bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic relationships between populations and intraspecific subdivision of Elaphe longissima (Laurenti, 1768) as suggested by plasma protein electrophoresis and DNA fingerprinting
Authors: Lenk Peter , Joger Ulrich 
Published: April 2008

AbstractSpecimens from the whole range of Elaphe longissima were analyzed for geographical variation of plasma proteins and DNA fingerprint loci. Albumins were identical throughout the range of the species, except for Sicilian specimens of E. l. romana which share bands with E. persica rather than with E. longissima. Transferrins indicate that Central European populations originate from the East, whereas Western European populations are indistinguishable from Northern Italian ones. DNA fingerprints reveal a low effective population size in Central European isolates with only few bands that could be informative for intraspecific groupings. Most of the repeated sequences are located on the female w-chromosome.
Les risques de prédation liés à la reproduction chez un Viperidae ovovivipare, Vipera aspis L., d'après les observations visuelles
Authors: Saint Girons H. 
Published: April 2008

AbstractIf one accepts that the number of times that vipers are observed in the field in any given season is an indirect measure of the overall risk of predation run by such diurnal predators hunting by vision, the results obtained in this study show that risk of predation is particularly high in males during the period of mating and in females when pregnant.
Post-hibernation behavior of a population of garter snakes (Thamnophis sirtalis)
Authors: Sexton Owen J. , Bramble Judith E. 
Published: April 2008

Abstract
The post-hibernation breeding activities of a small population of the common garter snake (Thamnophis sirtalis) were followed in the vicinity of their hibernaculum or den in St. Louis Co., Missouri, USA during the springs of 1981-85, inclusive. Individual males could emerge as early as mid-February and remain at the den and its immediate vicinity for three or more weeks. Each day, after elevating their body temperatures, males patrolled the ground surface within 2-3 m of the den entrance. During patrolling activities, males investigated each other at frequent intervals and often returned to re-enter the den briefly. Upon partial re-emergence, one or more males would assume a position such that the head and anterior portion of the body were elevated. This "blocking" activity may be a behavioral mechanism that controls access to the den by competing males and egress by females. Numerous males simultaneously court a single female. The social organization of garter snakes is compared to that typified by lek species and several similarities are noted.
Genetic data support the specific status of the Italian treefrog (Amphibia: Anura: Hylidae)
Authors: Nascetti Giuseppe , Lanza Benedetto , Bullini Luciano 
Published: April 2008

AbstractGenetic variation at 28 protein loci was analyzed electrophoretically in populations of the Central European treefrog, Hyla arborea arborea, from Italy, Switzerland, Germany and the Balkans. Two distinct population groups were detected, differing at 9 more or less diagnostic loci, one ranging from Sicily to peninsular Italy, northwards to the Italian slope of the Alps (Italian treefrog), the second parapatrically distributed with respect to the first, north of the Alps, east of the Isonzo river, and southwards to the Balkans (H. arborea arborea s.s.). In the area of close contiguity between the two population groups (approximately coinciding with the border between Italy and Slovenia), neither mixed populations nor hybrid individuals were found. However, a number of specimens with introgressed genotypes were detected in both forms in the contact area and its surroundings, possibly as the result of past hybridization events. The lack of present gene exchange in the contact area indicates that the Italian treefrog and H. arborea arborea (s.s.) are distinct biological species. Average Nei's genetic distance between the Italian treefrog and H. arborea arborea (s.s.) is 0.47, corresponding to an estimated time for evolutionary divergence of about 2-3 million years. The Italian treefrog and H. arborea arborea (s.s.) were found to be morphologically very similar, with a single significant difference (tympanum size) among the considered characters; this is larger in the Italian treefrog. The name Hyla italica nomen novum is proposed for the Italian treefrog, as the name Hylaria variegata assigned by Rafinesque (1814) to treefrog specimens from Sicily is unavailable.
Field metabolism of lizards from lower altitude regions of Baja California Sur (Mexico)
Authors: Grenot Claude J. , Galina-Tessaro Patricia , Alvarez-Cardenas Sergio 
Published: April 2008

AbstractWater flux rate and field metabolic rate of three free-ranging sympatric species of lizards (Uta stansburiana, Urosaurus nigricaudus and Cnemidophorus hyperythrus) were measured in the Cape Region, near La Paz (Baja California Sur, Mexico) using labelled water (3H2O and H2 18O). During the rainy season, the three species consumed the same prey. Caterpillars of Lepidoptera (7.1 ml H2O/g DM) were the most important in volume and mass. The lizards showed high water flux rates, which did not differ from those of non-desert species, but were 2 to 7 times higher than during the dry season. During the dry season the low rates of water flux were basically due to low metabolic rates. The water flux rate of C. hyperythrus in September was two to four times higher than rates in two other populations in the southern part of the Cape region, but the field metabolic rate was similar. Adult size in the El Comitán population (BM = 6.3 g) was larger than that in two Cabo San Lucas populations (BM = 4.4 and 3.9 g). These data suggest flexibility of responses of species and populations to environmental variation.
Energetics, osmoregulation, and food consumption by free-living desert lizards, Ctenophorus (= Amphibolurus) nuchalis
Authors: Nagy K.A. , Bradshaw S.D. 
Published: April 2008

Abstract
The ecophysiology of the agamid lizard Ctenophorus nuchalis was studied near Shark Bay, Western Australia, during three seasons, over four years, in order to evaluate seasonal and year-to-year variation in energy and material balance, and to compare this agamid with similar-sized iguanid lizards. We measured water influx and efflux rates and field metabolic rates with doubly-labelled water, sodium fluxes with radiosodium, and osmotic status (plasma osmotic and ionic concentrations) in free-ranging adults of both sexes, as well as juveniles. Feeding rates were calculated from diet composition information in conjunction with rates of water and sodium intake, and body condition indices were also determined. There were marked seasonal and year-to-year differences in body condition, and in rates of body mass gain or loss, and these correlated with drought periods. Rates of resource use were highest in spring, and declined through summer and autumn, and rates were lowest during 1983, a year having unusually low winter rainfall. Hatchlings, which emerged in autumn, were able to find and capture food resources, even though adults were eating little during that season. The annual pattern of energy, water and salt balance in this agamid lizard is quite similar to that of an equivalent-sized iguanid lizard.
Cost effective drift fences for toads and newts
Authors: Arntzen J.W. , Oldham R.S. , Latham D.M. 
Published: April 2008

Abstract
The construction, cost and performance of toad and newt drift fences and associated traps used at three study sites is described. Fence efficiency, in terms of the capture of animals immigrating to breeding sites, was calculated to lie between 39 and 63% of the estimated breeding population for the common toad (Bufo bufo), and between 45 and 61% for the crested newt (Triturus cristatus). Fences were consistently less efficient at intercepting emigrating animals; less than 10% of toads and between 34 and 40% of newts were captured. Cost and performance of the systems are compared with data from the literature.
Foraging ecology of the mangrove salt marsh snake, Nerodia clarkii compressicauda: effects of vegetational density
Authors: Mullin Stephen J. , Mushinsky Henry R. 
Published: April 2008

Abstract
The mangrove salt marsh snake (Nerodia clarkii compressicauda Baird and Girard) may experience varying levels of foraging success because the prop roots of the red mangrove (Rhizophora mangle L.) have a six-fold variation in density. Adult female N. c. compressicauda were allowed to forage for 24 h on a known density of prey in an enclosed habitat simulating one of four experimental prop root densities. Snake behaviors were recorded during the first hour of each trial, and the number of prey ingested was determined at the conclusion of the trial period. Individuals had the greatest success at the root density most often encountered in their habitat. More time was spent in the water than atop roots; but individuals were less likely to forage in the water at low root densities, suggesting that they, like their prey, may be afforded protection from avian and mammalian predation by the mangrove forest canopy. Mangrove salt marsh snakes spent the majority of time resting motionless and appeared to be opportunistic predators, attempting to ingest prey only during chance encounters.
Variations in brood size and birth rates of Salamandra salamandra (Amphibia, Urodela) from different habitats in northern Israel
Authors: Degani Gad , Warburg M.R. 
Published: April 2008

Abstract
Ovoviviparous births of larvae of Salamandra salamandra (L) were compared from a number of disjunct habitats in northern Israel, at the south-eastern limit of the Palearctic distribution of the species. The numbers, period and rate at which larvae were born varied between different habitats. In one winter pond, 90±11 larvae per brood were born at a rate of 5 per hour during December-January; in another pond, broods of 114±13 were born at 4 per hour during November-January; in a third, 112±15 were born at a rate of 4 per hour during November-December. In a perennial spring habitat, 68±2 larvae per brood were born at a rate one per hour during February-March, while in a stream habitat, brood size was 55±10 larvae, born at two per hour over the whole year. There were no significant differences in size between larvae from different habitats. Adjustments in birth parameters of larvae born in winter ponds indicate adaptation to an unpredictable habitat.
A field study of reproductive interactions in Bosca's newt, Triturus boscai
Authors: Faria Manuel Mouta 
Published: April 2008

AbstractObservations of a free-living population of Bosca's newt, Triturus boscai, show that courtship behaviour in nature is similar to the behaviour observed in earlier laboratory studies. Complementary evidence was obtained on the behaviour called flick, which is sometimes inserted at the end of the static display phase, and may be viewed as an equivalent behaviour to the retreat display of the other small-bodied newt species. Sexual interference in the natural population was mainly caused by males. Two characteristic male behaviour patterns were recognised, the waiting position and the push-tail. Females tend to withdraw from situations of interference. Courtship sequences solely consisting of orientation and spermatophore transfer phases, so-called short-circuit sequences, may be interpreted as a male strategy to avoid the very severe male-to-male interference that exists in a wild population.
Geographic variation, taxonomy, and distribution of Eumeces skiltonianus and E. lagunensis (Squamata: Scincidae) in Baja California, México
Authors: Lee Grismer L. 
Published: April 2008

AbstractAn analysis of scalation, color pattern, and distribution of Eumeces skiltonianus and E. lagunensis in Baja California indicates that these taxa are discretely diagnosable from one another and allopatric. In the context of an evolutionary species concept, they are considered to be separate species. New records extend the range of E. lagunensis 220 km to the north in central Baja California. An erroneous report on the southern extent of E. skiltonianus in northern Baja California is corrected, restricting its southern distribution 145 km further north than previously reported.
Ultrastructural changes of the air-blood barrier in the lung of Rana esculenta during natural hibernation
Authors: De Piceis Polver Paola , Bernini Franco , Barni Sergio 
Published: April 2008

Abstract
Possible changes of the air-blood barrier in naturally hibernating frogs were examined by transmission electron microscopy and measured with an eye-piece micrometer under light microscopy. During hibernation a reduction of the "alveolar" air-space and a folding of the air-blood barrier were noticed: the thickness of the latter in the deep lung septa was double that seen in the active phase, as a consequence of deeper changes of the interstitial and surface epithelial components. An increase in electron-dense multilamellar bodies inside the pneumocyte cytoplasm was also observed. These morphological characteristics are indicative of a hypofunctionality in the lung respiratory components and may be related to a decrease in oxygen consumption during this quiescent phase of the annual life cycle.
The effects of insulin on TSH secretion and the morphology and physiology of the thyroid in the lizard Podarcis s. sicula
Authors: Laforgia Vincenza , Cavagnuolo Antimo , Sciarrillo Rosaria , Capaldo Anna 
Published: April 2008

Abstract
Insulin was administered to Podarcis sicula in winter, when the thyroid gland is inhibited. The activity of the thyroid increased, plasma concentrations of thyroid hormones and hepatic 5'-monodeiodinase activity (MDA) increased, and thyroid stimulating hormone (TSH) concentrations fell to undetectable values. This result confirms the influence of insulin on the activity of the thyroid gland in the lizard species studied. The mechanisms are still unclear, although there is evidence which leads us to believe that insulin is directly responsible for thyroid activation.
Material and energy budget during incubation in a Chinese skink, Eumeces chinensis
Authors: Xiang Ji  , Fu Shui-Yu , Zhang Hua-Song , Sun Ping-Yue 
Published: April 2008

Abstract
The incubation time of Eumeces chinensis eggs at 30±0.3°C averaged 22.6 days. During incubation, the pliable-shelled eggs of E. chinensis increased in wet mass. Dried shells from freshly laid eggs averaged 4.1% of the entire egg dry mass. No significant difference in shell dry mass was found between freshly laid and hatched eggs with the same wet mass at oviposition. During incubation, approximately 66% of dry mass, 44% of non-polar lipids and 62% of energy in egg contents of the freshly laid egg were transferred to the hatchling, with 34% of dry mass, 56% of non-polar lipids and 38% of energy used for embryogenesis. Fully developed embryos could obtain all magnesium from yolk but withdrew approximately 19% of their total calcium requirements from sources other than yolk.
Dentitional surface features in snakes (Reptilia: Serpentes)
Authors: Young Bruce A. , Kardong Kenneth V. 
Published: April 2008

Abstract
The complexity of snake tooth morphology is more varied than has been recognized in functional, evolutionary, or taxonomic studies. We surveyed a broad sample of species across taxonomic groups to document and summarize the variation present. Our survey included a scoring of dentitional features of 1169 specimens representing 611 species of snakes on four dentiferous bones (dentary, pterygoid, palatine, maxilla). Besides presence or absence of teeth on these bones, we ranked the tooth type on each bone on the basis of a four category system: basic, furrowed, grooved, or hollow tooth. Basic teeth, without surface recesses or grooves, were the most common tooth type. Hollow teeth (fangs) were found most commonly on the maxilla and grooved teeth were often adjacent. Grooved teeth, when present, were found only on the maxilla although teeth with furrows, shallow creases in the surface enamel, were found in low numbers on the dentary, pterygoid, and palatine. Teeth exhibited further specializations, including multiple grooves, basal reinforcing ridges, development of a blade-like design, variation in the degree to which the secondary groove in hollow teeth might be in evidence, and variation in the position of the groove along the shaft of the tooth.
Sexual behaviour of the Chinese fire-bellied newt, Cynops orientalis
Authors: Sparreboom Max , Mouta Faria Manuel 
Published: April 2008

Abstract
The courtship of the Chinese fire-bellied newt, Cynops orientalis (David 1873), resembles that of Japanese congeneric taxa but shows significant temporal differences: the tail-fanning and creeping stages are of relatively short duration and one spermatophore is deposited a few seconds after the male starts to creep. The female loses interest in the male soon after the first spermatophore deposition. Instances of prolonged biting after spermatophore deposition are recorded. Successful insemination was a relatively rare event. In encounters with a potential rival present, a male may slightly alter the timing of his courtship. Observed behaviour patterns are compared to the sexual behaviour of other species of Cynops and Triturus.
Parentage of Caucasian parthenogenetic rock lizard species (Lacerta) as revealed by restriction endonuclease analysis of highly repetitive DNA
Authors: Grechko Vernata V. , Ryabinin Dmitry M. , Fedorova Larissa V. , Fedorov Alexey N. , Ryskov Alexey P. , Darevsky Ilya S. 
Published: April 2008

Abstract
The Caucasian parthenogenetic rock lizards of the L. saxicola complex probably originated by hybridisation of some bisexual species. We verified this hypothesis using a new approach based on comparison of repetitive DNA characters, which produce species-specific patterns (named "taxonprint"). The method relies on restriction endonuclease hydrolysis of genomic DNA, with the following 32P-end labeling and polyacrylamide gel electrophoretic separation of the fragments. The parthenogenetic species L. armeniaca and L. dahli possess specific features both of putative maternal L. mixta (in some taxonprints), and of paternal L. valentini (in other ones), whereas L. portschinskii and L. rudis also could be the paternal species. Parthenoclones L. unisexualis and L. uzzelli have the specific DNA features in several taxonprints of L. raddei or L. nairensis (which cannot be discriminated by taxonprints) which are supposed to be maternal species for L. unisexualis and paternal ones for L. uzzelli. The specific features of L. valentini (or L. portschinskii) are observed in L. unisexualis; L. uzzelli has not been investigated in this respect. Parthenogenetic L. rostombekovi also possesses properties of L. raddei or L. nairensis, but we have not be able to find any features of supposed paternal L. portschinskii in this parthenogenetic species.
Two new species of Leptolalax (Anura: Megophryidae) from northern Vietnam
Authors: Lathrop Amy , Murphy Robert W. , Orlov Nikolai , Thu Ho Cuc 
Published: April 2008

Abstract
Two new species of Leptolalax are described from two mountain ranges in northern Vietnam (Song Gam and Tam Dao) that are less than 150 km apart. Currently, only two species of Leptolalax, L. pelodytoides and L. bourreti, are described from Vietnam. The two new species are distinguished from other Leptolalax by a combination of characters including skin texture, ventral color pattern, presence or absence of spots on the flanks, and lateral fringes on the toes. Furthermore, the new species can be distinguished from the widely distributed and sympatric L. pelodytoides by their large size, indistinct color pattern, and an absence of granules under the chin. In addition, one of the new species has a higher cellular DNA content than sympatric L. pelodytoides.
Sexual dimorphism and testosterone responsiveness in hypaxial muscles of the northern leopard frog, Rana pipiens
Authors: Blackburn Daniel G. , Bernardo Vincent A. 
Published: April 2008

AbstractAbdominal hypaxial muscles of male anurans function in vocalization by causing forcible expulsion of pulmonary air through the larynx. The hypaxial muscles were studied in the leopard frog, Rana pipiens, to test whether functions of these muscles in males are reflected in sexual dimorphism and in androgen responsiveness. The combined abdominal oblique muscles and the rectus abdominis showed significant sexual dimorphism in wet mass and dry mass. However, the abdominal oblique muscles were less concentrated in protein content in males than in females. In overwintering males, exogenous testosterone cypionate stimulated a significant increase in mass and protein content of the abdominal oblique and rectus abdominis muscles. Castration had no effect on muscle mass or on the response to androgen treatment.
Growth in a population of Liolaemus wiegmannii (Squamata: Tropiduridae) in Central Argentina
Authors: Martori Ricardo , Cardinale Lisandro , Vignolo Pablo 
Published: April 2008

Abstract
Size frequencies in a population of the lizard Liolaemus wiegmannii were determined throughout the year, to evaluate the effects of recruitment and mortality on the population structure, and to estimate the daily growth rate and its variation. The cycle started in spring when most of the lizards had reached reproductive size, in December eggs were laid and the new lizards were born in January. This cohort grew rapidly and reached adult size in late March, while the postreproductive cohort died in late fall. The differences between growth rates during the year are due to the seasons and the size of the lizards during the period.
Feeding, reproduction and growth in the crowned snake
Authors: Marques Otavio A.V. , Puorto Giuseppe 
Published: April 2008

AbstractThe crowned snake Tantilla melanocephala is a small fossorial sonorine snake, widely distributed through South America. Dissection of 186 specimens, combined with observations of captive specimens, provided information on the natural history of this species in southeastern Brazil. Females attained larger body sizes than males. Apparently T. melanocephala forage at night for active prey. Centipedes of the genus Otostigmus were the main prey item. These centipedes are subdued by injection of venom. Data from preserved specimens showed no significant seasonal variation in the number of collected snakes. Reproduction seemed to be highly seasonal with vitellogenesis occurring from onset to the middle of the rainy season and hatching at the end of the rainy season. Clutch size ranged from one to three and was correlated with female body length. Neonates measured 10-12 cm snout-vent length and juveniles attained about 17.5 cm SVL during the first year. Apparently males attain sexual maturity at an age of about 10 months and females at about 20 months.
Immunocytochemical study of pituitary FSHß and LHß cells during the ontogeny of the toad Bufo arenarum
Authors: Miranda Leandro A. , Somoza Gustavo M. , Affanni Jorge M. 
Published: April 2008

Abstract
The ontogeny of gonadotrophs in the pituitary of Bufo arenarum was studied by immunocytochemical techniques using monoclonal antibodies against bullfrog lutropin ß-subunit and bullfrog follitropin ß-subunit. The first appearance of immunoreactive gonadotropic cells was at midprometamorphosis in the caudal zone of the pars distalis. During metamorphosis, in juveniles and especially in adult animals, follicle stimulating hormone (FSH) and luteinizing hormone (LH) producing cells were distributed throughtout the gland. The number of these cells was greatly increased in older stages. In all the stages studied colocalization of FSH and LH was observed. At least three types of gonadotrophs were identified: the first cell type containing only FSH; the second only LH; and the third, FSH and LH in the same cell.