doe. This delay is less marked during the spring acceleration than at other times of the year.The breeding of a North American species of hare flea (Cediopsyllu simplex (Baker)) parasitizing Sylvilagus floridanus (Allen) is also controlled by the sex hormones of the host.
Some factors affecting the location of Arthritica crassiformis (Bivalvia: Leptonacea) commensal upon Anchomasa similis (Bivalvia: Pholadidae).
Authors: Morton Brian 
Published: August 2009

Arthritica crassiformis Powell is found in New Zealand waters commensally associated with the pholad Anchomasa similis (Gray). Its location on the host is highly specific and is occasioned by the complex needs of the commensal and the facilities and limitations imposed by the tunnelling activity of the host. Other species of pholad because of different morphological adaptations do not serve as hosts. With increasing size of the host, the number of commensals/host increases which is due to (a) retention of young individuals within the parental burrow and (b) by colonization from the external environment. A. crassiformis typically, however, occurs in pairs and is probably a protandric consecutive hermaphrodite. The young are incubated in the interlamellar spaces of the ctenidia of the parental female. This anatomical adaptation together with others including strong rejectory tracts suit the commensal for a life with an active tunnelling host.The ciliary currents of the mantle cavity of A. similis are described.
The fine structure of the pallial eyes of Laternula truncata (Bivalvia: Anomalodesmata: Pandoracea)
Authors: Adal M. N. , Morton Brian 
Published: August 2009

The structure of the pallial eyes of Laternula truncata (Lamarck 1818) has been studied using the light and electron microscopes. The eye is complex and can be‐ considered to be‐ the most advanced yet described for a bivalve mollusc. The cornea consists of modified flattened epithelial cells with an external border of microvilli. The cornea covers a large, circular, multinucleate lens. The lens comprises (1) centrally located translucent lens cells, (2) laterally located supporting cells from which cell processes interdigitate with processes from the lens cells. The retina is two layered and inverted. The proximal and distal retinae are made up of concentrically arranged laminae derived from the membranes of ciliary basal bodies. The cilia comprise a base and feet, but no root system and have a 9+0 arrangement of filaments.The pigment cup or tapetum is bounded by a sclerotic coat and is three layered, each layer possessing characteristic pigment granules. From the base of the eye arises a large optic nerve.The eye possesses an eye appendage, the epithelium of which is invaginated on its internal border to form a groove within which are found some 28 cilia. The cilia, it is thought, make contact with the microvilli of the epithelium when the appendage is touched. Such an action serves to protect the delicate eye from damage.The structure of the eye is compared with that of other molluscs, particularly members of the Bivalvia.
Ecological studies on crater lakes in West Cameroon. Debundsha Lake
Authors: Green J. , A. Corbet Sarah , Betney Elaine 
Published: August 2009

Cape Debundsha receives 10 m (400 inches) of rain per year, and the water of the small crater lake on the cape has one of the lowest conductivities in Africa (11–13 µmho/cm/20 C). The lake has a maximum depth of 13·5 m. At the time of our visit in April 1972 the lake was stratified with a depletion of oxygen in the hypolimnion. The phytoplankton was dominated by Botryococcus, and the zooplankton was dominated by the ostracod Oncocypris debundshae. Both these organisms are closely associated with the surface film. Other zooplankters included Thermocyclops hyalitws, and in deeper water during the daytime the larvae of Chaoborus ceratopogones.The fauna of the lake includes 12 species of testacean rhizopods, six species of rotifers, two oligochaetes, one snail, seven crustaceans, 15 insects and three acarines. Of the last group two species were new to science and one had been found only once previously. The ectoproct polyzoan, Lophopodella carteri, is recorded for the first time from West Africa, and the second time from Africa. The general impression of the fauna is one of sparseness, with an unusually high proportion of larval Odonata.
Reproduction and “March madness” in the Brown hare, Lepus europaeus
Authors: Lincoln G. A. 
Published: August 2009

The reproductive physiology of hares was studied in 760 animals shot throughout the year, and these observations were related to seasonal changes of behaviour in an attempt to explain the significance of “March madness”.The hare was found to have a prolonged breeding season; at least some pregnant females were found in all months from January to August, and fertile males in all months except October and November. The nadir of the reproductive cycle occurred in October with no breeding amongst the females, and the males showing regressed accessory glands and involuted testes containing minimal amounts of testosterone. At this time hares were solitary and it was rare to see them active during the day.After the autumn rest period, the first indication of a new reproductive cycle occurred in November with an increase in the size and activity of the testes. This trend continued during December, January and February by which time the reproductive tract was again fully functional. During this time there were striking changes in behaviour and matings were witnessed. Females resumed breeding in January with a marked synchrony in the timing of the first ovulation of the season. Mating preceded ovulation, and the first pregnancy normally resulted in a single fetus, although pregnancy failure was common at this time. By March and April the hares showed full reproductive activity with 100% of females pregnant and most carrying three or more fetuses. Many aspects of behaviour (March madness) reached a peak at this time, and in males this was closely related to a depletion of sperm reserves in the epididymis and the secretions of the accessory gland reservoir. During May, June and July, the females continued to be highly fertile. There was, however, already a reduction in the overt behaviour characteristic of spring, and there was a conspicuous drop in testicular testosterone production.The reproductive cycle ended in July and August with a reversal of the changes seen earlier in the year. The testes regressed rapidly in August and sperm production ceased by September; the sperm reserves in the epididymis became progressively depleted and sperm were degenerating by October. There was a reduction in litter size towards the end of the breeding season and no pregnancies were observed after the end of August.Of the hares under one year old shot in the spring only about 16% were apparently conceived during the period of spring madness, with the majority arising from matings in May, June and July. The age at puberty was influenced by the date of birth.March madness appears to represent the rutting behaviour of male hares and is induced by the greatly increased testosterone production which occurs in spring. The behaviour is probably important in stimulating the females into breeding activity at the beginning of the new season.
The epidermis and its degeneration in the larval tail and adult body of Rana temporaria and Xenopus laevis (Amphibia: Anura)
Authors: Fox H. 
Published: August 2009

The tail epidermis of the larva and the body epidermis of adults of Rana temporaria and Xenopus laevis are described in terms of electron microscopy.The activity of lysosomes (determined by the localization of acid phosphatase) in relation to autolysis and the process of cellular cornification, is considered during the periods of climactic disappearance of the larval tail and skin sloughing of adults. The results obtained generally correspond for both genera.Larval tail epidermal cells completely disappear at metamorphic climax; those of the adult, which are shed, are replaced throughout life after each periodic sloughing. Nevertheless the mechanisms of their epidermal cell loss are comparable, though the level of lysosomal activity in larval tail epidermal cells is higher than in the adult body epidermis. This higher activity of lysosomal enzymes may facilitate the heavy necrosis which ensues in the larval tail at metamorphic climax.
Seasonal and age variation of circulating immunoreactive luteinizing hormone in captive Herring gulls, Lams argentatus
Authors: Scanes C. G. , Cheeseman P. , Phillips J. G. , Follett B. K. 
Published: August 2009

A study of the seasonal variation of circulating immunoreactive hormone (ir LH) was undertaken in captive Herring gulls (Lams argentatus) by estimating the hormone concentration in monthly plasma samples with a radioimmunoassay to chicken LH.In the mature gulls (in 4th or 5th year), the ir LH concentration increased significantly through the spring (from 0.71 to l.94ng/ml in males and from 0.59 to 2.34ng/ml in females). The ir LH peak in the females may occur marginally later. In younger birds, only a slight elevation of the hormone level was apparent. A subsequent small summer peak of ir LH was found only in mature male gulls. Another major feature of the annual secretion pattern was the dramatic increase found in all groups of gulls in the sample taken at the end of November. This level had fallen to near basal values only a month later in all birds except the mature male gulls.Throughout the winter, spring and summer, the circulating ir LH in the immature birds remained below that found in their mature counterparts.
The infrastructure of the orthochromatic mucous cells of some British lumbricids (Annelida)
Authors: Richards K. Sylvia 
Published: August 2009

The infrastructure of the orthochromatic mucous cells of 11 British lumbricids is described. The prominent secretory globules show species variation with standard fixation.In four genera the core material exhibits consistent and characteristic electron dense ultrastructural patterning, the four types being described, and species within these genera show specific differences. Such patterned globules are termed heterogeneous, in contrast to the homogeneous globules of the other two genera. The generic and specific ultrastructural patterns line up well with, and support, the modern, revised lumbricid taxonomy.The electron dense heterogeneity is first visualized at the mature Golgi face and the patterning is eliminated after proteolytic enzyme treatment, suggesting that the dense areas within the globule reflect the protein sites within the mucus, the final elaboration of which takes place within the polarized Golgi.No mucus extrusion mechanisms were observed and it is suggested, from the positioning of the supporting cell tonofilaments and the body wall musculature, that extrusion accompanies locomotory activities.A suggestion as to the possible function of a type of mucus with clear specific differences, as evidenced by the ultrastructure, is advanced.
Detailed analysis of fighting in polecats (Mustelidae) using ciné film
Authors: Poole Trevor B. 
Published: August 2009

The phenomenon of fighting was investigated under laboratory conditions using polecats (Mustela putorius, M. furo and interspecific hybrids). Diadic interactions between male polecats were recorded on 16 mm cine film in an unfamiliar area of 16 m2, one individual having been introduced ten minutes before its opponent.The behaviour patterns involved in fighting are described and their frequencies of occurrence, duration and average bout lengths specified. Biting, which occupied 41% of the animal's time in fighting, and attacking, which made up 27% of the bouts of behaviour, were the most important actions involved in fighting. Polecats most commonly bite their opponent's neck and bites in this region were the longest in duration. Success in gaining a bite was influenced by the opponent's behaviour at the time of the attack.Polecats fight when one individual bites its opponent and the opponent retaliates by biting; bite was shown to be the commonest response to being bitten. The length of a fight appears to be determined by the levels of motivation to bite of the two opponents, while biting and being bitten operate as a positive feed back mechanism. The fight terminates when the more aggressive opponent ceases to make spontaneous attacks. The reasons why one individual wins a fight are that it consistently spends more time than its opponent in biting, it persists for longer in making spontaneous attacks and its method of attacking is more efficient.
Experiments on whether schooling by their prey affects the hunting behaviour of cephalopods and fish predators
Authors: Neill S. R. J. , Cullen J. M. 
Published: August 2009

The experiments investigated the effects of a school of live prey fish on the hunting behaviour of squid, cuttlefish and pike (ambush predators) and perch (a chasing predator). The hunting behaviour of all species is described, including some previously unrecorded actions.For all species the increasing shoal size from one fish to six, to 20, decreased the success of the predators' attacks per encounter with a prey. This was partly because attacks on larger shoals lasted longer, and fish became increasingly difficult to catch as a hunt went on. However, for some of the species there was a clear effect of the shoals at the start of the hunt. For other species it was less conclusive.The disruptive effect of the shoals was shown to act for the ambush predators by interfering with the “optimal” sequence of an attack and causing avoidance actions together with so‐called irrelevant behaviour. For the perch, shoals seemed to disrupt by forcing the predator continually to switch targets during his pursuit.The artificiality of the experiments is discussed in relation to field observations. The relatively high incidence of avoidance and irrelevant behaviour seems to be an artefact, but the main results are quite compatible with field studies. In nature fish predators may be able to get sufficient food by restricting their attacks to individuals which are conspicuous either by an abnormal appearance or by becoming separated from the school. An individual prey fish no doubt gains a considerable advantage from the school by burying itself in the crowd. Our experiments show that a shoal can provide further protection in hampering the attack of a predator.
Social factors influencing reproduction in wild lions
Authors: Bertram Brian C. R. 
Published: August 2009

The paper summarizes seven years of records of the reproductive history of two wild prides of lions (Panthera leo L.) in the Serengeti National Park, Tanzania. These records are analyzed to demonstrate ways in which lion reproduction is influenced by their social group and by changes in that group.Females gave birth at any time of year; they did so sooner if their previous litter died. Females synchronized births with other pride members. Takeover of the pride by new males resulted in a drop in the birth rate. Most cubs died, before two years old. Birth synchrony resulted in better cub survival. The arrival of new males resulted in an increase in cub mortality. Females came into oestrus synchronously with other pride members. Males had a much longer effective reproductive life if they had male companions.The proximate causes of these features of lion reproduction are considered, and the evolution of aspects of the organization of reproduction in lions is discussed.
Hybridization between Red deer (Cervus elaphus) and Sika deer (Cervus nippon) with particular reference to stocks in N.W. England
Authors: Lowe V. P. W. , Gardiner A. S. 
Published: August 2009

Sika deer (Cervus nippon Temminck) from Japan were introduced into Great Britain and Ireland first in 1860, and, for a time, were much sought after by owners of deer parks. Later, they were introduced or allowed to escape into various parts of the country, and feral populations have become established in Scotland, England and Ireland.Hybridization between Sika and Red deer (Cervus elaphus L.) has occurred frequently in deer parks but has been reported only recently from feral and wild stocks.In part of north‐west England, there have been reports of hybrids from time to time ever since the 1920s, but these have become commonplace only recently. Since the Red deer inhabiting other parts of the region are all of the native race (Cervus elaphus scolicus Lönnberg) and no other population of this race exists elsewhere in England, work was begun to assess the threat to the survival of both the race and the species posed by Sika deer and, more particularly, by the hybrids on Cartmel Fell.Using multivariate methods of analysis on a range of skull measurements (see page 556) obtained from samples of both species and their hybrids, an attempt was made to find some means of distinguishing the hybrids from the species irrespective of the extent to which introgression had occurred. This was largely successful using canonical variate analysis, but only when the sets of data used to construct the basic matrix were both homogeneous and biologically relevant, i.e. of the same age and sex, and where the samples were obtained from the races involved in the hybridization. The present classification of the subspecies of Sika deer received little support from this study. Many of the subspecies as described in the literature were found to be indistinguishable from some of the hybrids, which suggests that some revision may be necessary.
A contribution to the functional analysis of the foot of the Tokay, Gekko gecko (Reptilia: Gekkonidae)
Authors: RUSSELL ANTHONY P. 
Published: August 2009

The foot of gekkonid lizards, because of the wide range of variation it displays within the family, is an ideal system on which to carry out a functional anatomical study. The wide range of variability and adaptation of the foot is unparalleled in other lizard groups. The Tokay (Gekko gecko (Linnaeus) 1785) has been used as a basis for a broader study of the comparative and functional anatomy of the foot within the family Gekkonidae.The acquisition of adhesive pads by Gekko has resulted in the development of a very distinctive mode of locomotion which has become modified both to deploy and, at the same time, protect the delicate subdigital setae. Analysis of the structure and function of the foot has been carried out in two stages: firstly a description of the mechanical units and then an interpretation of their function, with the aid of high speed cinematographic data. The skeletal elements of the foot exhibit several features which reflect the specialized method of locomotion and these are related to remarkable adaptations exhibited by the associated muscular, vascular and tendon systems.The functional significance of scansorial plates is discussed and the relationship between size and locomotory ability within the family Gekkonidae is also considered. Some ideas as to the selective advantage of the particular locomotory modifications under discussion are presented, but further consideration of this topic must wait until subsequent papers deal with a larger proportion of the family.
Feeding mechanisms and feeding strategies of Atlantic reef corals
Authors: LEWIS J. B. , PRICE W. S. 
Published: August 2009

The feeding behaviour of 35 species of Atlantic reef corals was examined in the laboratory and in the field. Observations were made during the day and at night, using freshly hatched brine shrimp nauplii and finely ground, filtered fresh fish as food sources. Three feeding strategies were observed: Group I–feeding by tentacle capture only; Group II–feeding by entanglement with a mucus net or mucus filaments; Group III–feeding by a combination of tentacle capture and mucus filament entanglement. Group I included corals of the families Poritidae and Pocilloporidae which were normally expanded during both day and night. Group II included corals of the family Agaricidae which were normally expanded at night and contracted during the day. Group III included corals of the other families examined which, with the exception of Dendrogyra cylindrus, were normally expanded only at night.Feeding responses were elicited by both chemical and tactile stimuli. A preparatory feeding posture was assumed in response to chemical stimuli and consisted of horizontal positioning of the tentacles, elevation of the oral disk to form a cone‐like mouth, a wide mouth opening and secretion of mucus by the epidermis of the oral disk. Following the assumption of the preparatory feeding posture, food capture and ingestive movements were elicited by tactile stimuli. However, food capture and ingestive movements were also elicited by chemical stimuli alone in those species which were normally contracted during the day.While expanded corals captured food with their tentacles or with mucus filaments, contracted corals were able to feed by capturing fine particulate matter with mucus filaments only and thus acted as suspension feeders. By a combination of feeding strategies, reef corals were able to feed both day and night and a wide range of potential food ranging from fine particulate matter to large zooplankton was available to them.
The basicranial axis in certain fossil hominoids
Authors: ASHTON E. H. , FLINN R. M. , MOORE W. J. 
Published: August 2009

The publication of accurate sagittal diagrams of the skulls of certain australopithecine fossils has permitted biometrical comparison of their basicranial axis, together with its anterior extension to the nasion, its posterior extension to the opisthion and the two associated angles, to be made with the corresponding regions in monkeys, apes and Man.Univariate study has shown that after appropriate correction for differences in overall size, each of these quantities effects discrimination between certain extant primate groups. All can be separated if the measurements are taken seriatim. Australopithecus transvaalensis and Australopithecus boisei are thus distinguished both from extant groups and from each other.Multivariate study (generalized distances and canonical coordinates) shows that both these fossils are distinct from all living groups which, in turn, are separate from one another.Such unique characterization of the basicranial axis in the Australopithecinae parallels taxonomic distinctiveness already established in respect of their teeth, their occipital condyles and several regions of their postcranial skeleton.