The Fin Whale is usually distinguished by its great length and slender build.
The Fin Whale has a brownish grey top and sides and a whitish underside.
It has a pointed snout, paired blowholes, and a broad, flat rostrum.
Two lighter-colored chevrons begin midline behind the blowholes and slant
down the sides toward the tail on a diagonal upward to the dorsal fin,
sometimes recurving forward on the back.

It has a large white patch on the right side of the lower jaw,
while the left side of the jaw is grey or black. This type of
asymmetry can be seen occasionally in Minke Whales, but the Fin Whale's
asymmetry is universal and thus is unique among cetaceans and is one of the
keys to making a full identification. It was hypothesized to have evolved
because the whale swims on its right side when surface lunging and it often
circles to the right while at the surface above a prey patch. However,
the whales just as often circle to the left. There is no accepted
hypothesis to explain the asymmetry.

Facts