Cartilaginous fishes (Class Chondrichthyes) include sharks, rays, skates, sawfish and chimaeras. These are ancient creatures, having survived on the Earth for hundreds of millions of years. They might have escaped the vagaries of nature but not the persecution of man. With the soaring demand for shark fins and the availability of technology (ships, radars, nets) to obtain it, they are facing the threat of extinction at the hands of ruthless fishing fleets.
An assessment report issued by the IUCN Species Survival Commission Shark Specialist Group for the Arabian Seas Region (ASR) states that three chondrichthyan species – the Pondicherry Shark (Carcharhinus hemiodon), the Red Sea Torpedo (Torpedo sinuspersici) and the Tentacled Butterfly Ray (Gymnura tentaculata) might have gone extinct in the zone (that covers the north western half of the Indian Ocean – the Red Sea, the Gulf of Aden, the Sea of Oman, the Persian Gulf and the Arabian Sea).
The Pondicherry Shark (Carcharhinus hemiodon) is an extremely rare shark of the family Carcharhinidae (that includes the likes of the Tiger, Silvertip, Bull, Blacktip Reef, Oceanic Whitetip, Dusky and Lemon Sharks). Unlike many of them, it is small in size. Only a handful of specimens were ever caught and examined after its description by two German biologists – Johannes Müller and Jakob Henle in their 1839 ‘Systematische Beschreibung der Plagiostomen’. Next to nothing is known of its life history. An inhabitant of the warm waters of the continental shelf, it was last seen in India in 1979.
Müller and Henle had obtained their specimens from the region around Puducherry (or Pondicherry, as it was known to the French who colonized it), a coastal enclave on the shores of the Bay of Bengal surrounded by the present day state of Tamil Nadu. Hence, the name. The Pondicherry Shark has been known to travel inland, into rivers whose low salinity would keep away most sharks (which would make it similar to the far larger, widely known, and much more dangerous Bull Shark). In fact, the last few sightings of the species are from a river in south-eastern Sri Lanka, the Menik. Given below is an excerpt from an English newspaper of South India, The Hindu, highlighting the IUCN report:
Three marine species — the Pondicherry shark, the Red Sea torpedo and the Tentacled Butterfly Ray might be possibly extinct in the oceanic waters of the Arabian Seas Region (ASR) since no evidence of their existence has surfaced in the last three decades. Scientists are also worried about the possible disappearance of other species from the region even before they were known to science. The ASR covers the waters of the Red Sea, Gulf of Aden, Arabian Sea, Sea of Oman, and the Gulf. The region is bordered by 20 countries including India, Bahrain, Egypt, Iraq, Iran, Israel and Pakistan.
The first-ever assessment of the conservation status of sharks, rays, and chimaeras (collectively called chondrichthyans) in the region has left scientists grim-faced as 78 of the 153 species revived were found fighting for survival. Though 184 species of sharks, rays, and chimaeras occur in the region, only the confirmed 153 species were considered for the analysis. The assessment also revealed that 27 species were “near threatened” and 19 others were of least conservation concerns. It was also noted that little information was known about 29 species to evaluate their risk of extinction.
The evaluators included K.V. Akhilesh of the Central Marine Fisheries Research Institute, Mumbai centre and K. K. Bineesh of the Zoological Survey of India, Andaman Nicobar unit. The assessors were of the view that the “increasing decline in the extent and quality of habitat as a result of coastal development and other anthropogenic disturbances, particularly for those critical habitats that many species depend on — coral reefs, mangroves, sea grasses — pose a serious threat to the survival of many species.” India, which banned the exploitation and trade of 10 species of sharks and rays, had in 2015 banned the export and import of shark fins of all species.
Image Attribution: The image above from Wikimedia Commons, is taken from an illustration in the booklet ‘Critically Endangered Animal Species of India’ issued by the Ministry of Environment and Forests, Govt. of India in March, 2011.
- The Hindu
- The IUCN Red List of Threatened Species
- Lost Species
- Critically Endangered Animal Species of India (2011)