TAG: GS 3: ECOLOGY AND ENVIRONMENT
THE CONTEXT: Scientists from the Zoological Survey of India (ZSI) have made a groundbreaking discovery with the identification of a new species of deep-water dogfish shark, Squalus hima.
EXPLANATION:
- This discovery, by the Marine Biology Regional Centre of ZSI, was made at the Sakthikulangara fishing harbor in Kerala, along the Arabian Sea, and has been published in the journal Records of the ZSI.
Squalus hima
- Squalus hima belongs to the genus Squalus within the family Squalidae, commonly known as spurdogs.
- These sharks are distinguished by their smooth dorsal fin spines.
- The species was previously misidentified with S. mitsukurii and S. lalannei, but detailed morphological, meristic, and morphometric evidence supports its classification as a distinct and undescribed species.
- Key differentiating characteristics of Squalus hima include:
- Number of Precaudal Vertebrae
- Total Vertebrae Count
- Teeth Count
- Trunk and Head Heights
- Fin Structure and Fin Color
- Squalus hima is similar to species in the Squalus megalops group, which are characterized by an angular short snout, a small mouth nearly as wide as the snout, the first dorsal fin origin behind the pectoral fins, and a body without spots.
Importance of the Discovery
- The identification of Squalus hima is significant due to the commercial and ecological importance of dogfish sharks.
- These species are often exploited for their liver oil, which contains high levels of squalene.
- Squalene, when processed into squalane, is highly valued in pharmaceutical industries for its use in high-end cosmetic products and anti-cancer treatments.
- Fishermen from the southern coast of India and the Andaman and Nicobar Islands harvest various shark species for this purpose.
Conservation Implications
- The discovery of Squalus hima underscores the necessity to conserve deep-sea shark species.
- Sharks from the genera Squalus and Centrophorus are targeted for their liver oil, fins, and meat, making them commercially important.
- Squalus species are sometimes incidentally caught as bycatch in fisheries aimed at other species, further threatening their populations.
- The need to conserve these species has been highlighted, emphasizing that the discovery aids in understanding the diversity and distribution of deep-sea sharks within India’s Exclusive Economic Zone (EEZ).
Exploration and Research
- The director of ZSI commended the discovery and noted that ZSI is conducting deep-sea habitat explorations at depths of 1000-3000 meters to study the species diversity of sharks and rays.
- This effort is part of the Deep Ocean Mission of the Ministry of Earth Sciences.
- Scientists teams have explored sharks and rays up to a depth of 1000 meters along India’s coastline.
- In the next phase, they aim to investigate species diversity up to 2000 meters.
Basis of Description
- The description of Squalus Hima is based on 13 specimens collected from the southwest coast of India.
- These specimens were gathered during surveys to understand the diversity and distribution of deep-sea sharks within the Indian EEZ.
- The detailed analysis and comparison with other species underscore Squalus Hima’s distinctiveness, which contributes significantly to marine biology and conservation efforts.
