The first country record of the Mexican Blind Snake , Anomalepis mexicanus Jan , 1860 ( Serpentes , Anomalepididae ) , in Colombia

We report the first Colombian record of the Blind Snake Anomalepis mexicanus Jan, 1860, based on a single specimen from Cantagallo municipality, department of Bolívar. Our new record fills a large gap and extends this species’ geographical distribution by approximately 630 km in a straight line east-southeast from its nearest previously known Panamanian locality, and approximately 1295 km in a straight-line north-northeast from its nearest previously known Peruvian locality.


Introduction
Belonging to the so-called blind snakes (Scolecophidia), the Neotropical snake family Anomalepididae is composed of 3 genera with 18 species, of which 8 are found in Colombia (Uetz et al. 2018).The anomalepidid genus Anomalepis Jan, 1860, is currently contains 4 species: Anomalepis aspinosus Taylor, 1939, A. colombia Marx, 1953, A. flavapices Peters, 1957, and A. mexicanus Jan, 1860.All these species are fossorial, adapted for burrowing, and most have been recorded below 600 m above sea level in moist and dry forest of lowlands and foothills.Only A. colombia has been recorded between 1000 and 1700 m above sea level (Marx 1953, Arroyo-Sánchez et al. 2016).In Colombia, until now, only 1 species has been reported: A. colombia, which is currently believed to be endemic to the country (Peters 1957, Peters and Orejas-Miranda 1970, Kofron 1988, Pérez-Santos and Moreno 1988, Arroyo-Sánchez et al. 2016, Uetz et al. 2018).
Three or fewer specimens each of A. aspinosus, A. colombia, and A. flavapices are currently known in collections (Dunn 1941, Peters 1957, Kofron 1988, Arroyo-Sánchez et al. 2016, Cisneros-Heredia 2016, GBIF 2018).In contrast, 23 specimens of A. mexicanus specimens have been reported in biological collections (Appendix 1) to date, collected at about 10 different loca-tions in 5 countries.Anomalepis mexicanus has 2 disjunct populations, 1 distributed from the west of Honduras to the center of Panama below 500 m above sea level, and another east of the Peruvian Andes in the Amazonas department below 200 m above sea level (Fig. 1; Dunn 1941, Taylor 1951, Kofron 1988, Savage 2002, Köhler et al. 2004, Wilson and Townsend 2006, Batista et al. 2013, Sunyer 2014).This species has been found in lowland rainforests and foothill moist forests from under rotten logs and in leaf litter (McCranie and Wilson 2002).Anomalepis mexicanus has been assessed as Data Deficient (DD) for the IUCN Red List of Threatened Species (Batista et al. 2013) because, although its documented range is relatively broad, it is rarely found and little is known about its full geographical distribution, abundance, and ecology.Moreover, there is uncertainty about the threats it faces.
Here, we report the first confirmed record of the Mexican Blind Snake, A. mexicanus, from Colombia.

Methods
A field survey, by means of active searching, was carried out in the Cimitarra River Valley Rural Reserve Zone (ZRC-VRC) in Cantagallo municipality, department of Bolívar, Colombia.The specimen was euthanized in 2% Roxicaine, fixed in 10% formalin solution, and preserved in 70% ethanol.We identified specimens of A. mexicanus by comparison to the original description of the species (Jan 1860) and the latest revision of the genus (Kofron 1988).The specimen's identification was verified by J.E. Carvajal-Cogollo.The specimen was deposited at the reptile collection of the Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá, Colombia (ICN-R), under the catalogue number ICN-R 13040, and collected under the permits #524 of 17 October 2017 and #664 of 7 December 2017 of the Asociación Campesina del Valle del río Cimitarra, Antioquia-Bolívar-Santander departments, Colombia.Scale counts follow the methodology established by Kofron (1988).
Head scale photos were taken with a Leica M205 C stereo microscope with Fusion Optics type.We obtained the geographic coordinates of the capture site using a Garmin Map 62S GPS receiver and locality records for other species of Anomalepis (Appendix, Table A1) were obtained from Kofron (1988) (Taylor 1939, Dunn 1941, Kofron 1988).Yellow circles: A. colombia (Marx 1953, Arroyo-Sánchez et al. 2016).Blue circles: A. flavapices (Peters 1957, Kofron 1988).Red circles: A. mexicanus in Central America and Peru (Dunn 1941, Kofron 1988).Red star: new record of A. mexicanus was found at Cantagallo municipality, department of Bolívar, Colombia.
The single specimen was found at noon under a fallen log during the rainy season.The forest fragment (Fig. 3A, B) had been burnt and was undergoing regeneration.
Identification.Anomalepis mexicanus has ventral and dorsal scales equal in size (Fig. 2), a pair of polygonal prefrontals in contact on midline behind rostral, followed by pentagonal frontal (Fig. 4A), and the eye scarcely visible under a scale (Fig. 4B).Apart from matching these characteristics, our specimen's low number of dorsal scales (265) and its scale-row formula of 24 / 22 / 20 are within the range expected for the species and distinguish it from the other 3 species of Anomalepis (Table 1; Dunn 1941, Taylor 1939, Marx 1953, Peters 1957, Peters and Orejas-Miranda 1970, Kofron 1988, Pérez-Santos and Moreno 1988).

Discussion
The distribution and even more the natural history of Anomalepis species, because of their secretive habits and small size, are poorly known (Dunn 1941, Peters 1957, Kofron 1988).The most recent review of the genus was 30 years ago (Kofron 1988) and included the different populations of A. mexicanus from Central America and Peru.Anomalepis mexicanus is an uncommon fossorial and seldom seen snake and the type species of the genus Anomalepis.It was first described from 1 specimen; however, the type locality ("Mexico") was in error, and the specimen is now believed lost (Kofron 1988).
Our record is the first of A. mexicanus for Colombia and extends its known geographic distribution by approximately 630 km in a straight line southeast from its nearest previously known locality in Panama, Corregimiento de Cristóbal, Barro Colorado Island (Kofron 1988).From the nearest previously known Peruvian locality, vicinity of La Poza, Santiago river, Amazonas  department, by straight-line distance 1295 km to the northeast (Peters 1957, Peters and Orejas-Miranda 1970, Kofron 1988).This is a rarely found species of snake that can be severely affected by deforestation and habitat loss; its populations are fragmented and distribution records are scattered.However, insufficient data prevent any Red List categorization other than Data Deficient (DD; Batista et al. 2013).We highlight the importance of our new record, which opens the possibility that the geographic range of A. mexicanus is still slightly larger and may even occupy future regionally protected areas in Colombia south of the Serranía de San Lucas.
However, the Cis-Andean distribution of the Peruvian specimens and the separation of these populations from Central American populations, as well as the differences in some scale counts (Table 1; Taylor 1939, Kofron 1988), suggest the possibility that there are 2 distinct species involved.The specimen we collected has scale counts between the recorded values for both populations (Table 1).Additional material for morphological comparisons and tissue samples allowing for molecular analysis will be necessary to clarify the uncertainty about this species and its populations.
,Sunyer (2014),Arroyo-Sánchez et al. (2016),Serrano et al. (2016), andGBIF 2018.In cases where the coordinates of the specimen were not explicitly provided, we inferred them using the closest point to the referred locality by searching it in Google Earth™.Institutional acronyms for museum collections follow those of Sabaj-Perez (2016), except for that of the herpetological reference collection of the Universidad del Quindío (ARUQ).The map was made using the open source software QGIS v. 2.18.4 (QGIS Development Team 2017).

Figure 3 .
Figure 3. Forest fragment in regeneration where the first Colombian specimen Anomalepis mexicanus was found.A. Overview.B. Detail of the interior.Photos: JG.