- A female Horseshoe Crab can lay as many as 90,000 eggs each season, usually in clusters of 4,000 – 5,000 at at time. However, only about 10 of those individual embryos will ever become adults. Before they get a chance to hatch, fish, sea turtles, and birds feed on the eggs.
- Horseshoe Crabs are actually not crabs. They are more closely related to spiders.
- Horseshoe Crabs have been around for 450 million years, predating the dinosaurs by more than 200 million years.
- Horseshoe crabs have blue blood because it is copper rather than iron based.
- The blood of Horseshoe Crabs contains a protein that will clot upon exposure with bacterial endotoxin. In this way, preparations such as insulin or antibiotics can be tested for contamination before being used in people.
- If you find a Horseshoe Crab upside down on the beach, pick them up like a bowl and turn them over. Never pick them up by their tails.
- Horseshoe crab eggs are an important food source for migratory birds such as the Red Knot.