''Thoropa saxatilis'' is a species 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 ...

in the family

Cycloramphidae The Cycloramphidae are a family of frogs endemic to southeastern Brazil. This family has seen large changes in its composition. Genera that have at some point been included in the Cycloramphidae are at present placed in the Alsodidae, Hylodidae ...

. 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 southern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

and occurs in the Santa Catarina and

Rio Grande do Sul Rio Grande do Sul (, , ; "Great River of the South") is a Federative units of Brazil, state in the South Region, Brazil, southern region of Brazil. It is the Federative_units_of_Brazil#List, fifth-most-populous state and the List of Brazilian st ...

states, corresponding to the southernmost extent of the

Atlantic Forest The Atlantic Forest ( pt, Mata Atlântica) is a South American forest that extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the northeast to Rio Grande do Sul state in the south and inland as far as Paraguay and th ...

biome. 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 ...

' refers to its association with rocks. Common name Brazilian river frog has been coined for it.

Description

Adult males measure in snout–vent length. The snout is rounded. The tympanum is distinct and relatively large (about as large as the eye ); the prominent supratympanic fold partly hides the tympanum dorsally. Finger tips have prominent discs; those of the toes are less prominent. The thumbs have a dark cluster of spines, and fingers have II–III rows of spines. Both fingers and toes have lateral ridges but no webbing. Preserved specimens are mottled with dark and light brown or grey. The upper surfaces of the limbs are barred. The venter is cream with some brown wash. No

vocal sac The vocal sac is the flexible membrane of skin possessed by most male frogs and toads. The purpose of the vocal sac is usually as an amplification of their mating or advertisement call. The presence or development of the vocal sac is one way o ...

is present. 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 are elongated and have a depressed body and a low tail fin with rounded tip. The largest tadpoles (

Gosner stage Gosner stage is a generalized system of describing stages of embryonal and larval development in anurans (frogs and toads). The Gosner system includes 46 numbered stages, from fertilized embryo (stage 1) to the completion of metamorphosis (stage ...

39) measure in total length. The body makes about third (29–33%) of the total length.

Habitat and conservation

''Thoropa saxatilis'' occurs on rocky cliffs in forested areas 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 ...

. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

was collected on a rock near a small waterfall. Other adult males have been collected along road cuts where water was trickling over steep rock faces;

s were collected from the same habitat. The eggs are laid under waterfalls on rocks. It is a rarely collected species, and it appears to have disappeared from some localities. It can be threatened by

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 modification (alteration of water causes, sedimentation, forest loss), but it has also vanished from some areas of apparently suitable habitat.

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 ...

is a possible threat. The species is present in the

Serra Geral The Serra Geral (General Mountains) is a mountain range in southern Brazil, constituting the southern portion of the Serra do Mar system which runs along Brazil's southeastern coast. The Serra Geral runs parallel to the Atlantic coast in Santa ...

and

Aparados da Serra National Park The Aparados da Serra National Park ( pt, Parque Nacional de Aparados da Serra) is a national park located in the Serra Geral range of Rio Grande do Sul and Santa Catarina states in the south of Brazil, between 29º07’—29º15’ S and 50º0 ...

References

{{Taxonbar, from=Q2210528 saxatilis Endemic fauna of Brazil Amphibians of Brazil Amphibians described in 1988 Taxonomy articles created by Polbot Fauna of the Atlantic Forest