Incilius pisinnus, commonly known as the Michoacan toad, is a species of true toad in the family Bufonidae. It is endemic to Mexico and is known only from the Tepalcatepec Valley in the state of Michoacán.
Taxonomy and Description
The species was formally described in 2005 by Mendelson, Williams, Sheil, and Mulcahy. Prior to its description, it was confused with Incilius coccifer and Incilius cycladen. The specific epithet pisinnus is derived from the Latin word for "small," referring to its comparatively small size among close relatives. Adult males measure 39–51 mm (1.5–2.0 in) and adult females 55–62 mm (2.2–2.4 in) in snout–vent length. The body is robust, with a pointed snout and distinct tympanum. The dorsal ground color is yellowish tan with dark brown spots and a deep yellow or cream mid-dorsal stripe. The venter is whitish cream, possibly with black flecks, and the iris is pale gold. Males possess a single, heavily pigmented vocal sac.
Habitat and Distribution
Incilius pisinnus inhabits grassy areas with mesquite shrub, rocks, and barren areas at elevations around 335 m (1,099 ft) above sea level. Males have been observed calling in muddy ditches and flooded grass fields after heavy rains. Its known range is restricted to the Tepalcatepec Valley in Michoacán, Mexico.
Conservation Status
The species is listed as Endangered on the IUCN Red List of Threatened Species (2020 assessment). Although believed to be somewhat adaptable to disturbance, severe habitat change and agricultural chemicals remain threats. It is not known to occur in any protected areas.
