A confirmed occurrence of Sphyrna tudes (Valenciennes, 1822) after more than 150 years in the state of Rio de Janeiro, Southeastern Brazil

This study documents a confirmed occurrence of the small-eye hammerhead shark Sphyrna tudes in the state of Rio de Janeiro, southeastern Brazil. The specimen was a female of about 1.0 m in total length, collected by artisanal fishers using a nylon monofilament gillnet (no. 50 twine) with a 60-mm stretched mesh size at depths of 5–80 m on the continental shelf, approximately 4 miles off Tamoios, Cabo Frio. Classified as Critically Endangered, S. tudes has a discontinuous distribution in the western Atlantic and is rarely recorded in Brazil south of Espírito Santo. The present record represents the first confirmed record from Rio de Janeiro state in more than 150 years, extending knowledge of its current distribution and providing relevant information for conservation and management efforts.