The Herpetological Journal

pp. 253-262

Authors: Levi Gray, Rubi Meza-Lázaro, Steven Poe & Adrián Nieto-Montes de Oca

Abstract: We describe a new species of semiaquatic Anolis (A. purpuronectes) from the Chimalapas region of eastern Oaxaca and adjacent Veracruz, Mexico, and investigate its phylogenetic relationships with the closely related species A. barkeri to which the populations under investigation have previously been assigned to. Anolis barkeri and the new species appear to be allopatric, and differ primarily in male dewlap colour (red and orange in A. barkeri, pale purple in A. purpuronectes). A partitioned Bayesian analysis of the mitochondrial genes encoding ND1 (part), ND2, and the intervening tRNAs revealed that A. barkeri and A. purpuronectes are genetically distinct (uncorrected genetic distance between them=11.5%), nested within the A. schiedii group as sister species, and most closely related to a clade composed of A. cymbops, A. milleri, and A. parvicirculatus.

Key words: Anole, Anolis barkeri, Anolis schiedii group, Chimalapas, Mexico, new species, semiaquatic lizard

pp. 263-269

Authors: Andrés E. Seijas Y.

Abstract: Populations of the Orinoco crocodile (Crocodylus intermedius) have not recovered from past exploitation, and current abundances cannot be used for assessing the suitability of habitats they occupy. Growth constitutes an alternative way of assessing habitat quality. Since 1990, more than 9000 captive-reared Orinoco crocodiles have been released into the Venezuelan Llanos. In the present study, the growth rates of 127 recaptured crocodiles from different regions were compared. All individuals from Middle Cojedes and the Aeolian savannahs grew slower than expected by the von Bertalanffy model, whereas individuals from Caños in the Apure floodplains grew faster than expected. These inferences are corroborated with growth rate measurements for crocodiles under four years of age, which were lowest in Middle Cojedes (average of 14.1 cm/ year) and highest at Caños (43.3 cm/year). Low growth rates can be explained by habitat deterioration due to human activities, and high growth rates in the Caños support that the lower reaches of whitewater rivers offer favourable conditions for the species. Crocodiles in high quality habitats may reach sexual maturity in six years, whereas more than a decade is required in poor-quality habitats.

Key words:  growth models, habitat quality, Orinoco crocodile, reintroduction

pp. 271-276

Authors: Eraqi R. Khannoon

Abstract: Lizards possess epidermal glands which produce secretions playing a role as semiochemicals. Classic anatomical studies do not give detailed information on the nature of the secretions. Here I used GC-MS analysis of gland secretions to focus on the molecular structure of femoral gland secretions in two xeric-adapted agamid lizards, Uromastyx aegyptia and U. ornata. Steroids, alcohols, carboxylic acids, alkanes, aldehydes, carboxylic acid esters and squalene were detected as lipidic compounds. Monoglycerides of fatty acids and glycerol monoethers of long chain alcohols previously only detected in Lacertidae and Gekkonidae were also identified. The compounds constituting femoral secretions are possibly an adaptation to hot and dry habitats, with specific chemical profiles for each species. The presented data support the hypothesis that Uromastyx (and lizards in general) use femoral gland secretions for chemical communication.

Key words: agamidae, chemical communication, femoral glands, pheromones, Uromastyx

pp. 277-286

Authors:  Inês Torres, Milena Matos, Michelle Alves, Carlos Fonseca & Eduardo Ferreira

Abstract:  Amphibians play an important role in ecosystems and are one of the most threatened taxa worldwide. In order to protect their populations, it is essential to understand the factors affecting their distribution, abundance and diversity. Baixo Vouga Lagunar is a heterogeneous, human-modified, coastal wetland in north-west Portugal, with seasonal or permanently flooded habitats. We characterised the patterns of distribution, abundance and diversity of amphibians and aimed to identify its environmental drivers. Species richness was best explained by distance to the nearest well, followed by presence of temporary water bodies. Distance to the nearest well was also the most important driver of the composition of local amphibian assemblages, followed by the distance to forested areas. Our results reflect the findings of other studies in the Mediterranean region that have revealed the importance of seasonally available habitats, and stress the need for conservation of natural as well as artificial water bodies and traditional agricultural practices which promote a mosaic of amphibian habitats.

Key words: Amphibians, anthropogenic habitats, conservation, Mediterranean wetlands, natural habitats, temporary water bodies

pp. 287-289

Authors: Laurence E. Jarvis

Abstract:  The great crested newt Triturus cristatus is declining in many parts of its range. Although the aquatic ecology of this species is well known, the terrestrial ecology of great crested newts remains poorly understood, especially that of juveniles. This study examined the terrestrial ecology of juvenile great crested newts from March to October, 2008 to 2011 over four years within Epping Forest, UK. Sixty-three cover objects (logs and stones) were sampled weekly. While 28% of juveniles were only encountered once, 72% were observed for between one and seven months per year, often exhibiting a pattern of repeated presence and absence. This suggests that juveniles may remain within small home ranges close to natal ponds to feed and grow. Body Condition Index (BCI) scores varied significantly with seasons, with the highest values in spring and the lowest values in summer. BCI scores were highest after milder winters. Apparent monthly survival of juveniles varied between 0.12 and 1.00 while the estimated number of juveniles present under refuges ranged between three and 50. Findings from this study increase our understanding of the ways in which juveniles utilise cover objects and demonstrate that estimates of body condition and monthly survival vary between March and October over a four year period.

Key words: amphibian, body condition, capture-recapture, juvenile, terrestrial, Triturus cristatus

pp. 297-304

Authors: Bruno O. Ferronato, Thiago S. Marques, Neliton R.F. Lara, Luiz A. Martinelli, Luciano M. Verdade, Plinio B. Camargo, John H. Roe & Arthur Georges.

Abstract: Urbanisation is one of the most common threats to many native species, while others are capable of taking advantage of urban areas and even expanding their niche in urban-natural systems. The analysis of stable isotopes of carbon and nitrogen in a tissue sample provides data that can elucidate food web dynamics and trophic ecology of an animal. Our study aimed to evaluate variation in food resource exploitation in the freshwater turtle Chelodina longicollis along a habitat gradient (natural, rural, and suburban areas), and intraspecific niche variation among demographic groups (juvenile, adult male, adult female). We found that isotopic composition of C. longicollis varied along the habitat gradient, with ?15N levels highest in suburban environments, intermediate in rural areas, and lowest in the nature reserve. ?13C values were higher in suburb and rural turtles compared to those on the nature reserve. Besides some intraspecific differences in ?13C as evidence of demographic partitioning of the foraging niche, demographic groups apparently feed on the same trophic level within habitats. Our study included samples from small juveniles (<10 cm) and helped to cover a gap of understanding in intraspecific niche for C. longicollis. Future research should evaluate the reasons turtles in suburban areas are enriched in ? 15N, either because they are foraging on different trophic levels or because they are feeding on prey enriched in nitrogen.

Key words: diet, generalist species, intraspecific variation, isotopic ecology, nitrogen

pp. 305-311

Authors: Yong Pu Zhang, Jun Ping, Shuang Li Hao & Hua Bin Zhou

Abstract: Life-history variation has been widely reported for species with variable clutch size, but detailed data on reproductive strategies for species with invariant clutch sizes are scarce. We collected gravid female geckos (Gekko japonicus) from three geographically separate populations to examine geographic and annual variation in reproductive strategies. The majority of females produced a fixed number of eggs (n=2). Females from the southern population had larger body size, produced larger eggs, and had heavier clutches than females from two more northern populations, which was largely attributable to among population differences in maternal body size. Within populations, female body mass varied between years; heavier females laid larger eggs and heavier clutches. The among-year difference in maternal body mass partly accounted for the annual variation in egg size and clutch mass. These results suggest that species with invariant clutch size can adjust egg size to increase or decrease per-clutch reproductive output.

Key words:  Annual variation, clutch size, geographic variation, offspring size, reproductive strategy

pp. 313-316

Authors: J. Gosálvez, C. López-Fernández & S.D. Johnston

Abstract: Saltwater crocodile spermatozoa examined in this study exhibited unusually high levels of extra DNA charged (2C and 4C) spermatozoa that can be explained by arrested cytokinesis at both meiotic divisions. From the ejaculates of five crocodiles, abnormal spermatozoa containing 2C (1–12%) and 4C DNA (0–2%) charges were discriminated after assessing 1500 spermatozoa using morphological characterisation under fluorescence microscopic and image analysis protocols. Individual crocodiles with a high proportion of 2C spermatozoa in their ejaculate, also showed a high level of DNA fragmentation in 1C sperm cells (8.7– 12.7%) but there was no such relationship between DNA fragmentation and 2C sperm. The value of whole extracharged sperm DNA in the ejaculate as a possible marker for fertility is discussed.

Key words: polyploid sperm, reptile, reproduction, saltwater crocodile, sperm DNA fragmentation