Six new non-native turtles in Portugal: A growing threat apart from the Red-Eared slider and Chinese stripe-necked turtle

By

Rato, João
Silva, Maria
Catarrinho, Tatiana
Filipe, Rúben
Matthys, Shaquille
Brandão, Pedro
Anastacio, Pedro
Banha, Filipe

Type

Article

Date of Publication

2026-1-7

Original Publication

Herpetozoa

Volume

39

Pages

1--5

Subjects

Alien species , Graptemys pseudogeographica , introductions , Mauremys sinensis , nesting , pet trade

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/herpetozoa.39.e167762

 

Abstract

<br> We report the first records of non-native freshwater turtles in Portugal, highlighting the growing diversity of species introduced in addition to the known<br> Trachemys scripta<br> and<br> Mauremys sinensis<br> . In 2024 and 2025, we surveyed 39 sites across Portugal and confirmed the presence of seven non-native species at seven sites. While<br> T. scripta<br> remained the most frequently recorded species (n = 68),<br> M. sinensis<br> ,<br> Graptemys pseudogeographica<br> and different species of<br> Pseudemys<br> , were also captured, especially in Lisbon and Sintra. Remarkably, a high number of<br> M. sinensis<br> juveniles (n = 12) were captured, which could be explained by reproduction in nature. Notably, we documented the first evidence of nesting behaviour by<br> G. pseudogeographica<br> in Sintra, indicating the potential for this species’ establishment in the wild. These findings suggest that both illegal and legal non-native turtle pets are being released into Portuguese ecosystems. Our results highlight the need for broader preventative measures, as other introduced species may follow similar invasion pathways with unknown ecological impacts.<br>