The Herpetological Journal

pp. 121-127
Authors: Ramírez-Bautista, Aurelio; Ramos-Flores, Omar; Stephenson, Barry P. & Smith, Geoffrey R.

Abstract: We studied the reproduction and sexual dimorphism of Sceloporus minor in two populations, El Oro and Las Lagunas, in the municipality of Guadalcázar, San Luis Potosí, Mexico. Males were larger and had larger heads and tibias than females. Males and females from El Oro were larger than those from Las Lagunas. Reproductive activity of males and females was asynchronous in both populations. Testes of the males from El Oro and Las Lagunas increased in size from July to September, reaching maximum size in October and regressing in November. Vitellogenesis occurred in September in both populations, with ovulation occurring in November–December. Embryonic development was observed from December to March in both populations. Parturition in the El Oro population occurred from late March to early July, whereas in Las Lagunas it occurred from mid-March to late May. Litter size for both populations was similar (El Oro: 6.6, Las Lagunas: 6.2). Litter size was positively related to female SVL in the El Oro population but not in the Las Lagunas population. These two populations show some similarities, but also show differences, possibly due to elevation.

Keywords: EMBRYONIC DEVELOPMENT, SEX DIFFERENCES, GEOGRAPHIC VARIATION, PHRYNOSOMATIDAE, LIZARD, SQUAMATA

pp. 129-135
Authors: Li-yan, Qing; Yi-ding, Wang; Xiao-mao, Zeng; Qin, Chen & Mian, Hou

Abstract: The karyotype of Hynobius maoershanensis, a newly described salamander species from mainland China, is described for the first time using Giemsa conventional stain, C-banding and Ag-NORs techniques. All individuals have a diploid number of 56 chromosomes, which is consistent with karyotypes of the pond-type Hynobius group that lives in the lowlands and spawns in small ponds. Several differences distinguish H. maoershanensis from other Hynobius karyotypes: chromosome no. 13 is subtelocentric while in others it is metacentric; there is a prominent and unique dark C-banding pattern encompassing the whole short arm of chromosome no. 13, which can be used as a marker to distinguish this species from other species of Hynobius; multiple C-bands are found only in chromosomes 4, 9 and 13 in this species, much fewer than in other species; NORs are rarely located at the terminal position on the short arm of a large biarmed chromosome (no. 8) in H. maoershanensis, but are commonly observed on the small telocentric microchromosomes (nos. 20, 21 or 23) in other species with 2n=56. All five species from six populations of Hynobius from mainland China can be ecologically attributed to the pond-type group and have 2n=56. Karyologically, they form two subgroups. One subgroup has ten while the other has only nine pairs of telocentric microchromosomes.

Keywords: AG-NORS, C-BANDING, CHINESE HYNOBIID SALAMANDER

pp. 137-140
Authors: Lazar, Bojan; Lacković, Gordana; Casale, Paolo; Freggi, Daniela & Tvrtković, Nikola

Abstract: Sea turtles exhibit sexual dimorphism only as adults, hence diagnosing the sex of hatchlings and juveniles requires the employment of different techniques that vary in their level of accuracy and costs. In order to validate the observation of external gross morphology of gonads as a sexing method for juveniles, we compared results obtained in this way with those obtained through histology in 99 loggerhead turtles with curved carapace length (CCL) ranging from 24.0 to 69.0 cm, found in the Adriatic Sea and in the central Mediterranean. Sex was correctly diagnosed in 92.9% of the 99 cases. The highest error rate due to wrong or uncertain sexing was found in turtles with a CCL less than 30.0 cm (33.3%). In turtles with a CCL of 30.0–40.0 cm and 40.0–50.0 cm, the error rates were low (5.3% and 6.7%, respectively), while no errors occurred in larger individuals (CCL greater than 50.0 cm). The results show that gonadal morphology is a reliable sexing method for large juveniles, but for those of less than 30 cm CCL we recommend verification by histology.

Keywords: HISTOLOGY, METHODS, GONADS, SEX DETERMINATION

pp. 141-146
Authors: Capizzi, Dario; Capula, Massimo; Capula, Massimo; Rugiero, Lorenzo & Luiselli, Luca

Abstract: The food habits of two species of colubrid snakes (Hierophis viridiflavus and Zamenis longissimus) were studied in three areas in Mediterranean central Italy representing a gradient of natural habitat alteration from a natural mixed oak forest towards an entirely deforested, urban–agricultural habitat. Two diet descriptors were used: 1) total number of prey items eaten by each species in each study area, and 2) number of individual snakes containing a given prey type. Only adults were studied. There was no significant body size difference within species or among sites, and the diets of males and females were similar in both species. Our results revealed that habitat alteration drives some directional changes in the diet composition of these snakes: food niche breadth decreased in the two species from the least to the most altered study area, thus suggesting higher dietary generalism of snakes in natural areas. Food niche overlap values were similar interspecifically and intraspecifically, but tended to increase interspecifically with habitat alteration.

Keywords: ITALY, REPTILIA, NICHE BREADTH, NICHE OVERLAP, VEGETATION GRADIENT, FOOD HABITS

pp. 147-153
Authors: Amat, Fèlix

Abstract: The persistence of populations is based on the optimization of reproductive processes as a means of compensating for the loss of individuals through mortality. One way of reaching this equilibrium is the coadaptation of reproductive traits defining different strategies. I explored these tactics in lacertid lizards by analysing the covariation between, on the one hand, clutch size and frequency, and on the other, egg mass, using independent contrast data from 42 species. In addition, I examined the influence of female and newborn size on these variables. All the traits investigated, with the exception of clutch frequency, are influenced by female body size, reflecting physical constraints on reproductive output. The negative trade-off between clutch size and newborn size on one hand and egg mass on the other is congruent with the partitioning of energetic resources to produce a few large or numerous small descendents. Clutch frequency is unrelated to the other female reproductive traits.

Keywords: EGG MASS, CLUTCH SIZE, COMPARATIVE METHOD, REPRODUCTION, CLUTCH FREQUENCY

pp. 155-163
Authors: Tarkhnishvili, David; Kaya, Uğur; Gavashelishvili, Alexander & Serbinova, Irina

Abstract: The Caucasian salamander (Mertensiella caucasica sensu lato) is an endemic taxon of the western Lesser Caucasus, classified as Vulnerable in the IUCN Red List. Two isolated evolutionary lineages occur within its range – one in the Black Sea basin, and the other in the basin of the Caspian Sea. We identified and described 51 locations throughout the range of the species, from the easternmost to the westernmost known location and within an elevational range of 50–2400 m a.s.l. We applied binary logistic regression and a maximum entropy approach to predict the range of the salamander within the polygon delimited by extreme values of 19 bioclimatic parameters for the locations identified. The models were based on the analysis of bioclimatic data, terrain ruggedness and some other environmental variables. The presence or absence of the salamander depends on the level of and variations in rainfall, temperature and terrain ruggedness. Absence of the species from the Greater Caucasus is explained by unsuitable climatic conditions. Separate analysis of the “eastern” and “western” lineages showed no overlap of their predicted ranges, and the model based on the complete data set showed good results only for the “western” evolutionary lineage. This suggests that the genetic isolation of these two lineages is caused by differential climatic requirements rather than by existing fragmentation of suitable habitats.

Keywords: REFUGIA, MERTENSIELLA CAUCASICA, CLIMATIC PREFERENCES, RANGE MODELLING, CAUCASUS

pp. 165-170
Authors: Deepak, V. & Vasudevan, Karthikeyan

Abstract: Salea anamallayana is an endemic agamid restricted to the high altitudes of the southern Western Ghats. Distance sampling along line transects was used to estimate its density in Eravikulam National Park (ENP). The habitat association of the species was also examined. Thirty-three 100 m transects were laid randomly in four different habitat types. Eighteen were in 12 shola patches covering an area of 140.87 ha. The density was 55 individuals ha^-1 in shola. Males, females and juveniles used similar microhabitats in the shola. Five transects were laid in each of three other habitats: mid-elevation evergreen forest, tea plantations and eucalyptus plantations. The species was detected only in the tea plantations. Density in tea plantations was estimated to be 65 individuals ha^-1. Distance sampling can thus be used to monitor populations of this species. The tea plantations surrounding ENP probably support a sizable population, and conservation and management of a landscape dominated by different land uses in the Western Ghats will be crucial for the species.

Keywords: ENDEMIC, TRANSECTS, SHOLA, INDIVIDUALS, TEA PLANTATION

pp. 171-174
Authors: Deeming, D.C.

Abstract: This study examined the hypothesis that numbers of newts captured were correlated with the phase of the moon. During the spring of 2008 smooth newts and great crested newts were captured in bottle traps laid in two ponds at Riseholme Park, University of Lincoln, UK. Highest rates of capture for smooth newts were either side of the new moon but for great crested newts the highest rate was immediately before the new moon. Identification of individuals showed that during the observation period smooth newts regularly moved between aquatic and terrestrial habitats, but great crested newts appeared to leave ponds and did not return. This is the first report that numbers of newts captured are affected by the lunar cycle. Activity during the darkest nights may limit the risk of predation as individuals leave breeding ponds to forage on land or to move between ponds. These results have implications for surveys of newt breeding sites because lack of individual identification and trapping events at the wrong time of the month can both seriously undermine estimates of population sizes.

Keywords: SURVEYS, BOTTLE TRAPPING, PREDATION, PHASE OF THE MOON, ACTIVITY