By Amanda Lamerato
Geographic Range
Along the Atlantic Coast, from Nova Scotia to the Yucatan.
Biogeographic Regions:
nearctic 
(native ); neotropical (native ); atlantic ocean (native ).
Habitat
The horseshoe crab can generally be found in shallow water, over sandy or muddy bottoms.
Aquatic Biomes:
coastal .
Reproduction
The first pair of the six, flap-like appendages on the underside of the abdomen acts as a cover for the genital pore. The egg or sperm are released through this pore during spawning.
Behavior
The horseshoe crab generally walks along the bottom of shallow water, but it can also swim awkwardly on its back by using its flap-like gills as paddles.
Food Habits
The horseshoe crab feeds at night on worms, small molluscs, and algae. Food is picked up by the chelicerae and passed back to the bristle bases, where it is "chewed." The food is then moved forward to the mouth.
Economic Importance for Humans: Positive
The study of a horseshoe crab's central nervous system processing functions provided the principles necessary to understand information processes in virtually every other organism investigated.
Conservation Status
The horseshoe crab is a "living relic" of the Merostomata, most of which went extinct millions of years ago.
Other Comments
Although the horseshoe crab appears to be and is named a crab, it is not. It is, in fact, related to Arachnids.
For More Information
Find Limulus polyphemus information at
Contributors
Amanda Lamerato (author), University of Michigan.
