Horseshoe Crabs

• Context (TH): Environmental groups have recently petitioned the U.S. government to grant endangered species protection for the American horseshoe crab.

  

• Horseshoe crabs are marine chelicerate arthropods found in shallow coastal waters on soft, sandy, or muddy bottoms.
• They belong to the Subphylum Chelicerata, which includes animals like spiders, scorpions, harvestmen, mites, and ticks.
• Horseshoe crabs are marine arthropods, not true crabs, but are chelicerates, closely related to arachnids like spiders, ticks, and scorpions.
• Their segmented body, segmented limbs, and thick chitinous cuticle (exoskeleton) are typical features of arthropods.
• They predominantly spawn (release eggs) on intertidal beaches during summer-spring high tides.
• Horseshoe crabs are often regarded as “living fossils” due to their ancient lineage.
• Lifespan: 20 – 100 years.
• Conservation Status: IUCN Status: American horseshoe crab: Vulnerable, Tri-spine horseshoe crab: Endangered | WPA, 1972: Schedule IV
• Threats: Commercial harvest for biomedical use, habitat loss.
• The IUCN decided to observe the International Horseshoe Crab Day on 20^th June.

Species and Distribution

• American horseshoe crab (Limulus polyphemus): Found along the eastern coast of the USA and in the Gulf of Mexico.
• Tri-spine horseshoe crab (Tachypleus tridentatus).
• Coastal horseshoe crab (Tachypleus gigas).
• Mangrove horseshoe crab (Carcinoscorpius rotundicauda)
• Odisha is their largest habitat in India.