Leptodactylid Frogs: Leptodactylidae

Physical characteristics: The Rock River frog has a typical frog shape: long hind legs with long toes, shorter front legs and toes, and a slender body and head with large, bulging eyes. The toes on its unwebbed front and back feet end in slightly widened tips. Eardrums show on each side of its rather wide head, just behind the rust-colored eyes. The frog is tan to reddish brown on its head, back, and legs, often with a noticeable dark stripe on each side of the body and running from almost the tip of the rounded snout to the start of the back leg. Its hind legs have dark brown to black bands. Its front legs have less banding. Its belly is gray, and it has a yellowish color at the The Rock River frog lives in warm and moist forests, especially along streams. (Photograph from the Kansas University Natural History Museum. Reproduced by permission.) tops of its hind legs. Males and females usually look alike, but in the breeding season, the males develop tiny spines on three of the front toes on each foot. Males are also slightly smaller than females. Females grow to 3.2 inches (8.1 centimeters) long from snout to rump, while males reach 2.8 inches (7.1 centimeters) in length.

Geographic range: It lives in a small area of southeastern Brazil near the Atlantic coast.

Habitat: It lives in warm and moist forests, especially along streams.

Diet: The Rock River frog probably eats arthropods, as do many of the other species in this family.

Behavior and reproduction: The Rock River frog becomes active at night, when it hops about on land looking for food. In the breeding season, the males climb onto streamside rocks and call. When females follow the calls to the males, they mate, and the females lay their eggs in the water. The eggs hatch into tadpoles, which use their long, strong tails to swim to the shoreline and up onto wet rocks.

Rock River frogs and people: People rarely see this species. It is not common in the pet trade.

Conservation status: The IUCN does not consider this species to be at risk, but it does live in areas where the habitat may disappear due to the cutting of trees and plants and the construction of buildings and dams. Scientists are also watching it to see whether a fungus that is killing off many different types of frogs worldwide may affect this species, too. ∎