Husbandry and first record of captive breeding of the Asian giant river toad Phrynoidis asper

Abstract

The Asian giant river toad Phrynoidis asper is a large species of bufonid from south-east Asia that is apparently obtained by the international exotic-pet trade from wild populations. Captive breeding of this species seems not to have been documented. The donation to Chester Zoo in October 2021 of an adult group of five males and one female of this toad species provided an opportunity to study captive breeding. The specimens were maintained separated by sex until signs of reproductive condition were apparent and then they were placed together in a large breeding enclosure. This had three distinct environmental zones simulating a riverbank. Six days after mixing the sexes a large spawn mass was laid. On hatching, the tadpoles were transferred to a rearing aquarium and then, after reaching Gosner stage 42, the developing toads were transferred to terrestrial vivaria to complete development. Captive breeding of this species could replace collection from the wild.