Agonistic Displays in the Blacktip Shark (Carcharhinus limbatus)
Agonistic displays in the Blacktip Shark (Carcharhinus limbatus) were triggered by divers slowly ascending to the surface. Two locomotor elements, rolling and tilting, were identified. They closely resemble the behavior patterns of sharks trying to shake off Sharksuckers (Echeneis naucrates). Agonistic displays and the shaking off of sharksuckers could each derive directly from the the feeding act. Alternatively the similarity of the agonistic displays and the shaking off of sharksuckers offers the possibility as well that only one of the two is directly derived from the feeding act and the other subsequently derived from the first.Abstract
Rolling display in sequential frames. The numbers in the top right corner indicate the actual time in seconds. (A) normal body position; (B–C) start of lateral rolling including snout raising and pectoral fin lowering; (D) full display; (E–F) end of rolling by gliding back into a normal swimming position
Tilting display in sequential frames. The numbers on the top right corner indicate the actual time in seconds; (A) lowering the pectoral fins out of the normal swimming position; (B–C) bending the caudal fin; (D) fully displayed tilting position; (E–F) end of tilting by turning into a horizontal position by bending the body