International Horseshoe Crab Day | 20 Jun 2020

Why in News

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

• The celebration of the day aims to generate greater awareness for these ancient creatures and help in their conservation.

Key Points

• Horseshoe Crab:
  • It is a marine chelicerate arthropod living in shallow coastal waters on soft sandy or muddy bottom and spawns (release or deposit eggs) mostly on intertidal beaches at summer spring high tides.
    
    • Subphylum Chelicerata is a division within the Phylum Arthropoda containing animals such as spiders, scorpions, harvestmen, mites and ticks. Like all arthropods, they have a segmented body and segmented limbs and a thick chitinous cuticle called an exoskeleton.
    • Other than the marine horseshoe crabs, the Chelicerata are found primarily in terrestrial environments worldwide.
  • It is regarded as a marine ‘living fossil’.
  • There are four extant horseshoe crab species:
    
    • The American horseshoe crab (Limulus polyphemus) along the eastern coast of the USA and in the Gulf of Mexico.
    • The tri-spine horseshoe crab (Tachypleus tridentatus)
    • The coastal horseshoe crab (Tachypleus gigas)
    • The mangrove horseshoe crab (Carcinoscorpius rotundicauda)
      
      • The last three are Indo-pacific species found in the coastal waters of India, southeast Asia, China and Japan.
  • Odisha is their largest habitat in India.
• Importance:
  
  • They have existed since the time of the dinosaurs and are important ecosystem engineers and predators of small organisms.
  • Their ecological function is to lay millions of eggs on beaches to feed shorebirds, fish and other wildlife.
  • Their large hard shell serves as a microhabitat for many other species such as sponges, mud crabs, mussels and snails.
  • They are a critical link to world health, biodiversity and hold cultural importance across the globe.
• Threats:
  
  • Overharvesting for use as food, bait and biomedical testing.
  • Habitat Destruction:
    
    • Habitat loss from coastal reclamation and development.
    • Shoreline alterations that are engineered to protect beaches from erosion and sea level rise due to climate change also affect their spawning habitats.
  • Poachers kill them for their meat which is popularly believed to have aphrodisiac qualities.
  • Trade in horseshoe crabs is rampant in many Indian states as it is believed that consumption of horseshoe crab meat can lengthen a person’s lifespan, even though there is no scientific evidence to support this.
  • Its carapace (hard upper shell) is crushed and mixed with water to prepare a paste, which is applied onto scars.
• 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.
  • The crackdown on horseshoe crab poachers requires superior, inter-state coordination among police and wildlife authorities of Odisha, Bihar, Jharkhand and other states.
  • The Zoological Survey of India has suggested declaring the habitat of horseshoe crabs as Eco-Sensitive Zones for their conservation and proper management.

Source: DTE