Bell's False Brook Salamander

Pseudoeurycea bellii is the largest of the lungless salamanders (family Plethodontidae) and one of the largest terrestrial salamanders, with a maximum size of 36 cm in total length. Pseudoeurycea bellii has a stout body, long, muscular limbs, and a long tail, constricted at the base. The tongue is projectile. This salamander has shiny dark black skin with two red to red-orange spots on the occipital area (back of the head) generally present. The subspecies P. b. bellii has a dorsal mark in the shape of a chevron, generally followed by paired rows of red to red-orange spots (sometimes joined into chevrons) running along the back, down to the base of the tail. In contrast, the subspecies P. b. sierraoccidentalis (found in northern Mexico, in an area straddling the border of Sonora and Chihuahua) has greatly reduced reddish coloration, with asymmetric and irregular small dorsal markings (Parra-Olea et al. 2005).This species can be distinguished from P. boneti by having a smaller amount of reddish coloration: P. bellii usually has paired rows of dorsal markings (vs. fused into large chevrons, often interconnected, in P. boneti) and lacks a pair of large scapular spots (vs. present, lateral to the row of chevrons and often connected to them in P. boneti); it can be distinguished from P. maxima by having a narrower head and shorter limbs, having a greater amount of reddish coloration (a conjoined occipital spot, which is absent in P. maxima, and larger dorsal spots, vs. smaller dorsal dots in P. maxima); from P. naucampatepetl by having dark red or orange coloration (pale pinkish in P. naucampatepetl), lack of a triangular shoulder spot (present in P. naucampatepetl) and lack of a broad U-shaped spot posterior to the insertion of the hindlimb (present in P. naucampatepetl); from P. gigantea by the presence of large red occipital spots (generally absent in P. gigantea) and a preference for drier habitat (vs. wetter forests and cloudforests for P. gigantea) (Parra-Olea et al. 2005).This species was first described by Gray (1850), as Spelerpes bellii. Two subspecies were recognized by Lowe et al. (1968): P. b. sierraoccidentalis (straddling the border of Sonora and Chihuahua in northern Mexico) and P. b. bellii (in central Mexico, with isolated populations ranging from the Sierra Madre Oriental in the state of Tamaulipas to the Sierra Madre Occidental in Nayarit and Zacatecas and central Guerrero). It is part of a species complex; Oaxacan populations have been placed into the resurrected species P. boneti (eastern and northern Oaxaca) and into the new species P. maxima (Putla area, western Oaxaca) by Parra-Olea et al. (2005). Populations in Tamaulipas differ in color and morphology and some may represent yet another cryptic species in this complex (Parra-Olea et al. 2005; Alvarez and Martín 1967).

Pseudoeurycea bellii is endemic to Mexico. Two subspecies are recognized; P. b. sierraoccidentalis occurs in a region straddling the border between the states of Sonora and Chihuahua (Lowe et al. 1968; Tanner 1989), while P. b. bellii is found mainly in central Mexico along the southern and western margins of the Mexican plateau (Parra-Olea et al. 2005; Stuart et al. 2008). The range of the subspecies P. b. bellii includes the Sierra Madre Occidental (Jalisco, Michoacán, Nayarit, Zacatecas), the Sierra Madre Oriental (Guanajuato, Hidalgo, Queretero, San Luis Potosí, Tamaulipas), the Trans-Mexican Volcanic Belt (Distrito Federal, México, Morelos, Puebla, Tlaxcala), and the Sierra Madre del Sur (Guerrero) (Parra-Olea et al. 2005), in addition to the Sierra Fría (Aguascalientes; Sigala-Rodríguez and Greene 2009). Although P. bellii was reported to occur in Arizona by Dunn (1926), the specimens have been lost and this report has never been confirmed (Bezy et al. 2004; Parra-Olea et al. 2005). P. bellii is found at elevations ranging from 750-3,300 m above sea level (Parra-Olea et al. 2005). The habitat is pine forest and pine-oak forest (both inside the forest and at forest edges), as well as more disturbed areas such as coffee plantations, rural gardens, grazed areas, and degraded forest (Parra-Olea 2005).This species is strictly terrestrial (Parra-Olea et al. 2005). Juveniles and subadults are generally found under logs and rocks in the woods; adults also make use of burrows, as well as holes in road banks (Parra-Olea et al. 2005). Individuals can also be found under brush piles or in leaf litter (Stuart et al. 2008).

This salamander is terrestrial and nocturnal (Wake 2003). The diet consists mainly of insects (Wake 2003). Females lay clutches of at least 20 large eggs; four clutches from Michoacán were described by Duellman (1961). It is thought to reproduce by direct development (Stuart et al. 2008). Artificially induced courtship was described for a pair of salamanders collected from Tejocotes, Oaxaca; although these were referred to as P. bellii by the authors (Salthe and Salthe 1964), it is likely from the locality that these were actually P. maxima.

Pseudoeurycea bellii was once common but has declined in recent years. The decline is somewhat enigmatic as this species is able to tolerate some habitat degradation; it has been found in coffee plantations, rural gardens, grazed areas, and degraded forest, and near urbanized areas (Stuart et al. 2008). Deforestation is a threat, as forests are cleared for farming, urbanization, and logging (Stuart et al. 2008). P. bellii occurs in a number of protected areas, including the Reserva de la Biosfera Sierra Gorda in Queretero; it was noted as the most common salamander in this reserve as of 2000 (Gillingwater and Patrikeev 2004).

Isthmura bellii, commonly known as Bell's false brook salamander or Bell's salamander, is a species of salamander in the family Plethodontidae. It is endemic to Mexico and occurs mostly along the western and southern margins of the Mexican Plateau, with isolated populations elsewhere.