Presence of Hexanchus vitulus (Hexanchiformes, Hechanchidae) in shallow waters off the northeastern Campeche Bank, Mexico

Resumen

Background. The Atlantic bigeye sixgill shark Hexanchus vitulus is found throughout the central Atlantic Ocean, including the Gulf of Mexico and the Caribbean Sea, and is rarely observed in the Mediterranean Sea. Objective. This paper reports the presence of a juvenile female specimen of H. vitulus in the shallow water’s northeast of the Campeche Bank, Mexico. In Mexico, records of H. vitulus are scarce. There are records from Tamaulipas, Veracruz, Tabasco, and the Campeche Sound. Methods. During a semi-industrial fishing fleet sampling campaign, carried out on May 5, 2025, in Progreso, Yucatan, the presence of a sixgill shark (H. vitulus) was recorded. Biometric data was collected from the specimen using an ichthyometer and digital scale. The captain of the vessel was interviewed, providing information about the capture of the specimen, such as: geographical location, depth, and type of bait. Results. The sixgill shark was a female measuring 101 cm in total length and weighing 2.4 kg after evisceration. It was captured with a long bottom longline with circular hooks on April 29, 2025. The capture point was approximately 139 km from Río Lagartos, Yucatán,and 55 meters deep. It represents the second shortest specimen of H. vitulus recorded in the southern Gulf of Mexico. Furthermore, this is the first record of the species in shallow waters (depths less than 80 m). Conclusion. This new record of H. vitulus in shallow waters off the northeastern Campeche Bank expands the spatial and ecological distribution of the species in the southern Gulf of Mexico.