Pacific White-sided Dolphin
Lagenorhynchus obliquidens


Other Names: Lag, Pacific Striped Dolphin, White-striped Dolphin, Hook-finned Porpoise

Habitat: Offshore and Inshore

Status: Common

Population: Unknown

Threats: Hunting/whaling and entanglement in fishing nets

Group Size: 10- 100, smaller groups may be found inshore

Fin Position: Center

Newborns: 32 in-4 ft (80 cm-1.2 m), 35 lb (15 kg)

Adults: 5 -8 ft (1.7-2.4 m), 185-330 lb (85-150 kg)

Diet: Fish and squid or octopus

Teeth: 42-64 on both top and bottom rows


Description

Dorsal fin:

- front third dark gray or black
- tall, falcate dorsal fin (more triangular in young animals)
- rear two-thirds pale gray

Flukes:

- concave trailing edges
- slight notch in middle
- flukes dark on both sides

Flippers:

- front third black or dark gray
- rear two-thirds pale gray

Head:

- pale gray patch on sides
- barely discernible black beak
- dark ring around eyes
- pale gray streak along body

Porpoising:

- animal leaves water to breathe when swimming fast
- distinctive spray of water behind tail

Other characteristics:

- dark gray or black upper side
- pale gray streak widens at tail stock
- underside of tail stock black or dark gray
- narrow tail stock
- white underside
- fairly robust body in front of fin


Behavior

- very active and demonstrative, creating lots of splashes
- frequently breaches, sometimes spinning in midair or turning a complete somersault and landing on its side or belly
- fast, powerful swimmer; several may porpoise in unison
- enjoys surfing on ocean waves and wake-riding, and is an avid bow-rider, often seeming to appear from nowhere
- sometimes swims very close to the surface with only its dorsal fin visible, like a shark
- large schools may split into smaller groups when feeding but reassemble when resting or traveling
- often associates with other cetaceans; may also be seen with sea lions and seals
- it is extremely inquisitive and may even approach stationary boats
-


Distribution

- deep temperate waters of the northern North Pacific, predominately offshore
- tends to remain south of colder waters influenced by artic currents and stays north of the tropics
- although common in the Gulf of Alaska, and also around the southern Kamchatka Peninsula, it is absent from the Bering Sea
- mainly found offshore, as far as the edge of the continental shelf, but does come closer to shore where there is deep water, such as over submarine canyons
- may be north-south or inshore-offshore movements with the seasons (may move inshore or southward in the winter), but some populations are probably resident year-round



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This page was created by:Candice Orca Mottet