Pacific White-sided Dolphin

Lagenorhynchus obliquidens

Summary 3

The Pacific white-sided dolphin (Lagenorhynchus obliquidens) is a very active dolphin found in the cool to temperate waters of the North Pacific Ocean.

Description 4

The Pacific white-sided dolphin has three colors. The chin, throat and belly are creamy white. The beak, flippers, back, and dorsal fin are a dark gray. Light gray patches are seen on the sides and a further light gray stripe runs from above the eye to below the dorsal fin, where it thickens along the tail stock. A dark gray ring surrounds the eyes.

The species is an average-sized oceanic dolphin. Females weigh up to 150 kg (330 lb) and males 200 kg (440 lb) with males reaching 2.5 m (8.2 ft) and females 2.3 m (7.5 ft) in length. Pacific white-sided dolphins tend to be larger than dusky dolphins. Females reach maturity at seven years. The gestation period is one year. Individuals live 40 years or more.

The Pacific white-sided dolphin is extremely active and mixes with many of the other North Pacific cetacean species. It readily approaches boats and bow-rides. Large groups are common, averaging 90 individuals, with supergroups of more than 300. Prey includes mainly hake, anchovies, squid, herring, salmon, and cod.

They have an average of 60 teeth.

Range and habitat 4

The range of the Pacific white-sided dolphin arcs across the cool to temperate waters of the North Pacific. Sightings go no further south than the South China Sea on the western side and the Baja California Peninsula on the eastern. Populations may also be found in the Sea of Japan and the Sea of Okhotsk. In the northern part of the range, some individuals may be found in the Bering Sea. The dolphins appear to follow some sort of migratory pattern — on the eastern side they are most abundant in the Southern California Bight in winter, but further north (Oregon, Washington) in summer. Their preference for off-shore deep waters appears to be year-round.

The total population may be as many as 1 million. However, the tendency of Pacific white-sided dolphins to approach boats complicates precise estimates via sampling.

Sources and Credits

  1. (c) Paruula, some rights reserved (CC BY-NC-SA),
  2. (c) Joe McKenna, some rights reserved (CC BY),
  3. (c) Wikipedia, some rights reserved (CC BY-SA),
  4. (c) Wikipedia, some rights reserved (CC BY-SA),

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