Species Description: The knotfingered mud crab is a member of the family Panopeidae. It is distinguished from other member in the family by a very broad major claw forming joint (chela) with cusps of teeth in "molar area" of an immovable finger. This claw is often coalesced and worn (Abele and Kim 1986). The carapace and dorsal sides of the chelae have a mottled appearance with dark reddish spots, while the abdomen and ventral sides of the claws are white. Cave specimens of Panopeus lacustris were reported to be lighter in color and have conspicuous white spots on their antennules (Manning and Hart 1989).
Regional Occurrence: The knotfingered mud crab is found in the shallow and subtidal waters from Bermuda and extreme southern Florida, through the West Indies, and along the continental margin of the Caribbean Sea and South America to Cabo Frio, Brazil. The species has been introduced in Hawaii in the 1950s, and, apparently has been known on the California coast for a number of years (Abele and Kim 1986). It is frequently found in burrows under rocks or dead corals (Manning and Hart 1989).
IRL Distribution: Panopeus lacustris is found in the Indian River Lagoon.
Abele LG and W Kim. 1986. An illustrated guide to the marine decapod crustaceans of Florida. State of Florida Department of Environmental Regulation Technical Series Vol. 8, No. 1 pp. 225.
ITIS Integrated Taxonomic Information System. Available online.
Manning RB and CW Hart, Jr. 1989. The occurrence of Panopeus lacustris Schramm in marine caves of Bermuda. Crustaceana 57:313-315.