bluuebunny/crossref_metadata_2025 huggingface dataset:
Inheritance of Vertebral Stripe in Rana ridibunda PaLL. (Amphibia, Ranidae)
Authors: Berger Leszek , Smielowski Jan
Published: April 2008

The authors examined the inheritance of the vertebral stripe in the progeny of F1,F2 and F3 generations of Rana rridibunda from Turkey. The female as unstriped and the male as striped. All F1, froglets were striped, in F2 froglets this colour pattern segregated according to MENDEL'S law 3:1 (95 frogs were striped and 29 unstriped). In F3 froglets which were received from unstriped parents, only unstriped individuals appeared. Numbers of females and males among individuals of both colour patterns were normal (1:1). The authors concluded that the vertebral stripe in R. ridibunda is controlled by an autosomic gene and that the allele responsible for the presence oflight stripe is dominant and its antagonistic one is recessive.
Lacerta siculimelitensis sp. n. (Sauria: Lacertidae), a giant lizard from the Late Pleistocene of Malta
Authors: Böhme Wolfgang , Zammit-Maempel George
Published: April 2008

Lacerta siculimelitensis sp. n., an extinct giant lizard species is described from the Late Pleistocene of Malta. It is shown that this species lived contemporaneously also on Sicily. The zoogeographical aspects of the fossil form as compared with recent members of the genus are discussed.
The true Status and Future of Hermann's Tortoise Testudo hermanni robertmertensi WERMUTH 1952 in Western Europe
Authors: Cheylan Marc
Published: April 2008

Hermann's tortoise of western Europe, Testudo hermanni robertmertensi WERMUTH 1952, is in fact seriously endangered throughout its range of distribution. In Spain, one comes across only a few in Minorca and Majorca (Balearic Is.) and in an area confined to the north of the province of Gerona. In France, it occurs in the Maures and Estérel mountains (Var), the Albères (Pyrénées-orientales) and Corsica. The importance of the Italian populations is less understood. On the mainland, it is mainly on the west coast and in the south. It also occurs on the islands of Sicily, Sardiniaand Elba. In all these areas, Hermann's tortoise is in strong decline on account of forest fires, increased urbanisation of the coastal areas and commercial and individual collecting. Proper safeguards are extemely limited and will not allow populations of this tortoise to be maintained. Prompt action to safeguard the species is required. One of the most effective means qould be to increase breeding in populations reduced by fire. The formation of nature reserves is also desirable to protect the small isolated populations of the Albères, Maurea, Minorca and Mallorca.
An F2-Generation of Testudo hermanni hermanni GMELIN Bred in Captivity with Remarks on the Breeding of Mediterranean Tortoises 1976-1981
Authors: Kirsche W.
Published: April 2008

Hatchlings were obtained from eggs laid by Testudo hermanni hermanni GMELIN, which had hatched in captivity in 1965. To our knowledge this is the first report of a second generation breeding of Testudinidae under conditions in captivity. Two hybrid hatchlings between a male T. h. hermanni and female Testudo horsfieldii (GRAY) were also obtained.
The simulation of mechanochemical chain scisson in organic polymers
Authors: A. Ikekawa
Published: April 2008

Variation in the molecular mass distribution (MMD) of straight polymers, with molecular mass (M) of (1.1-2) x 106, upon central, random or terminal chain scisson (CCS, RCS or TCS, respectively) was simulated. The peak in the MMD was shown to shift to a lower M upon CCS or RCS and the randomly cut polymers were more widely distributed than the centrally cut polymers. A bimodal distribution was obtained upon TCS. A parameter 'n1' in a modified Rosin-Rammler plot, where M is substituted for particle size in Rosin-Rammler's equation, stayed at 2.1-2.3 for CCS at the range of large t and it stayed at 1.3-1.7 for RCS. n1 for TCS decreased to zero with increasing t. Application of these simulation results to ball-milling of polyvinylpyrrolidone (PVP) in nitrogen showed that TCS of PVP was accompanied with its RCS. It was also shown that addition of phenothiazine or acridine increased the rate of RCS.
Karyological Divergence in three Platymantine Frogs, Family Ranidae
Authors: Kuramoto Mitsuru
Published: April 2008

The karyotypes of three platymantine frogs, Platymantis hazelae and P. dorsalis from Philippines and P. papuensis from Papua New Guinea, were described and compared. P. hazelae has 2n = 26 chromosomes consisting of five large and eight small pairs, as in many other species of Ranidae. The karyotypes of P. dorsalis (2n = 20) and P. papuensis (2n = 22) may be derived from the basic karyotype of 2n = 26. Simple fusions and pericentric inversions explain the karyotypic relationships between P. hazelae and P. papuensis, while the karyotype of P. dorsalis seems to have resulted from more complicated chromosome rearrangements.
Haematopoiesis and Regeneration: Changes in the Liver, Spleen, Bone Marrow and Hepatic Iron Content during Tail Regeneration in the Scincid Lizard, Mabuya Carinata (Boulenger)
Authors: Ramachandran A.V. , Kinariwala R.V. , Shah R.V.
Published: April 2008

In response to the observed changes in blood during tail regeneration, a detailed histophysiological study of the haemopoietic organs such as liver, spleen and bone marrow was undertaken. During regeneration, all three organs were found to undergo histophysiological changes. Increased haemopoietic activity in the marrow and hyperplasia of the white pulp were the important changes shown by the bone marrow and spleen respectively. In the liver, the most marked effect appeared to be the formation of large numbers of lymphocytopoietic nodules. Another interesting observation was the influx and destruction of red blood cells both in the liver and spleen, once during the early regressive phase and once during the late progressive phase of regeneration. An attempt is made to correlate these changes in the three haemopoietic organs with the possible involvement of lymphocytes in the formation of a regeneration blastema and a possible haemoglobin transition during regeneration. The present observations are in concordance with the previous observations on blood.
The Histochemistry of the labial Salivary Glands of the Spiny-Tailed Lizard Uromastyx microlepis (Blandford)*
Authors: Jarrar Bashir M. , Taib Noory T.
Published: April 2008

The labial salivary glands of the spiny-tailed lizard, Uromastyx microlepis (Blandford) were used in morphometric, histological and histochemical investigations. Both supra and infralabial glands are of the compound tubulo-acinar type and are of a mixed nature containing both mucous and mucoserous cells. The mucous cells secrete and elaborate neutral mucosubstances, sialomucins and hyaluronidase resistant sulfomucins, whereas the mucoserous cells secrete protein radicals as well. The histoenzymological tests used have detected alkaline phosphatase, succinic dehydrogenase and carbonic anhydrase in these glands.
Notes on nesting and parental care in Caiman crocodilus crocodilus in northern Suriname and an analysis of crocodilian nesting habitats
Authors: Ouboter Paul E. , Nanhoe Lurly M.R.
Published: April 2008

Caiman c. crocodilus constructed nests on small elevations in swamps during the long rainy season (May-July). Eggs were buried just beneath ground level and in addition covered by a small mound of dry leaves. This nest type is intermediate between the hole-type and the mound-type nest. Hatching occurred from the beginning until midway into the long dry season. One of two egg-containing nests studied was destroyed by predators. In the other nest 18 of 28 eggs hatched, which coincides with estimates based on pod sizes and estimated mean clutch sizes. Hatchlings stayed together (sometimes associated with second year caimans) for up to 18 months. Most of these pods were attended by an adult caiman for about seven months, until the beginning of the long rainy season. The sex ratio of newborn young was 0.5, but some pods seemed to consist of one sex only (sex ratio being 0 or 1). These results are compared with data on other populations of C. crocodilus and other crocodilians. In general there is a correlation between the nest type used and the nesting season; hole-nesting species nest in the dry season, whereas mound-nesting species usually nest in the rainy season. Nesting in the dry season by mound-nesting species occurs and possibly can be explained by avoidance of competition with sympatric moud-nesting species.
Comparative Aspects of Diet and Habitat in some New Caledonian Lizards
Authors: Bauer Aaron M. , De Vaney Kathleen D.
Published: April 2008

No comparative ecological studies have previously been conducted on the lizards of New Caledonia. This study examines two parameters of resource partitioning-diet and microhabitat, for eleven species of native lizards (Gekkonidae and Scincidae). Differences in diel activity patterns and coarse habitat differences tend to segregate geckos from skinks. Microhabitat and dietary differences were found among four sympatric species in a forest assemblage at Mt. Koyaboa, but retreat sites and some food resources were employed by all. Rock piles and crevices are important retreats for all the forest species studied and are a crude predictor of lizard abundance. Crickets and terrestrial isopods are the most important items in the diet of the predominant gecko Bavayia sauvagii. Though generally considered arboreal, this lizard is frequently active on the ground as well. Ants are an important food source of the forest skink Leiolopisma tricolor, whereas the ubiquitous ground skink Leiolopisma austrocaledonicum eats a wide variety of prey, with smaller individuals selectively taking smaller prey. Larger individuals consume feew large prey items but these may be of great energetic importance.
Taxonomic Implications of NOR-Localization in Lacertid Lizards
Authors: Cobror O. , Olmo E. , Odierna G.
Published: April 2008

Nucleolar organizer position was studied by means of AgNOR technique in 11 species of the Lacerta-complex. NOR position is the same in species within a subgenus, but it is different in different subgenera. This observation supports Arnold's (1973) and Guillaume and Lanza's (1982) suggestion that the different subgenera of Lacerta (Gallotia, Lacerta part I, Lacerta part II and Podarcir) are distinct genera. The results of this study also support the hypothesis that the evolution of lacertid karyotypes is characterized by progressive translocation of microchromosomes to macrochromosomes.
The Phylogenetic Significance of Morphological Characters in the Holarctic Racers of the Genus Coluber Linnaeus, 1758 (Reptilia, Serpentes)
Authors: Schätti Beat
Published: April 2008

The Holarctic racers (Coluber s.l.) do not represent a holophyletic genus. The unifying characters of Old and New World species are mainly those of external morphology and represent convergence. Differences in hemipenes and osteological characters (basisphenoid, vertebrae) necessitate generic distinction of Old and New World species and thus the restriction of Coluber s.s. to Nearctic forms. The results, moreover, do not justify the separation of the genus Masticophis Baird and Girard from the single Nearctic species, C. constrictor Linnaeus. Sixteen of twenty Palearctic species can be assigned to three species groups most typically represented by C. jugularis, C. rhodorachis, and C. hippocrepis, respectively. Changing or proposing new generic names for these groups must be avoided until the evolutionary polarity of characters is known for the Oriental and Ethiopian forms.
Ecological structure of a herpetological assemblage in South India
Authors: Inger Robert F. , Shaffer H.B. , Koshy M. , Bakde R.
Published: April 2008

We collected detailed microhabitat information on 1460 specimens comprising 52 species of amphibians and reptiles from a small area of tropical evergreen forest in South India. Although most individuals were found in non-riparian situations, the number caught in and along streams was higher than expected on the basis of collecting effort. Very few animals were caught under logs and rocks. When niche breadth values are corrected for variation in sample size, we find no correlation between magnitude of niche breadth and general habitat usage, such as terrestriality vs. arboreality. A cluster analysis of 28 common species using niche overlap values reveals one group of 6 terrestrial species with very high niche overlap values and high co-occurrence within collecting sorties; this group probably represents a genuine terrestrial guild. Another set of 4 terrestrial species is peripherally associated with the first 6, whereas the remaining species show generally low overlap values. Altitudinal restriction is an almost ubiquitous feature of the distribution of species in this fauna, with distinct groups of low (below 300 m), intermediate (300-399 m), and high altitude (above 399 m) taxa roughly corresponding to major shifts in forest types. At a broader level of analysis, we find considerable evidence for local endemism within partially isolated hill ranges in the Western Ghats, suggesting that geographic isolation may be an important contributing factor to the diversity of the South Indian herpetofauna.
Karyotype of horvath's rock lizard Lacerta (Archaeolacerta) horvathi Mehely, 1904 (Reptilia: Lacertidae)
Authors: Dulic Beatrice , De Luca Nina
Published: April 2008

Karyotype analysis of 2 male horvath's rock lizard, Lacerta (Archaeolacerta) horvathi, found 2n = 36 in both somatic and spermatogonial metaphases. All the chromosomes are acrocentric. In diakinesis, 18 bivalents are visible. Microchromosomes, characteristic of most lacertid karyotypes, are absent in this species. In a single metaphase, satellites were observed on the 8th pair of chromosomes. Male sex chromosomes have not been determined. Overall, the karyotype of Lacerta horvathi is similar to that of Lacerta vivipara,
Multiple clutches, egg mortality and mate choice in the mid-wife toad, Alytes obstetricans
Authors: Clarke R.T. , Reading C.J.
Published: April 2008

Egg laying, clutch brooding, egg survival and mate choice were investigated in the mid-wife toad, Alytes obstetricans (Lataste) at a small reservoir in central Spain during 1986 and 1987. Females divided their total egg production into at least three separate clutches. The majority of males brooded between one and three clutches of eggs, though one may have brooded four. First clutches received by males were 24-34% larger than subsequent clutches. No significant differences were found in egg fertilisation, survival and hatching success between individual clutches. The results show that females prefer to spawn with non-brooding males rather than brooding males but that they will spawn with brooding males. When spawning with brooding males they lay smaller clutches than with non-brooding males.
An experimental study of microhabitat selection and microhabitat shifts in European tadpoles
Authors: Waringer-Löschenkohl Andrea
Published: April 2008

The presence or absence of heterospecific tadpoles or of vegetation and changes in population density influenced the microhabitat distribution of 5 sympatric tadpole species in laboratory experiments. Most species, except Hyla a. arborea, occupied the bottom of the aquaria. In some experiments the presence of vegetation caused a significant shift in the tadpole distribution towards the water surface. The presence of Pelobates fuscus, especially under higher density had a similar effect on tadpole distributions. In most species-combination tests one or both species shifted their distribution pattern due to the presence of the other species. In many cases this behaviour can be interpreted as spatial avoidance reaction especially in species which feed in the same water column in the field (Löschenkohl, 1986). The significance of microhabitat shifts as a mechanism to avoid competition is discussed.
Cytogenetic studies on Sauria (Reptilia). I. Mitotic chromosomes of the Agamidae
Authors: Solleder E. , Schmid M.
Published: April 2008

The karotypes of nine species of the family Agamidae were analyzed with various banding techniques and conventional cytogenetic stainings. Whereas the examined species of the genera Calotes and Leiolepis exhibit conservative karyotypes, the chromosome number and chromosome morphology varies considerably within the genus Agama. This is attributed to centric fusions between telocentric chromosomes and pericentric inversions within the chromosomes. None of the species demonstrated multiple quinacrine banding patterns in the euchromatic segments of the metaphase chromosomes. This is probably due to the special DNA organization in these organisms.
Tests for age and size effects on male mating success in a plethodontid salamander
Authors: Francillon-Vieillot Hélène , Houck Lynne D.
Published: April 2008

We used the skeletochronological method to obtain estimates of age for male Desmognathus ochrophaeus (Urodela: Plethodontidae). Age estimates were compared with body size and with a measure of matiing success obtained from an earlier study. Body size is significantly correlated with age, but there is much variation in age among animals having the same body size. Mating success was not significantly correlated either with size or age when males had equal access to potentially receptive females.
An analysis of Hydrophis ornatus (Gray), H. lamberti Smith, and H. inornatus (Gray) (Hydrophiidae, Serpentes) based on samples from various localities, with remarks on feeding and breeding biology of H. ornatus
Authors: Redsted Rasmussen Arne
Published: April 2008

Hydrophis ornatus (Gray) is described from Phuket Island, Andaman Sea, Siam Gulf, and the Philippine Islands, with remarks on feeding and breeding biology. Hydrophis lamberti Smith, is recognised as a distinct species and described from type locality (Bight of Bangkok), Siam Gulf, and the Philippine Islands. The type specimen of Hydrophis inornatus was reexamined. The results showed certain similarities between H. ornatus and the type specimen of H. inornatus, however, in the present paper the type specimen is maintained as a distinct species. Position of internal organs, in relation to number of vertebrae and ventral scales, is used as a new method for identifying sea snakes. Furthermore the number of vertebrae appeared to be a useful character to distinguish between H. ornatus and H. lamberti.
A multivariate clustering approach to display repertoire analysis: headbobbing in Anolis equestris
Authors: Font Enrique , Kramer Matthew
Published: April 2008

Display repertoire analysis requires and unbiased estimate of the number of different displays. Anolis lizards, with easily quantifiable visual displays, provide a system amenable to determining display repertoire size. We used multivariate clustering techniques to classify Anolis equastris headbobbing displays. Forty displays, to conspecifics and mirrors, were graphed and 23 variables from each were used in a cluster analysis. Displays were classified into four distinct groups and a single odd display. The most important variables for classifying displays, assessed with a stepwide discriminant analysis, were associated with the general cadence, number of headbobs, and location of large and small headbobs. Most headbobbing displays ended in lateral head movements, possibly arising from ritualized mouth-wiping. All displays analyzed were apparently aggressive ("threat") displays, suggesting a rich display repertoire for this species but leaving unexplained the reasons so many display types are used. Social and defensive displays, while sharing a number of motor patterns, are readily distinguished by the long duration of dewlap extension and gaping in defensive behavior.
Alimentación de Coluber hippocrepis en el SE de la península Ibérica
Authors: Pleguezuelos Juan M. , Moreno Manuel
Published: April 2008

The food habits of 214 specimens of C. hippocrepis were analyzed throughout the year in an extensive area (44000 km2). This species mainly fed on vertebrates, especially mammals and reptiles which constituted more than 92% of its prey; other items included birds and invertebrates. Mammals represented more than 70% of the total prey mass. There was an ontogenetic shift in prey type; small snakes fed almost exclusively on small lizards, large snakes on rodents, although this change was gradual. There was not an ontogenetic shift in the percentage of snakes with gut contents, number of prey types or food diversity. C. hippocrepis captured relatively small prey. Most of them were taken head first, and those taken tail first were significantly smaller. We discuss the type of prey and the ontogenetic food shift in relation to the habits of this species in the south of Iberian Pcninsula.
Descripcion del renacuajo de Colostethus leopardalis Rivero con algunos comentarios sobre su historia natural
Authors: Mijares-Urrutia Abraham
Published: April 2008

n. Se describe el renacuajo de Coloslethus leopardalis, Rivero (Dendrobatidae), en base a tres ejemplares provenientes de La Corcovada, Páramo de Mucubají, Edo. Mérida, Los renacuajos se distinguen de las demás larvas conocidas del género en los Andes de Mérida, por los siguientes detalles: 1) Reborde de las narinas con papilas; 2) Sierras del pico anterior más grandes que las del pico posterior; 3) Sistema de lineas de poros caracteristico. El renacuajo fue observado principalmente en las partes torrentosas de las quebradas, comportamiento novedoso en las larvas de las especies de la familia Dendrobatidae.
Adaptation and evolution in Gallotia lizards from the Canary Islands: age, growth, maturity and longevity
Authors: Castanet Jacques , Baez Marcos
Published: April 2008

Qualitative and quantitative comparisons of histological data recorded from growing bone from seven extant and extinct taxa of Gallotia show that these lizards do not have the same longevity, reach sexual maturity at various ages and probably have different growth rates which are in reverse proportion to the specific size of individuals in each taxon. In term of relative growth, the highest rate is seen in the smallest taxon (G. atlantica) and the lowest in the largest taxon (G. goliath). It appears that differences between the maximum size reached, irrespective of the size of hatchlings, are only the consequence of changes in longevity allowing a more or less protracted growth; they are not due to differences in growth rates. On the basis of these data we discuss some points relating to adaptive strategies and evolutionary features of these lizards.
Biennial reproduction in the female viviparous lizard Cordylus giganteus
Authors: Van Wyk J.H.
Published: April 2008

Cordylus giganteus is a large, terrestrial, viviparous lizard, endemic to the Highveld grasslands of South Africa. Autopsy and mark-recapture methods were used to study the female reproductive cycle. Although reproduction was distinctly seasonal, most mature females reproduced biennially, with 53 % of the females not reproducing in a given year. Vitellogenesis commenced in late summer (February), and continued through winter hibernation to culminate in ovulation during spring (October). The onset of vitellogenesis correlated inversely with both ambient temperature and photoperiod. Reproducing females were pregnant for most of the summer and gave birth in late summer (January-February). At the onset of vitellogenesis, fat body mass was generally small in all females but smallest in late-gravid and nonreproductive females. Only in vitellogenic females did the fat body mass increase significantly prior to hibernation. These data are consistent with the hypothesis that biennial reproduction is determined by the magnitude of energy reserves at the onset of vitellogenesis and that the potential for annual reproduction remains in any year.
Preliminary analysis of phylogenetic relationships among Galapagos Island lizards of the genus Tropidurus
Authors: Lopez T.J. , Hauselman E.D. , Maxson L.R. , Wright J.W.
Published: April 2008

Albumin evolution in six species of Galapagos iguanid lizards of the genus Tropidurus was measured using the quantitative immunological technique of micro-complement fixation. We propose a phylogeny for these species based upon their albumin differentiation. Our data suggest several colonizations from the South American mainland are needed to account for current species diversity on the Galapagos Islands. The standard calibration for the albumin molecular clock yields divergence estimates for Galapagos Tropidurus that are similar to those previously reported for the iguanas in the Galapagos and are not in conflict with recent understanding of the geological history of these islands.
Female reproductive biology of the southeastern crowned snake (Tantilla coronata)
Authors: Aldridge Robert D. , Semlitsch Raymond D.
Published: April 2008

Female Tantilla coronata reach sexual maturity in the spring of their third calendar of life (about 21 months of age) at about 150 mm snout-vent length. Vitellogenesis occurs in the spring, ovulation in June and oviposition in June and early July. Both ovaries are fully functional despite the lack of a functional left oviduct. The number of vitellogenic follicles is correlated with snout-vent length, however, the number of eggs or corpora lutea are not correlated with snout-vent length. Mean litter size and percent of females reproductive varied between years. The difference in the expected litter size between snakes with vitellogenic follicles and snakes with oviducal eggs or corpora lutea is due to atresia of vitellogenic follicles. Coelomic fat mass of adults showed a significant negative correlation during the course of vitellogenesis. Fat mass increased significantly following oviposition, however, some females had low coelomic reserves in late summer.
Seasonal variation in field body temperatures of the lizard Mabuya striata punctatissima
Authors: Patterson J.W.
Published: April 2008

Field body temperatures (Tbs) were studied in Mabuya striata punctatissima, a high altitude lizard from central Africa. Body temperatures were recorded in the middle of the day when the sun was shining brightly (high activity) and in other weather conditions (low activity). There was a significant correlation between Tb and air temperature (Ta) under both of these conditions, although the slope of the regression was higher in the former. The slope was negative for high activity times during the rainy season. In general, Tbs were higher during high activity than low activity. There were significant differences in the regressions of Tb on Ta between early dry, late dry and wet season.
The current taxonomic status of Tornier's cat-snake (Crotaphopeltis tornieri)
Authors: Rasmussen Jens Bødtker
Published: April 2008

The recent collection of more than 50 specimens and more than 140 eggs of Tornier's cat-snake, Crotaphopeltis tornieri, together with an examination of material already deposited in various museums provides new records outside the previously known geographical range. Variation in external and internal characters has been examined and the results have been analyzed. In regard to several characters, including the internal ones, the population of the East Usambara Mountains in Tanzania is significantly different from the population of the West Usambara Mountains, probably indicating an early vicariance event between the two areas. Due to the lack of data relating to internal characters, the affinities of the populations further south remain obscure, and no nomenclatural conclusions have so far been reached. The recently acquired specimens provide new information on the natural history of the species.
Phylogenetic relationships of the African egg-eating snake Dasypeltis scabra
Authors: Lopez T.J. , Maxson L.R. , Dowling H.G.
Published: April 2008

The unusual morphological adaptations associated with specialization on a diet of eggs have been used as evidence to justify familial or subfamilial status for the egg-eating snakes, including the African genus Dasypeltis. We evaluate the phylogenetic relationships of Dasypeltis scabra by comparing albumin evolution in Dasypeltis and available representative colubrine taxa using the quantitative immunological technique of micro-complement fixation. We find that Dasypeltis scabra is included among a large colubrine assemblage containing racers (Coluber, Masticophis, Spalerosophis, and Ptyas), the ratsnake Elaphe, and the kingsnake Lampropeltis. Further, these data suggest that Dasypeltis is genetically most similar to some members of a racer lineage and arose from an ancestral colubrine stock as early as ten million years ago.
The internal oral morphology of some anuran larvae from south India: a scanning electron microscopic study
Authors: Das Indraneil
Published: April 2008

The internal oral morphology of the larvae of four species of sympatric anuran amphibians from a locality in south India was examined by scanning electron microscopy. A close fit between diet and oral structures was found. The mouthparts are considerated as adaptive for a variety of feeding modes, including filter-feeding, algal-scraping and macrophyte-snipping.
Biomechanical reasons for bipedalism in reptiles
Authors: Christian A. , Horn H.-G. , Preuschoft H.
Published: April 2008

Bipedal locomotion can be observed in numerous species of recent tetrapodal reptiles which usually have well developed tails and hindlimbs while the forelimbs are considerably shorter and weaker than the hindlimbs. It is commonly used when the reptiles move at the highest possible speeds of locomotion. The different development of the extremities is a common feature among recent reptiles that can be understood as an adaptation to quick acceleration. Additionally it reduces the interference of fore-and hindlimbs at high speeds. We present some biomechanical arguments to show how and why bipedalism can facilitate quick running in recent reptiles in which the hindlimbs are much longer and stronger than the forelimbs. Our main arguments can also be applied to some dinosaurs.
Courtship behaviour of the salamander Desmognathus imitator (Amphibia: Caudata: Plethodontidae)
Authors: Verrell Paul A.
Published: April 2008

Courtship in the imitator salamander, Desmognathus imitator, follows a predictable course that appears characteristic for the genus. Three more-or-less consecutive phases are recognized: orientation of the male to the female, persuasion of the female by the male (involving both tactile and chemical stimuli) and indirect sperm transfer by means of a spermatophore. The individual behaviour patterns that comprise courtship in D. imitator are similar to those observed for congeneric species of similar body size, except for "bite-and-seize", which has previously been described only in two dwarf species. Understanding the evolution of courtship in the genus Desmognathus will be greatly facilitated when behavioural characters in all taxa can be optimized onto an independent phylogenetic tree.
Spontaneous haploid-triploid mosaicism in the progeny of a Rana kI. esculenta female and Rana lessonae males
Authors: Berger Leszek , Ogielska Maria
Published: April 2008

A female Rana kl. esculenta was crossed with three different R. lessonae males. Three froglets with unexpected phenotypes appeared. Two of them were chimerae with one side of the body of lessonae, and the other of escutenta phenotype, and one displayed lessonae, instead of the expected esculenta, phenotype. Blood of three individuals was composed of small haploid and large triploid erythrocytes. These results indicate that the froglets were 1n/3n mosaics.
Dynamics of predation in Lacertidae: the relation between locomotor pattern and prey-capture probability in three contrasted species
Authors: Avery Roger , Tosini Gianluca
Published: April 2008

The probability that lizards would capture crickets declined with distance from the snout, at rates which were significantly more rapid in all directions in Lacerta vivipara than in Podarcis muralis or L. viridis, i.e. the former species responded to potential prey over a smaller area. Capture probabilities at any distance in front of or behind the snout were lower in P. muralis or L. viridis which were pausing during locomotion than in basking lizards, confirming previous results with L. vivipara. Using capture probabilities for pausing lizards to calculate the average time it would take to find a single item of prey (tf) in relation to the mean length of locomotor bursts, on the assumption that prey could only be detected while a lizard was pausing, showed that actual mean burst distance corresponded exactly with the burst distances which gave rise to minimum tf in L. vivipara. Mean locomotor burst distances in P. muralis and L. viridis were lower than the distances which gave minimum tf values. It is suggested that, in these species, the mean burst length has evolved as a compromise between minimising tf and avoiding the high overall energy expenditures which would result from long burst lengths.
The systematic status of the Ramphotyphlops flaviventer (Peters) complex (Serpentes: Typhlopidae)
Authors: Wallach V.
Published: April 2008

An examination of the type specimens of Typhlops aluensis Boulenger, T. buehleri Hediger, T. depressus Peters, T. flaviventer Peters, T. philococos Wemer, T similis Brongersma, and T. supranasalis Brongersma, in conjunction with external and internal morphology, indicates that Ramphotyphlops flaviventer (sensu McDowell) consists of two easily recognizable allopatric populations here considered as valid species, a western one referred to R. flaviventer and an eastern one referred to R. depressus. Two additional taxa (R. similis and R. supranasalis), closely related to R. flaviventer, appear to deserve recognition. Ramphotyphlops similis is distinct from R. flaviventer in external morphology and thus elevated to full species status. The status of R. supranasalis is debatable but it is provisionally treated as a full species based upon discrete supranasals and an insular distribution. A taxonomic synopsis and preliminary identification key to the Ramphotyphlops flaviventer complex are provided.
The reproductive cycles of the oviparous lizards
Authors: van Wyk J.H. , Mouton P. le F.N.
Published: April 2008

We examined the reproductive cycles of two species of the only oviparous genus Platysaurus in the predominantly viviparous family Cordylidae, endemic to Southern Africa. The reproductive cycles of Platysaurus capensis and P. minor were determined using data obtained from field caught and museum specimens. Males of both species exhibit testicular recrudescence during autumn (April-May) and maximum testicular volumes together with peak spermiogenic activity occur during winter through early summer (July-November). Small testicular volumes associated with testicular regression occur during mid-summer (December) through early autumn (March). Similarly, females of both species begin vitellogenesis in autumn, culminating in ovulation during spring (September-October). Females are ovigerous in summer (November through December). Clutch size is fixed on two eggs. In both species, male and female cycles are well synchronised. The fact that the autumn/winter ovarian cycles of these oviparous lizards correspond to that of viviparous members of the family Cordylidae adds to the data that suggest that the oviparous mode of reproduction in the genus Platysaurus represents one of the few known cases of an evolutionary reversal from the derived viviparous mode. Along with the viviparity-oviparity reversal a postnuptial-prenuptial testicular cycle reversal is suggested. Data presented in this paper support the hypothesis that the ancestral oviparous Platysaurus evolved on the Mozambique lowlands from a viviparous montane Pseudocordylus ancestor.
The effect of temperature on calling energetics of the spring peeper (Pseudacris crucifer)
Authors: Wells Kentwood D. , Taigen Theodore L. , O'Brien Jennifer A.
Published: April 2008

Oxygen consumption of calling male spring peepers (Pseudacris crucifer) was measured at five temperatures (7, 10, 15, 19, and 23°C) encompassing the natural range of variation encountered during the breeding season. Oxygen consumption increased as a linear function of calling rate, which in turn was a linear function of temperature. Hence, nearly all the increased cost of calling at warmer temperatures was accounted for by increases in calling rate; temperature did not appear to have any independent effect on activity metabolism. During one breeding season, ambient temperature increased throughout the season, resulting in an hourly cost of calling at the end of the season that was double the cost at the beginning. Periodic warm spells also resulted in major increases in the cost of calling.
Battles for mates and food: Intraspecific combat in island tigersnakes (Notechis ater) from southern Australia
Authors: Firmage M. , Shine R.
Published: April 2008

Male-male combat occurs in mainland populations of tigersnakes (Notechis scutatus), but authorities have disagreed as to whether or not this behaviour also occurs in island tigersnakes (Notechis ater). In this paper, we confirm that intraspecific combat frequently occurs between island tigersnakes maintained in captivity. Two different kinds of combat bouts were observed. We interpret the first type (ritualised "wrestling" matches between large adult males) as a reflection of sexual competition. This behaviour was seen in snakes from each of the island populations investigated, including Tasmania. Agonistic behaviour was exhibited by females and juveniles as well as by adult males: however, this second type of combat was always initiated by the introduction of food items to the enclosure, and incorporated vigorous biting as well as (or instead of) wrestling. Further observations, in the field as well as in captivity, are needed before we can interpret the functional significance of this behaviour. The food-induced combat may be an artifact of high densities of captive snakes, or alternatively may be exhibited in the wild also. We speculate that the high abundance of tigersnakes on some islands, and the highly clumped nature of prey resources (e.g. muttonbird chicks) in both space and time, may have favoured direct interference competition for prey items between island tigersnakes. If so, some elements of the social system of island tigersnakes may resemble the condition seen in many lizard species, rather than in other snakes.
Reproductive ecology of Bombina variegata: characterisation of spawning ponds
Authors: Barandun Jonas , Reyer Heinz-Ulrich
Published: April 2008

The use of spawning sites by Bombina variegata was analysed in a dynamic habitat containing a variety of different ponds. Cool or shadowy as well as permanent ponds were not used for spawning at all. Among the ephemeral ponds that were used, egg numbers increased with water temperature, both when compared among ponds and between different areas within ponds. Egg numbers were also higher in ponds of intermediate duration than in those persisting for shorter or longer periods. Ponds of intermediate duration with moderate predator densities and with larvae of competing anuran species (Hyla arborea, Bufo calamita) were used more often than short-lived ponds with no predators and competitors. This pattern of spawn deposition can be interpreted as an attempt to select sites allowing rapid larval development (warm water) and to avoid sites with high numbers of newts and invertebrate predators (permanent ponds). The selection critera seem to be adaptive, because pond duration and desiccation are more important for larval survival than predators and competitors. Yet, optimal reproductive conditions remain highly unpredictable for Bombina variegata, as the characteristics and dynamics of spawning ponds are mainly determined by climatic conditions. Consequently, survival chances of tadpoles can change within a few days or weeks, depending on rainfall and evaporation.
Evaporative water loss of Australian goannas
Authors: Thompson G.G. , Withers P.C.
Published: April 2008

The common intra-specific mass exponent for the standard evaporative water loss was 0.86 for nine species of goanna (V. gilleni, V. caudolineatus, V. brevicauda, V. eremius, V. acanthurus, V. tristis, V. gouldii, V. rosenbergi and V. panoptes). The inter-specific mass exponent for evaporative water loss (EWL) was 0.95; EWL (mg h-1) = 2.149M0.95 The overall resistance to water loss was significantly lower inter-specifically for larger species than smaller species; however, there was no significant intra-specific relationship between resistance and body mass. The evaporative water loss of arboreal goannas (V caudolineatus, V gilleni and V. tristis) was less than that of terrestrial goannas (V brevicauda, V eremius, V acanthurus, V. gouldii, V rosenbergi and V. panoptes); this presumably reflects the exposure of these arboreal goannas to higher wind velocity and drier air. The more mesic V. rosenbergi had a higher evaporative water loss than the more arid species.
The tadpole of Pseudis minuta (Anura: Pseudidae), an apparent case of heterochrony
Authors: de Sá Rafael O. , Lavilla Esteban O.
Published: April 2008

The external morphology, oral disc, and coloration pattern of the larva of Pseudis minuta are described. Tadpoles are mostly bottom dwellers that have a small, terminal oral disc with a labial tooth row formula 1(1-1)/(1-1)2. Internal oral anatomy is characterized using scanning electron microscopy, representing the only description available for the family Pseudidae. The coloration pattern of P. minuta tadpoles is compared with that of other pseudids. Pseudis minuta larvae do not exhibit the ontogenetic coloration change reported for P. paradoxa. Considering larval coloration, larval size, and reports of adult size, acceleration or hypermorphosis are suggested as possible heterochronic mechanisms involved in the evolution of Pseudis.
A new species of rainfrog of the Eleutherodactylus diastema group from the Alta Talamanca Region of Costa Rica
Authors: Savage Jay M.
Published: April 2008

A new species of Eleutherodactylus is described from southeastern Costa Rica. It is a member of the Eleutherodactylus diastema group characterized by a vivid pattern of dark spots on a yellow-orange ground color and features of digital disk morphology.
Differences in an ensemble of streamside salamanders (Plethodontidae) above and below a barrier to brook trout
Authors: Resetarits William J.
Published: April 2008

I examined the species composition, relative abundances, and size distributions of an ensemble of streamside salamanders in two contiguous sections of an Appalachian headwater stream: one containing brook trout and one that was trout free. The two stream sections were separated by a natural waterfall that formed a permanent barrier to the upstream movement of fish. The two stream sections differed in the overall abundance of salamanders, the relative abundance of the six species present, and the size-distribution of the salamander ensemble. These results suggest that brook trout have an effect on the structure of co-occurring ensembles of salamanders, and that the continued coexistence of stream salamanders with brook trout does not indicate lack of strong ecological interactions.
Seasonal variation in nocturnal calling activity of a savanna anuran community in central Brazil
Authors: Moreira Glória , Barreto Larissa
Published: April 2008

We studied the calling activity of a savanna anuran assemblage and correlated two climatic parameters, rainfall and air temperature, with anuran calling. We made observations from September 1991 until March 1993 and quantified nocturnal calling activity by counting the number of calling males for each species present in a permanent pond. Bufo paracnemis had the shortest calling activity period and Physalaemus cuvieri had a seasonal calling period, lasting a maximum of four months. Diversity of calling males and species richness reached a peak in the first three months of the rainy season. Comparisons with other populations indicate that the reproductive period of P cuvieri varies along its geographical distribution in a manner related to regional climatic conditions.
Evolutionary and paleogeographical effects on the distribution of the Triturus cristatus superspecies in the central Balkans
Authors: Crnobrnja-Isailović J. , Dzukić G. , Krstić N. , Kalezić M.L.
Published: April 2008

A synthesis of all known data on the crested newt group assigns the Balkan peninsula as the center of origin or, at least, the area where the basic lineage of its species was limited in the late Miocene. According to the recent literature, the geological structure of the Balkan region changed considerably during the Tertiary. These geological processes could have had a considerable impact on crested newt divergence and on the recent distribution of species. Using the number of rib-bearing vertebrae (RBVN), recently suggested as a simple and powerful tool for distinguishing four taxa of the T cristatus superspecies, we analysed 36 population samples collected all over former Yugoslavia. The hypothesised recent distribution of the crested newt species, based on frequency distribution of RBVN, appears to correspond well to neotectonic events in the past.
The effect of inundation on hibernating Bufo bufo and Bufo calamita
Authors: Bosman W. , van Gelder J.J. , Strijbosch H.
Published: April 2008

Inundation effects on terrestrially hibernating Bufo bufo and B. calamita are reported. Mortality caused by experimental inundation of seminatural hibernation sites was high in B. calamita and very low in B. bufo. In a floodplain eight telemetrically monitored B. bufo withstood flooding during a period of 25-35 days without leaving their hibernation sites. After this period the emerging toads suffered mortality by floating down the river depending on the water level at the moment of emerging. The importance of floodsafe areas in floodplains is demonstrated.
Thermal ecology and reproductive cyclicity of the snake Natrix tessellata in south-eastern Austria and central Italy: a comparative study
Authors: Luiselli Luca , Zimmermann Petra
Published: April 2008

Aspects of thermal ecology and reproductive cyclicity are compared in two populations of the dice snake (Natrix tessellata), a semi-aquatic natricine species widely distributed across Europe. One population was studied near Leibnitz, Styria (south-eastern Austria), and the other one was studied in the Mounts of Tolfa near Rome (Latium, central Italy). The climate was strongly colder in the Austrian than in the Italian site. Snakes of both populations were similar in various traits, including average body temperature, higher mean body temperature of gravid than non-gravid individuals, significantly higher substratum temperatures selected by gravid than by non-gravid individuals, trends of relationships between body, air and substratum temperatures, average length of reproductive females, and average preparturition mass of reproductive females. However, Austrian snakes were found in water significantly less often than their Italian conspecifics (although in both populations nearly all individuals occurred close to water bodies), and showed a lower frequency of reproduction (biannual rather than annual) than Italian ones. The presented data are discussed in the light of suboptimal occupation of the colder area by Austrian snakes, and conservative rigidity of natural history and ecological traits of such a widespread species as N. tessellata.
The taxonomic status of the sea snake Hydrophis czeblukovi (Kharin, 1984) from north-west Australian waters
Authors: Rasmussen Arne Redsted , Smith Lawrence
Published: April 2008

Hydrophis czeblukovi, a species only known from north-west Australian waters, is redescribed using external and internal morphological characters and is compared with its congeners. Hydrophis geometricus Smith, 1986 is synonymized with H. czeblukovi.
Una especie nueva de Epipedobates (Amphibia, Anura, Dendrobatidae) de Perú
Authors: Morales Víctor R. , Velazco Paul M.
Published: April 2008

n. Se describe una especie nueva de Epipedobates del grupo petersi de la ladera occidental de la cordillera Yanachaga-Chemillen, Departamento de Pasco, Perú, y se sugiere la inclusión de E. bilinguis y E. parvulus en el grupo petersi.