Detailed Taxonomic Description and Molecular Confirmation of Thryssa encrasicholoides (Clupeiformes: Engraulidae) From the Andaman Islands

We provide a detailed taxonomic description of Thryssa encrasicholoides based on five specimens collected from the Andaman Islands, India. The species taxonomic status and distribution have historically been misinterpreted across the Indo-West Pacific due to close similarities with T. baelama, leading to frequent misidentification. To address this, we performed comprehensive morphological and molecular analyses, targeting the COI gene, to confirm the identity of T. encrasicholoides. A 594 bp long sequence was obtained and submitted to GenBank (Accession Number: PV936664). The COI sequence showed high similarity to T. encrasicholoides sequences available in the NCBI database. The Neighbour-Joining (NJ) phylogenetic tree revealed that the Andaman isolate clustered in a distinct clade with conspecific sequences from GenBank, thereby confirming its identity. Although T. encrasicholoides closely resembles T. baelama in having fewer prepelvic scutes and a short upper jaw, it can be distinguished by the presence of weakly developed scutes just behind the isthmus and a blunt posterior tip of the maxilla. By integrating morphological and molecular data, this study clarifies species boundaries, resolves taxonomic ambiguities in Indian marine fishes, and strengthens regional biodiversity records for better conservation and management.