Large larvae. Vallei van de Grote Nete (België), 5 august 2008. Photo Annemarie van Diepenbeek.
The American bullfrog Rana catesbeiana has been found in the Netherlands several times. At at least three locations reproduction took place: in a garden pond in Breda (1989-1991) and in two outdoor terrariums in the province of Limburg (at least until 2003). Many reports are not detailed and mistakes have been made, misidentifying large water frog larvae and loud calling water frogs; especially marsh frogs Rana ridibunda. The species is present in some large populations in Belgium, only a few kilometres from the Dutch-Belgian border, south of the province of Noord-Brabant. It is likely that colonisation of sites in the Netherlands will take place in the near future.
Records in the Netherlands. Source: RAVON.
Because of the potential threat to European fauna and flora import of American bullfrogs into the European Union has been prohibited (EU-decree 338/97/EC). In some European countries campaigns to exterminate the species have been carried out. The Breda population has been exterminated successfully.
American bullfrogs can function as vector for Batrachochytrium dendrobatidis (chytrid fungus), causing mass mortality amongst many amphibian species. RAVON and the Ghent University (Belgium) investigated the presence of chytrid fungus in Belgian bullfrog populations. The fungus turned out to be present; the first outdoor record of chytrid fungus in Belgium.
Delft, J.J.C.W. van, Veenvliet, P.