Zoological Survey of India Discovers New Deep-Sea Skate Fish Species 'Dipturus dhritia' in the Arabian Sea
Indian marine researchers and scientists have achieved a monumental milestone in biodiversity exploration. In a collaborative scientific endeavor, researchers from the Zoological Survey of India (ZSI), working alongside the ICAR-Central Marine Fisheries Research Institute (CMFRI) and international experts, have successfully discovered and identified a brand-new species of deep-sea skate fish in the Arabian Sea off the coast of Kerala. The groundbreaking discovery was made under the ambitious Deep Ocean Mission spearheaded by the Union Ministry of Earth Sciences.
Named 'Dipturus dhritia' in Honor of ZSI's First Female Director
Formally classified under the scientific name Dipturus dhritia—and commonly referred to as the Arabian skate—this newly discovered marine species has a recorded body length of up to 131.5 centimeters. Its most distinctive physical characteristic is the presence of five distinct rows of spines running along its tail. Specimens of the fish were retrieved from extreme depths ranging between 400 and 600 meters near the Kerala coastline and the ecologically sensitive Wedge Bank region.
To establish its absolute genetic identity, scientists sequenced its entire mitochondrial genome. The molecular analysis revealed that Dipturus dhritia is genetically distinct from its closest relative, the Travancore skate (Dipturus johannesdavisi), exhibiting a genetic sequence divergence of 3.8 to 4.7 percent. Intriguingly, historical records show that for more than four decades, this species was mistakenly misidentified as Dipturus springeri, frequently getting caught inadvertently in the nets of commercial deep-sea shrimp trawlers.
The new species has been proudly named Dipturus dhritia to honor Dr. Dhriti Banerjee, the first-ever female director of the Zoological Survey of India (ZSI), which operates under the Union Ministry of Environment, Forest and Climate Change.
Deep-Sea Exploration and Conservation Significance
Reflecting on the discovery, Dr. Dhriti Banerjee emphasized that vast expanses of the deep sea remain entirely unexplored, making every marine expedition vital for expanding human understanding of aquatic ecosystems. She noted that deep-sea sharks, rays, and skates are exceptionally vulnerable to overexploitation due to their slow reproduction rates and prolonged population recovery timelines. Identifying these hidden species is a critical prerequisite for formulating targeted conservation and management frameworks.
The collaborative research team featured prominent scientists, including Dr. K.K. Binish and Anil Kasinath from ZSI, Akhilesh K.V. from CMFRI, and renowned international expert Dr. David A. Ebert from the United States. During the course of the expedition, the team also successfully mapped and documented the Kollam Slope, establishing it as a critical habitat for sharks and rays within India's Exclusive Economic Zone (EEZ). ZSI officials confirmed that taxonomic and genetic surveys targeting deep-sea marine life will continue aggressively across the Indian Ocean under the Deep Ocean Mission, paving the way for more such remarkable discoveries.
