A comprehensive overview of evolutionary relationships and geographic distributions of cownose rays: more valid taxa needing protective measures

Rays of the family Rhinopteridae Jordan & Evermann, 1896 are highly migratory and widely distributed in warm tropical and temperate waters. Along the Brazilian coast, the presence of two species has been recorded: Rhinoptera bonasus Mitchill, 1815 and Rhinoptera brasiliensis Müller, 1836. These sting- rays are commonly caught as bycatch in trawl fisher - ies, however, the two species lack distinctive external morphological features that allow for reliable differ - entiation—species identification is primarily based on the shape and arrangement of teeth in the buccal plates. This study aimed to investigate the evolutionary history of the genus Rhinoptera and to explore which evolutionary drivers, such as biogeographic events or behavioral traits, have influenced its diversification. To achieve this, we analyzed both mitochondrial and nuclear genetic markers, focusing on the species occur- ring along the Brazilian coast. Specimens of both spe- cies were collected across various locations in Brazil, and additional sequences from other Rhinoptera species were obtained from GenBank. Our results reveal the presence of multiple cryptic species within Rhinoptera, particularly within R. bonasus, and likely in Rhinoptera Supplementary Information The online version contains supplementary material available at https:// doi. org/ 10. 1007/ s11160- 026- 10038-3. Y. T. C. Cunha · L. G. Pereira da Silva · J. S. Ready · J. B. L. Sales (*) Integrated Biological Research Group (GIBI), Center for Advanced Biodiversity Studies., Federal University of Pará, Av. Perimetral 01, PCT-Guamá, Terrain 11, Belém, PA CEP: 66075-750, Brazil e-mail: braullio@ufpa.br R. D. Leite · N. Wosnick Associação Mar Brasil, Pontal Do Paraná, Paraná, Brazil V. P. Cruz Laboratory of Fish Biology and Genetics, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil J. L. S. Nunes Laboratory of Aquatic Organisms, Department of Oceanography and Limnology, Federal University of Maranhão, Avenida Portugueses, 1968, Bacanga, São Luis, Maranhão 65080-805, Brazil M. M. Rotundo Graduate and Postgraduate in Marine Biology (Biodiversity), Zoological Collection at Santa Cecília University (AZUSC), Santa Cecília University, Oswaldo Cruz Street, Boqueirão, Santos, SP 11045‐307, Brazil P. Palacios-Barreto SQUALUS, Fundación Colombiana Para La Investigación y Conservación de Tiburones y Rayas, Cali, Colombia P. Diaz-Jaimes Unidad Académica de Ecología y Biodiversidad Acuática, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico A. P. B. Martins South Australian Research and Development Institute, Adelaide, South Australia, Australia Rev Fish Biol Fisheries (2026) 36:37 37 Page 2 of 26 Vol:. (1234567890) steindachneri Evermann & Jenkins, 1891 and Rhinoptera javanica Müller & Henle, 1841. Notably, R. bonasus does not occur in Brazilian waters nor in parts of the Caribbean where a distinct cryptic sister lineage was identified. Based on our findings, we propose the resurrection of Rhinoptera lalandii Müller & Henle, 1841 as the species representing the lineage found along the Brazilian coast and the Eastern Atlantic Ocean. We suggest that philopatric behavior may represent one of several factors potentially influencing diversification within Rhinopteridae, although this hypothesis requires direct behavioral and population level validation. These findings highlight the urgent need for a comprehensive taxonomic revision of the family, as well as a reassessment of current conservation strategies to better reflect the hidden diversity within this group of species. Graphical abstract