Narrative

Lobsters and Crayfish (Decapoda/Astacidae Section) contains the American Lobster and the North American Crayfish.

Shrimps and Crabs (Order Decapoda) contains most of the larger freshwater and marine species of crabs, crayfish, shrimp, and lobsters. They have a total of ten pairs of legs, four of which are used for walking. The first pair of legs is often modified into pinchers used for eating and defense.

The following list is based on the division of the Decapoda into five different suborders based on adult shapes of the various life forms:

Natantia - Shrimp-like
Brachyura - Crab-like
Nomura - Hermit Crabs and relatives
Astacidae - Crayfish and Lobster-like
Palinura - Spiny Lobsters and Spanish Lobster

The sub-classification of the Order Decapoda is in a state of change. For a short summary of this situation, please refer to pages two and three of Shrimps, Lobsters, and Crabs of the Atlantic Coast of the Eastern United States by Austin Williams published by the Smithsonian Press, Washington, D.C., in l984. If one uses adult shape as a method of classification, one gets one organization, and if one uses larvae shape for classification, one gets a different organization.

Taxonomy

References