The rough-toothed dolphin is robust, with a conical head lacking
demarcation between the melon and the beak. It has a somewhat
reptilian appearance.
This species has large flippers (seemingly oversized for the
animal), and a prominent sickle-shaped dorsal fin. The body is
dark grey, with a prominent narrow dorsal cape that dips slightly
below the dorsal fin. The belly, lips, and much of the lower jaw
are white, often with a pinkish cast. White scratches and spots,
apparently caused in part by bites of cookie-cutter sharks and
other rough-toothed dolphins, often cover much of the body.
The jaws contain 20-27 teeth in each row with subtle, but detectable,
vertical ridges. These ridges give rise to the species' English
common name. Adults are up to about 2.8 m long. They are known
to reach weights of up to 150 kg. Length at birth is unknown.
Rough-toothed dolphins are generally easy to identify when seen
at close range; however, they may be mistaken for bottlenose dolphins
if seen at a distance. The narrow cape and cone-shaped head will
be the best clues to identification of rough-toothed dolphins
in such situations.
The Rough-toothed dolphin, Steno bredanensis, feeds on fish and
squid as well as molluscs and cephalopods. Steno bredanensis is
a gregarious species found in groups of 10-30 on average, as well
as schools of up to 160 dolphins containing up to 8 smaller subgroups.
Like other dolphins, Rough-toothed dolphins communicate and echolocate
using clicks and whistles. It appears that Rough-Toothed Dolphins
take a variety of fish species, free-swimming octopi and squid.
The typical family unit contains between 10-50 individuals,
but occasionally can number more than 100. Rough-Toothed Dolphins
also associate with other small cetaceans, and are powerful swimmers.
They do not bow ride as often as other species, but do 'skim',
swimming rapidly with only the dorsal fin exposed above the surface.