New record of the snake Geophis turbidus ( Squamata : Dipsadidae ) from Hidalgo , Mexico , with annotations of a juvenile specimen

We record for the first time the recently described snake Geophis turbidus from the state of Hidalgo, Mexico. The species was recorded in cloud and pine forests, and this report extends the distribution of this species approximately 25 km from its previously known occurrence. In this paper, we also report the first description of a juvenile specimen, along with data on the natural history, morphology, and conservation of this species.

The description of Geophis turbidus Pavón-Vázquez, Canseco-Márquez & Nieto-Montes de Oca, 2013, contains information on morphological variation, distribution, natural history, and conservation (Pavón-Vázquez et al. 2013).In this study, we report the occurrence of G. turbidus in Hidalgo state, Mexico, for the first time, and we also include information on the species' natural history, as well as the morphological description of a juvenile (scutellation and color pattern), which is not available in the original description (Pavón-Vázquez et al. 2013).Based on the little information that exists on the species, our new data adds to the knowledge on morphological variation, potential distribution in different environments, and how best to conserve this recently described species.
From June 2009 to February 2010 field surveys were conducted to determine species richness and diversity of reptiles in the Municipality of Tenango de Doria, Hidalgo, Mexico.Vegetation types present in Tenango de Doria include cloud forest, pine forest, oak-pine forest, and tropical rain forest to a lesser extent (Luna-Vega et al. 2000).On 19 June 2009, we located an adult male of G. turbidus (CIB-4450; Figure 1a) at Agua Zarca, Tenango de Doria (20°18ʹ38.08ʺN, 098°16ʹ02.78ʺW; datum WGS84), at an elevation of 2,255 m above sea level (a.s.l.), under a rock in pine forest (Figure 1b).This specimen has a snout-vent length (SVL) 255.6 mm and a body length (BL) of 298.8 mm.A second individual, a juvenile male (CIB-4451; Figure 1c These new records of the adult male and juvenile male from Hidalgo, represent a straight-line range extension of 24 km and 25 km, respectively, from the nearest locations, 16.09 km southwest of Villa Juárez, Xicotepec de Juárez, Puebla, and 83.6 km and 82.5 km, respectively, from the type locality, 3.5 km west of Xocoyolo, Municipality of Cuetzalan, Puebla, Mexico (Pavón-Vázquez et al. 2013; Figure 2).
The adult male (CIB-4450) resembles the holotype and the paratypes in scutellational features (Table 1; Pavón-Vázquez et al. 2013); however, it has a larger SVL, TL and body length (BL; Table 1).The juvenile specimen (CIB-4451) differs from the adult male in characteristics at La Viejita (20°19ʹ42.34ʺN, 098°14ʹ47.65ʺW; datum WGS84) under a rock on the edge of a grazing area in a patch of cloud forest (Figure 1d) at 1,711 m a.s.l.This second specimen has a SVL of 99.7 mm and a BL of 114.1 mm.The environmental temperature was 10°C and the microenvironmental temperature was 12°C.Specimens of G. turbidus were collected and transported to the Laboratorio de Ecología de Poblaciones of Centro de Investigaciones Biologicas (CIB) from the Universidad Autónoma del Estado de Hidalgo (UAEH) under an approved scientific permit from SEMARNAT (#SGPA/ DGVS/02726/10).Photographs of the specimens were taken in life and after they were fixed in formalin (10%) and preserved in ethanol (70%; Casas-Andreu et al. 1991).Morphological measurements were made by using an electronic calliper (0.01 mm).
The nomenclature and analysis of scutellation were based on the methods by Downs (1967), Savage and Watling (2008) 2013).The juvenile has two postoculars on the right side (Figure 3B, Table 1) compared with the adult holotype (MZFC 27254) and adult male of Hidalgo (CIB-4450), which have one postocular (Table 1).On the right and left side, there are six and five supralabials, respectively (6/6 in MZFC 27254 and CIB-4450; Table 1), third and fourth supralabials in contact with the orbit on the right side (Figure 3b); on the left side, the third labial enters the orbit (Figure 3d).The mental scale scarcely is in contact with the first pair of chin shields.The second pair of chin shields is in medial contact, not separated by a first gular scale as occurs in the adult specimens (MZFC 27254, CIB-4450; Figure 3c).The color pattern in preserved specimen (CIB-4450) is similar to holotype (MZFC 27254).The background color of the dorsal and lateral portions of the head is olive gray with indistinct dark gray spots on the parietal and frontal scales; the mental region and chin shields are cream colored.The dorsal surface of the body and tail are predominantly dark gray (Figure 1a), which becomes pale gray toward the ventral region of the body.The ventral scales are cream colored, with pale brown spots on their anterior portion, and the ventral region of the tail is uniformly dark brown.
In life, the juvenile specimen (CIB-4451) color pattern is: dorsal region of head pale gray (Figure 1c); dorsal region of body and tail dark gray, with a vertebral line cream; lateral region of body pale pink to edge of ventrals, which are cream colored, as are subcaudals.Pale pink collar on posterior region of head, beginning on posterior edge of parietal scales and extending posteriorly to posterior end of second mid dorsal scale; laterally across temporal scales to reach supralabials posterior to eye and sublabials; collar reaches the fifth and sixth supralabials on right side (Figure 1c), and third and fourth supralabials on left side.
The two specimens from the Municipality of Tenango de Doria inhabit cloud forest (CIB-4451) at an elevation of 1,711 m a.s.l. and also pine forest (CIB-4450) at an elevation of 2,255 m a.s.l.These environmental features (vegetation type of pine forest and altitude) had not been previously reported for the species (Pavón-Vázquez et al. 2013).Specimens were found under rocks, which is a common microhabitat of species of the genus Geophis (Downs 1967).The stomach contents of the adult male contained ants (Hymenoptera: Formicidae), and vegetable and mineral matter, which suggests an insectivorous diet.The stomach of the juvenile specimen was empty.The adult male and juvenile had large fat bodies, with a mass of 0.1970 g and 0.0320 g, respectively.
The discovery of this snake species in pine forest and cloud forest vegetation (as already known at the type locality in Puebla) in Hidalgo points the importance of the conservation of these forest types as repositories of a considerable number of endemic Mexican amphibians and reptiles (Flores-Villela et al. 2010).In addition, the records reported here extend its distribution to the northwest of the previously-reported records from the Sierra Madre Oriental (Pavón-Vázquez et al. 2013).
Given the importance of the mountains of central Mexico for endemic reptile (Flores-Villela et al. 2010), it is critical to note that these are areas subject to significant anthropogenic damage in pine, oak, pineoak, or cloud forests (Ponce-Reyes et al. 2012).It is in cloud forests where most specimens of G. turbidus have been found, and given the restricted distribution of this snake, we have used the Environmental Vulnerability Score (EVS) proposed by Wilson et al. (2013a) to assess its conservation status.We determined the EVS as 14, which places this species in the category of high vulnerability, based on the following calculations: (i) geographic distribution (5: occurrence only in Mexico, but not restricted to the type locality); (ii) ecological distribution (7: occurrence in two vegetation types, cloud forest and pine forest), and (iii) degree of human persecution (2: semifossorial habits, not venomous, sometimes escapes the attention of humans).Because of its recent description, its conservation status has not been assessed yet by the Mexican government (NOM-059-SEMARNAT; SEMARNAT 2010) or by the International Union for Conservation of Nature and Natural Resources (IUCN).Accordingly, there is a need for an assessment of the level of degradation of its habitat, its population status, and aspects of its natural history.
This new record of G. turbidus increases the number of snake species in Hidalgo state to 84 (Ramírez-Bautista et al. 2010;Badillo-Saldaña et al. 2014).With the new record of this species from Hidalgo, the importance and necessity for conservation of the pine and cloud forests where G. turbidus and other species of amphibians and reptiles live is highlighted.
, and Pavón-Vázquez et al. (2013).The specimens were identified according to the keys to the genus Geophis (Wilson and Townsend 2007) and from description of the species (Pavón-Vázquez et al. 2013).