Horseshoe Crabs

Horseshoe crab belongs to a class called Merostomata, living fossils, or those organisms that haven’t changed in millennia.

Horseshoe Crabs
Table of Contents

About Horseshoe crab:

  • It belongs to a class called Merostomata, living fossils, or those organisms that haven’t changed in millennia. 
  • It is a marine chelicerate arthropod. The Chelicerata is a division within the 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.
  • Habitat: They are living in shallow coastal waters on soft sandy or muddy bottoms and spawns mostly on intertidal beaches at summer-spring high tides. 
  • 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 mainly in the coastal waters of India, Southeast Asia, China and Japan.
    • In India Odisha is the largest habitat of horseshoe crabs
  • Conservation status in India
    • Wildlife Protection Act 1972: Schedule IV
  • IUCN Status
    • American horseshoe crab: Vulnerable
    • Tri-spine horseshoe crab: Endangered
    • The two other species are not listed yet

Q1: What are Arthropods?

These are invertebrates with jointed legs. They make up about 75% of all animals on Earth and have a major role in maintaining ecosystems as pollinators, recyclers of nutrients, scavengers and food for other animals. 

Source: The blue-blooded sea creature on Odisha’s coastline

Update Icon
Latest UPSC Exam 2026 Updates

Date IconLast updated on Sep, 2026

UPSC 2027 Notification will be released on 13 January 2027 at upsconline.nic.in.

Asian Games 2026 are being held in Aichi-Nagoya, Japan, from 19 September to 4 October.

→ Check out the latest UPSC Syllabus here.

→ Download UPSC Model Answers for Mains 2026

UPSC Mains Question Paper 2026 is out now for Essay & GS Paper 1, 2, 3 & 4.

UPSC Calendar 2027 has been released.

→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2027 for structured answer writing practice, expert evaluation, and exam-oriented feedback.

→ Join Vajiram & Ravi’s UPSC Mentorship Program 2027 for personalized guidance, strategy planning, and one-to-one support from experienced mentors.

→ Go through the UPSC Mains Previous Year Papers to enhance your preparation.

→ UPSC has released UPSC Toppers List 2025 with the Civil Services final result on its official website.

→ Also check Best UPSC Coaching in India

Vajiram Content Team
At Vajiram & Ravi, our team includes subject experts who have appeared for the UPSC Mains and the Interview stage. With their deep understanding of the exam, they create content that is clear, to the point, reliable, and helpful for aspirants.Their aim is to make even difficult topics easy to understand and directly useful for your UPSC preparation—whether it’s for Current Affairs, General Studies, or Optional subjects. Every note, article, or test is designed to save your time and boost your performance.
UPSC GS Course 2027
UPSC GS Course 2027
₹1,80,000
Enroll Now
GS Foundation Course 2 Yrs
GS Foundation Course 2 Yrs
₹2,45,000
Enroll Now
UPSC Mentorship Program
UPSC Mentorship Program
₹65000
Enroll Now
UPSC Sureshot Mains Test Series
UPSC Sureshot Mains Test Series
₹27000
Enroll Now
Prelims Powerup Test Series
Prelims Powerup Test Series
₹14000
Enroll Now
Enquire Now