hite on belly (older animals speckled on belly).
Head blunt; jaw underslung; false gills or bracket marks on side
of head.
Dorsal fin small; located in last one-third of body.
Has not been reported to ride bow waves.
Distribution in tropical and temperate waters.

[Sidenote: DWARF SPERM WHALE

_Kogia simus_

p. 148]

Body to about 9 feet (2.7 m) long.
Body dark steel gray on back; lighter gray on sides; pinkish to
white on belly.
Head blunt; jaw underslung; false gills or bracket marks on side
of head.
Body has two small creases on throat.
Dorsal fin like that of Atlantic bottlenosed dolphin; located
near midpoint of back.
Has not been reported to ride bow waves.
Distribution poorly known; at least from Georgia to the tropical
seas.

[Sidenote: HARBOR PORPOISE

_Phocoena phocoena_

p. 150]

Body to 5 feet (1.5 m) long.
Body dark brown above and white below; transition zone on sides
often speckled or streaked; ventral white extends high onto
side in front of dorsal fin.
Head rounded; beak small and indistinct.
Dorsal fin short and triangular.
Distribution in shallow waters from at least Delaware north;
generally found inshore; often in bays, river mouths and
inlets.
Does not approach boats.

SPECIES ACCOUNTS

Large Whales With a Dorsal Fin

BLUE WHALE (B)[9]

_Balaenoptera musculus_ (Linnaeus 1758)

[Footnote 9: The letter in parentheses indicates whether the species is
a baleen (B) or a toothed (T) whale.]

Other Common Names

Sulphur-bottom.

Description

Blue whales are the largest living mammals. Though reports of maximum
length and weight vary from one account to another, Antarctic blue
whales are known to have reached lengths to 100 feet (30.5 m) and
weights of over 150 tons (136,363 kg)[10] before stocks were severely
depleted by whaling operations. North Atlantic blue whales may be
expected to reach lengths of 80-85 feet (24.4-25.9 m). In all known
populations of blue whales, females are slightly larger than males of
the same age.

[Footnote 10: The largest measured specimen was "just over" 100 feet
(30.5 m); the largest specimen weighed, the 150-ton individual noted
above, was 89 feet (27.1 m) long.]

Viewed from above, the blue whale's rostrum is broad, flat, and nearly
U-shaped (actually shaped like a Gothic arch, slightly flattened on the
tip), with a single ridge extending from the rai