Category: Horseshoe Crabs view all from this category

Description 24" (61 cm) long, 12" (30 cm) wide. Horseshoe-shaped carapace convex, with triangular abdomen and spikelike tail; older individuals usually covered with algae. Greenish-tan. Pair of compound eyes on each side of carapace, 2 simple eyes on forepart of midline. Sides of abdomen scalloped, with 6 spines. 1 pair of pinchers in front of mouth. Mouth surrounded by 5 pairs of walking legs, each walking leg with a burrlike base; last pair of walking legs with circle of leaflets; first pair on male heavy and rounded; others with pincher tips. Underside of abdomen has 6 pairs of overlapping flaps, the first covering openings of six ducts, the others covering 5 pairs of book gills comprised of many flat sheets.

Habitat On mud or sand bottoms; from near low-tide line to water 75’ (23 m) deep.

Range Gulf of Maine to Gulf of Mexico.

Discussion This animal is the only one of its kind in American waters, and cannot be confused with anything else. It feeds on clams, worms, and other invertebrates which it grinds with the burrlike bases of the walking legs that surround its mouth. In spring, horseshoe crabs congregate near the shore, males holding onto the abdomens of females with their heavy walking legs. When the tide is high, each female digs a hole above the low-tide line and lays 200-300 pale greenish eggs. As she does, the male spawns sperm to fertilize them. The eggs are then buried in sand, where they remain for several weeks, until hatching as miniature horseshoe crabs with tiny button tails.