Acanthochelys spixii, 131

Acanthochelys spixii (Duméril and Bibron 1835) –
Black Spiny-necked Turtle, Spix’s Sideneck Turtle,
Tortuga de Canaleta, Cágado do Cerrado

Thiago S. Marques¹, Andrés Estrades², Alejandro Fallabrino²,
Gabriel de F. Horta³, Thiago C.G. Portelinha⁴, André Yves⁵,
Rafael M. Valadão⁶, Mario R. Cabrera⁷,
M. Florencia David², and Priscila S. Miorando⁸

¹Laboratório de Ecologia Aplicada, Universidade de Sorocaba (UNISO),
Vila Artura, 18023-000 Sorocaba, São Paulo, Brazil [[email protected]];
²Karumbé, Centro de Tortugas Marinas, 11600 Montevideo, Uruguay [[email protected], [email protected]];
³Laboratório de Herpetologia da Universidade de Brasília, Departamento de Zoologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, 70910-900 Brasília, Distrito Federal, Brazil [[email protected]];
⁴Laboratório de Caracterização de Impactos Ambientais (LCIA), Universidade Federal do Tocantins (UFT),
Plano Diretor Norte, 77001-090 Palmas, Tocantins, Brazil [[email protected]];
⁵Programa de Pós-Graduação em Zoologia, Universidade Federal do Paraná, Curitiba,
81531-980 Curitiba, Paraná, Brazil [[email protected]];
⁶Centro Nacional de Pesquisa e Conservação de Répteis e Anfíbios, Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), 74605-090 Goiânia, Goiás, Brazil [[email protected]];
⁷Museo de Zoología, Universidad Nacional de Córdoba, and Instituto de Diversidad y Ecología Animal
(IDEA, CONICET-UNC), Córdoba, Argentina [[email protected]];
⁸Universidade Federal do Oeste do Pará, Bairro Salé, 68035-110 Santarém, Pará, Brazil [[email protected]]

Summary. – Acanthochelys spixii (family Chelidae) is a medium-sized freshwater turtle with a reasonably wide distribution in South America, including southeastern Brazil, Uruguay, and northeastern Argentina. The species inhabits diverse wetland areas in slow-moving or standing shallow water such as swamps and ponds, often with abundant submerged vegetation, showcasing adaptability to various environments. Most aspects of the ecology of A. spixii remain unknown. The diet is composed mainly of insects and some results suggest the species has a generalist habit. Activity is mainly nocturnal, but diurnal courtship and nesting events have been reported. Nesting occurs from February to May, and clutch size ranges from 4–8. Eggs are nearly round and measure 25–27 mm in length. Acanthochelys spixii has recently been assessed as globally Vulnerable on the IUCN Red List, but the scarcity of population status and life history data for the species is a limitation to proposing potential conservation measures.

Distribution. – Argentina (Corrientes), Brazil (Bahia, Distrito Federal, Goiás, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina, São Paulo), Uruguay (Rivera, Tacuarembó, Cerro Largo, Treinta y Tres, Rocha, Maldonado, Canelones).

Synonymy. – Emys depressa Spix 1824 (junior homonym, not = Emys depressa Wied-Neuwied in Merrem 1820 [= Phrynops geoffroanus]), Emys aspera Cuvier in Gray 1830 (nomen oblitum), Platemys spixii Duméril and Bibron 1835 (nomen novum), Hydraspis spixii, Acanthochelys spixii, Platemys radiolata spixii.

Subspecies. – None recognized.

Status. – IUCN Red List: Vulnerable (VU A2c+4c; assessed 2023 [in press 2025]); Near Threatened (NT, assessed 1996); Uruguay: Least Concern (LC).