Life history of Cobia, Rachycentron canadum (Osteichthyes : Rachycentridae), in North Carolina waters

Cobia (n = 416) were collected primarily along the central North Carolina Atlantic coast from recreational anglers between 1983 and 1994. Males (n 174) ranged up to 136-cm fork length (FL) and 32.0 kg, and females (n = 182) up to 142-cm FL and 32.2 kg. Most cobia greater than 100-cm FL were females. Ages of cobia (to age 14) were estimated by counting opaque zones on cross-sectioned sagittal otoliths. Von Bertalanffy growth parameter (k) estimates were 0.37 for males and 0.24 for females. Adult cobia occurred in major sounds and coastal Atlantic waters of North Carolina from May through July, and in nearshore oceanic waters through fall. Cobia may overwinter between Cape Fear and Cape Canaveral at depths of 30-75 m. Cobia fed chiefly on demersal crustaceans and fishes in the study area. Cobia may be one of the few teleosts that regularly consumed small elasmobranchs. Male cobia were sexually mature at 60-65-cm FL (age 2), and females at 80-cm FL (age 2). Cobia spawned May through July along the North Carolina coast, and ocean waters adjacent major coastal inlets were probable sites for cobia spawning activity.