Perception Channels: tactile ; chemical
Pacific white-sided dolphins are not considered to be endangered. A recent estimate of the population of these mammals in the central North Pacific ranged between a minimum of about 500,000, to a maximum of 930,000. Therefore there is not any immediate danger for the extiction of these animals. They are hunted by Japanese coastal fishermen in the East China and Japan seas and taken accidentally in the North Pacific purse-seine fishery.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Pacific white-sided dolphins eat fish that live in large schools, such as anchovies, herring, smelt, capelin, and mackerel. They feed in groups of 10-20 dolphins, each adult eating about 9 kilograms (20 lbs ) of food each day.
Animal Foods: fish
Primary Diet: carnivore (Piscivore )
Pacific white-sided dolphins have a primarily temperate distribution, remaining north of the tropics and south of the colder waters caused by arctic currents. Their range is from the Aleutian Islands through the Gulf of Alaska to the tip of Baja California in the eastern Pacific; and from Japan to the Kuril Islnads in the western Pacific.
Biogeographic Regions: pacific ocean (Native )
They are usually seen in deep waters up to 160 km (100 miles ) offshore. There seem to be local migrations inshore in the winter months.
Aquatic Biomes: coastal
Average lifespan
Status: captivity: 20.0 years.
Pacific white-sided dolphins have torpedo-shaped bodies which help them move quickly through water. Body length of Pacific white-sided dolphins ranges from 150 to 310 cm. Their coloration is one of their most distinguishing features, they are black or dark gray on the dorsal surface with a white underside, and have bicolored fins and flippers. This coloration is believed to act as a form of camouflage in their aquatic environment.
Range mass: 82 to 124 kg.
Other Physical Features: endothermic ; bilateral symmetry
Pods are made up of one dominant male and a number of other males and females. The dominant male mates with reproductively available females.
Mating System: polygynous
Female Pacific white-sided dolphins reach sexual maturity around 5-6 years of age, males are sexually mature at 8-10 years. Generally breeding occurs in the summer or fall, and gestation lasts approximately 11-12 months. Females give brith to a single calf, which is almost 3 feet long and can weigh up to 14 pounds.
Breeding season: Generally breeding occurs in the summer or fall.
Average number of offspring: 1.
Range gestation period: 11 to 12 months.
Range age at sexual or reproductive maturity (female): 5 to 6 years.
Range age at sexual or reproductive maturity (male): 8 to 10 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 14000 g.
Average number of offspring: 1.
