Taxonomic Note: Herds with variant color patterns have in the past been referred to as Stenella styx or Stenella euphrosyne, although these names are rarely if ever used today and are not valid. The lifespan of the striped dolphin is thought to be about 58 years.
The striped dolphins are the largest and most robust of the five recognized Stenella species. While they are relatively numerous, they are not often known to ride bow waves and will usually not approach ships, thus affording comparatively little opportunity for close-range study or observation. The blue blade-shape color pattern on the flanks and the thin dark stripe running from each eye along the lower flanks to the genital region add to the animals’ distinctive appearance. In the eastern tropical Pacific Ocean, these animals have been known to associate with yellowfin tuna, although the relationship is extremely limited compared to spinner, spotted, and common dolphins of the same region.
Physical Description: Robust animals as Stenella goes, with well-defined Stenella characteristics.
Color: The dorsal region is blue-black from the tip of the beak to midway between the tail and dorsal fin. The blue-black color continues from just behind the dorsal fin halfway to the eyes, narrowing to a blade-shaped stripe. Thin black stripes run from each eye converging near the anus. A second stripe begins at each eye and terminates above and just past the flippers. A third dark stripe runs from just under each eye terminating at the leading edge of the flippers. White flippers blend where they join the body, with its dark areas.
Fins and Flukes: A tall dorsal fin is falcate and situated on the mid-back region. The flippers are small and curved at the leading edge, pointed at the tips. The flukes are small, thin, and pointed at the tips, with a slight median notch.
Length and Weight: This dolphin reaches 9 ft (2.7 m) and 250 lb (115 kg).
Teeth: There are 45 to 50 small, conical teeth on each side of the upper jaw, and 43 to 50 on each side of the lower jaw.
Feeding: Small fish, shrimp, squid, and other organisms.
Breathing and Diving: They are capable of diving up to 2300 ft. (700 m). They are surface-active swimmers, often leaping from the water up to 20 ft. (7 m).
Mating and Breeding: Calves are just over 40 in (1 m) and are born after a gestation period of approximately 12 months, and weaned at about one year. Sexual maturity is attained at 9 years. Striped dolphins are thought to have two distinct breeding seasons — spring and autumn. Females give birth every 3 to 4 years.
Herding: Groups may be from 20 to over 100, but occasionally up to 1,000 as well. They are apparently separated by age and sex.
Distribution: Worldwide in tropical and temperate waters.
Migration: No information available.
Natural History Notes: These animals are thought to live to at least 50 years.
STRIPED DOLPHIN DISTRIBUTION