BIOLOGY OF THE BLACKTIP SHARK, CARCHARHINUS LIMBATUS, OFF THE SOUTHEASTERN UNITED-STATES

The blacktip shark is a cosmopolitan species found throughout tropical and subtropical waters. It is common along the southeast coast of the United States, where it migrates northward to Georgia and the Carolin as in summer and southward to Florida in winter. The blacktip shark fe eds on small bony fishes, primarily menhaden, and small elasmobranchs. Males mature between 1,425 and 1,450 mm TL, and all males over 1450 m m TL are mature. Females mature at about 1,560 mm TL. The reproductive cycle lasts 2 years and includes biennial ovulation with a 1-year ges tation period. Mating and ovulation occur in Bulls Bay, South Carolina , from mid-May to early June. Parturition occurs the following year fr om early May to early June in the shallow coastal waters of the Caroli nas. The blacktip shark is a viviparous, placental species. Implantati on usually occurs during the 10th and 11th weeks of gestation when the embryos measure 178-194 mm TL. The young are born at about 550-600 mm TL during May and early June in the shallow water, coastal nurseries of Georgia and the Carolinas. The neonate stage lasts about a month. T he young remain in the shallow water nurseries until fall.