Limulus polyphemus

Ge­o­graphic Range

Along the At­lantic Coast, from Nova Sco­tia to the Yu­catan.

Habi­tat

The horse­shoe crab can gen­er­ally be found in shal­low water, over sandy or muddy bot­toms.

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.

Con­trib­u­tors

Amanda Lam­er­ato (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

coastal

the nearshore aquatic habitats near a coast, or shoreline.

native range

the area in which the animal is naturally found, the region in which it is endemic.

Ref­er­ences

Day, Cherie H. 1987. "Life on In­ter­tidal Rocks." Na­ture Study Guild Pub­lish­ers, Rochester, NY.

Gould, James L.; Kee­ton, William T. 1993. "Bi­o­log­i­cal Sci­ence." W.W. Nor­ton and Com­pany, Inc. New York and Lon­don.

Hick­man, Cleve­land P.; Roberts, Larry S. 1995. "An­i­mal Di­ver­sity." Wm. C. Brown Pu­bish­ers. Dubuque, Iowa.

Williams, Austin B. 1984. "Shrimps, Lob­sters, and Crabs of the At­lantic Coast." Grolier Elec­tronic Pub­lish­ing, Inc.