Context—In August this year, for the first time in over a century, scientists from the Zoological Survey of India (ZSI), in collaboration with the Odisha Forest Department, began tagging horseshoe crabs.
Key facts related to Horseshoe crabs:
- A horseshoe crab's blood has a blue to blue-green color when exposed to the air. The blood is blue because it contains a copper-based respiratory pigment called hemocyanin.
- As fossils show, it has survived 445 million years without undergoing any morphological change.
- It belongs to a class called Merostomata, living fossils, or those organisms that haven’t changed in millennia.
- IUCN Category – Data deficient
- Listing of the crab in the Schedule IV of the Wildlife (Protection) Act, 1972.
- Distribution - There are four species of horseshoe crab: the mangrove (Carcinoscorpius rotundicauda), which inhabits the coastal waters of South and Southeast Asia; the Atlantic or American (Limulus polyphemus), found along the Atlantic coast of the United States and the southeastern Gulf of Mexico; the coastal (Tachypleus gigas), also native to South and Southeast Asia; and the tri-spine (Tachypleus tridentatus), found in Southeast and East Asia. India is fortunate to have two species: Carcinoscorpius rotundicauda and Tachypleus gigas, both found along the Odisha coast.