The first dorsal fin is large with a black tip on the rear. The second dorsal fin is much smaller yet contains a black tip as well. Occasionally blacktips even consume small sharks. Reproduction Female blacktips are viviparous and contain a yolk-sac placenta. The young are born in late spring or early summer.
Pregnant females move inshore to drop their young in nursery and pupping grounds.
Behavior Blacktip sharks fast-swimming sharks that often travel in schools. Blacktips are often confused with related spinner sharks because of their feeding method. Blacktips, at times, can be an aggressive species which approaches swimmers and divers. Aside from this behavior, very few blacktip attacks on humans have been documented. They are often found on or near the continental and insular shelves.