Rheohyla, Duellman, William E., Marion, Angela B. & Hedges, Blair, 2016

Duellman, William E., Marion, Angela B. & Hedges, Blair, 2016, Phylogenetics, classification, and biogeography of the treefrogs (Amphibia: Anura: Arboranae), Zootaxa 4104 (1), pp. 1-109 : 19-20

Rheohyla new genus

Rheohyla . Type species: Hyla miotympanum Cope, 1863:47 .

Definition. Medium-sized treefrog (SVL in females to 51 mm) with smooth skin on dorsum, fingers about onethird webbed and toes about three-fourths webbed. Dermal fringes absent on outer edges of forelimbs and feet; prepollex not enlarged ( Fig. 7A ). Tadpoles being generalized stream inhabitants with a LTRF 2/3.

Content. Monotypic; Rheohyla miotympanum new combination.

Distribution. Eastern Mexico—Cloud forests at elevations of 1000–2800 m on the Atlantic slopes of the Sierra Madre Oriental; disjunct populations in Sierra de Los Tuxtlas and on the northern slopes of the highlands of Chiapas.

Etymology. The generic name is a combination of the Greek rheos meaning stream and Hylas of Greek mythology. The name refers to the breeding site of the species. The gender is feminine.

Remarks. The molecular phylogenetic tree produced by Faivovich et al. (2005) contained one clade with two taxa— Hyla miotympanum and H. miliaria (Cope) ; they recognized this clade as a new genus Ecnomiohyla . However, these authors noted the morphological differences between the species, a factor emphasized by Mendelson et al. (2008), who eliminated E. miotympanum from their discussion of species of Ecnomiohyla . The analysis of the 16S rRNA gene by Batista et al. (2014) resulted in a tree with seven species of Ecnomiohyla with E. miotympanum well separated from the other species. In our tree ( Fig. 4 ) there are three species of Ecnomiohyla plus a well-supported (87%) long branch to Rheohyla miotympanum . In contrast to the canopy-dwelling species of Ecnomiohyla that breeds in tree holes, the sister genus, Rheohyla , breeds in comparatively slow moving streams, whereas members of the genera Charadrohyla, Plectrohyla , and Sarcohyla breed in cascading streams. The tadpoles of Rheohyla do not have enlarged ventral mouths, whereas species in the other three genera have tadpoles with enlarged ventral mouths with multiple rows of labial papillae.

Figures

FIGURE 4. Maximum likelihood phylogeny of arboranan frogs based on DNA sequence data from 19 genes (16,128 aligned sites). The tree is rooted with Ceuthomantis smaragdinus, Dendrobates auratus, Haddadus binotatus, and Rhinoderma darwinii (not shown). Bootstrap support values are indicated at nodes.

FIGURE 7. A. Rheohyla miotympanum, KU 100965. Salto Cola de Caballo, 710 m, Nuevo León, Mexico. B. Ecnomiohyla miliaria, KU 101610, Finca Santa Clara, 1200 m, Chiriquí, Panama. Both by W. E. Duellman.