Horseshoe crab decline sparks urgent conservation plea

Horseshoe crab decline sparks urgent conservation plea

Subject :Environment

Section: Species in news

About Horseshoe crab:

• 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.
• Tetrodotoxin (a form of neurotoxin) may be present in one horseshoe crab species, Carcinoscorpiusrotundicauda.
• They live primarily in and around shallow coastal waters on soft, sandy or muddy bottoms. They are generally found in the intertidal zone at spring high tides.
• In recent years, population declines have occurred as a consequence of coastal habitat destruction and overharvesting.
• Species of Horseshoe crabs and their conservation status:
  • Tri-spine horseshoe crab (Tachypleustridentatus)- Endangered in IUCN Red list
  • American horseshoe crab (Limulus polyphemus)- Vulnerable
  • Coastal horseshoe crab (Tachypleus gigas) and Mangrove horseshoe crab (Carcinoscorpiusrotundicauda) are not yet included in the IUCN Red List.

Horseshoe crabs in India:

• The coast of Odisha is home to two of the three horseshoe crab species found in Asia — the coastal horseshoe crab (Tachypleus gigas) and the mangrove horseshoe crab (Carcinoscorpiusrotundicauda).
• Globally recognised as living fossils (as their basic form has remained nearly unchanged over millions of years).
• Medicinal properties of Horseshoe crabs.
  • These blue-blooded crabs play a vital role in medical sciences and biomedicine.
  • The blood of horseshoe crabs can clot in the presence of bacteria, rendering them harmless. This clotting ability has been extensively utilised in testing injectable medicines, vaccines, and sterile medical equipment, including its recent use in COVID-19 vaccines.
  • Their outer layer consists of chitin, enhancing wound healing and serving as a crucial component in treating severe wounds like burns.
• Conservation status:
  • In India, the species is included in Schedule IV of the Wildlife (Protection) Act 1972.
• Threats:
  • Shoreline alterations, sea level rise that affects their spawning habitats, and destructive fishing practices that lead to the crabs becoming bycatch, threaten the population of the species. Only a few remaining populations might be left in West Bengal and some parts of Andaman and Nicobar. 
• Conservation measures:
  • Scientists and conservationists working on horseshoe crabs have urged the government to develop a robust protection mechanism for the conservation of these living fossils.
  • The IUCN Horseshoe Crab Specialist Group (SSG) is pursuing the possibility of designating horseshoe crabs as the first “World Heritage Species” under the UNESCO World Heritage Programme.
  • In 2020, the IUCN SSC Horseshoe Crab Specialist Group formally designated June 20 as International Horseshoe Crab Day annually.
  • The Beibu Gulf Declaration on Global Horseshoe Crab Conservation was declared in 2019 in Guangxi, China.

Source: Mongabay