Fin Whale

Fin whales are long, slender and highly streamlined, more pointed at the head than the blue whale and more torpedo-like than the humpback or minke. The back is dark grey to brownish-black, with a lighter underside and mottled shading that differs between individuals. A pronounced ridge runs from the dorsal fin to the tail — giving rise to the nicknames "finback" and "razorback" whale.

One unusual trait is the fin whale's asymmetrical jaw: pale white on the lower right side, dark on the left — unique among great whales, and thought to help herd prey during feeding lunges. The dorsal fin is tall, curved and set well back, usually appearing seconds after the blow as the whale rolls through the surface.

In Antarctic waters, fin whales feed almost exclusively on krill. In the Northern Hemisphere their diet is broader, including small schooling fish like herring and capelin. Like all rorquals, they're lunge feeders — accelerating into dense prey swarms and engulfing huge volumes of water, then filtering it through their baleen.

Fin whales often feed on their right side, turning the pale jaw toward their prey to disorient it before the lunge. They dive to 200 metres or more and can stay submerged for up to 15 minutes. Unlike humpbacks, they're rarely seen in large feeding aggregations, tending to feed alone or in small groups across open water.

Breeding follows a seasonal pattern by hemisphere: Southern populations mate May–July, Northern populations December–February. After roughly 11 months' gestation, females give birth to a single calf around six metres long — already larger than many adult dolphins. Calves nurse for six to eight months, and females typically calve every two to three years. Much of fin whale breeding biology remains poorly understood, as it largely takes place far offshore.