Dipturus dhritiae
Why in News?
Dipturus dhritiae is in the news because scientists recently discovered and described it as a new species of deep-sea skate (commonly called the Arabian Skate) in the southeastern Arabian Sea off India's southwestern coast.
Discovery & Research Details
- Collaborative Effort: Discovered by Zoological Survey of India (ZSI) scientists alongside experts from the ICAR-Central Marine Fisheries Research Institute (CMFRI) and international researchers.
- Deep Ocean Mission: Found during exploratory investigations under the Ministry of Earth Sciences' flagship project, "Deep-Sea Chondrichthyans of India: Taxonomy, Distribution, Biology and Current Status".
- Historical Misidentification: The species went unidentified for over 40 years, frequently caught as accidental bycatch in commercial shrimp trawls and mistaken for Dipturus springeri.
- Genetic Confirmation: Full mitochondrial genome sequencing verified a 3.8%–4.7% genetic divergence from its closest relative, the Travancore Skate (Dipturus johannisdavisi).
Biological & Morphological Features
- Physical Structure: A flat, shark-related fish adapted to live on the dark ocean bed.
- Maximum Size: Can grow up to a length of 131.5 cm (approximately 1.3 metres).
- Distinct Feature: Easily identified by five distinct rows of thorn-like structures running along its tail.
Habitat & Geographical Range
- Depth Range: Inhabits deep waters at depths between 400 to 600 metres.
- Key Locations: Collected primarily off the Kerala coast and the Wadge Bank region.
- Critical Mapping: Its discovery helped researchers map the Kollam Slope Important Shark and Ray Area (ISRA) inside the Indian Exclusive Economic Zone.
- Naming: Named in honour of Dr. Dhriti Banerjee, the first woman Director of the Zoological Survey of India (ZSI), recognizing her leadership in biodiversity studies.
- High Vulnerability: Like most deep-sea skates, Dipturus dhritiae has a slow reproduction rate, low offspring counts, and slow population recovery, making it highly vulnerable to overfishing and commercial trawling.
