Invertebrate · GBIF taxon 1010610
Atlantic Horseshoe Crab
Limulus polyphemusAlso known as American Horseshoe Crab, Horsefoot, Helmet Crab
Atlantic horseshoe crabs have inhabited coastal waters for over 440 million years, predating the dinosaurs with an unchanged body plan. Each spring during full and new moons, thousands emerge onto sandy Atlantic beaches to spawn, dropping millions of tiny eggs that fuel migrating shorebirds. Their copper-rich blue blood contains a vital clotting agent used globally to test vaccines and medical equipment for bacterial contamination.
AncientMarineCoastal
1 / 7—observations
—countries
—peak records
VulnerableConservation statusIUCN Red List categoriesLCNTVUENCREWEXVulnerableRed List categories, explained →
Diet & prey
- Marine Worms
- Bivalves
- Detritus
Predators
- Red Knot
- Gulls
- Loggerhead Sea Turtle
ThreatsBiomedical harvesting, bait harvesting, shoreline development
HabitatsShallow coastal waters, estuaries, sandy beaches
Life span20 to 40 years
Size / weightNot available
Classification
- FamilyLimulidae
- SpeciesLimulus polyphemus
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Harmless to humans; safe to observe from a respectful distance.
- What to notice
- Look for a large brownish dome-shaped shell with a long spike-like tail on sandy estuary beaches.
- Support conservation
- Observe quietly along the tide line and flip stranded individuals gently by holding the shell sides, never the tail.
Responsible observation
- Flipping stranded crabs: If a crab is stuck upside down on a beach, gently turn it right side up by grabbing the shell edges.
- Avoid the tail: Never pick up a crab by its pointed telson, which can easily snap and leave the animal permanently injured.
- Respect spawning beaches: Give spawning pairs space during peak spring high tides so they can lay eggs undisturbed.
Predator (c) Paolo, some rights reserved (CC BY), uploaded by Paolo · cc-by
Predator "Loggerhead Sea Turtle (Caretta caretta)" by brian.gratwicke is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/. · cc-by
Close Relative Amada44 / CC BY 3.0 · cc-by
Close Relative (c) 呂一起(Lu i-chi), some rights reserved (CC BY), uploaded by 呂一起(Lu i-chi) · cc-by
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