Thoropa is a genus of frogs in the family Cycloramphidae.[1][2] They are endemic to eastern and southeastern Brazil. They are sometimes known as river frogs.[1]
Thoropa are associated with rocks and have cryptic coloration. Their size ranges from small to medium, 28–102 mm (1.1–4.0 in) in snout–vent length.[3] They occur at elevations up to 1,500 m (4,900 ft) above sea level;[3] Thoropa miliaris and Thoropa taophora can even live on rocky marine shores, foraging in the intertidal zone.[4][5] Male Thoropa are associated with wet rock faces, whereas the females seem to range more widely.[6]
In species where reproduction is known, males are territorial—suitable wet rock faces are a scarce resource. Furthermore, mature male Thoropa feature characteristic clusters of dark spines on the inner portions of the hand. It appears that these are associated with male-male combat, probably in conjunction with territorial disputes. Scratch marks in males, but not in females, support this interpretation.[6]
The eggs are laid on rocks with a thin layer of water. Tadpoles are semiterrestrial and have a depressed shape, long tail, and bulging eyes.[3]
Male T. taophora frogs mate exclusively and repeatedly with two females per season in a polygynous system in which the semiterrestrial tadpoles from both females share the same freshwater seep.[7] The females have a dominance hierarchy, and the males mate more with the dominant female.[7]