Establishment risk and potential invasiveness of the selected exotic amphibians from pet trade in the European Union

Abstract

The pet trade has grown in recent years and become the most important pathway for the introduction of non-indigenous species of amphibians and reptiles worldwide. Amphibians traded on the pet market have been widely overlooked in systematic invasion studies, so their establishment potential and invasion dynamics remain poorly understood, despite the fact that the impact of invaders from this taxonomic group on native biota may be considerable. The determination of the most common species of amphibians traded as pets was based on a survey of the market in the Czech Republic, which is an export hub for ornamental aquatic animals into the European Union (EU). Subsequently, the establishment potential of the most common species for EU was determined using a proven risk assessment model. Amphibians that scored higher than the established species Xenopus laevis were additionally evaluated for their invasion potential using the Amphibian Invasiveness Screening Kit (AmphISK).Sixteen species of amphibians in pet market (14 Anura, 2Caudata) have an establishment potential in the EU. However, none of these species have reached the invasion potential score of already spreading species X. laevis and Lithobates catesbeianus. The species closest to the threshold value were Lithobates pipiens and Pelophylax saharicus. Amphibians represent a rather small group within all traded animals but this fact should not lead us to an underestimation of their potential invasiveness.