Pacific White-Sided Dolphin
Lagenorhynchus obliquidens


Physical Description

  • Marine mammal with thick body and short snout.
  • Large, curved or hooked dorsal (back) fin.
  • Their back, lips, and tail are black; their sides, dorsal (back) fin, and flippers are gray; their belly is white. They have a white stripe that extends from their eye to their tail.
  • They can reach a weight of 300-400 pounds and a length of 5-8 feet.
  • Males are generally larger than females.


  • North Pacific Ocean.
  • Yellow and East China Sea to the south of Japan, Sea of Japan, Sea of Okhotsk, southern Bering Sea, Aleutian Islands, coasts of Canada, Alaska, Washington, Oregon, California.


  • Open ocean, nearshore waters.
  • Rarely found close to shore.


  • Males reach sexual maturity around 10, females around 8-11 years old.
  • They mate and give birth in late spring-fall, except in the central Pacific, when it is from later winter-spring.
  • Gestation is 9-12 months.
  • Calves are 3-4 feet long and 30 pounds at birth.
  • Mothers nurse their calves for up to 18 months.
  • A female usually gives birth every 3 years.


  • Squid, small schooling fish (like capelin, herring, and sardines), salmon, hake, rockfish, pollock.
  • They can dive underwater for more than 6 minutes to feed.


  • Orcas and sharks.

Interesting Facts

  • Pod sizes are usually between 10-100 animals, but they can be seen in schools of thousands.
  • These very playful dolphins are often seen riding the bow of ships, jumping, somersaulting, or spinning in the air.
  • A primary threat to Pacific white-sided dolphins is entanglement in fishing gear, so reporting any lost fishing gear you see is very important for their safety!
  • They use their teeth to hold on to their food before they swallow it whole, and they eat 20 pounds a day! 

Sources: NOAA Fisheries; Nature Mapping Foundation; Voices in the Sea

Photo: Howard Hall

To hear a Pacific white-sided dolphin’s call, visit Voices in the Sea, a collaboration between the Pacific Life Foundation and Scripps Institution of Oceanography.