bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors influencing the fecundity of Moniliformis moniliformis (Acanthocephala): constant dose and varied diet
Authors: Crompton D. W. T. , Keymer A. E. , Walters D. W. , Arnold S. E. , Marrs R. W.
Published: March 2009

The reproductive performance, including survival, growth and mature egg production, of Moniliformis moniliformis was studied experimentally during primary infections in rats given 10 cystacanths each. Four isoenergetic purified diets containing either 1, 3, 6 or 12% fructose (w/w) were used and the amounts of fructose in the intestinal lumen of rats fed on these diets were measured. It was concluded that, while dietary composition had no effect on parasite establishment, there were associations between diet and the survival, growth and fecundity of the parasite. The host diet containing 3% fructose was considered to be more favourable for the worms than the others; 12% fructose was associated with a curtailment of survival time without any compensatory production of eggs. Female worms from rats fed on diets containing 3 or 6% fructose grew larger, and consistently carried more ovaries and produced more eggs than those from rats fed on the 1% fructose diet. It was concluded that these and other findings might be mediated not only through the amount of available fructose in the intestine for worm metabolism, but also by the responses of the host's intestinal physiology to the varying concentrations of fructose in the diet.
Reproductive biology of Nilgiri tahr, Hemitragus hylocrius (Mammalia: Bovidae)
Authors: Rice Clifford G.
Published: March 2009

The reproductive biology of Nilgiri tahr (Hemitragus hylocrius) was studied in Eravikulam National Park, Kerala, India from August 1979 to September 1981.

The rutting season occurred during the monsoon (July and August) and the main birth season was January to mid‐February. Gestation was estimated at 179 days.

Three females which lost their first young in 1981 conceived 18 to 21 days post‐partum. One female conceived of her second young while the first was 15 days old. The remainder of the individually identified females gave birth to one young (n=40) or none (n=4).

Infant mortality was highest during the first two weeks after birth. Young born during the monsoon also had a high mortality rate (0.50/week).

Oestrus during the rut was discontinuous in 1980 and 1981. Periods of frequent oestrus corresponded with periods of low rainfall with a mean lag time of 4.9 days.

The ultimate factor determining the birth season in Nilgiri tahr appears to be weather. The main birth season is timed so as to minimize thermal stress.

Several proximal factors may be important in stimulating reproductive activity. These include photoperiod, temperature, the presence of males in mixed groups, and nutrition. The photoperiod response is unusual in that Nilgiri thar evidently respond to the abrupt decrease in apparent day length associated with the onset of the monsoon.

The inverse correlation of rainfall and oestrous activity may have been effected through the sudden decrease in thermal stress on the females or heavy rainfall (5.7 cm/day) masking pheromonal stimulation.

The pattern of lactation anoestrus observed in Nilgiri tahr approximates results obtained from some studies of domestic Caprini.

Nilgiri tahr females are presumably able to increase their lifetime reproduction by giving birth twice in one year. However, this strategy seemed counterproductive in 1981 as survival was low for second offspring.
Note on olfactory activity in mysticetes
Authors: Cave A. J. E.
Published: March 2009

The manner of operation of the mysticete olfactory apparatus is described and its source of activation is indicated.
Activity and thermoregulation of the snake Natrix maura. 2. A synoptic model of thermal biolgy and the physiological ecology of performance
Authors: Hailey A. , Davies P. M. C.
Published: March 2009

Biophysical, physiological and behavioral approaches to reptilian thermal biology have been combined in a synoptic model, using data derived from a study of the snake Natrix maura in a Spanish river and in the laboratory. The model investigates the relations between the costs and benefits of physiological performance, body temperature, the season of activity, and the thermal benefits of physiological performance, body temperature, the season of activity, and the thermal environment. The performance variale chosen was aerobic metabolism. The cost associated with high aerobic metabolism at low body temperatures is the energy requirement for maintenance; the benefit is an increased activity season.

The cost of maintenance was more sensitive to differences in the level and temperature sensitivity of metabolism than was the benefit of the time for activity. The pattern of performance and body temperature obesrved in N. maura was close to that predicted for maximum efficiency, in terms of the activity season produced per unit of annual maintenance cost. It is noted, however, that animals will be selected for net benefit, and not for efficiency as such.

A definition of fitness for the study of the physiological ecology of performance was developed, to take account of the level of performance available during activity, and of selection for net benefit. This definition is: the energy intake above maintenance costs x the probability of survival. It is related to general ecological fitness by considering lifetime strategies of survival and reproduction, and the energy equivalence of offspring. These strategies are the subject of the physiological ecology of allocation, which is thus complementary to that of performance.

The following are also discussed: the role of performance in interactions with predators and prey; other possible evolutionary determinants of body temperature; the limitations of different approachs to thermal biology; suitable systems for further study.
Mathematical and biological intermediacy in bone shape. Fourier analysis of cervical and upper thoracic vertebrae in the mouse
Authors: O'Higgins P. , Johnson D. R. , McAndrew T. J.
Published: March 2009

We have used Fourier transforms and discriminant analysis to look at the shapes of cervical and upper thoracic vertebrae from two pairs of mouse strains and biological intermediates (the F1s) between them. We have also constructed mathematically intermediate shapes and compared mathematical and biological intermediates.

Mathematical and biological intermediates did not correspond in any of the 18 cases studied. We suggest that failure in correspondence is due to complex genetical and environmental factors acting on the F1 phenotype, and that multivariate shape inheritance may be modelled in a similar way to univariate inheritance. Both depend on a large number of genetic loci.
Annual patterns in reproduction and perirenal fat of hares (Lepus europaeus) in sub‐alpine Canterbury, New Zealand
Authors: PARKES J. P.
Published: March 2009

The aim of this paper was to describe how the age, sex and reproductive state of hares affected the amount of fat found around their left kidney. A total of 2208 hares (Lepus europaeus) was shot and autopsied over 13 years from sub‐alpine grasslands in Canterbury, South Island, New Zealand. Adult females may be pregnant from July to mid‐March. Adult males' testis weights were highest from July to January, and some fertile males may have been present in all months but April. The amount of perirenal fat in adults increased in autumn, peaked in early winter, and decreased thereafter to low levels through spring and summer. Autumn fat deposition in males was not clearly related to reproductive state in individuals, although it coincided with seasonal testicular development. Autumn fat deposition in females may have been caused in part by the cessation of lactation, but, like that in males, the increase was also part of an endogenous pattern. Fat utilization in winter was related to breeding. In males, utilization coincided with reproductive activity and the amount of perirenal fat remained consistently low throughout the breeding season. In females, net fat utilization was associated with lactation but this was balanced to some extent by fat deposition induced by pregnancy. Females simultaneously lactating and pregnant were in finer balance between utilization and deposition. Other factors, such as the number of embryos and the stage of gestation, altered the fat balance in these hares. Fat was also deposited as a ‘yolk‐sac’ in embryos.
Life cycle, production, microdistribution and diet of the damselfly Euphaea decorata (Odonata: Euphaeidae) in a Hong Kong forest stream
Authors: DUDGEON DAVID
Published: March 2009

Euphaea decorata in Tai Po Kau Forest Stream (Hong Kong) was univoltine. Most recruitment took place in summer, and larval growth proceeded throughout the year. Life‐cycles recorded in 1977–78 and 1978–79 were similar. Annual production estimates, using the removal‐summation, instantaneous growth and size‐frequency methods, were more similar for the 1978–79 generation (ranging from 158.7–174.7; mean 1671 mg dry wt m‐2) than for the 1977–78 generation (93.9‐173‐6; mean 131.7 mg dry wt m‐2). Mean biomass was similar for both generations (ranging from 33.5–33.9 mg dry wt m‐2), and mean P/B ratios were 3.9 1977–78) and 5.0 (1978–79). These are the first estimates of annual production by an Oriental stream insect.

Larvae were most abundant at microsites in the middle of the stream. Multiple regression analysis indicated that substratum characteristics were a major determinant of microdistribution. Euphaea decorata apparently favoured poorly‐sorted sediments with highly peaked grain size‐frequency distributions, containing few fine particles.

The carnivorous larvae showed ontogenetic changes in diet. Small individuals consumed mainly chironomid (Diptera) larvae; the diet expanded to include (successively) larvae of Ephemeroptera and Trichoptera as E. decorata grew. Seasonal changes in diet were also apparent, although larval diets during spring and summer were similar. There was also considerable overlap between autumn and winter diets. Ontogenetic influences upon prey consumed were not sufficient to account for the observed seasonal differences.
Variation in length and body weight of the red squirrel(Sciurus vulgaris) in two different habitats
Authors: WAUTERS L. A. , DHONDT A. A.
Published: March 2009

Body measurements of squirrel populations are described. The relation between body length and body weight was examined and factors causing individual or seasonal variation in body weight were studied.
Enzymes in the epidermis of Natrix piscator during its sloughing cycle
Authors: SINGH J. P. N. , MlTTAL A. K.
Published: March 2009

Acid phosphatase, non‐specific esterase, alkaline phosphatase, monoamine oxidase and true lipase activities, in the epidermis of Natrix piscator in different stages of the sloughing cycle, have been localized using various histochemical techniques.

Different layers in scale epidermis have staining properties similar to corresponding layers in hinge epidermis.

Acid phosphatase and non‐specific esterase activity in cell layers undergoing keratinization, and the lacunar tissue undergoing disintegration are associated with hydrolytic and catabolic wasting processes involving cell death. The activity of these enzymes in the clear layer is associated with the breaking down of the cementing substance resulting in the separation of clear layer from underlying tissue and facilitating the shedding of old slough.

Alkaline phosphatase activity in the stratum germinativum and undifferentiated epidermal cells has been associated with cell proliferation and differentiation. The presence of alkaline phosphatase in the lacunar tissue and clear layer has been correlated with the synthesis of mucopolysaccharides in these layers.

Monoamine oxidase and true lipase activity could not be located in the epidermis at any stage of the sloughing cycle.
Carbohydrate histochemistry of the epidermis of Natrix piscator during its sloughing cycle
Authors: SINGH J. P. N. , MlTTAL A. K.
Published: March 2009

Carbohydrate histochemistry of the scale and hinge epidermis of the chequered water snake, Nalrix piscator, throughout the sloughing cycle, has been described. The small amount of mucopolysaccharide present in the Oberhautchen, mesos layer, α‐layer and β‐Mayer (in its initial stage of differentiation) is comparable with that in amphibian epidermis and the epidermis of certain freshwater fish undergoing keratinization. Moderate amounts of mucopolysaccharide in the lacunar tissue and clear layer may protect against environmental pathogens and retain water to protect the epidermis from desiccation. Mucous cells could not be located in the epidermis throughout the sloughing cycle, contrary to some previous observations that they occur in the hinge region. The general absence of glycogen in the epidermis in most stages of the sloughing cycle suggests that the glycogen metabolized in the epidermis is utilized immediately, in view of the high energy requirements of proliferation and differentiation. Accumulation of glycogen granules in the presumptive α‐layer in stage 2 and in the clear layer, presumptive Oberhautchen and presumptive β‐Mayer in stage 3 is correlated with low energy requirements, indicating a slowing down of the process of keratinization of cells in these layers.
Tail skin of the dipnoan Neoceratodus larva: fine structure and differentiation
Authors: FOX HAROLD
Published: March 2009

The fine structure of the tail skin oflarval Neoceratodusforsteri, between stages 40 and 50 (Kemp, 1982), is described and where applicable specific cellular components are compared and contrasted with comparable ones in the skin of adult dipnoans, teleosts and larval and adult amphibians.

The epidermis of the early developing tail, within the range studied, differentiates a variety of different cell types. Surface epithelial lucent and vacuolated lucent cells and basal cells are distinguished, and goblet (mucous) cells, Merkel cells and macrophages appear in the epidermis towards the end of the series.

Below a poorly developed collagenous basement lamella, immature melanophores with premelanosomes are present, and likewise there are non–myelinated nerves, some striated muscle fibres, capillaries and mesenchymal fibroblasts.

The tail epidermis is innervated by naked neurites from the beginning of the series, and the earliest recognizable Merkel cell is in synaptic association with neurites.
On the spatial behaviour of Indian crested porcupines (Hystrix indica)
Authors: SALTZ D. , ALKON P. U.
Published: March 2009

Nocturnal activity of six Indian crested porcupines (Hystrix indica), inhabiting two nearby dens in the Negev desert highlands of southern Israel, was monitored for nine months by radio location telemetry. From movement simulation of 1121 relocations (187 ± 56 per animal) on a grid representation of the 20 km2 study area, mean home ranges (i.e. 90% domains) were 1–5 ± 0–4 km2 and the animals moved 2.8 ± 0.7 km per night. Spatial activity differed by main foraging habitat which, in turn, corresponded to den affiliation. Porcupines that foraged regularly on crops had narrow domains with bimodal activity centres near the den and in potato fields; and their movements were relatively stable across seasons. Animals dependent on natural forage had larger and seasonally variable domains, and more diffuse dispersions with a single activity centre near the den. Home range overlap was greater among crop foragers, and all porcupines remained closer to dens during moonlit periods. We conclude that crested porcupine dispersion patterns are flexible, and strongly linked to forage availability. The array of analytical procedures used here are recommended for future studies of animal spatial activity.
Social interactions and reproductive tactics in red–necked wallabies (Macropus rufogriseus banksianus)
Authors: JOHNSON C. N.
Published: March 2009

Male red–necked wallabies established dominance relationships by fighting, and dominance rankings among males were positively correlated with body size. Females became outstandingly attractive to males during the week preceding mating, and males, who normally ranged widely and solitarily in search of mates, gathered in groups around such females. It is suggested that females, by prolonging their advertisement of oestrus, and thereby inciting sustained competitive interactions among the males who were attracted to them, contributed to a bias in the distribution of male mating success in favour of very large dominant individuals. High–ranking males mated within discrete but undefended areas of absolute dominance (‘dominions’). Direct interactions between dominion–holding males were rare, but males just below dominion–holding status often fought with one another, and were frequently harassed by dominional males.
Seasonal changes in the distribution and composition of common seal (Phoca vitulina) haul‐out groups
Authors: THOMPSON PAUL M.
Published: March 2009

Seasonal changes in the distribution and composition of common seal haul–out groups were followed in a study area in Orkney, Scotland. A marking programme was also undertaken, using both conventional and radio–tags, to study individual movements between sites and seasonal changes in site–use. Certain haul–out sites were used only in the breeding season, while others were used during the winter. Seals were seen at one site all year round and at another during only the pre–pupping and moult period. On one island where two sites were used during the summer, there were significant differences in the sex ratio of groups at the two sites: at one site males predominated and few pups were seen; on another, nearby, mothers and pups were regularly seen, although the site was also used by males. There was also evidence for segregation of the sexes outside the breeding season. Repeated observations of marked seals showed that seals used several different haul–out sites throughout the year, and that the seasonal changes in abundance at different sites resulted from individual changes in site–use. These changes in site–use are discussed in relation to feeding movements, breeding requirements and the physical characteristics of different sites.
An analysis of fertilization in Bulinus cernicus (Gastropoda: Planorbidae)
Authors: ROLLINSON D. , KANE R. A. , LINES JILL R. L.
Published: March 2009

Experiments have been carried out to determine whether cross–fertilization, multiple insemination and sperm sharing occur in Bulinus cernicus. Snails collected from Canal La Paix, Mauritius, were found to be polymorphic for glucose phosphate isomerase, and from this stock three snail colonies homozygous for GPI 2/2, GPI4/4 and GPI6/6 were selected. Thus, three markers were available to monitor cross–fertilization. Isolated snails produced egg–masses by self–fertilization 40 days post–hatching. Egg–masses produced by self–fertilizing individuals tended to be smaller than those from cross–fertilizing snails, 367 eggs per egg–mass as opposed to 5–34. The majority of snails (70%) switched rapidly to cross–fertilization after pairing. Multiple insemination by two partners was common, heterozygous progeny were produced in a random manner and did not reflect the sequence of mating. No evidence of sperm sharing was found, snails were found to be capable of passing on their own sperm while still producing eggs fertilized by sperm received from an earlier mating. Differences in mating behaviour were noted between snails representing the homozygous GPI colonies, with snails from one colony adopting the female role more readily than those from the other two, which predominantly mated as males.
Effects of mammalian pituitary gonadotropins on the seasonally quiescent ovary of the Indian wall lizard, Hemidactylus flaviviridis
Authors: RAI U. , HAIDER S.
Published: March 2009

Adult Indian wall lizards, Hemidactylus flaviviridis (Rüppell) with seasonally quiescent ovaries were treated either with ovine FSH or LH. Quantitative as well as histochemical observations revealed that only FSH could stimulate the ovarian growth and steroidogenesis whereas LH had no effect either on ovarian growth or on ovarian steroidogenesis.
Resource partitioning among Odonata (Insecta: Anisoptera and Zygoptera) larvae in a Hong Kong forest stream
Authors: DUDGEON DAVID
Published: March 2009

Larvae of four odonate species were common in Tai Po Kau Forest Stream, Hong Kong: Euphaea decorata (Zygoptera: Euphaeidae), Zygonyx iris (Anisoptera: Libellulidae), Heliogomphus scorpio and Onychogomphus sinicus (Anisoptera: Gomphidae). All co‐occurred within a single riffle reach and had similar life cycles. Consequently, available dimensions for niche partitioning were likely to have been microhabitat and diet.

Across–stream gradients in population density, and the results of multivariate regression analyses of abundance against microhabitat parameters, were similar for all species except Z. iris. This species avoided microsites near the stream banks, and had no significant best–fit regression model predicting abundance. Nevertheless, microhabitat overlaps among all four species were high (Oxy > 0–81). The scale of this investigation (sampling units = 1000 cm2) may have obscured partitioning of space within microsites, because burrowing O. sinicus were unlikely to have occupied the same sediment patches as epibenthic H. scorpio or Z. iris.

Dietary overlaps between Z. iris and the other species were low. Heliogomphus scorpio and O. sinicus had the most similar diets of any species–pair, but among these two species intraspecific overlaps between large and small individuals were generally less than interspecific comparisons between equivalent–sized larvae. Ontogenetic dietary shifts and asynchronous larval development in both of these gomphids may have contributed to intraspecific partitioning of food.

Euphaea decorata had the broadest niche axes along food and microhabitat dimensions, whereas Z. iris was relatively specialized. Heliogomphus scorpio and O. sinicus made similar use of resources. In the absence of evidence that resources were limiting or depletable, competition could not be invoked as an explanation for niche partitioning. Instead, determination of morphology by phylogeny, and resultant influences on microhabitat selection and foraging behaviour, probably determined patterns of resource use resulting in closely related species showing the greatest niche overlap.
The growth rate of the tarsometatarsus bone in birds
Authors: KIRKWOOD J. K. , DUIGNAN P. J. , KEMBER N. F. , BENNETT P. M. , PRICE D. J.
Published: March 2009

Twisting and bending deformities of the long limb bones of growing birds are common. In domestic poultry they are associated with rapid growth. In order to examine the variation in bone growth rates amongst the Class Aves as a step towards learning about the aetiology of growth deformities, we collected data on this and several other variables from a large sample of species. Adult tarsometatarsal length (ATL) was proportional to adult weight (W)0.36. The exponent did not differ significantly from 1/3. Mean legginess (L), defined as ATL/W1/3 (i.e. ATL.W‐1/3), was 80 mm.kg‐1/3 but varied according to the habitat occupied; terrestrial and arboreal birds had relatively longer legs than aquatic and aerial ones. ATL growth rate (GR) averaged 20 mm.d‐1 and was not correlated with W. It was highly influenced by pattern of development, being on average about three times greater in altricial compared with precocial birds of the same adult weight. Amongst birds of the same developmental pattern, GR was linearly related to L. Tarsometatarsal growth rate varied from 0.35 to 60 mm.d‐1 in the Class Aves and there was no evidence of intrinsic limits to GR from our results. How rapidly such bone growth rates are achieved remains to be determined.
Functional design and prey capture dynamics in an ecologically generalized surfperch (Embiotocidae)
Authors: CHU CHARLEEN T.
Published: March 2009

Kinematic and electromyographic analyses of prey capture in two species of surfperch (Embiotocidae) reveal differing abilities to modulate strike activity in response to different prey types. Both the black perch, Embiotoca jacksoni, and the shiner perch, Cymatogaster aggregata, demonstrate stereotyped and conserved neuromuscular and kinematic activity in suction feeding. A distinguishing anatomical trait in this family, the interopercular shelf, enhances the coupling of hyoid movement with mandibular depression. Analyses of variance suggest a preprogrammed motor output that is ballistically launched for suction generation, with the possibility of more plasticity in latter phases of the strike. While the trophically limited shiner perch displays a stereotyped repertoire of this one strike pattern, very small prey, larger conglomerates of these, and large distinct prey elicit three modulated patterns in the black perch. Functional characteristics that enable the ecologically generalized black perch to exploit a variety of prey types include energy–conserving modulatory ability, behavioural flexibility in utilizing a conserved suction–generating programme, and the addition of specialized winnowing and spitting activity.
The food habits of suni antelopes (Neotragus moschatus) (Mammalia: Artiodactyla)
Authors: LAWSON D.
Published: March 2009

Suni antelopes were previously thought to be exclusively browsers and to feed on such highly nutritious food as fruits, flowers and the growing tips of shoots. A detailed examination of their food habits shows that this may not be their natural diet. Instead the main dietary component appears to be freshly fallen leaves of a large number of plant species.
Developmental anatomy of the tailed frog (As cap hits truei): a primitive frog with large eggs and slow development
Authors: BROWN HERBERT A.
Published: March 2009

The embryonic and early larval development of Ascaphus was studied by culturing embryos at 11 °C. Twenty stages of normal development are morphologically defined by using a standard staging system for anuran amphibians.

Cleavage stages are distinctive. The first cell division is unique because two separate furrows develop and then fuse to form a single cleavage plane. The large, yolky cytoplasm continues to influence cell divisions, and a blastula develops with very large vegetal cells and small, irregular shaped animal cells. There is a conspicuous, translucent blastocoel in the late blastula, and during gastrulation this structure is displayed forward by the internal migration of cells. Except for slight differences in proportions, the gastrula and neurula stages resemble the typical anuran pattern. Circulation (stage 20) begins when large vitelline veins develop on the yolk sac and direct the return of blood flow to the heart.

At hatching, the tadpole has a large yolk sac, little skin pigmentation, and no gills. Mouthparts and opercular coverings of the branchial arches develop slowly. Hind limb buds develop at the base of the tail, but they are soon concealed as a skin membrane develops and covers these structures.

The reproductive strategy for this primitive and highly aquatic frog is unusual: there is a small number of large eggs that develop slowly and produce tadpoles that continue this slow developmental process.
Ecology and physiology of the northern quoll, Dasyurus hallucatus (Marsupialia, Dasyuridae), at Mitchell Plateau, Kimberley, Western Australia
Authors: SCHMITT L. H. , BRADLEY A. J. , KEMPER C. M. , KITCHENER D. J. , HUMPHREYS W. F. , How R. A.
Published: March 2009

Breeding, population dynamics and seasonal changes in physical and physiological parameters were examined in the northern quoll (Dasyurus hallucatus) at Mitchell Plateau, Western Australia, between September 1981 and November 1982. Females gave birth to a single litter of young in July or August. Births were earlier on near‐coastal sites than on inland sites. Litter size was greater on inland sites and litter size differed between years. By September all females were either carrying pouch young or were lactating. Lactation ceased by April. Testosterone levels in males peaked in July. There were significantly more male than female pouch young. However, in only one grid was the adult sex ratio different from parity, with an excess of females in September 1981 and 1982. Embryonic mortality was > 53% but loss of pouch young was small. Although males and females moved similar distances between successive recaptures, the extent of movement varied seasonally, being greatest in September. Males were generally larger and heavier than females. Seasonal variations were recorded for most physical and physiological parameters. The most pronounced changes occurred towards the end of the dry season (July to September) for both males and females. Over this period there was a significant decline in weight (males), haematocrit (males), plasma albumin (males) and leucocytes (both males and females) and significant elevations in values of haemoglobin and both free and protein‐bound Cortisol in both males and females. Few males survived the post‐mating period from July to September. They appeared to decline in condition over this period more markedly than females: they lost more weight, their haematocrit and plasma albumin values declined to a greater extent, and they were more heavily infected with lice (Boopia uncinata). Males with lower testosterone and higher free and protein‐bound Cortisol had increased prospects of surviving the breeding season, which suggests that it is the dominant males that are less likely to survive the breeding season. Individuals in the three major populations at Mitchell Plateau differed greatly in their physiological values. The high‐density population in a sandstone area had intermediate levels of free Cortisol and higher haematocrit values than both the other populations, and higher levels of haemoglobin than the population on laterite substratum.
The function of the intramaxillary joint in the Round Island boa, Casarea dussumieri
Authors: CUNDALL DAVID , IRISH FRANCES J.
Published: March 2009

The bolyeriid snakes Casarea dussumieri and Bolyeria multocarinata are unique among vertebrates in possessing an intramaxillary joint that separates the maxilla into anterior and posterior segments. In contrast to previous studies, which suggest that this joint permits enhanced elevation of the anterior maxillary teeth, our films of live Casarea show that the snout and anterior maxillary teeth are actively depressed 15° 20° below rest position through bilateral retraction of the palatomaxillary arches. Patterns of bone movement in living Casarea support the hypothesis that a caudally directed force is transmitted to the snout via the medial bones of the palatomaxillary arch, suggesting functional affinities between Casarea and higher henophidians.

The intramaxillary joint, in conjunction with the curvature of the mandibles, allows the jaws of Casarea to encircle hard, cylindrical prey held transversely in the mouth. Because the Mauritian terrestrial vertebrate fauna lacks mammals and is dominated by skinks and geckos, which Casarea is known to consume, we suggest that the intramaxillary joint functions in a manner analogous to that achieved by quite different maxillary modifications in colubrid scincivores. Although the origin of the bolyeriid intramaxillary joint remains unclear, its structural refinement and evolutionary stability may be due to selection pressures arising from limited prey diversity.
The structure and function of the digestive system of terrestrial isopods
Authors: HAMES C. A. C. , HOPKIN S. P.
Published: March 2009

The functional morphology of the digestive system of terrestrial isopods (woodlice) has been investigated. Observations have been made on live juveniles of Oniscus asellus and Porcellio scaber in which some digestive processes can be observed directly through the cuticle. The fine structure of the foregut of juveniles and adults of these two species has been studied by light microscopy and scanning and transmission electron microscopy. The passage of coloured dyes and colloidal gold through the digestive system has also been followed.

The digestive system of Oniscus asellus and Porcellio scaber is divided into five regions. The foregut (1), and the anterior chamber (2), papillate region (3) and rectum (4) of the hindgut, are ectodermal in origin and lined with cuticle. The hepatopancreas (5), which opens into the foregut, consists of four blind‐ending tubules which are endodermal in origin and not lined with cuticle. A powerful muscular sphincter is present between the papillate region and the rectum. There is no peritrophic membrane in the lumen of either the hepatopancreas or the hindgut.

Fragments of food pass via the oesophagus to the proventriculus of the foregut where they are briefly masticated before passing rapidly into the anterior chamber of the hindgut. During this process, the food is mixed with secretions derived from the hepatopancreas. The anterior chamber possesses a pair of dorsal channels formed from a typhlosole and lateral infoldings of the gut wall. When the hindgut is full of food, contraction of muscles surrounding the gut forces liquids and fine food particles back into the foregut via the typhlosole channels which open at the junction of the anterior chamber and papillate region. This material, which contains fluids derived from the hepatopancreas, and products of digestion, is filtered in the foregut and passed into the lumen of the hepatopancreas where further digestion, and absorption of nutrients, takes place. The hepatopancreas may secrete these fluids back on to the food in the anterior chamber and receive products of digestion via the typhlosole channels several times during a digestive cycle.

The lumen of the foregut, hindgut and hepatopancreas often contains a dense population of microorganisms which may be involved in digestion. Residual material in the hindgut passes eventually into the rectum where faecal pellets are compacted before they are voided.

The ability of terrestrial isopods to recycle and retain fluids within the digestive system, by the development of the typhlosole channels (which are not present in marine isopods), may have been a major contributory factor in their successful transition from water to land.
The ecological significance of resting sites and the seasonal habitat change in polecats (Mustela putorius)
Authors: WEBER DARIUS
Published: March 2009

The daytime resting sites of 13 radio‐tracked polecats (Mustela putorius) were recorded in a mountainous and a lowland study area in Switzerland. Information on breeding sites was collected from questionnaires distributed throughout the country. At all resting sites, the polecats were completely invisible from more than a metre distant. During summer, when polecats mainly live in forests, individuals used many different hiding‐places (e.g. small self‐dug burrows, woodpiles, heaps of branches and dry leaves, dense vegetation). Such places were used for short periods, and then abandoned. Above ground, the polecats sometimes built nests of dry grass or moss. In winter, the polecats slept mainly inside barns, stables and other buildings. These resting sites were changed less frequently. In rainy weather throughout the year, subterranean places were preferred. Breeding polecats were often found inside houses, and obviously did not avoid human presence.

The importance of different types of resting sites for polecats is discussed. In summer, the quality of a resting place is of less importance than its distance from the foraging area, but in winter, warm resting places are essential and buildings are therefore considered an important resource for polecats in Switzerland. The seasonal habitat change can more readily be explained as a consequence of thermoregulatory problems than of food availability, and the distribution of polecats in Switzerland may be affected by the availability of suitable winter resting places. The northern limit of polecat distribution and its historical changes can be explained by the changing availability of human buildings which provide winter resting sites.
Comparative studies on the reproductive biology of three species of laboratory bred Australian conilurine rodents (Muridae: Hydromyinae)
Authors: BREED W. G.
Published: March 2009

The reproductive biological parameters of laboratory bred and maintained individuals from three species of Australian conilurine rodents, Notomys alexis, Pseudomys australis and P. nanus were determined. Considerable' divergence was found in interbirth intervals (indicative of gestation length) in nonsuckling and suckling mothers, litter size, growth rate of pups, age at weaning, and time of sexual maturity in both males and females. It is concluded that selection has been for rapid production and development of young in P. nanus, whereas in P. australis and, especially N. alexis, litter size has been maximized within the constraints of the mammary formula. These data further emphasize the high degree of plasticity of the reproductive system in this assemblage of old endemic murid rodents of Australasia.
Embryonic growth rates of marsupials with a note on monotremes
Authors: ROSE R. W.
Published: March 2009

Earlier workers suggest that marsupial embryonic growth rates are slower than those of many eutherians and that there is little correlation between marsupial gestation lengths and their weight at birth. Previously, this latter observation has been explained as being due to the considerable variability in duration of the initial slow phase of marsupial embryonic growth. The latter phase of pregnancy has always been regarded as rapid and highly uniform in all marsupials. However, this review shows that there can be considerable variation in growth rate during this ‘fast’ phase and also that marsupials have similar rates of embryonic growth to most eutherians. Development within the monotreme egg may proceed at a similar rate to intra‐uterine growth in therian mammals.
Lipid histochemistry of the epidermis of Natrix piscator during its sloughing cycle
Authors: SINGH J. P. N. , MlTTAL A. K.
Published: March 2009

The lipid histochemistry of the scale and hinge epidermis of the chequered water snake, Natrix piscator, throughout the sloughing cycle, has been described. The presence of comparatively high concentrations of phospholipids in the mesos layer and a‐layer, in comparison to neutral lipids, has been associated with a permeability barrier to transcutaneous water flux. Free fatty acids, present in almost all epidermal layers and in eosinophilic granular cells, may protect the epidermis from bacterial and fungal attacks. Cholesterol, in addition to phospholipids, in various keratinized layers, is assumed to be derived from membranous structures of epidermal cells and is regarded as a stabilizer of the phospholipids in membranes.
Are the New and Old World wapitis (Cervus canadensis) conspecific with red deer (Cervus elaphus)?
Authors: LOWE V. P. W. , GARDINER A. S.
Published: March 2009

Some taxonomists have classified red deer and wapiti as being conspecific (Ellerman & Morrison‐Scott, 1951; Flerov, 1952); others have split them into two species, Cervus elaphus and Cervus canadensis (Hall & Kelson, 1959; Whitehead, 1972). The decision has been made each time largely on the basis of the size and form of the antlers, the proponents arguing that antler form is a good genetically‐based character, while the opponents view the antlers as being phenotypically very variable, depending largely on the environment for their formal expression.

To avoid this controversy, we have used skull measurements, and only female material to reduce the possible effects of bias due to selection by hunters.

The enzyme study methods of Gyllensten et al. (1983) and Dratch & Gyllensten (1985) were considered inappropriate as they may reflect only physiological relationships, and rely on living material. Several races of New and Old World wapiti are now either extinct or very rare. Moreover, skull morphology will remain the basis for the classification of most vertebrate species.

Sixteen variables, comprising length, breadth and depth measurements, were measured on 298 skulls, representing most of the different races of red deer and wapiti in both the Old World and the New. These sets of variables were analysed by Principal Component Analysis, and the first two components, accounting for 86.4% of the total variance, were plotted as a graph.

The first component was clearly a measure of skull size, while the second component gave the greatest weightings to the breadth of the nasals and depth of the nose, in other words, skull shape.

All the Old World red deer and wapiti samples formed a continuum of variation in skull size and shape; the only discontinuity being between these races and the North American wapiti, which differed from them mainly in size.

The latter could therefore be classified as a subspecies of red deer, Cervus elaphus canadensis. However, because differences in other characters such as behaviour and reproduction are so slight, there appears to be no justification for distinguishing between them at the species level.
Mechanical properties of very young bone in the axis deer (Axis axis) and humans
Authors: CURREY J. D. , POND CAROLINE M.
Published: March 2009

The mechanical properties of bone from a pregnant axis deer, her full‐term foetus, three young children, and an adult man, were compared. The properties of the bone of the foetal deer were more similar to those of the man than to those of the children, and corresponded to the high degree of mineralization of the foetal bone. These properties accord with the different habits and selective pressures acting on children, and on neonatal deer.
The condition and age of Thomson's gazelles killed by cheetahs and wild dogs
Authors: FITZGIBBON CLARE D. , FANSHAWE J. H.
Published: March 2009

The condition and age of Thomson's gazelles (Gazella thomsoni) killed by two species of predators were compared. The wild dog, a coursing predator, was predicted to take a greater proportion of young, old and sick animals than the cheetah, a stalker. As measured by the marrow fat content of limb bones, wild dogs captured more Thomson's gazelles in poor condition than cheetahs. This appeared to be a consequence of their preference for male gazelles, which were in worse condition than females. Cheetahs did not capture fewer young and old gazelles than wild dogs.
Prey detection by some predatory Coleoptera (Carabidae and Staphylinidae)
Authors: WHEATER C. P.
Published: March 2009

The prey detection methods of 12 species of Carabidae and one species of Staphylinidae were investigated using video and orientation techniques. The species examined were Cicindela campestris, Cychrus caraboides, Carabus problematicus, C. violaceus, Calosoma maderae, Nebria complanata, Scarites abbreviates, Broscus cephaloles, Pterostichus madidus, P. melanarius, P. niger, Abax parallelepipedus and Staphylinus olens.

All the species examined were seen to respond to prey upon contact (either by tactile or gustatory reception) during locomotor activity. Tests using orientation chambers showed that some of the species would orientate towards prey in the absence of contact. Some species orientated using vision (C. campestris, C. maderae, S. abbreviates, A. parallelepipedus). This was most frequent when tested with fast‐moving prey. In others, orientation towards prey occurred when olfactory cues were available (P. madidus, P. melanarius, P. niger and A.parallelepipedus). All of the species employing this method of prey detection belonged to the Pterostichini and it appears that the receptors involved are situated on the antennae. Although some species did not orientate towards prey in the absence of contact cues, some of these species were found to respond to slug mucus (C. caraboides, C. problematicus, C. violaceus and S. abbreviates). The receptors for this are probably situated on the terminal ends of the palps. The method of prey detection used is discussed in relation to the ecology of the species.
Microscopic investigation of feather remains from the head of the Oxford dodo, Raphus cucullatus
Authors: BROM T. G. , PRINS T. G.
Published: March 2009

Feather fragments collected from the head of the Oxford specimen of the dodo were examined with light‐ and scanning electron microscopy. The material proved to be heavily abraded but still yielded characteristics from which some conclusions on feather type and taxonomy can be drawn. The microstructure of the barbules examined indicates that the fragments belong to the pennaceous feather type. The feathering shows some characters apparently peculiar to the dodos. In other respects the feather structure is more similar to that of the Columbidae than that of the Rallidae.
The evolution of hymenopteran wings: the importance of size
Authors: DANFORTH BRYAN N.
Published: March 2009

The allometric relationships between body size and several aspects of wing morphology in the insect order Hymenoptera were investigated using multivariate morphometric techniques. The study focused primarily on wing allometry in five monophyletic genera of bees (Perdila, Halictus, Ceratina, Trigona and Apis), but the patterns of size‐related evolutionary change found within each of these genera are also found to exist in numerous other hymenopteran taxa. Increased body size in hymenopteran lineages is correlated with the following changes in wing morphology: (1) decreased relative stigma area, (2) distal extension of wing vein elements, (3) increased aspect ratio and (4) proximal shift in the centroid of wing area. The reverse is true for decreased size. The widespread allometric trends most likely result from adaptive change in wing morphology due to size‐related changes in the physical properties impinging on the organism–principally the quality and magnitude of drag. The fact that similar wing morphologies among distantly related species can result from similarity in body size has important implications for the study of hymenopteran phylogeny, especially at lower taxonomic levels and when a high proportion of wing characters are employed.
Resistance to desiccation and distribution patterns in the land snail Sphincterochila
Authors: SHOSHANA GOLDENBERG Z. ARAD , HELLER J.
Published: March 2009

The land snail Sphincterochila is represented in Israel by five species that replace one another along a climatic gradient that ranges from the Mediterranean areas receiving up to 1000 mm down to arid areas receiving only 70 mm of rain per year.

The resistance to three weeks of desiccation was studied in all five species. Total water loss was lowest in the desert‐dwelling species S. zonata and highest in the Mediterranean S. aharonii and the desert‐dwelling S. prophetarum, while the steppe‐dwelling S. cariosa and S. fimbriata were intermediate. Sphincterochila zonata had a significantly thicker epiphragm, the lowest area specific water vapour conductance, the quickest response to desiccation (secretion of epiphragm), and a favourable surface‐to‐volume ratio compared to all other species. The Mediterranean‐type water economy of S. prophetarum, despite its desert distribution, is related to its being an under‐rock‐dweller while S. zonata, which has the best adaptions to desiccating conditions, thrives in exposed areas. It is concluded that the differences in resistance to desiccation among the five species of one genus correspond to the gross distribution patterns and reflect the abiotic regime and the microhabitat of each species.
Ontogenetic changes in the feeding system of the red‐sided garter snake, Thamnophis sirtalis parietalis. I. Allometric analysis
Authors: YOUNG BRUCE A.
Published: March 2009

The ontogenetic growth pattern of selected components of the skeleton, muscle mass, and muscle lever arms within the head of the red‐sided garter snake, Thamnophis sirtalis parietalis, were investigated. The results of this analysis appear to indicate an ontogenetic shift from an early emphasis upon prey manipulation to a later emphasis upon striking. The ecological, morphological and phylogenetic evidence for this shift is described and specific testable hypotheses are proposed.