- Compound eye – eye containing numerous lenses.
- Gills – respiratory organ which extracts oxygen from water.
- Rudder – used for steering.
- Toxin – a poison or substance which can cause harm to the health of a living thing.
- Harvest – to gather or collect.
- Migration – seasonal movement from one region to another.
- Compound – composed of 2 or more separate elements.
- Prehistoric – the time before there were written records.
- Copper – a reddish-brown metal.
- Antibody – a protective protein produced by the immune system in response to the presence of a foreign substance,
- Pollution – the presence or introduction into the environment of a substance or thing that has harmful or poisonous effects.
- 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.
- 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.