Ictalurus nazas sp. nov., a new species of North American catfish (Siluriformes, Ictaluridae) from Mexico

Catfishes of the genus <i>Ictalurus</i> (Ictaluridae) range geographically from southern Canada to northern Guatemala and Belize. The systematics of this genus remain unresolved, with recent studies suggesting the presence of cryptic diversity. This is the case for a potentially undescribed catfish species distributed in the Nazas River basin, which has been recorded to date as a population of <i>Ictaluruspricei</i>. Recent phylogenetic studies suggest that it represents an independently evolving lineage that is distinct from <i>I.pricei</i>. This study aimed to determine the diagnostic characters that differentiate the Nazas River basin lineage and to describe this lineage as a new taxon. Morphological comparisons were made using meristic and morphometric characters. The study identified useful meristic and morphometric characters for diagnosing <i>Ictalurusnazas</i> <b>sp. nov.</b>, which differentiate it from <i>I.pricei</i>.