The Herpetological Journal

Authors: Beebee, Trevor

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Abstract: The joint scientific meeting of Amphibian and Reptile Conservation (ARC) and the British Herpetological Society took place in the lecture hall of the Bournemouth Natural Science Society on 6 December 2009. The meeting was dedicated to the late Julia Wycherley, and encompassed the following contributions.

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Authors: Nadachowska, Krystyna

Abstract: Advances in molecular and computational biology as well as in population genetics theory open new avenues in the study of speciation, for example enabling the explicit estimation of the amount of gene flow that has occurred during population divergence. Developments in two areas seem particularly important. First, novel coalescent-based methods can be applied to multilocus sequence data to infer the time of population divergence, long-term effective population sizes and their changes and the extent of gene flow between diverging populations. Second, the advent of ultra high-throughput sequencing technologies enable the inexpensive generation of vast amount of sequence data for any organism. Many amphibian species have been shown to be incompletely reproductively isolated and can hybridize for prolonged periods of time, making them ideal models to study the divergence of populations to form new taxa despite ongoing gene flow. Here I discuss the new findings emerging from multilocus DNA sequence-based approaches that have already been applied in amphibian population genetics. I also outline future directions of research, emphasizing the utility of parallel sequencing technologies together with methods of population genetic and phylogenetic inference, which are likely to provide a better understanding of the process of population differentiation and divergence to ultimately form new species.

Keywords: COALESCENT-BASED METHODS, ISOLATION WITH MIGRATION, ULTRA HIGH-THROUGHPUT SEQUENCING, DIVERGENCE MODELS, AMPHIBIANS

pp. 17-24
Authors: Vignoli, Leonardo; Silici, Romina; Brizzi, Rossana & Bologna, Marco A.

Abstract: In Salamandrina, the lack of visible external sexual dimorphism makes the sexing of individuals difficult without sacrifice. The cloaca of Salamandrina in both males and females appears externally as a slit on an unswollen surface, a trait which is consistent throughout the year. Nonetheless, a slight divarication of its borders allows the recognition of three morphs (A, B and C), respectively characterizing male cloaca (all phases), female cloaca without protruding oviductal papillae (courtship phase) and female cloaca with prolapsed oviductal papillae (oviposition phase). Figures and schematic diagrams are provided to illustrate the differences in detail, which are all recognizable to the naked eye or by means of a hand magnifier. In addition to morphology, another reliable method of sexing salamanders is urine examination, albeit only during the courtship and post-courtship phases. Applying these methods for sex determination, we found a male-biased operational sex ratio in two populations, ranging from 6.6:1 (autumn–winter) to 14:1 (May). Males were confined to terrestrial environments, whereas females were also found in water during oviposition. Salamandrina perspicillata was active throughout the year, except during the hottest months (July–August).

Keywords: CLOACA, SEXUAL DIMORPHISM, SALAMANDER, SEX RATIO, SEX DETERMINATION

pp. 25-30
Authors: Echwikhi, Khaled; Jribi, Imed; Bradai, Mohamed Nejmeddine & Bouain, Abderrahmen

Abstract: Some gillnets used in the south of Tunisia (Gulf of Gabes) target shark species (Mustelus sp., Carcharhinus plumbeus) and guitarfish (Rhinobatos cemiculus, Rhinobatos rhinobatos). These artisanal nets interact with sea turtles. Here we present an analysis of the bycatch of loggerhead sea turtles Caretta caretta in these gillnets in the Gulf of Gabes, an important Mediterranean wintering and foraging area for this threatened species. We quantified mean catch per unit effort (CPUE) in three ways to account for uncertainty and found high levels of interaction in each case. The number of turtle captures per km² of gillnet per day, the number of turtle captures per km of net and the number of turtle captures per set were 0.527 (0.403–0.649), 0.339 (0.250–0.438) and 0.800 (0.654–0.904), respectively. Captured loggerheads were mainly juveniles (mean = 56.6cm CCL_n-t) and direct mortality was estimated as 69.4% (n=25). These are the first estimates of sea turtle interactions with artisanal fisheries for northern Africa, and one of very few estimates of turtle mortality in set gillnets in the Mediterranean. Our results indicate a need for research into ways for fishermen to avoid turtle captures and to raise awareness of this problem throughout the Mediterranean Sea. The following specific actions are recommended: 1) management of gillnet fisheries in the Mediterranean Sea, 2) minimizing gear soak time, particularly in foraging and inter-nesting habitats and along the migration pathways of sea turtles, 3) technical modifications of the gear by reducing the number of floats, and 4) carrying out an awareness campaign with fishermen to reduce post-release mortality.

Keywords: GILLNET, CATCH RATE, CARETTA CARETTA, BYCATCH, MORTALITY

pp. 51-58
Authors: Antelo, Rafael; Ayarzagüena, José & Castroviejo, Javier

Abstract: We present data on the reproductive ecology of the Orinoco crocodile (Crocodylus intermedius) in a newly established population at the El Frío Biological Station, Venezuela, from 2003 to 2007. Nesting occurs during the dry season, and hatching of young takes place at the beginning of the rainy season. Elliptical hole-like nests are constructed in artificial sand beaches with a median nest depth of 42.6 cm. Nest depth is positively correlated with female total size, enabling us to predict the size of the female based on nest characteristics. Temperature in the egg chamber was on average 31.9 °C. The thermal amplitude of the nest was positively correlated with nest depth, and less than 1.3 °C when the nest was deeper than 30 cm. The average clutch size was 41.2 eggs, the average clutch mass was 4256.2 g, and egg viability was 75.4%. The average length, width and weight of eggs was 7.61 cm, 4.73 cm and 111.07 g, respectively. As part of the conservation programme, we also artificially incubated eggs from the species. Hatching rate in the incubator was 84.3%. Total length and mass at hatching were 28.6 cm and 66.9 g, respectively. Our data demonstrate that head-starting our population through egg incubation is a suitable conservation strategy for this endangered species.

Keywords: HEAD-STARTING, MANAGEMENT, CONSERVATION, REINTRODUCTION

pp. 31-39
Authors: Nunes, Simone de Fátima; Kaefer, Igor Luis; Leite, Pedro Terra & Cechin, Sonia Zanini

Abstract: Dissection of preserved specimens of Rhinocerophis (previously Bothrops) alternatus, combined with data on captive individuals, provided information on the reproductive biology, sexual dimorphism and feeding habits of this viperid snake, forming the first comprehensive study on the natural history of this species in subtropical Brazil. Females were longer than males in snout–vent length (SVL), averaging 992 mm. Males averaged 664 mm in SVL and had relatively longer tails. Mating was observed in July under conditions of captivity. Mature males were found throughout the year, as were females with enlarged follicles. Nevertheless spermatogenesis, inferred by an increase in testicular volume, occurred during the early mating period and its preceding months. Oviductal embryos were recorded only from November to January and parturition occurred from February to August, characteristics of a seasonal reproductive cycle, a recurrent pattern for snakes from the subtropical domain. We observed asynchrony in the timing of mating and parturition, indicating long-term sperm storage after mating by females. In addition, our observations of muscular contraction and the presence of spermatozoids in the posterior portion of the uterus of mature females allowed us to suggest utero-muscular twisting as a possible mechanism used by R. alternatus for controlling the timing of its reproductive cycle. The number of newborns per litter varied from five to 20 (mean = 12). Feeding frequency was 29.7%, and the analysis of gut contents indicated a highly specialized diet, which is restricted to rodents (Muridae and Caviidae) and marsupials (Didelphidae). Most of the prey was ingested head-first.

Keywords: VIPERIDAE, BOTHROPS, DIET, REPRODUCTION, MORPHOLOGY, SERPENTES

pp. 41-50
Authors: Kaliontzopoulou, Antigoni; Carretero, Miguel A. & Sillero, Neftalí

Abstract: Podarcis carbonelli is a lacertid lizard endemic to the western Iberian Peninsula, with a highly fragmented distribution and complex patterns of phylogeographic structure. Here, we investigate intraspecific morphological variability in this species, considering both biometric and pholidotic traits. Our results reveal local patterns of variation in total body size and scalation, but also indicate the existence of gradual, geographically structured morphological variation when size-independent biometry is considered. Total body size is the main factor determining variation across our sample, but this seems to be the result of within-population variability in this trait and is not geographically structured. The southern isolated populations seem highly differentiated in morphological terms, a pattern that also corresponds to singular environmental conditions and distinctive genetic variation, and should therefore be the focus of special attention for future investigation and conservation.

Keywords: SCALATION, IBERIAN PENINSULA, INTRASPECIFIC VARIATION, BIOMETRY