IAS Gyan

Daily News Analysis


18th March, 2023 Environment

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Context:  Horseshoe crabs, one of the oldest living creatures on earth and medicinally priceless, appear to be disappearing from their familiar spawning grounds along Chandipur and Balaramgadi coast in Odisha’s Balasore district.



  • Like olive ridley sea turtles, these crabs are basically deep-sea animals.
  • The blood of this crab is very important for the preparation of rapid diagnostic reagents.
  • Only a few countries in the world have horseshoe crab population and India is one among them.
  • Palaeontological studies say the age of horseshoe crabs is 450 million years.
  • Horseshoe crabs are marine and brackish water arthropods of the family Limulidae and the only living members of the order Xiphosura.
  • Despite their name, they are not true crabs or crustaceans: they are chelicerates, most closely related to arachnids such as spiders, ticks, and scorpions.
  • Horseshoe crabs live primarily in and around shallow coastal waters on soft, sandy or muddy bottoms.
  • They are eaten in some parts of Asia, and used as fishing bait, in fertilizer and in science (especially Limulus amebocyte lysate).
  • Because of the destruction of habitat and shoreline development, use in fishing, plastic pollution, status as a culinary delicacy in some areas, and use for scientific research and advancements, the horseshoe crab is facing down endangered and extinct statuses.
  • One species, T. tridentatus, has already been declared extinct in one area of Taiwan.
  • Facing a greater than 90% population decrease in T. tridentatus juveniles, it is suspected that Hong Kong will be the next to declare the horseshoe crab extinct in its area.
  • The species is listed as endangered on the IUCN Red List, specifically because of overexploitation and loss of critical habitat leading to a steep decline in population size.


Q) Which of the following statements is/are correct with reference to Horseshoe crabs?

a. The age of horseshoe crabs is 450 million years.

b. The blood of this crab is very important for the preparation of rapid diagnostic reagents.

  1. Only a
  2. Only b
  3. Both a and b
  4. Neither a nor b

Answer: Option 3