First report of hybridization between <em>Mauremys leprosa</em> and <em>Mauremys sinensis</em> highlights the risk of exotic <em>Mauremys</em> spp. pet trade
The global exponential growth in the number of exotic turtle species exploited in the pet trade market facilitates hybridization events between distantly related species. The 1997 EU trade ban on red-eared slider turtles (Trachemys scripta elegans), followed by the Spanish ban on all T. scripta subspecies in 2011, resulted in the importation of other chelonians (e.g. Graptemys spp., Pseudemys spp., Mauremys spp.), mainly from America and Asia to Spain. The importation of the Chinese stripe-necked pond turtle, Mauremys sinensis, via the pet trade market resulted in its release into natural environments across Europe, including the Iberian Peninsula where it co-occurs with the Western Mediterranean pond turtle, Mauremys leprosa. We maintained three M. leprosa females and two M. sinensis males in captivity, and analysed the obtained offspring (two hatchlings) with mitochondrial (cytochrome b) and nuclear (R35) genetic markers. Both morphological (i.e. with intermediate morphological characters) and genetic (heterozygous hatchlings) results confirmed the hybridization between these two species and raise concern about the negative effects of acclimatised Mauremys sinensis across the Mauremys leprosa range.