Amero-Australian Treefrogs: Hylidae

Physical characteristics: The paradox frog, also known as the paradoxical frog, has large, bulging eyes on the top of its head and a rounded and somewhat pointed snout. It has long and powerful hind legs and shorter but still strong front legs. Its toes are webbed. Its back is light brown to greenish brown, sometimes with light-colored stripes, and its underside is white. Females grow to 1.7 to 3.2 inches (4.0 to 6.5 centimeters) from snout to rump, while males reach 1.6 to 2.7 inches (3.8 to 6.5 centimeters) in length.

This frog remains in the water most of the time, often with just its eyes poking above the surface. (R. Andrew Odum/Peter Arnold, Inc.)

Geographic range: Populations of this frog are scattered through parts of northern and central South America, from Uruguay and southern Brazil in the south to Venezuela in the north.

Habitat: It lives in grassy or open forest areas near marshes, ponds, or slow-moving creeks.

Diet: It eats water-living arthropods, as well as small frogs.

Behavior and reproduction: This frog remains in the water most of the time, often with just its eyes poking above the surface. It is mainly active at night except during its breeding season, when the males may make their loud, croaking calls at any time of night or day. Females come to the males and mate with them, laying their eggs among the plants that grow in the water. The eggs, which are grouped together in foamy clusters, hatch into tadpoles. Tadpoles continue to grow in the water and can reach lengths of 11 inches (27 centimeters) before changing into froglets. Much of the length of the tadpole is in its tail, and once that shrinks away, the froglet is much smaller.

Paradox frogs and people: Some local people eat the large tadpoles of this species.

Conservation status: The paradox frog is not considered threatened or endangered. ∎