Species profiles: life histories and environmental (Gulf of Mexico) -- brown shrimp

Species profiles are literature summaries on the taxonomy, morphology, range, life history, and environmental requirements of coastal aquatic species. They are designed to assist in environmental impact assessment. The brown shrimp, Penaeus aztecus, is the major species in the Gulf of Mexico shrimp fishery, the most valuable ($302 million in 1980) commercial fishery in the United States. It is heavily preyed on by many fishes. Spawning occurs offshore from about September to May and most postlarvae move into estuaries from February through April. Within the estuary they occupy shallow water near marshes with soft substrate. Juveniles emigrate from estuaries to offshore areas from May through August. They grow as fast as 3.3 mm per day in estuaries. Adults concentrate around the 55-m contour offshore. Postlarval and juvenile shrimp are normally taken in water temperatures above 10 degrees and rapid growth occurs above 18 degrees. Few shrimp are collected below 5 ppt salinity. Brown shrimp are benthic feeders and prefer soft substrates. High populations are associated with coastal marshes.