They use their dorsal fin to inflict cuts and they can punch enemies with their nose.
Dolphins defend themselves with their nose.
i have no idea maybe by calling fish to suround it to protect themselves from other sharks
they don't really protect themselves
Well, if the Shark is coming towards you, don't panic. If you do, you swim too fastly or something, then you start to sink. Either calmly swim away in a fast motion, or call for help. A lifeguard or...