Scolecophis mutabilis, (Stickel 1943)

Cox, Christian L., Davis Rabosky, Alison R., Holmes, Iris A., Reyes-Velasco, Jacobo, Roelke, Corey E., Smith, Eric N., Flores-Villela, Oscar, McGuire, Jimmy A. & Campbell, Jonathan A., 2018, Synopsis and taxonomic revision of three genera in the snake tribe Sonorini, Journal of Natural History 52 (13 - 16), pp. 945-988 : 978-980

Sonora mutabilis ( Stickel 1943)

Sonora michoacanensis mutabilis Stickel 1943:116 . Holotype: The holotype is in the Field Museum of Natural History (FMNH) 105257, with paratypes FMNH 105296, British Museum of Natural History (BMNH) BMNH 1946.1.14.63–BMNH 1946.1.14.64 and American Museum of Natural History (AMNH) 19714–19716 ( Stickel 1943; Echternacht 1973). Type locality: ‘Magdalena, Jalisco’ ( Stickel 1943).

Sonora aequalis Smith and Taylor 1945:128 . Holotype: Museum of Comparative Zoology (MCZ) 6444. Type locality: Originally given as ‘Matagalpa, Nicaragua’ ( Stickel 1943), later concluded it to be ‘within or somewhat to the east of the ranges of mutabilis and michoacanensis , on the southern part of the Mexican plateau or in the surrounding mountains’ ( Stickel 1943; Echternacht 1973).

Sonora michoacanensis mutabilis Echternacht 1973:8–9

Sonora aequalis Ponce-Campos et al. 2004:144–148

Sonora mutabilis Ponce-Campos et al. 2004:144–148

Sonora mutabilis Cox et al. 2012:103

Diagnosis

This species is distinguished from Sonora cincta , S. fasciata , S. straminea , S. aemula , S. annulata , S. occipitalis , and S. palarostris by the lack of rostral or caudal adaptations. Both bicoloured and tricoloured forms of this species can be distinguished from S. michoacanensis based on complete banding on the tail.

Variation

Sonora mutabilis possesses bicoloured (red and black) and tricoloured (red, black, and yellow) morphs ( Echternacht 1973). In tricolour morphs, the extent of black interspaces between bands may be quite variable, and bands may have red dorsal or lateral inclusions. Bands may be regular, irregular, or absent ventrally. Morphological measurements and meristic characters are mostly overlapping between S. mutabilis and S. michoacanensis . The hemipenis of S. michoacanensis was described by Stickel (1943). His description was based on one specimen of S. michoacanensis and one of S. mutabilis . Cox et al. (2012) describe the hemipenis of S. mutabilis ( Figure 6 ) and compare it to that of S. michoacanensis ( Cope 1895) .

Distribution

Sonora mutabilis is found in the Mexican states of Aguascalientes, Jalisco, Nayarit, southern Zacatecas and extreme southern Sinaloa ( Figure 6 ).

Remarks

This species is in the subgenus of Eosonora with S. michoacanensis .

Figures

Figure 6. Map of the geographic distribution from IUCN and georeferenced occurrence records from GBIF (grey crosses) for the subgenus Eosonora, including Sonora mutabilis and S. michoacanensis. The top of the map has images of the bicolour (a) and tricolour (b and c) morphs of S. mutabilis. The bottom panel depicts the tricolour morphs (d and e) of S. michoacanensis that vary in the expression and number of bands. Photos by C. Grunwald (a), C. L. Cox (b), J. Reyes-Velasco (c), A. Mendoza (d) and O. Medina-Aguilar (e). Colours of shaded ranges and circular points on the map correspond to the phylogenetic tree in Figures 1 and 2.