Requiem sharks are sharks of the family Carcharhinidae in the order Carcharhiniformes, containing migratory, live-bearing sharks of warm seas (sometimes of brackish or fresh water) such as the spinner shark, the blacknose shark, the blacktip shark, the blacktail reef shark, and the blacktip reef shark. Requiem sharks are responsible for a large proportion of attacks on humans; however, due to the difficulty in identifying individual species, a degree of inaccuracy exists in attack records.