Atlantic Horseshoe Crab
⚡ Key Facts & Quick Answers (AEO Summary)
- Taxonomic Class: Invertebrates & Insects
- Dietary Niche: Omnivore (Marine worms, clams, algae)
- Max Speed: 2 km/h (1.2 mph)
- Adult Weight: 1 - 4.5 kg (2.2 - 10 lbs)
- Typical Lifespan: 20 - 40 years
- Primary Habitat: Shallow sandy ocean floors, coastal bays, estuaries
- Native Region: Atlantic coast of North America
- IUCN Red List: Vulnerable
📊 Physical & Biological Metrics
🧬 Scientific Taxonomy & Biological Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Merostomata |
| Order | Xiphosura |
| Family | Limulidae |
| Genus | Limulus |
| Species Binomial | Limulus polyphemus |
📖 1. Species Overview
The Horseshoe Crab is a marine arthropod. Regarded as a living fossil, they have existed virtually unchanged for 450 million years. Their unique copper-based blue blood is critical for medical safety testing.
🦿 2. Physical Appearance, Anatomy & Adaptations
Features a dome-shaped horseshoe carapace, a long pointed tail (telson), 10 eyes, and 6 pairs of legs under the shell.
🗺️ 3. Habitat, Geographic Distribution & Territorial Range
Crawl along sandy ocean floors. They migrate to beaches in massive numbers during spring high tides to spawn.
🥩 4. Diet, Feeding Strategy & Hunting Tactics
Forage in sand, grinding food between their leg joints (gnathobases) since they lack jaws.
🐣 5. Reproduction, Lifecycle & Social Hierarchy
Females lay thousands of green eggs in sand nests, which are fertilized by males and provide essential food for migrating shorebirds.
🛡️ 6. Conservation Status, Population Threats & Protection
Vulnerable. Threatened by harvesting for medical blood extraction, bait use, and shoreline habitat developments.
💡 Fascinating Facts & Trivia
- Horseshoe crabs are closer relatives of spiders and scorpions than true crabs.
- Their copper-based blue blood contains LAL, a chemical that coagulates instantly in the presence of bacterial endotoxins, used to test all human vaccines for safety.
❓ Frequently Asked Questions (FAQ)
Direct authoritative answers regarding the biology, feeding habits, and habitat of the Atlantic Horseshoe Crab.
The Atlantic Horseshoe Crab is scientifically classified as Limulus polyphemus. It belongs to the genus Limulus within the family Limulidae, class Merostomata, and phylum Arthropoda.
In the wild, Atlantic Horseshoe Crabs inhabit Shallow sandy ocean floors, coastal bays, estuaries. Their native geographic range primarily spans Atlantic coast of North America.
The Atlantic Horseshoe Crab is classified as a Omnivore. It feeds primarily on specialized nutrients suited to its ecological niche in Shallow sandy ocean floors, coastal bays, estuaries.
A Atlantic Horseshoe Crab can achieve top speeds of 2 km/h (1.2 mph) and weighs approximately 1 - 4.5 kg (2.2 - 10 lbs). Its expected natural lifespan is 20 - 40 years.
The Atlantic Horseshoe Crab (Limulus polyphemus) is currently designated as Vulnerable on the IUCN Red List of Threatened Species.
Cite this Article
FaunaWiki Zoological Database (2026). "Atlantic Horseshoe Crab (Limulus polyphemus) Species Profile."
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