HorseShoe Crab

About Horseshoe Crab

Characteristics and Features

These crabs are closely related to spiders and scorpions.
Living Fossils:
- They are marine arthropods belonging to the family Limulidae.
- They are considered “living fossils” due to their existence for over 450 million years with minimal morphological changes.
Physical Traits:
- Hard, horseshoe-shaped carapace, long tail spine (telson), and multiple pairs of legs.
- Their blood is bright blue due to the presence of copper-based hemocyanin, which is crucial for their immune response.
- Horseshoe crabs glow under UV light.
  - This is because of a process called cuticular fluorescence.
- They have six pairs of legs but only five are for walking.
- One horseshoe crab can lay about 4,000 eggs.
- Lifespan: 20 – 100 years.

Did you Know?

Blue blood contains a substance called Limulus Amebocyte Lysate (LAL) – crucial for testing medical equipment for bacterial contamination in the biomedical industry.

Conservation Status
- IUCN Status: Data deficient (for both types which are found in India)
- Wildlife Protection Act (WPA): Schedule IV
Threats:
- Overharvesting for bait and biomedical use
- Habitat loss from coastal development
- Destructive fishing practices.
Distribution in India
- Species Found: India is home to 2 species:
  - Coastal Horseshoe Crab
  - Mangrove Horseshoe Crab
- Location: Northeastern coast of Odisha (Balasore and Kendrapara districts) and in parts of the Sundarbans in West Bengal.
- Recent Initiatives for Protection
  - Tagging Program: The Zoological Survey of India (ZSI) and the Odisha Forest Department have initiated a tagging program to study horseshoe crab populations and their habitats.
    - This first-of-its-kind effort in India aims to monitor threats and conservation needs over the next three years.