Narrative

Shrimps (Decapoda\Natantia) are a group of the Shrimp and Crab Order (Order Decapoda). They may be divided into three main categories: Penaeidae, Stenopodidea, and Caridea. Here they are grouped into one mega order with the families in alphabetical sequence.

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 pairs of which are used for walking. Frequently the first pair of legs has been modified into pinchers used for eating and defense.

Here the Decapoda are divided into five different sub-orders which match the adult shapes of the various life forms. Also, the subdivision followed is close to the Borrandaile l907 system. The divisions are as follows:

Natantia - Shrimp-like
Brachyura - Crab-like
Anomura - Hermit Crabs and relatives
Astacidea - 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 as a method of classification, one gets a different organization.

Taxonomy

References