bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allozyme relationships of some frogs (genus Rana) from Yunnan, China
Authors: Li Fanglin  , Green David M. , Sharbel Timothy F. 
Published: April 2008

Abstract
The genetic relationships of four species of frogs, genus Rana, from Yunnan, China, were investigated using starch gel electrophoresis of isozymes. Rana chaochiaoensis, R. pleuraden, R. phrynoides and R. limnocharis, representing four different species groups, were compared to each other and to representative species from other parts of Asia: R. amurensis from eastern Siberia, R. japonica from Japan, and R. nigromaculata from Korea. Twenty-four isozyme loci were reliably detected and scored, of which all but one were variable. R. chaochiaoensis, R. japonica and R. amurensis, all members of the Eurasian "brown frog" group, clustered together as a group although genetic distances were comparatively high. The "pond frogs", R. nigromaculata and R. pleuraden, similarly clustered together. Both R. phrynoides and R. limnocharis were highly divergent from the other species, but R. phrynoides seemed to be more closely affiliated with the "pond frogs" than with the "brown frogs". The data indicate that the highly enigmatic 64-chromosome karyotype of R. phrynoides arose from among 26-chromosome ancestors. The relationships of R. limnocharis cannot be precisely defined. Genetic divergence among Asiatic Rana appears to be very high.
Real vs apparent distributions of dwarf amphibians: Bufo lindneri Mertens 1955 - a case in point
Authors: Clarke B.T. 
Published: April 2008

AbstractThe literature records only four specimens identified as Bufo lindneri Mertens, and gives the distribution of this species as Dar es Salaam, Tanzania and a locality 23 km from Dar es Salaam. The discovery of a further fourteen specimens provides evidence of a wider distribution including S. Tanzania, Malawi and Mozambique. B. lindneri is redescribed on the basis of this new material. It is suggested that specimens of dwarf species have often been overlooked, either because of their size, choice of habitat or cryptic coloration or a combination of these factors, leading to the erroneous conclusion that they are rare, or that the species has a restricted distribution. It is further suggested that dwarf species are of particular biological interest. They may be important as ecological indicator species, as indicators of distinct microhabitats, modes of reproduction and associated behaviours.
Non-random mating by size in the midwife toad Alytes obstetricans: Bigger males carry more eggs
Authors: Raxworthy C.J. 
Published: April 2008

AbstractThe European midwife toad Alytes obstetricans is unusual because the males exhibit parental care. The male carries eggs (possibly from several females) wrapped around his hind limbs until they are ready to hatch. The mating pattern of this species is not random; a significant correlation was found between male snout-vent length and dorsal egg count. Bigger males have larger broods and therefore father more offspring. Because brood size does not appear to affect egg hatching success, larger males may enjoy higher fitness. This non-random pattern of mating may be achieved by male intra-sexual competition, and both male and female mate choice.
Seasonal changes in material and energy balance associated with reproduction in the green lizard, Lacerta viridis, in western France
Authors: Bradshaw S.D. , Saint Girons H. , Bradshaw F.J. 
Published: April 2008

Abstract
Rates of turnover of oxygen, water and sodium were measured in free-ranging and captive Lacerta viridis in western France during their period of reproduction in May, and again in late autumn prior to their entering winter hibernation. Rates of C02 production and turnover of water and sodium in captive lizards showed little significant variation and these animals appeared to be buffered to a large extent from environmental changes, even though they were exposed to external climatic influences. Overall means for rates of CO2 production in free-ranging individuals did not vary statistically between seasons but considerable individual variation was observed during the breeding season in May. The animals could be divided into 'active' and 'inactive' groups on the basis of their rate of CO2 production and other significant differences were apparent between these two groups: 'active' individuals had increased rates of sodium turnover, lower body water contents and lost body mass during the period of observation whereas the 'inactive' individuals gained mass over the same period. These data suggest that not all individuals necessarily participate in the activity associated with breeding in spring in this species and further behavioural studies would seem appropriate in the light of these physiological data. Calculation of the 'Water Effectiveness Index' for this species from the ratio of water to energy turnover suggests that Lacerta viridis is a profligate utiliser of available resources when compared with similar-sized species of lizards inhabiting desert environments.
Embryonic development of the myobatrachine frogs Geocrinia laevis, Geocrinia victoriana, and their natural hybrids
Authors: Gollmann Birgit , Gollmann Günter 
Published: April 2008

Abstract
The Australian frogs Geocrinia laevis and Geocrinia victoriana undergo prolonged embryonic development inside their egg capsules, before hatching as advanced tadpoles. Despite the presence of large amounts of yolk, the course of development follows the typical anuran pattern rather closely, and is essentially identical in the two species and their natural hybrids. We present a modification of Gosner's (1960) staging table, using mainly changes in the eye and the mouthparts to define stages (20 to 26) in a phase of development, when the Gosner table is not applicable to myobatrachine frogs.
The role of the tail in channel passage by the sand skink, Neoseps reynoldsi
Authors: Mushinsky Henry R. , Gans Carl 
Published: April 2008

AbstractThirteen sand skinks, Neoseps reynoldsi, were observed and videotaped traversing variously spaced plexiglass channels and spacings of pins to investigate locomotory patterns of a slender elongate lizard, with reduced limbs. Five individuals were recorded both before and after tail autotomy. Neoseps moves its limbs in locomotion on a flat surface; the hindlimbs participate in propulsion and their position, relative to their body, reflects the curvature of the trunk. Distance between pins, width of the plexiglass channel, and surface texture influence locomotory patterns. Individuals move more rapidly in wide channels, and movement is most irregular in channels with sandpaper floors. Whether on a plexiglass or a sandpaper floor, individuals travel more rapidly down the 2cm wide channel than the 1 cm channel. Fewer bends in the trunk in the wider channels may allow for more rapid movement. Autotomy of the tail slows movement on a plexiglass or sandpaper floor. The anterior portion of the tail contributes to the establishment of a static friction site that is jerked toward the head during locomotion, advancing the center of gravity in that direction. From the new site the trunk can be straightened by pushing against the friction site. The posterior portion of a tailless individual slides backward as the trunk is straightened, slowing their forward movement. The backward slide may reflect the lower mass and reduced static friction of the partial tail. In channels, Neoseps uses limbed concertina rather than simple concertina to generate a propulsive force. Evolutionarily, it appears that elongation of the tail and trunk did not incorporate the capacity for lateral undulation; as the curves of the trunk and tail seem preprogrammed and do not adjust to local points of contact.
The dorsal stripe in newt efts: a method for distinguishing Triturus vulgaris and T. helveticus
Authors: Roberts J.M. , Griffiths R.A. 
Published: April 2008

AbstractWithin a few weeks of metamorphosis, a dorsal stripe develops in smooth and palmate newts (Triturus vulgaris and T. helveticus). A method for distinguishing between the efts of these two species using characters based on the dorsal strip is described and evaluated. The method was tested using both experienced and inexperienced observers who, on average, classified 87% of the T. vulgaris and 97% of T. helveticus correctly. No misclassifications were made by any of the observers but a small proportion of the efts could not be classified with confidence into either category because the dorsal stripes were only faintly discernible.
The skeleton of a juvenile Lanthanotus (Varanoidea)
Authors: Rieppel Olivier 
Published: April 2008

AbstractThe cleared and stained skeleton of a juvenile Lanthanotus bomeensis provides additional evidence for the "cervicalization" of an anterior dorsal vertebra, resulting in the 9 cervical vertebrae thought to be diagnostic of the Varanidae. Lanthanotus shows two complete sternal ribs associated with the vertebral segments 10 and 11, and an incomplete sternal rib associated with the 9th segment; Varanus shows three complete sternal ribs associated with the vertebral segments 10, 11 and 12. The loss of a sternal rib associated with the 12th segment is autapomorphic for Lanthanotus. Nine cervical vertebrae may be diagnostic for the genus Varanus only, since Lanthanotus preserves a rudimentary sternal rib associated with the 9th vertebral segment, at least at some stage of its ontogeny. A free carpal "intermedium" is absent (or variably present) in Lanthanotus. The pattern of epiphyseal calcification in the carpus and tarsus of Lanthanotus is described and compared to Varanus.
The status of the races of the graceful crag lizard, Pseudocordylus capensis, from South Africa
Authors: Herselman Y.M. , Mouton P. le F.N. , Van Wyk J.H. 
Published: April 2008

Abstract
To evaluate the taxonomic status of the races of the graceful crag lizard, Pseudocordylus capensis, geographical variation in 44 external morphological characters was determined, using 97 specimens from 31 localities. Two different epiphenotypes predominate in the northern and southwestern parts of the distribution range. These epiphenotypes are, however, connected by a continuum of variation. It is therefore suggested that the recognition of races be abandoned in the formal taxonomy. Several new distribution records for the species are provided.
Residence in water by the newts Triturus vulgaris, T cristatus and T. alpestris in a pond in northern Italy
Authors: Fasola Mauro , Canova Luca 
Published: April 2008

Abstract
The annual cycle of residence in water differed considerably among the three syntopic newts Triturus vulgaris, T cristatus and T. alpestris at a pond in northern Italy. T. vulgaris were resident in water for only short periods, which were used exclusively for reproduction. Adult T cristatus were present in the water for 3-4 months after reproduction, and regained weight during autumn. T. alpestris were present throughout the year; branchiate juveniles and neotenics were more abundant than adults.
Morphological analysis of two Hungarian water frog (Rana lessonae-esculenta) populations
Authors: Gubányi A. , Korsós Z. 
Published: April 2008

AbstractTwo water frog populations, Rana lessonae-esculenta systems, have been studied in Hungary from the morphological point of view. Multivariate analyses of selected morphological measurements based on biochemical identification of the species provide two ratios as possible key characters for determination of the two forms.
Ontogeny of the oral apparatus of the tadpole of Bufo americanus
Authors: Tubbs Lydia O.E. , Stevens Rebecca , Wells Marion , Altig Ronald 
Published: April 2008

Abstract
The development of the oral apparatus of tadpoles of Bufo americanus was described from late embryonic through to metamorphic stages. Although sufficiently detailed developmental studies are not common, especially of species with tooth row formulae greater and less than 2/3, it appears that differences in timing rather than in sequence are the primary interspecific differences. Species with rapid developmental times (e.g. Bufo) seemingly start and complete developmental sequences slightly earlier than species with longer developmental times. Species with labial tooth row formulae greater than 2/3 start development sooner, complete it later and retain mouth parts longer into metamorphosis than species with 2/3 tooth rows. Lentic species tend to form the oral structures later and faster and atrophy the oral apparatus earlier and faster than lotic forms. For these reasons, oral development is often discordant with features of limb development used in staging.
On the acoustic profile of the rattlesnake rattle
Authors: Young Bruce A. , Brown Ilonna P. 
Published: April 2008

AbstractA survey of the acoustical profile of 74 rattlesnakes, representing 27 taxa was performed. A close relationship was found between the size of the proximal rattle segment and acoustic properties of the rattling sound. No evidence of distinct interspecific variation in the acoustic profile of the rattle was found. The results suggest that measurements of the proximal rattle segment may be useful as a predictor of the sound produced by the snake.
Reproductive biology of the parsley frog, Pelodytes punctatus, at the northernmost part of its range
Authors: Toxopeus A.G. , Ohm M. , Arntzen J.W. 
Published: April 2008

Abstract
The reproductive biology and population dynamics of Pelodytes punctatus were studied at the breeding season over a three year period in a coastal dune system located at the extreme northwestern border of the species' range. Adult population size estimates ranged from about 100 in the first year to 60 in the third year. Males were remarkably sedentary near the pond under artificially provided shelters. Many were observed during the most of the breeding season which lasted from mid-March or the end of March to the end of April or mid-May. Most spawning took place in the second half of March or early April. In two years out of three a second period of spawning involving fewer animals was observed in the first half of May. Both periods of spawning coincided with, or shortly followed, periods of rising median air temperature. Egg-clutches were deposited in the deepest parts of pond, mainly on submerged vegetation not reaching the surface. An average sized clutch contained approximately 360 eggs. Development of the embryos until hatching took from 4 to 14 days, depending on the ambient temperature. Larval development and growth were fast. Recently metamorphosed froglets at a size of around 18 mm were found from the end of May onwards. Juveniles may reach adult size in the autumn of the year that they were born. Adult frogs did not show a strong fidelity to the breeding pond between years. In the study area the population structure of Pelodytes punctatus seems to be best described by a source - sink model in which flourishing populations in the dunes give rise to short lived satellite populations outside the dunes.
Progesterone induces bright orange throat coloration in female Petrosaurus mearnsi
Authors: Cooper William E. , McGuire Jimmy A. 
Published: April 2008

Abstract
Female Petrosaurus mearnsi develop orange throat coloration when gravid. This coloration was induced in the nonbreeding season (late fall) by exogenous progesterone delivered by subcutaneous implantation in Silastic capsules or intramuscular injection. Color change was first apparent after five days of administration. The time course of brightening was similar for the two methods. Color change was first apparent after five days, and was detectable in most females receiving implants after six days. For both routes of administration, maximum brightening usually occurred within three days of the time that brightening was first detected. Following removal of implants or termination of daily injections, the throat coloration of most females had begun to fade within 25 to 30 days. However, two injected females did not fade at all after sixty days and none faded completely to pretreatment coloration. This suggests that endogenous steroid production by early winter is insufficient to induce brightening, but it might maintain some degree of artificially induced brightening. Because progesterone has also been shown to induce orange female coloration in a distantly related phrynosomatid species and two species of crotaphytids, we hypothesize that induction of bright female secondary sexual coloration by progesterone may be a widespread trait in iguanian lizards.
"Scan" behaviour in Podarcis muralis: the use of vantage points by an actively foraging lizard
Authors: Avery Roger , Basker Annabel , Corti Claudia 
Published: April 2008

AbstractTwo adult Podarcis muralis whose normal movements incorporated the flat top of a wall, frequently paused so that they were looking outwards from an edge ("scan" posture), especially during longer (≥9 s) periods immobile. Investigations of the posture on raised wooden platforms in outdoor enclosures, using two juvenile lizards, showed that (1) lizards spent significantly more time on platforms than would be expected from random movement, and this was not because wood is a favoured substrate for basking; (2) lizards which were immobile on platforms spent significantly more time at edges than would be expected by chance; (3) body orientations at 67.5-112.5° to the edge were the most frequent and these were maintained for significantly longer periods than the remaining orientations; exceptions were from 0800-0900 h when orientation was often parallel to the edge facing the sun and from 1200-1300 h with only a thin strip of shade at 45°, into which the lizards fitted themselves. Lizards basking in the laboratory beneath a tungsten bulb at the edge of a raised platform adopted outward-facing orientations when the platform height was ≥6 mm. When presented with a choice between basking more effectively (i.e. rapid heating rate) or adopting the "scan" posture at an edge with a lower heating rate or with no heating, they opted for the former. Podarcis sicula, P. filfolensis, Lacerta viridis and L. vivipara all showed an excess of outward-facing orientations when the basking bulbs were place near edges of platforms, but Psammodromus hispanicus did not. Only the two Podarcis species, however, spent more time on raised platforms than would be expected by chance when basking was possible at many sites in an arena.
The identity of Mantella cowani Boulenger, 1882 and Mantella haraldmeieri Busse, 1981 (Anura: Mantellinae)
Authors: Böhme Wolfgang , Busse Klaus , Glaw Frank 
Published: April 2008

Abstract
The synonymization of Mantella madagascariensis haraldmeieri Busse, 1981 with M. cowani Boulenger, 1882 by Blommers-Schlösser and Blanc (1991) is unjustified. Re-examination of the type material and descriptions demonstrates the specific distinctness of both, regardless the possibility that cowani and other nominal taxa commonly considered as synonyms of M. madagascariensis are actually taxonomically distinct from the latter.
Relations entre la glycémie et l'activité saisonnière chez Vipera aspis L
Authors: Bonnet Xavier , Naulleau Guy 
Published: April 2008

AbstractBlood glucose levels in Vipera aspis show great variations, both between months during the annual cycle, and between males and females. The seasonal variations are clearly related to climatic conditions, and particularly air temperatures and possibilities for thermoregulation. The blood glucose levels of the snakes are very low during the hibernation period and high in summer. Nevertheless, climatic conditions alone cannot explain changes of blood glucose levels observed during the period when the vipers are active, particularly the peaks measured soon after emergence from hibernation (males in February, females in March). Testicular activation, vitellogenesis and digestion need high body temperatures for long periods, thus the blood glucose level in reptiles chould be the result of a balance between climatic and physiological conditions expressed by the thermoregulatory behaviour. Plasma glucose levels are higher when the body temperatures are high and when the vipers spend more time in the sun (e.g. males in February, females in March); however, hormonal factors probably play a role.
Effects of feeding on set point temperatures and thermoregulatory behaviour in the lizards
Authors: Tosini Gianluca , Jones Scott , Avery Roger 
Published: April 2008

Abstract
Feeding resulted in immediate upward shifts of between 0.62 and 3.00 K in the mean set points at which basking started and ceased (Tbask and Tmove) in P. muralis allowed to thermoregulate beneath tungsten bulbs giving three different levels of radiant heat, except for Tmove in lizards at the highest level (70 mW cm-2 measured in the range 8 000-14 000 nm). Mean bask durations decreased following feeding, but mean forage durations also decreased and the overall times spent basking increased. Values for all four variables declined gradually, returning to pre-feeding levels after 30-50 min. Feeding had no effect on mean heating rates. Feeding in Lacerta vivipara also resulted in increases in set point temperatures, but mean bask durations increased following feeding in this species.
Fat body and liver cycles in the large girdled lizard
Authors: van Wyk J.H. 
Published: April 2008

AbstractCordylus giganteus is a large viviparous lizard endemic to the Highveld grasslands of South Africa. Seasonal morphometric changes in fat body mass, liver mass and a carcass condition index in male, female and juvenile C. giganteus are described for a 15 month period. In the adult male and juvenile classes, abdominal fat bodies increase during late summer and autumn followed by a dramatic depletion during winter hibernation. Although that fat body cycles of adult reproducing females are similar to those of males, the magnitude of lipid storage in these females was considerably greater. Adult females showing early vitellogenic activity and significantly larger fat bodies than non-reproductive females. Seasonal liver mass changes paralleled the fat body cycles in all classes. Fat body stores appear to be used by all classes for winter and early spring nutrition. Energy needs during winter vitellogenesis in females and mating activity during spring in males may also benefit from fat body and liver energy stores. The hypothesis that biennial reproduction in females is determined by the magnitude of energy reserves at the onset of vitellogenesis in autumn is upheld.
Non-invasive sex identification of juvenile gopher and desert tortoises (genus Gopherus)
Authors: Burke Russell L. , Jacobson Elliott R. , Griffith Michele J. , Guillette Louis J. 
Published: April 2008

Abstract
Using previously preserved specimens, we attempted to develop multivariate discriminating functions that could accurately identify the sex of hatchling Gopherus agassizii and juvenile G. polyphemus based on external morphometrics. A simple and successful function was determined for G. polyphemus, but not for G. agassizii. The failure in the latter case may have becn due to the use of individuals from morphologically distinct populations.
Reproduction in Agama aculeata aculeata and Agama planiceps planiceps females from Windhoek, Namibia
Authors: Heideman N.J.L. 
Published: April 2008

AbstractAgama aculeata aculeata and Agama planiceps planiceps females were reproductively active during summer, which is the rainy season in Namibia. Both species were iteroparous; clutch size and relative clutch mass in the smaller A. a. aculeata were significantly larger than in A. p. planiceps. Egg and newborn hatchling size of A. a. planiceps on the other hand were significantly greater than in A. a. aculeata. It is suggested that these differences may have evolved as a result of different strategies which the two species possibly employ to cope with predation pressure, namely, evasion through crypsis in A. a. aculeata and through speed of escape in A. p. planiceps.