Cetacean Society International

Working for whales, dolphins and porpoises worldwide

CSI Photo Gallery

Northern Right Whale Dolphin

(Lissodelphis borealis)

Far at sea the right whale dolphins are often seen speeding in very large groups. They are very impressive, but we can't get close enough to understand much about their lives. Their slim bodies are obviously built for speed, but why do they not have dorsal fins? Perhaps they don't need the drag-shedding fin because of their slim "aspect ratio", or they don't have to flex their bodies as much as other dolphins to swim fast.