ower jaw. ragged in arrangement.

[Illustration: Figure 147.--A Guiana dolphin from Kartabo, British
Guiana. In the coastal portion of its range along the northeastern South
American coast, this species is most likely to be confused with the
Atlantic bottlenosed dolphin. Guiana dolphins are much smaller, rarely
exceeding 5.6 feet (1.7 m), have a more triangular dorsal fin, and tend
to be found more frequently in estuaries and rivers. (_Photo by A. B.
Van Beneden from Zoologica VII(4), by permission of the New York
Zoological Society._)]

[Illustration]

[Illustration: Figure 148.--Guiana dolphins harpooned in Kartabo,
British Guiana. Guiana dolphins have from 26 to 35 teeth in each jaw.
Atlantic bottlenosed dolphins, which are larger but somewhat similar in
appearance, have from 20 to 26 teeth in each upper jaw and from 18 to 26
in each lower jaw. (_Photo by A. B. Van Beneden from Zoologica VII (4),
by permission of the New York Zoological Society._)]

ROUGH-TOOTHED DOLPHIN (T)

_Steno bredanensis_ (G. Cuvier in Lesson 1828)

Other Common Names

Rough-toothed porpoise, goggle-eyed porpoise.

Description

Rough-toothed dolphins reach a length of at least 8 feet (2.4 m). The
coloration of the rough-toothed dolphins is quite variable. Individuals
are often dark gray to dark purplish gray on the back with pinkish-white
blotches on the sides and belly. The flippers and flukes are dark and
the belly is white. Individuals are frequently scarred with numerous
white streaks.

The most distinctive characteristic of the rough-toothed dolphin is its
beak, which is quite long and slender, may be white or pinkish white
along both sides, including one or both lips and the tip of the snout,
and is not separated from the forehead by the transverse groove present
in other long-snouted dolphins. Because the forehead and the sides of
the head slope smoothly into the rostrum, when this animal is seen from
above or from the side, its entire head appears very long and nearly
conical.

Natural History Notes

Rough-toothed dolphins occur in small groups of 50 animals or fewer and
are usually found off the edge of the continental slope. They may ride
the bow waves.

May Be Confused With

In their offshore habitat, rough-toothed dolphins are most likely to be
confused with Atlantic spotted dolphins (p. 104) and with Atlantic
bottlenosed dolphins (p. 128). They may be distinguished from Atlantic
spotted