Bridging the gap: Seven new distributional records from the west coast of India with phylogenetic reconstruction of the Indian deep-sea Ophidiiformes

Abstract

The Ophidiiformes are known for vast depth range and cryptic appearances, which poses a formidable identification challenge based solely on traditional meristic and morphological characters. A comprehensive integrated taxonomic approach of 19 Ophidiiform species from the west coast of India is presented here and also documented are the first records of Ophidion smithi; Pycnocraspedum squamipinne; Neobythites analis; Neobythites fasciatus; Neobythites stefanovi; Grammonus robustus and Saccogaster maculata in the region. This study confirms the presence of Dicrolene introniger in Indian waters, previously regarded as doubtful. The majority of the species collected in the study belonged to the Ophidiidae family. The genetic analyses suggest a close kinship between the species Neobythites stefanovi and Neobythites steatiticus (3.4 %) while Pycnocraspedum squamipinne and Glyptophidium oceanium emerge as the most distinctly divergent pair (39.4 %). The phylogenetic reconstruction revealed that Ophidiiformes form a monophyletic arrangement. Among the five families observed in the study, Ophidiidae family exhibited a monophyly while Bythitidae and Dinematichthyidae resolved as sister taxa. This study advocates for further comprehensive research on Indian deep-sea fishes to explore deep-sea fisheries and sustainable utilization of these often-overlooked fishery resources.