DNA Barcode based species delineation within Freshwater Garfish Xenentodon cancila (Hamilton, 1822) (Beloniformes: Belonidae) reveals the existence of multiple lineages under single nominal taxon

Abstract

The present correspondence provides the first DNA barcode-based evidence of multiple evolutionary lineages within the freshwater garfish Xenentodon cancila across South Asia. Taxonomically validated specimens from the Ujani Reservoir, Maharashtra, India, were analyzed with 77 publicly available mt COI sequences. Phylogenetic and species delimitation analyses revealed seven distinct clades within Xenentodon, substantially exceeding the currently recognized two species. The Ujani population formed a strongly supported monophyletic cluster with sequences from India, Bangladesh, and Korea, corresponding closely to the nominal X. cancila. Other geographically structured lineages from southern, northeastern, and central India, exhibit deep genetic divergence, indicating potential undescribed taxa. These findings highlight persistent taxonomic gaps within Xenentodon and emphasize the need for integrative revision combining molecular and morphological datasets.