Variación geográfica de Ninia atrata en Colombia (Colubridae: Dipsadinae)

Abstract

Se describe la variación y distribución geográfica de Ninia atrata en Colombia basada en 128 ejemplares de mas de 24 localidades. Los ejemplares colombianos presentan un alto grado de polimorfismo en su coloración, mostrando una clara diferencia entre las poblaciones Cis-andinas y Trans-andinas, tanto en coloración del collar nucal, como en su forma, prominencia y en siete de doce proporciones morfométricas. Lavariación encontrada e nestas poblaciones colombianas sugiere una relevancia taxonómica. Sin embargo, teniendo en cuenta el tipo de datos disponibles hasta el momento, lo más prudente es conjeturar que Ninia atrata posee en Colombia una gran variación intraespecífica y dos formas fenotípicas distinguibles.

A new species of Ninia (Serpentes: Dipsadidae) from Chocó-Magdalena biogeographical province, western Colombia

“…During the study of the role of African oil palm plantations in the conservation of snakes in Colombia, we found six specimens of the genus Ninia from the municipality of Tumaco, department of Nariño, Colombia (biogeographical-Chocó region;Poveda-M, et al 2004), that share certain unique similarities traits with each other, but differ from the more northern populations (from Costa Rica and Panamá) of N. maculata stated by Savage & Lahanas (1991) and Auth (1994), or sympatric populations of N. atrata reported by Angarita-Sierra (2009. Also, we made a direct examination of the specimens cited by Castaño-M, et al (2004) as N. maculata and N. atrata, finding that these specimens do not match with the previous descriptions of the taxa or any recognized species of the genus (Hallowell 1845;Peters 1861;Dunn 1935;Savage & Lahanas 1991;Smith & Campbell 1996;Savage 2002;Köhler 2008;Angarita-Sierra 2009, but they shared unique similarities with the specimens collected at the municipality of Tumaco. Hence, it has become clear that these specimens were previously confused with N. maculata as well as with N. atrata by Castaño-M et al (2004) and represent an undescribed species.…”

“…Variation in meristic, color pattern, morphometric and hemipenial characters was evaluated for 70 specimens of Ninia atrata from northern South America. General terminology and morphometric characters of the cephalic shields follows McCranie & Wilson (1995) and Angarita-Sierra (2009). Measurements of the following variables were made with a vernier caliper to the nearest 0.1 mm: head length (HL); head width (HW), paretial length (PL), paretial width (PW), frontal length (FL), frontal width (FW), prefrontal length (PFL), prefrontal width (PFW), internasal length (INL), internasal width (INW), supraocular length (SPL), supreocular height (SPH), loreal height (LH), loreal length (LL), internasal suture (INS) prefrontal suture length (PFS), parietal suture length (PS).…”

“…Distribution and natural history. Ninia teresitae is known to inhabit in the Chocó-Magdalena biogeographic province of Colombia (Hernández-Camacho et al 1992) between 50-1400 m asl, and occurs in sympatry with N. atrata (McCranie & Wilson 1995;Angarita-Sierra 2009. This province extends from southwestern Ecuador through the Chocoan region to eastern Panamá, including the western margin of the lower Cauca River Basin in Antioquia, the upper San Jorge and Sinu River Basins and reaching the middle Magdalena River Basin (Rangel-Ch & Arellano-P, 2004).…”

“…McCranie and Wilson (1995) were the first to attempt a comprehensive taxonomic assessment of specimens of N. atrata and found that populations from South America could be distinguished at the species level from those from Costa Rica, western Panama (posteriorly described as N. celata), Honduras and El Salvador (posteriorly described as N. espinali). Likewise, Angarita-Sierra (2009 evaluated the geographic variation of N. atrata in Colombia as well as the hemipenial morphology from throughout its geographic range of distribution. Angarita-Sierra's findings show that the genus Ninia in Trinidad is represented by two sympatric species, the previously recognized species Ninia atrata (Dunn 1935;Murphy 1997;Boos 2001) and an undescribed species (described there as Ninia franciscoi).…”

“…Ninia atrata is the most widely distributed species of the genus in South America. It ranges from western Panama, Colombia, Ecuador, Venezuela and Trinidad and Tobago with disjunct populations inhabiting in the trans-Andean Magdalena Valley, on the western slopes of the Cordillera Occidental and Chocoan rainforest (Colombia and Ecuador), as well as the Caribbean coast reaching the northern slopes of the Cordillera de Merida (Venezuela) to Trinidad and Tobago, and Orinoquia and Amazon basins (McCranie & Wilson 1995;Ingrasci 2011;Rivas et al 2012;Angarita-Sierra 2009Mesa-Joya 2015;Medina-Rangel 2015).…”