The Herpetological Journal

pp. 1-8

Authors: J.M.A. Ishara K. Jayamanna, Anslem de Silva & Kanishka D.B. Ukuwela

Abstract: Colour polymorphism is a pervasive phenomenon in both the animal and plant kingdoms and understanding its evolution and maintenance is of great interest. Among the lizards of Sri Lanka, the endemic skink Lankascincus fallax shows throat colour polymorphism in which the underlying basis is not clearly known. In this study, we examined the relationship of the three different throat colour morphs observed in this species with sex, body size and geographic location. Live skinks were sampled from two locations in Sri Lanka and sex and throat colour were categorised visually and the snout-vent length (SVL) was measured. Tail tips of some selected individuals from the two locations were taken and a fragment of the 12S rRNA gene was sequenced in representative individuals having different throat colour morphs. Pairwise genetic distance of the three colour morphs ranged between 0.4–0.5%, confirming that the three colour morphs were the same species. The three throat colour morphs (red, black and white) were observed in males in both locations, while the females only had the white morph. This suggests that throat colour in this species is linked to sex and that the throat colour polymorphism was confined to males. There was a significant difference between the mean SVL of males with red and black throat colours (39.36 mm) and males with white throat colours (31.93 mm), suggesting that the throat colour is associated with the body size in males. However, future studies are necessary to understand the underlying drivers for the presence and maintenance of sexual dichromatism and throat colour polymorphism in L. fallax.

Keywords: DNA-barcoding, colour polymorphism, geographic variation, sexual dimorphism, sexual dichromatism

pp. 9-22

Authors: Diego O. Di Pietro, Federico P. Kacoliris, David G. Vera, Tomás Martínez-Aguirre, Melina A. Velasco, María L. Arellano & Igor Berkunsky

Abstract: Climate change is one of the main causes of biodiversity loss worldwide. However, detailed knowledge about the impacts of climate change on most species in the Neotropical region is incipient, and the herpetofauna from Pampas grassland is no exception. In this frame, we model the suitable habitats of nine endemic amphibian and reptile species that inhabit the Pampas grassland of Argentina, under current climatic conditions and future climate change scenarios, with the general objective of prioritising conservation and management strategies. To model the suitable habitat of each species we used the Maxent algorithm, while the complementary spatial analyses were carried out with DIVA-GIS. We found a significant loss in both suitable habitat surfaces and known populations in most studied species. The relationship between these two parameters provided a ranking of species for long-term conservation and monitoring. Finally, based on the conservation priorities obtained for each species, we identified and discussed the main management strategies to mitigate the impacts of climate change. Our results were consistent with previous reports in the Neotropical region, highlighting the negative climate change impacts on herpetofauna species, and the urgent need for management strategies to mitigate it. In conclusion, our results establish the bases to develop monitoring, conservation and management strategies to face the predicted changes in the suitable habitats of the endemic and threatened herpetofauna from Pampas grassland.

Keywords: biodiversity, conservation, habitat loss, management, population loss

pp. 9-22

Authors: Diego O. Di Pietro, Federico P. Kacoliris, David G. Vera, Tomás Martínez-Aguirre, Melina A. Velasco, María L. Arellano & Igor Berkunsky

pp. 23-30

Authors: Martín Alejandro Ortiz, Judith Victoria Bentancourt, María Teresa Sandoval & Nora Ruth Ibargüengoytía

Abstract: Estimation of individual age is key to answering questions on evolution and population ecology and to the conservation of species. Herein, we studied individual age, age at first reproduction and maximum life span of Kentropyx viridistriga (Boulenger, 1894), a lizard inhabiting the subtropical region of wet Chaco of Corrientes province, Argentina. We also estimated life history parameters such as lifetime reproductive effort, relative reproductive time and fecundity rate. Kentropyx viridistriga exhibited a lamellar pattern of bone growth, as typical of reptiles. Adult females exhibited thinner cortical bone than adult males. Males and females attain sexual maturity during their second activity season and reach a maximum life span of two and three years, respectively, suggesting a trade-off between maturation and longevity. Kentropyx viridistriga has a short life span, small clutch size and short relative reproductive time, suggesting that its capacity to demographically recover from habitat perturbations is limited, and populations are highly vulnerable to climatic and anthropogenic disturbances.

Keywords: Age estimation, life-history traits, longevity, Gran Chaco, Teiid

pp. 31-40

Authors: Ernesto Raya-García, Taggert G. Butterfield, José Garrido, Carlos Anaya-Merchant, Daniel Antelo-Barbosa, Raúl López-Vivanco, Misael Sánchez-Salazar, Josie Jaime Zúñiga-Vega & Rodrigo Macip-Ríos

Abstract: The Jalisco mud turtle Kinosternon chimalhuaca is an endemic species from the Pacific coast of Jalisco and Colima states, Mexico. The species has been poorly studied and much of its natural history and ecology are unknown. We analysed the demography and basic reproductive ecology of a population inhabiting a canal in a peri-urban area on the coast of Jalisco, Mexico. We use a mark-capture-recapture dataset collected over four years (2019–2022) to perform multi-state and time-symmetric open models (Pradel) to calculate population growth, recapture and transition probabilities. A total of 530 turtles were captured and marked during the study. Survival probability was higher in adults compared to juveniles. The estimated abundance of the population studied was between 699 and 778 turtles, with a sex ratio biased toward females. Using radiographs, we found that clutch size was 3.89 (± 0.81) eggs, with a range from 3 to 6 eggs, we also found evidence of pelvic constraint on egg size. The studied population is restricted to subsidised man-made canals and was considered stable. The information generated in this paper will be useful for the much needED conservation assessments of mud turtles.

Keywords: abundance, survivorship, recapture probability, reproduction, pelvic constraint, subsidised population

pp. 31-40

Authors: Ernesto Raya-García, Taggert G. Butterfield, José Garrido, Carlos Anaya-Merchant, Daniel Antelo-Barbosa, Raúl López-Vivanco, Misael Sánchez-Salazar, Josie Jaime Zúñiga-Vega & Rodrigo Macip-Ríos

pp. 41-51

Authors: Maliha Ayub, Tao Pan, Peng Yan, En Li, Misbah Hanif & Xiaobing Wu

Abstract: Reintroduction of threatened species is a common strategy used to mitigate population decline and reduce the risk of extinction. In order to assess the success of such reintroduction programs, it is critical to monitor the demographic and genetic features of reintroduced populations. In this work, we conducted a genetic assessment of the Critically Endangered crocodile species Crocodylus siamensis to determine the genetic diversity, utilising both microsatellite markers and mitochondrial DNA D-loop region. The genetic analysis revealed a moderate level of genetic diversity within the sampled populations, as indicated by the microsatellite markers (Ho = 0.505 ± 0.080; He = 0.297 ± 0.091) and mtDNA D-loop (hd = 0.622 ± 0.061; Pi = 0.01294 ± 0.00041). Notably, 22 distinct haplotypes were observed. Additionally, we identified evidence of hybridisation that might have occurred between C. siamensis and Crocodylus niloticus raising concerns about the potential compromise of the species' genetic integrity. This study represents the first genetic assessment of captive bred C. siamensis populations in China, encompassing both microsatellite and mtDNA D-loop analyses. To ensure preservation of C. siamensis, we recommend identifying and excluding hybrid individuals from conservation programmes. Our findings support the feasibility of implementing breeding and captive management plans for C. siamensis, providing a solid theoretical basis for their reintroduction and captive breeding to safeguard and augment the population of this Critically Endangered freshwater crocodile. This research marks the initial step towards establishing a scientifically sound source population for the conservation of C. siamensis in China.

Keywords: protection, reintroduction genotype, haplotypic diversity, nucleotide diversity

pp. 41-51

Authors: Maliha Ayub, Tao Pan, Peng Yan, En Li, Misbah Hanif & Xiaobing Wu

pp. 52-72

Authors: Luis Alejandro Arias-Sosa, Francisco Javier Ruiz-Gómez, Esteban Betancourt & Mario Vargas-Ramírez

Abstract: The South American rattlesnake corresponds to a species complex, and debates persist regarding its systematics and taxonomy. Similarly, the understanding of its phylogeography has been incomplete, due to a lack of information concerning north-western populations. This knowledge gap hinders the development of conservation strategies to address threats like habitat destruction and illegal trade. This research aimed to provide a genetic analysis of these north-western populations. Additionally, we aim to delineate conservation units and evaluate the utility of mitochondrial sequencing in tracing the origin of illegally traded individuals. We sequenced DNA from five loci in 25 snakes from north-west South America, and subsequently integrated these data with homologous sequences from previous studies. Phylogeographic analyses, coalescent simulations, approximate Bayesian computation and species delimitation algorithms, were used to examine the species’ phylogeography, systematics and delimited conservation units. Furthermore, we inferred the geographic origins of 16 confiscated rattlesnakes from Colombia by genotyping. We identified four major genetic groups within the South American rattlesnake, including a new group from the Colombian Orinoco Llanos. Our findings indicate the need for a taxonomic reevaluation, including the identification of two new candidate subspecies in Colombia. Our results suggest a rapid colonisation of South America, facilitated by climate fluctuations during the Pleistocene. This included the initial colonisation of arid Trans-Andean ecoregions currently isolated by natural barriers, followed by an invasion of the Cis-Andean ecosystem through low elevation passages and a final colonisation of the Amazon, most probably facilitated by changes in vegetation cover. To safeguard the genetic diversity of this species, we propose the establishment of 11 conservation units. Lastly, we demonstrate the efficacy of mitochondrial sequencing in tracing the origins of illegally traded individuals in Colombia.

Keywords: species complex, Neotropical rattlesnake, genetic structure, management units, illegal trade

Resumen: La serpiente de cascabel sudamericana corresponde a un complejo de especies, y persisten debates sobre su sistemática y taxonomía. Del mismo modo, la comprensión de su filogeografía ha sido incompleta debido a la falta de información sobre las poblaciones del noroeste. Esta laguna de conocimiento dificulta el desarrollo de estrategias de conservación para enfrentar amenazas como la destrucción del hábitat y el comercio ilegal. Esta investigación tuvo como objetivo proporcionar un análisis genético de estas poblaciones del noroeste. Además, buscamos delinear unidades de conservación y evaluar la utilidad de la secuenciación mitocondrial para rastrear el origen de individuos comercializados ilegalmente. Secuenciamos ADN de cinco loci en 25 serpientes del noroeste de Sudamérica, e integramos estos datos con secuencias homólogas de estudios previos. Se utilizaron análisis filogeográficos, simulaciones coalescentes, computación bayesiana aproximada y algoritmos de delimitación de especies para examinar la filogeografía, sistemática y delimitación de unidades de conservación de la especie. Además, inferimos los orígenes geográficos de 16 serpientes de cascabel confiscadas en Colombia mediante genotipado. Identificamos cuatro grandes grupos genéticos dentro de la serpiente de cascabel sudamericana, incluido un nuevo grupo en los Llanos del Orinoco colombiano. Nuestros hallazgos indican la necesidad de una reevaluación taxonómica, incluyendo la identificación de dos nuevas subespecies candidatas en Colombia. Nuestros resultados sugieren una rápida colonización de Sudamérica, facilitada por las fluctuaciones climáticas durante el Pleistoceno. Esto incluyó la colonización inicial de ecorregiones áridas transandinas actualmente aisladas por barreras naturales, seguida por una invasión del ecosistema cisandino a través de pasos de baja elevación, y una colonización final de la Amazonia, probablemente facilitada por cambios en la cobertura vegetal. Para salvaguardar la diversidad genética de esta especie, proponemos el establecimiento de 11 unidades de conservación. Por último, demostramos la eficacia de la secuenciación mitocondrial para rastrear los orígenes de individuos comercializados ilegalmente en Colombia.

Palabras clave: complejo de especies, cascabel neotropical, estructura genética, unidades de manejo, comercio ilegal

pp. 52-72

Authors: Luis Alejandro Arias-Sosa, Francisco Javier Ruiz-Gómez, Esteban Betancourt & Mario Vargas-Ramírez

pp. 73-80

Authors: Tong Lei Yu, Tao Yang, Ze Ye Re & Kai Wen Dong

Abstract: Organisms with complex life cycles, like amphibians, are greatly affected by environmental factors and maternal effects, which in turn influence their morphological variation. The Asiatic toad Bufo gargarizans is found throughout East Asia and is not only valued for its economic medicinal properties in China but also considered a potential indicator species for assessing environmental pollution in inland rivers. However, the specific responses of this species to environmental toxicants, including trace metals, are not well comprehended at present. In this study, we experimentally examined the plasticity in larval period, body mass and size, and survival at metamorphosis in tadpoles of B. gargarizans under different combinations of food quality and zinc (Zn). We found that larval period, survival, SVL and mass at metamorphosis were sensitive to food quality, larval period increased significantly with increasing Zn concentration. The interaction between food quality and zinc primarily influenced the larval period. Tadpoles that were fed a high-energy diet, rich in protein and lipids, tended to have a shorter larval period as zinc concentration increased. Conversely, tadpoles fed a low-energy diet had a longer larval period with increasing zinc concentration. Thus, zinc plays a role in determining the extent to which food quality affects development of B. gargarizans. Additionally, larvae that consume a low-energy diet tend to have higher survival rates as zinc concentration increases, suggesting that moderate levels of zinc concentration (below 150 μg/L) are beneficial for normal physiological and biochemical processes in these organisms. The findings from this study provide valuable insights into the toxicological responses of this species to trace metals, contributing to a better understanding of their impact.

Keywords: Bufo gargarizans, acute toxic effect, zinc, interaction effects, age and size at metamorphosis, phenotypic plasticity

pp. 81-88

Authors: Ernesto Elgue, Arley Camargo & Raul Maneyro

Abstract: Current knowledge in conservation genetics emphasises that the priority value of an area also depends on the genetic diversity it harbours, therefore fine-scaled studies of the spatial genetic structure are necessary for making informed decisions about prioritisation of natural areas and wild populations for conservation and/or management. Homonota uruguayensis is a threatened lizard according to IUCN criteria, with a distribution restricted to rocky outcrops of the Pampa biome in northern Uruguay and southern Brazil. The aim of this work was to establish conservation priorities of H. uruguayensis populations based on the spatial distribution of genetic phylodiversity and the delimitation of management and evolutionary significant units. Sequence data from the nuclear PRLR and the mitochondrial cytochrome b genes were obtained from most of the species distribution in order to estimate genealogies through Bayesian inference, delimit populations with Geneland, and calculate phylodiversity statistics. The results showed the presence of six geographically well defined populations with a strong structure, which we assign to different management units for conservation. The highest phylogenetic diversity were found in northern Artigas (Uruguay), and in the southernmost locations of Rio Grande do Sul (Brazil). However, northern Salto (Uruguay) is the region that best complements the protected area Paisaje Protegido Valle del Lunarejo in Uruguay, and we suggest that both areas would jointly ensure the conservation of the greatest proportion of the total phylogenetic diversity within the species.

Keywords: reptile, phylogenetic diversity, population genetics, DNA, Gekkota, management units

pp. 81-88

Authors: Ernesto Elgue, Arley Camargo & Raul Maneyro

pp. 89-98

Authors: Manuela Santos-Pereira & Carlos Frederico Duarte Rocha

Abstract: We evaluated how anuran species richness and composition changed along altitude, whether species distribution was consistent with predictions of the mid-domain effect, Rapoport effect and the possible existence of Rapoport rescue effect. Our study was conducted in the Salto Morato Natural Reserve, southern Brazil, between February 2013 and August 2015. We sampled anurans in sites between 25–918 m a.s.l. using Visual Encounter Surveys method. We ran simple linear regressions to evaluate altitude and band area effects on species richness and the species turnover along altitudinal gradient estimating beta diversity. We used cluster analysis to show those most similar altitudinal bands in species composition. We tested whether Rapoport effect explained species altitudinal variation, by simple linear regression between altitudinal range and the midpoint range of each species. We compared anuran species richness with that expected by the mid-domain effect, by simple linear regression determining whether species richness predicted by this effect was adjusted to empirical richness. We recorded 41 anuran species. Anuran species richness decreased in a linear fashion with increasing altitude and increased as the area of the altitude band increased. Anuran species turnover increased with distance among altitudinal bands. Similarity analysis indicated the existence of two primary groups. There was a significant relationship between species’ altitudinal range and midpoints, as predicted by Rapoport effect. There was no significant relationship between anuran species richness and that predicted by the mid-domain effect. This study contributed for the understanding of the anuran species distribution altitudinal effects in the Atlantic Forest biome and other areas and reinforced the tendency for a reduction in species richness with increasing altitude.

Keywords: amphibian, elevational gradient, mid-domain effect, rainforest, Rapoport rule