DOI: 10.3897/zoologia.36.e27357

Authors: Nastaran Heidari

Abstract: Acanthodactylus micropholis Heidari, Rastegar-Pouyani, Rastegar-Pouyani & Rajabizadeh, 2013 and A. khamirensis Blanford, 1874 are genetically and morphologically distinct, but their ecological differentiation has not previously been evaluated. The ecological niche models of these two sister species Acanthodactylus were reconstructed using climate and geographical data. Species distribution modeling for A. micropholis and A. khamirensis was used to make predictions and showed that most parts of southern and southeastern Iran are suitable for the distribution of both species. Habitat suitability was mostly dependent upon minimum temperature of the coldest month and seasonal precipitation for A. micropholis and A. khamirensis, respectively. Niche similarity tests (niche overlap and identity tests) were performed to evaluate species differentiation based on the ecological species criterion. Our results indicate that both species have different ecological niches and are significantly separated from each other. Therefore, our study corroborates previous analyses based on molecular and morphological evidences that suggested that A. micropholis and A. khamirensis were valid species.

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DOI: 10.3897/zoologia.36.e22909

Authors: Teresa C. Avila-Pires, Cristiano de C. Nogueira, Marcio Martins

Abstract: A new species of the lizard genus Stenocercus Duméril & Bibron, 1837 is described based on six specimens from Serra da Canastra, Minas Gerais, southeastern Brazil. Similar to S. tricristatus (Duméril, 1851), S. dumerilii (Steindachner, 1867), S. quinarius Nogueira & Rodrigues, 2006, and S. squarrosus Nogueira & Rodrigues, 2006, the new species has a pyramidal head and an enlarged, dorsally projected post-supraciliary scale, like a small horn. It is most similar to S. tricristatus, from which it differs in having a more elongated head in ventral view; a larger number of scales around midbody; a distinctly enlarged, smooth preauricular scale; and probably a larger body size. Moreover, the new species has distinctly keeled scales, with phylloid and mucronate dorsals; no enlarged supraoculars; no neck folds; a vertebral, and a pair of dorsolateral and (weak) lateral crests. A redescription of S. tricristatus is presented for comparison with the new species.

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DOI: 10.3897/zoologia.35.e24575

Authors: Thiago Maia-Carneiro, Gisele R. Winck, Mariana Rodrigues Pereira, Carlos Frederico Duarte Rocha

Abstract: We investigated the daily activity and thermoregulatory body orientation of Mabuya macrorhyncha (Hoge, 1947), a lizard species that occurs in the Brazilian Atlantic Forest. We conducted this investigation in a sandy coastal dune remnant (“restinga” ecosystem) in Grussaí, state of Rio de Janeiro, Brazil, during the summer. The daily activity cycle of the lizards started around 6:00 am and ended before 7:00 pm. This is longer than observed in other populations of M. macrorhyncha (approximately 7:00 am to 5:00 pm). The activity cycle of the lizards was bimodal, with the first peak between 6:00 and 11:00 am and the second from 2:00 to 7:00 pm. This contrasts with observations on other populations of this species, which revealed an unimodal pattern. The mean body temperature of M. macrorhyncha in Grussaí was 34.2 ± 1.5 °C, which was comparatively higher than observed in other populations of the species. The differences in the daily activity and of body temperature of these lizards between our study and previous studies on this species may reflect environmental thermal conditions. The mean air and mean substrate temperatures when individuals were active were 27.8 and 30.5 °C respectively. Lizard orientation was significantly correlated with the direction of the solar incidence, suggesting that solar radiation, and particularly behavioral adjustments that maximize exposure to the sun, are important for the thermoregulation of M. macrorhyncha. Circular structures at the site, such as bromeliads, offer microhabitats with different orientations to the sunlight, favoring lizard thermoregulatory behaviors.

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DOI: 10.3897/zoologia.34.e11923

Authors: Bilal A. Paray, Mohammed K. Al-Sadoon

Abstract: Histology and electron microscopic studies of the dorsal skin of the Fringe-toed lizard, Acanthodactylus orientalis Angel, 1936, showed three types of dermal chromatophores: xanthophores, iridophores and melanophores. These pigment cells were observed in vertical combination, with an uppermost layer of xanthophores, an intermediate layer of iridophores and a basal layer of melanophores. The ultrastructure of the melanophore is characterized by oval nucleus and numerous pigment granules, the melanosomes of different stages that remain scattered in the cytoplasm. The chromatophores of this species contain significant information of anatomical similarity with lower as well as higher vertebrates. They can help to better understand the inter relationships between vertebrate pigment cells and their role in skin dysfunctions.

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