Researchers from the Zoological Survey of India (ZSI) have described a new species of deep-sea catshark, Apristurus drona, found along the Kollam slope off the southeastern Arabian Sea, on India’s southwest coast. The slender, black-bodied shark is immediately recognisable by its striking pale, almost white eyes and an angular, pointed snout — features that set it apart from its closest relatives in the genus Apristurus, a group of poorly known deep-sea catsharks found in oceans worldwide.
Found in the bycatch of deep-sea trawlers
The specimens that led to the discovery were not collected on a dedicated expedition. They turned up as bycatch in deep-sea shrimp trawl nets operating at depths of roughly 400 to 650 metres off Kerala, with additional specimens recorded during biodiversity monitoring surveys of commercial landings at Sakthikulangara Fisheries Harbour in Kollam. Deep-sea trawl bycatch and harbour landing surveys have become an important, low-cost window into species that live far below the depths routinely sampled by research vessels, and this discovery is a direct result of that kind of systematic monitoring.
DNA barcoding and morphology, together
To confirm that the shark was in fact a species new to science rather than a variant of an already-described one, the research team combined two independent lines of evidence. Tissue samples were taken from fresh specimens for DNA barcoding, and the resulting genetic sequences were compared against those of closely related Apristurus species. The comparison showed a 5.5 to 5.7 percent genetic divergence between Apristurus drona and its nearest relative, Apristurus nayakai — comfortably above the roughly 3 percent divergence threshold conventionally used to distinguish separate shark species by DNA barcode.
That molecular signal was then checked against traditional morphological analysis: careful measurement and comparison of body proportions, fin placement, snout shape, dermal denticles, and other physical characteristics against closely related species in the genus. It was the agreement between the molecular and morphological evidence — rather than either one alone — that gave the team confidence to formally describe Apristurus drona as new. The description was published in the taxonomic journal Zootaxa, volume 5828, issue 2 (2026).
Who did the work, and who funded it
The species was described by Sweta Beura, a Senior Research Fellow, along with Bineesh K.K. and Dhriti Banerjee, all working through the Marine Biology Regional Centre (MBRC) of the Zoological Survey of India in Chennai. The underlying research was carried out under India’s Deep Ocean Mission, a government programme run by the Ministry of Earth Sciences that funds systematic exploration of the country’s deep-sea waters — including biodiversity surveys of exactly the kind that turned up this shark. The mission’s broader remit covers deep-sea mineral exploration, ocean climate services, and marine biodiversity research, and this discovery is a concrete example of that biodiversity mandate translating into a formally named new species.
Why a new shark species is still turning up in well-fished waters
India’s southwest coast, including the waters off Kerala, is among the most intensively fished stretches of coastline in the country, which might suggest its marine life is already thoroughly catalogued. Apristurus drona is a reminder that this is not the case once depth is factored in. Deep-sea habitats below a few hundred metres remain poorly sampled everywhere, including in heavily fished coastal regions, because commercial trawling and routine biodiversity surveys rarely overlap with dedicated deep-sea taxonomic expeditions. Researchers involved in the description noted that current understanding of deep-sea biodiversity along India’s coast remains limited, and that species restricted to narrow depth bands or small geographic ranges — as Apristurus drona may be — are considered data-deficient and could be vulnerable to local decline from ongoing deep-sea trawling before they are even fully studied.
Source
This account draws on the formal species description in Beura, Bineesh K.K., and Banerjee, Zootaxa 5828(2), 2026, and on reporting by Mongabay India, “Scientists identify new deep-sea shark species from India’s southwest coast” (4 August 2026).
