Appendage of any of the first five abdominal somites, usually formed by an unsegmented peduncle which carries two branches usually formed of a single flat, leaf-like and oval segment. The outer of these branches is the exopod, the inner the endopod. The pleopods may be reduced or entirely absent from some somites, the endopod may have an appendix. In some species, the pleopods of the first or first two abdominal somites may be transformed into rigid copulatory stylets, which play a role during copulation. In females the pleopods may be larger and wider than in males, especially when the females carry eggs. The eggs are fastened to the pleopods and are carried as a conspicuous mass under the abdomen, the mass being protected on the outer side by the pleopods.

Alternative form for pleopod : pleopods.