Stenella frontalis
A rather small, long-snouted, spotted dolphin; ground color
purplish gray, appearing blackish at a distance, usually with
numerous small white or gray spots on sides and back; sides
paler, belly whitish; young grayish, unspotted; dorsal fin
high and strongly recurved, strongly concave at rear; beak
deeper than wide and about 6% of total length of animal; teeth
small and slightly incurved, especially toward tip of snout
in upper jaw, varying in number from 31/31 to 37/34; height
of teeth above jawbones seldom over 10 mm; diameters of largest
tooth at alveolus, 5.5 by 4.0 mm; total length, 2.2 m; girth
in front of dorsal fin, 1.2 m; length of anterior edge of
dorsal fin, 431 mm; width of flukes, 661 mm. Weight, 125 kg.
These dolphins are a common, offshore resident of tropical
and warm temperate waters of the Atlantic Ocean. Not known
outside of the Atlantic. In the Gulf of Mexico, this dolphin
is second in abundance only to the bottlenose dolphin, Tursiops
truncatus.
Atlantic spotted dolphins may be seen in groups of up to 50
animals, but smaller groups of six to 10 are more common.
They eat small fishes including herring, anchovies, and flounder,
as well as squid.
These dolphins make a variety of sounds used in echolocation
and communication. Sounds are described as "loud whistles,
chirps, low intensity click trains, squawks, barks, growls,
and cracks."
These dolphins mate and calve in summer. Sexual behavior
has been observed in the Gulf of Mexico in mid-May. The gestation
period lasts 12 months and calves are born in offshore waters.
Although this dolphin is a common offshore resident of the
Gulf of Mexico, the dolphins may move into nearshore waters
in late spring and summer in Florida. This movement may be
related to the movements of certain prey species for the dolphins;
such migrations are not known for Texas waters.
Remarks. This dolphin was previously known as Stenella plagiodon.
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