The New World coralsnakes are currently composed of two genera: Micrurus and Micruroides (Campbell and Lamar, 2004). Micruroides is a monotypic genus that differs from the other New World coralsnakes in having a single pair of gular shields, separated prefrontal bones, a red ring that follows the pale nuchal ring, and the presence of solid maxillary teeth situated posterior to the fangs (Roze, 1974; Campbell and Lamar, 2004; Meik et al., 2007).

The Sonoran Coralsnake, Micruroides euryxanthus (Kennicott, 1860), is the only species in the genus, and is distributed in Arizona and New Mexico, in the southwestern United States, southward into northwestern and western México, in the Mexican states of Chihuahua, Sonora, Sinaloa, Nayarit, and Jalisco (Roze, 1974; Campbell and Lamar, 2004; Woolrich-Piña et al., 2016, Bezy et al., 2017; Cruz-Sáenz et al., 2017; Ahumada-Carrillo et al., 2018). Three subspecies are currently known on the basis of lepidosis and colour pattern (Campbell and Lamar, 2004): M. euryxanthus euryxanthus Kennicott, 1860, M. euryxanthus australis Zweifel and Norris, 1955, and M. euryxanthus neglectus Roze, 1967.

Herein we present a new record of Micruroides euryxanthus for the state of Jalisco, in western Mexico. On 4 March 2017, while conducting diurnal fieldwork in the surroundings of Cocula, in central Jalisco (5 km SW of Cocula, municipality of Cocula, Jalisco; 20.3421, -103.8305, WGS-84; 1399 m), we found an adult Micruroides euryxanthus (CEZUG-R394; Fig. 1). The snake was found dead on a hillside covered by tropical deciduous forest with secondary vegetation. The body showed two injuries in the posterior region of the body; and since there are no vehicle-accessible roads on this hill, we assume that the snake was probably trampled upon by one of the cows that graze in the area.

The specimen, an adult female, measures 368.4 mm snout-vent length (SVL) and 22.9 mm tail length. Its colour pattern consists of 15 black body rings that are 5–7 dorsal scales in length plus two black tail rings; a pale nuchal ring 2–3 scales in length that does not extend onto the parietals; pale body rings 1.5 scales in length; 15 red body rings, and a total of 106 red scales along the middorsal line of the body. Although

Herpetology Notes, volume 12: 681-683 (2019) (published online on 30 June 2019)

A new southern-most record of the Sonoran Coralsnake, Micruroides euryxanthus Kennicott, 1860, (Squamata: Elapidae)

from the state of Jalisco, Mexico

Aldo Dávalos-Martínez1,*, Daniel Cruz-Sáenz1,2, Jorge A. Najar-Sánchez1, and Francisco J. Muñoz-Nolasco1,3

1 Universidad de Guadalajara, Centro Universitario de Ciencias Biológicas y Agropecuarias. Km 15.5 Carretera Guadalajara-Nogales, Predio Las Agujas, Zapopan, Jalisco, 1-1919, México.

2 Centro de Estudios en Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Zapopan, Jalisco, 1-1919, México.

3 Posgrado en Ciencias Biológicas, Laboratorio de Herpetología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, 70515, México.

* Corresponding author. E-mail: aldodavalosmartinez@gmail.com

Figure 1. Micruroides euryxanthus (CEZUG-R394) collected in the municipality of Cocula, state of Jalisco, Mexico.

Aldo Dávalos-Martínez et al.682

the specimen’s injuries on the ventral region of the body made counting scales difficult, after a thorough examination, we counted approximately 232 ventrals and 20 subcaudals. These morphological characteristics correspond to Micruroides euryxanthus neglectus (Roze, 1967; UMMZ-114637 and J.F.C. 62-65) and are consistent with the more recently found specimens of this subspecies described by Meik et al (2007; MZFC 19683) and Ahumada-Carrillo et al. (2018; ECO-CH-H-3991). The higher number of black body rings (15) of CEZUG-R394 is similar to ECO-CH-H-3991 (16), whereas this number is lower (12–13) in the rest of the known specimens.

This record extends the known distribution of Micruroides euryxanthus 81 km SW from the nearest published locality, Techaluta de Montenegro, in the municipality of San Cristobal de la Barranca (Cruz-Sáenz et al., 2008), and 195 km SE from the other published locality in Jalisco, San Miguel Huaxtita, in the municipality of Mezquitic (Ahumada-Carrillo et al., 2018). This is the southernmost record of the species and is the third published locality in the Jalisco state, in western Mexico (Fig. 2). It is worth mentioning that, according to the physiographic regionalization proposed by Cruz-Sáenz et al (2017), our record lies in the western limit of the Central Plateau of the Trans-Mexican Volcanic Belt, while the two previous records

from Jalisco (Cruz-Sáenz et al., 2008; Ahumada-Carrillo et al., 2018) were from the Sierra Madre Occidental.

The specimen has been deposited in the vertebrate collection of the Centro de Estudios en Zoología of the Universidad de Guadalajara (CEZUG-R394), under collection permit SGPA/DGVS/01205/17, granted to Fausto R. Méndez de la Cruz by the Secretaria de Medio Ambiente y Recursos Naturales. The identification was verified using the keys in Campbell and Lamar (2004) and the descriptions provided by Roze (1967; 1974).

Acknowledgments. We thank Carlos A. Guzmán Hernández for his support in the fieldwork, Fausto R. Méndez de la Cruz for providing the collection permit, and Robert L. Bezy for reviewing the manuscript.

References

Ahumada-Carrillo, I.T., Carbajal-Márquez, R.A., López-Cuellar, M.A., Weatherman, G.N. (2018): The Sonoran Coralsnake, Micruroides euryxanthus (Kennicott, 1860), in the state of Jalisco, Mexico. Mesoamerican Herpetology 5: 185–188.

Bezy, R.L., Rosen, P.C., Van Devender, T.R., Enderson, E.F. (2017): Southern distributional limits of the Sonoran Desert herpetofauna along the mainland coast of northwestern Mexico. Mesoamerican Herpetology 4: 138–167.

Campbell, J.A., Lamar, W.W. (2004): The Venomous Reptiles of the Western Hemisphere. 1st Edition. New York, USA, Comstock Pub. Associates.

Figure 2. Localities of Micruroides euryxanthus in Jalisco, Mexico.

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Meik, J.M., Smith, E.N., Mendoza-Hernández, A.A. (2007): Rediscovery of the Rare Coralsnake Micruroides euryxanthus neglectus (Serpentes: Elapidae). Herpetological Review 38: 293–294.

Roze, J.A. (1967): A check list of the New World venomous coral snakes (Elapidae), with descriptions of new forms. American Museum Novitates 2287: 1–60

Roze, J.A. (1974): Micruroides, M. euryxanthus. Catalogue of American Amphibians and Reptiles: 163.1–163.4.

Woolrich-Piña, G.A., Ponce-Campos, P., Loc-Barragán, J., Ramírez-Silva, J.P., Mata-Silva, V., Johnson, J.D., García-Padilla, E., Wilson, L.D. (2016): The herpetofauna of Nayarit, Mexico: composition, distribution, and conservation status. Mesoamerican Herpetology 3: 375–448.

Zweifel, R.G., Norris, K.S. 1955. Contribution to the herpetology of Sonora, Mexico: descriptions of new subspecies of snakes (Micruroides euryxanthus and Lampropeltis getulus) and miscellaneous collecting notes. The American Midland Naturalist 54: 230–249.

A new southern-most record of the Sonoran Coralsnake from Mexico 683

Accepted by Andrew Durso