Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). Blue Crab

Abstract

Abstract : Species profiles are summaries of the literature on taxonomy, life history, and environmental requirements of coastal fishes and aquatic invertebrates. They are prepared to assist with impact assessment. The blue crab, Callinectes sapidus, occurs in lower reaches of freshwater rivers, estuaries, and coastal waters along the Atlantic seaboard and Gulf of Mexico, and the species supports the largest crab fishery in the United States. Chesapeake Bay provides the greatest production of blue crabs on the east coast. The blue crab's high abundance in estuaries, diverse feeding habits, and importance as prey for other marine animals indicate its important role in the structure and function of estuarine communities. Female blue crabs spawn in high-salinity lower estuaries of coastal areas; the resulting larvae are planktonic and develop into juveniles at 5 to 10 weeks of age. Juveniles gradually migrate into shallower, less-saline upper estuaries and rivers where they grow and mature at 1-2 yr of age. Mating occurs in the upper estuaries after which females migrate to areas having higher salinities. Growth and survival of blue crabs are strongly affected by water temperature and salinity, but tolerances vary with life stage. Larvae require temperature tolerances are broad for advanced juveniles and adults. Blue crabs use nearly all areas within estuaries as nursery habitat, and crab populations are sensitive to changes in physical features of contamination of these areas. Keywords: Estuaries; Shellfish; Crustacea; Growth physiology; Feeding; Spawning; Blue crab; Callinectes sapidus; Temperature requirements; Habitats; Life cycles; Reproduction physiology.(KT)