Goliath frog  (Conraua goliath)

The massive goliath frog, as its name alludes, is the largest frog in the world with individuals weighing over three kilograms (2). The granular skin is greenish in colour with a yellowish-orange underside, and the feet and hands are webbed (3).

Found in a narrow range in Equatorial Guinea and Cameroon, south from the basin of the Sanaga River to the Benito, Wolo and Mbini Rivers (3).

Inhabits fast-flowing rainforest rivers and cascades, which have sandy bottoms and rocks covered with Dicraea warmingii warmingii, the primary food source for the goliath frog tadpoles (3).

Unlike most other frogs and toads, goliath frogs have no vocal sac and therefore courtship does not involve displaying any calls (2). Females lay large clutches of several hundred eggs onto vegetation on the river bottom (3). Once the tadpoles hatch they feed on the food plant, which is only located near to waterfalls and rapids (2). It takes around 85 to 95 days for complete metamorphosis into the adult form (3). Adults feed on insects, crustaceans and fish (2).

Much of the dense rainforest of the goliath frog's habitat has been deforested for timber and to make way for agriculture. The construction of dams also threatens the breeding habitat of these frogs and this species is particularly vulnerable to habitat alteration due to its highly restricted range (2). Additionally, goliath frogs are considered a delicacy and are collected by local people for food (3); their large size has also encouraged collection for the pet trade in the past (2).

The goliath frog is not currently protected under any trade restrictions and collection continues to threaten remaining populations. Captive breeding programmes have not proven successful and the only method of effectively preserving this amphibious giant is to safeguard areas of remaining habitat (2).

For more information on the goliath frog see:

• Amphibia Web:
  www.amphibiaweb.org

Authenticated (28/7/03) by Andrew Gray. Curator of Herpetology, University of Manchester.