ed to reach 79 feet (24 m). Females are
slightly larger than males of the same age.

The back is distinctly ridged towards the tail, prompting the common
name "razorback" whale.

The rostrum is narrower and more V-shaped than that of the blue whale
and has the same sort of single distinctive head ridge. The top of the
head is flat, though slightly less than that of the blue whale.

The dorsal fin is up to 24 inches (61 cm) tall; angled less than 40 deg. on
the forward margin, located slightly more than one-third forward from
the tail, and appears on the surface shortly after the blow.

All individuals are dark gray to brownish black on the back and sides
with none of the mottling present on blue whales and are rarely as
heavily scarred as sei whales. Along the back, just behind the head,
there is a grayish-white chevron, with the apex along the midline of the
back and the arms of the chevron oriented posteriorly, which is
sometimes distinctive and may be visible as the animals surface to
breathe. The undersides, including the undersides of the flukes and
flippers, are white. On the head, the dark coloration is markedly
asymmetrical, reaching farther down on the left than on the right side.
The right lower lip, including the mouth cavity, and the right front
baleen (approximately one-fifth to one-third) are yellowish white.
Occasionally the right upper lip is also white. The remainder of the
plates on the right side and all those on the left side are striped with
alternate bands of yellowish white and bluish gray. The fringes of the
plates are brownish gray to grayish white.

Natural History Notes

Fin whales are one of the most common baleen whale species in the world
and constitute a major portion of the whaling catch. They are reportedly
one of the fastest of the big whales (sei whales may be slightly faster)
possibly reaching burst speeds in excess of 20 knots, and were not an
important commercial species until the comparatively recent development
of fast catcher boats and the depletion of blue whale stocks.

A fin whale's blow can be from 15 to 20 feet (4.6 to 6.1 m) tall and has
been described as an inverted cone or an elongated ellipse.

Fin whales dive to at least 755 feet (230.1 m). This depth is probably
deeper than that of either blue or sei whales, a factor usually
reflected in differences among the surfacing, blowing, and diving
characteristics of these three species. When they are moving leisurely