Animal Biodiversity and Conservation | 2019
Haplotypic characterization of the olive ridley turtle (Lepidochelys olivacea) in northwest Mexico: the northernmost limit of its distribution
Abstract
espanolLa tortuga golfina (L. olivacea) tiene una distribucion pantropical. En el Pacifico oriental, los limites oficiales de su zona de reproduccion son la peninsula de Baja California y el sur de Sinaloa, en Mexico. La playa de Ceuta en Elota, Sinaloa, Mexico ha servido de sitio de proteccion para L. olivacea durante mas de tres decenios. En este estudio, se caracterizo geneticamente la poblacion de L. olivacea de la playa de Ceuta. Concretamente, se amplifico un fragmento de 712 pb de la region de control del ADNmt de 32 tortugas golfinas. Se identificaron ocho haplotipos (siete tras reducir a ~468 pb) y se incluyeron dos haplotipos nuevos (Lo–T7 y Lo–T8) y cinco haplotipos que se habian identificado anteriormente en otras playas de anidacion. El haplotipo Lo–T2 era dominante (~60%) en las muestras: h = 0,6048 (± 0,0974) y π = 0,002212 (± 0,001504). Si bien este estudio se realizo en el limite septentrional de la zona de anidacion de la tortuga golfina en el Pacifico oriental, el grupo estudiado presenta una diversidad genetica moderada y pertenece a una poblacion que, en la escala evolutiva, ha pasado recientemente por una expansion demografica. Debido a que la tortuga golfina del Pacifico oriental se considera resiliente a la variacion ambiental, es necesario estudiar las zonas de anidacion en el noroeste de Mexico. EnglishThe olive ridley sea turtle (L. olivacea) has a pantropical distribution. In the Eastern Pacific, the official limits of its reproduction area are south of the Baja California peninsula and south of Sinaloa, Mexico. Ceuta beach in Elota, Sinaloa, Mexico, has served as a protection site for L. olivacea for over three decades. In this study, the L. olivacea population from Ceuta beach was genetically characterized. Specifically, a 712–bp fragment from the control region of mtDNA was amplified from 32 olive ridley turtles. Eight haplotypes (seven after cutting to ~468 bp) were identified, and these included two novel haplotypes (Lo–T7 and Lo–T8) and five haplotypes that were previously identified in other nesting beaches. The Lo–T2 haplotype was dominant (~60%) in the samples: h = 0.6048 (± 0.0974) and π = 0.002212 (± 0.001504). Although this study was conducted in the northernmost limit of the olive ridley turtle nesting distribution in the eastern Pacific, the sampled group presents moderate genetic diversity and belongs to a population that, on an evolutionary scale, only recently underwent demographic expansion. Because the olive ridley turtle in the eastern Pacific is considered resilient to environmental variation, nesting area studies in northwest Mexico are necessary.