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Photograph of back and fin of a white sided dolphin on the surface of a calm sea

(Photo: Tracey Dean)

Head Harbour Passage to the Wolves

Atlantic White-Sided Dolphin

Lagenorhynchus acutus

Atlantic white-sided dolphins have a white belly with grey sides and a black back. They have a yellow lateral stripe and a distinctive black ring around the eye. They have an average length of 2.8 metres and average weight of 200 kilograms.

Authority

Gray, 1828

Classification Details

Phylum: Chordata (chordates); Subphylum: Vertebrata (vertebrates); Class: Mammalia (mammals); Infraorder: Cetacea (whales and dolphins); Family: Delphinidae (ocean dolphins).

Habitat

Found in the western Atlantic from Greenland to New England, including subarctic Canadian waters. In the eastern Atlantic, they range from Norway to northern France. They occur in coastal shelf and oceanic waters in groups of a few individuals to several thousand animals.

Diet

Predators that feed on herring, mackerel, squid, smelt, hake, and shrimp. They do not dive very deep or for very long (no longer than 4 minutes).

Reproduction

Sexes are separate. These dolphins reach sexual maturity at six to 12 years. Females typically give birth every two years. After an 11-month gestation they give birth to a single 1.2 metre long calf. Their calving period is from May to August. Females nurse their calf for 18 months or more. They can mate again once their most recent calf is at least one year old. The species has a typical lifespan of 25 to 30 years.

Fun Facts

This dolphin species is acrobatic and a fast swimmer. They will ride the bow waves of boats and even of large whales.

References

Eder T (2012) Whales and Other Marine Mammals of Atlantic Canada. Vancouver: Lone Pine Publishing.

Jefferson TA, Leatherwood S and Webber MA (1993) FAO species identification guide. Rome: FAO.

Weinrich MT, Belt CR, Morin D (2006) Behavior and ecology of the Atlantic white-sided dolphin (Lagenorhynchus acutus) in coastal New England waters. Marine Mammal Science 17, 231–248.

Photograph of back and fin of a white sided dolphin on the surface of a calm sea