- Jointed carapace (shell) with three sections including a broad “U” shaped head region
- Spines on rear abdominal region for protection from predators
- Harmless telson, or tail, used to right them when overturned
- Ten eyes scattered all over the body including two large compound eyes on top of head section of carapace
- Has several light receptors near the tail in addition to eyes
- Five pairs of legs on bottom and no antennae
- Gills underneath carapace resemble pages in a book
- Mature adult males first leg is shaped like a hook
Genetically, they are more closely related to spiders and scorpions than to true crabs
Up to 1 foot in carapace width; males are typically one-third the size of females
Atlantic Ocean and Gulf of Mexico; nest on sandy beaches with low wave action.
Known to gather in large nesting aggregations, or groups, on beaches. Horseshoe crabs nest year-round in Florida, with peak spawning occurring in the spring and fall.
Feeds on various invertebrates