''Rheohyla'' is a genus of

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

s in the family

Hylidae Hylidae is a wide-ranging family of frogs commonly referred to as "tree frogs and their allies". However, the hylids include a diversity of frog species, many of which do not live in trees, but are terrestrial or semiaquatic. Taxonomy and s ...

. As currently recognized, it is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

, containing only ''Rheohyla miotympanum'', also known as the small-eared hyla or small-eared treefrog. However, the nominal species likely is a complex of more than one species. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to eastern and central Mexico. The generic name refers to streams, the breeding habitat of this frog (from Greek meaning 'stream' combined with ''

Hylas In classical mythology, Hylas () was a youth who served as Heracles's (Roman Hercules) companion and servant. His abduction by water nymphs was a theme of ancient art, and has been an enduring subject for Western art in the classical tradition. ...

''). The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

is derived from Greek , a diminutive prefix, together with Greek (='drum') and refers to the small tympanum.

Taxonomy

This genus was erected in 2016 to accommodate former ''Ecnomiohyla miotympanum''; AmphibiaWeb still uses this earlier classification. Faivovich and colleagues argued in 2018 that splitting ''Rheohyla miotympanum'' from ''

Ecnomiohyla ''Ecnomiohyla'', commonly known as fringe-limbed treefrogs or marvelous frogs, is a genus of frogs in the family Hylidae. This genus was erected in 2005 following a major revision of Hylidae. The ten original species in this genus (''E. rabborum ...

'' was not necessary on the grounds of obtaining

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

''Ecnomiohyla'', but is nevertheless convenient because it allows associating ''Ecnomiohyla'' with several putative phenotypic

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

, which ''Rheohyla miotympanum'' lacks. There is no phenotypic

autapomorphy In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

defining ''Rheohyla''.

Description

Males can grow up to and females to in

snout–vent length Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent)."direct line distance from tip of snout to posterior margin of vent" It is the most c ...

. The tympanum is distinct but dorsally obscured by the well-develop supratympanic fold. The fingers are about one-third webbed while the toes are about three-fourths webbed. Dorsal skin is smooth. Coloration is dorsally pale green and ventrally creamy white. The

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

s have a relatively small oral disc.

Habitat and conservation

''Rheohyla miotympanum'' inhabits a variety of habitats and vegetation zones in the

Sierra Madre Oriental The Sierra Madre Oriental () is a mountain range in northeastern Mexico. The Sierra Madre Oriental is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that f ...

Sierra Madre de Oaxaca The Sierra Madre de Oaxaca is a mountain range in southern Mexico. It is primarily in the state of Oaxaca, and extends north into the states of Puebla and Veracruz. Geography The mountain range begins at Pico de Orizaba, and extends in a southeas ...

, and

Sierra de los Tuxtlas The Sierra de Los Tuxtlas (Tuxtlas Mountains) are a volcanic belt and mountain range along the southeastern Veracruz Gulf coast in Eastern Mexico. The Los Tuxtlas Biosphere Reserve (Biósfera Los Tuxtlas) includes the coastal and higher elevations ...

at elevations of

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

. It is often associated with

bromeliad The Bromeliaceae (the bromeliads) are a family of monocot flowering plants of about 80 genera and 3700 known species, native mainly to the tropical Americas, with several species found in the American subtropics and one in tropical west Africa, ...

s or elephant-ear plants, but can also be found on the ground, in bushes, or on small plants. Reproduction takes place in streams and ponds, in contrast to ''Ecnomiohyla'' that breed in tree holes and ''

Charadrahyla ''Charadrahyla'' is a genus of frogs in the family Hylidae. It is endemic to tropical southern Mexico. The generic name was derived from Greek ''charadra'' ("ravine") and ''Hyla'', in reference to the habits of these frogs. Accordingly, common na ...

'', '' Plectrohyla'', and '' Sarcohyla'' that breed in cascading streams.

Amplexus Amplexus (Latin "embrace") is a type of mating behavior exhibited by some externally fertilizing species (chiefly amphibians and horseshoe crabs) in which a male grasps a female with his front legs as part of the mating process, and at the same ...

between ''Rheohyla miotympanum'' and '' Charadrahyla taeniopus'' has nevertheless been observed. ''Rheohyla miotympanum'' is a fairly common species. Although the overall population is estimated to be stable, this species is facing some threats, most importantly

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

and degradation caused by small-scale agricultural development and logging. Other potential threats are collecting for human consumption, pet trade,

chytridiomycosis Chytridiomycosis ( ) is an infectious disease in amphibians, caused by the chytrid fungi ''Batrachochytrium dendrobatidis'' and ''Batrachochytrium salamandrivorans''. Chytridiomycosis has been linked to dramatic population declines or extincti ...

, and pesticides. Its range includes several protected areas.

References

{{Taxonbar, from=Q28098129, from2=Q4680170 Hylinae Monotypic amphibian genera Endemic amphibians of Mexico Taxa named by William Edward Duellman Taxa named by Stephen Blair Hedges Fauna of the Sierra Madre Oriental Fauna of the Sierra Madre de Oaxaca Fauna of Los Tuxtlas