Ampliación de la distribución geográfica y estado de conservación de Ctenoblepharys adspersa (Tschudi, 1845)

Ampliamos la distribución geográfica de Ctenoblepharys adspersa (Liolaemidae), una especie de saurio endémico y amenazado del desierto peruano. Nuestro nuevo registro extiende la distribucion de esta especie en 60 km (línea recta) de la localidad más oriental previamente conocida, la Reserva Nacional de Paracas. Registramos dos tipos de hábitat nuevos para C. adspersa al interior de las estribaciones andinas e identificamos las plantas nativas asociadas a sus hábitats. Además, revisamos el estado de conservación de esta especie y los desafíos que implican su conservación, resaltando que la mayoría de las poblaciones son vulnerables a los impactos en su hábitat producto del desarrollo de infraestructura urbana y/o agrícola.

We extend the geographical distribution of Ctenoblepharys adspersa (Liolaemidae) an endemic and threatened lizard species from the Peruvian desert. Our new record extends the known species distribution ca. 60 km (straight line) east-southeastern from the eastemost record at Paracas National Reserve. We recorded two new type of habitat for C. adspersa that reach to the Pacific foothills and identified the native plants associated to its habitats. Moreover, we review the conservation status and the challenges that facing it, highlighted that most of its populations are vulnerable to the impacts on their habitat caused by the development of urban and agricultural infrastructure.

Sequence variation in the melanocortin-1 receptor (MC1R) pigmentation gene and its role in the cryptic coloration of two South American sand lizards

In reptiles, dorsal body darkness often varies with substrate color or temperature environment, and is generally presumed to be an adaptation for crypsis or thermoregulation. However, the genetic basis of pigmentation is poorly known in this group. In this study we analyzed the coding region of the melanocortin-1-receptor (MC1R) gene, and therefore its role underlying the dorsal color variation in two sympatric species of sand lizards (Liolaemus) that inhabit the southeastern coast of South America: L. occipitalis and L. arambarensis. The first is light-colored and occupies aeolic pale sand dunes, while the second is brownish and lives in a darker sandy habitat. We sequenced 630 base pairs of MC1R in both species. In total, 12 nucleotide polymorphisms were observed, and four amino acid replacement sites, but none of them could be associated with a color pattern. Comparative analysis indicated that these taxa are monomorphic for amino acid sites that were previously identified as functionally important in other reptiles. Thus, our results indicate that MC1R is not involved in the pigmentation pattern observed in Liolaemus lizards. Therefore, structural differences in other genes, such as ASIP, or variation in regulatory regions of MC1R may be responsible for this variation. Alternatively, the phenotypic differences observed might be a consequence of non-genetic factors, such as thermoregulatory mechanisms.