text: do dolphin's have hair?   dolphins have hair at one point in their life. when they are born, dolphins have whiskers on their rostrum. a dolphin’s whiskers are about one quarter inch long, and will fall out shortly after birth, as a result of water pressure. even so, the follicular pits remain open. one can see these follicular pits on the rostrum of any dolphin. they probably serve some sort of sensory function, like the detection of speed or current. some great whales and one type of river dolphin retain whiskers their entire lives.