Context: Recently, the International Union for Conservation of Nature (IUCN)’s has decided to observe the first-ever International Horseshoe Crab Day on 20th June 2020.
About Horseshoe Crabs

• Horseshoe crabs are marine and brackish water arthropods. They are not true crabs, which are crustaceans.
• The crabs are represented by four extant species in the world. Out of the four, two species are distributed along the northeast coast of India.
• Only T gigas species of the horseshoe crab is found along Balasore coast of Odisha.
• The crab was included on September 9, 2009, in the Schedule IV of the Wild (Life) Protection Act, 1972, under which, the catching and killing of a horseshoe crab is an offence.

Their significance

• The horseshoe crab is one of the oldest marine living fossils whose origin date back to 445 million years before the dinosaurs existed.
• One of their ecological functions is to lay millions of eggs on beaches to feed shorebirds, fish and other wildlife.

Threats

• Poachers kill them for their meat that is popularly believed to have aphrodisiac qualities.
• The blood of horseshoe crabs, which is blue in colour, is used for detection of bacterial endotoxins in medical applications.
• Conservation: It is in the Schedule IV of the Wildlife Protection Act 1972, under which the catching and killing of a horseshoe crab is an offence.

IUCN Status

• American horseshoe crab: Vulnerable.
• Tri-spine horseshoe crab: Endangered.
• The two other species are not listed yet.

Protection: The Zoological Survey of India has suggested declaring the habitat of horseshoe crabs as Eco-Sensitive Zones for their conservation and proper management.