An Integrative Taxonomic Study on Needlefishes (Belonidae) Unveils Two New Species within the Genus Ablennes from the Indian Ocean

25 Pages Posted: 16 Jan 2024

See all articles by TOJI THOMAS

TOJI THOMAS

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute

Dr E. M. Abdussamad

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute

Shijin Ameri

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute

Badarul Sijad

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute

Sajikumar K K

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute

Abstract

The needlefish genus Ablennes remains monotypic, characterized by the globally distributed flat needlefish known as Ablennes hians. Their taxonomy has been mired with ambiguities due to the greater-than-average morphological variations observed in samples from different regions. Utilizing integrated taxonomic methods relying on mitochondrial molecular markers, it was revealed that the species initially perceived as a single entity is, in fact, a complex comprising three distinct species. In this context, we introduce two new species: Ablennes joseberchmansis sp. nov. and Ablennes gracalii sp. nov., They are morphologically distinct: in view of the morphometry and meristic characteristics. A. joseberchmansis sp. nov.and A. gracalii sp. nov. display distinct differentiation characteristics from A. hians in terms of dorsal fin features, nostril position, dorsal fin origin, vertebrae count, scale counts, head length, eye diameter, interorbital width, maxilla length, dorsal ray height, depth at pelvic origin, lower lobe of the caudal fin, and caudal peduncle width. These variations highlight their unique morphological traits and aid in their differentiation within the genus Ablennes. We assessed genetic relationships using a Maximum likelihood (ML) phylogenetic tree, revealing three distinct clades of morphological differences in Ablennes specimens from different morphological groups. The genetic variation, as represented by Kimura 2 parameter (K2P) distances, within the three Ablennes species spans from 6.5% to 9.4%. More specifically, we observed a 7.5% genetic difference between A. hians and A. joseberchmansis sp. nov., and a 6.5% distinction between A. hians and A. gracalii sp. nov. The interspecies divergence between the two newly identified species measured at 9.4%. These findings, which showcase the genetic distinctions among the three morphologically distinct Ablennes specimens, provide strong confirmation for the existence of three separate species within the Ablennes genus of needlefish in the Indian Ocean.

Keywords: Needle fish, Mitochondrial DNA, New species, Bay of Bengal, Andaman Sea

Suggested Citation

THOMAS, TOJI and Abdussamad, Dr E. M. and Ameri, Shijin and Sijad, Badarul and K K, Sajikumar, An Integrative Taxonomic Study on Needlefishes (Belonidae) Unveils Two New Species within the Genus Ablennes from the Indian Ocean. Available at SSRN: https://ssrn.com/abstract=4696454 or http://dx.doi.org/10.2139/ssrn.4696454

TOJI THOMAS (Contact Author)

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute ( email )

Kerala
India

Dr E. M. Abdussamad

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute ( email )

Kerala
India

Shijin Ameri

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute ( email )

Kerala
India

Badarul Sijad

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute ( email )

Sajikumar K K

Indian Council of Agricultural Research (ICAR) - Central Marine Fisheries Research Institute ( email )

Kerala
India

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