Pacific white-sided dolphins are so named because of the white coloration on their sides and underneath. The Pacific White-sided Dolphin has a short, rounded, thick beak containing 23 to 32 small, rounded slightly curved teeth in each side of the upper and lower jaws. The Pacific white-sided dolphin is attractively marked with gray, black and white. Its back is dark gray and its sides are light gray with thin, white stripes that extend from above the eye along the sides, widening towards the tail; its belly is white. It has a black beak and lips and a black ring around each eye. The dorsal fin, at the center of the back, is tall and sharply hooked. The leading edge of the fin is black and the cresent-shaped rear section is light gray. Its small rounded flippers are rounded at the tips.
Ten Facts about Pacific White-sided Dolphin
- Females weigh up to 150 kilograms (330 lb) and males 200 kilograms (440 lb) with males reaching 2.5 metres (8.2 ft) and females 2.3 metres (7.5 ft) in length.
- Large groups are common; averaging 90 individuals, with supergroups of more than 300.
- 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.
- The total population may be as many as 1 million.
- Females reach maturity at 7 years. The gestation period is one year.
- Pacific White-sided Dolphin females have their first calf when they are 7-9 years old.
- When the calves are first born they are approximately one meter (3ft) long and weigh roughly 15 kg. Females will nurse their calves for 8-10 months.
- Females, give birth approximately every 4.5 to 5 years.
- The maximum age recorded for a female Pacific white-sided dolphin is 46. The oldest male recorded is 42.
- Pacific White-sided Dolphins eat squid and small schooling fish such as anchovies, herring, sardines, hake, salmon, rockfish, and pollock.