Stripped dolphin
 
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Stenella coeruleoalba

Names

Azores : Toninha riscada - POR : Golfinho riscado - ITA : Stenella striata - SPAIN : Delfine listado - GB : striped dolphin - GER : Blauweier delphin - JAP : Suji iruka - NEDER : Gestreepte dolfijn

Biology

The average length of adults is 2.2 m long, and a maximum of 2.7 m in length. Weight is up to 140 kg. Each jaw can have 40 to 50 pairs of teeth. At birth, the striped dolphin's maximum length is 1 m and weight is about 15 kg. The reproductive cycle is biannual to triennial. The gestation period is estimated at 12 months and lactation lasts 1 to 2 years. They have two characteristic black bands : one from behind the eye and extending to the anus; the other from the eye and extending to the flipper. Their longevity is estimated to be 35 to 50 years. They feed on small mesopelagic fish, as well as shrimp and cephalopods. They can dive to a depth of 200 m.

Observation

Groups of striped dolphins are frequently observed together with herds of common dolphins. They cannot be confused with this latter species, though, because of the characteristic black stripes along their flanks (this is the reason for their English common name). This species is usually observed farther away from the coast than the common dolphin or the spotted dolphin. Striped dolphins are gregarious, moving in groups of tens to several hundred individuals, with a swimming speed of about 20 knots, and a maximum speed of 28 knots. They usually jump clear of the water (at times to more than 6 or 7 m height) and re-enter the water on their sides. Less friendly than the common dolphin, this animal usually maintains a safe distance from the boats. The striped dolphin can remain submerged around 8 minutes.

Cetaceans in the Azores