Scientific name

Lagenorhynchus acutus


Where does it get its name?

Their common name comes from the prominent white stripes on their sides, which span from below the dorsal fin to their tail, where it turns into a yellow or amber color. 

Their scientific name comes from the Greek word lagenos (which means bottle), rhynchus (which means snout or nose), and acutus from Latin (which means sharp or pointed, referring to their sharply-pointed dorsal fins).


Whale SENSE Region Found:

ATLANTIC


Protection status

Protected throughout its range


Where to watch:

Typically found in cold, deep waters of the north Atlantic Ocean, not often seen close to shore.  *If they are spotted within a couple miles of the coast, it’s best to call your local stranding response organization.


What to watch for:

Dorsal fin: Tall falcate dorsal fin is located in the center of the back.

Body: This dolphin’s distinguishing characteristics are the black rings around their eyes and the yellow-white patches on their sides

Size: Length: 8 – 9 feet, Weight: 425 – 525 pounds

Behavior: Known to be surface active, often breaching and tail slapping. Sometimes attracted to ride the bow or stern waves of vessels. 

Associations: Usually found in groups between two and 50 individuals. However it is possible to see much larger pods where they have found dense concentrations of food.  Atlantic white-sided dolphins are also known to associate with other species of whales and dolphins including fin whales, humpback whales, and bottlenose dolphins.

May be confused with: White-beaked dolphin: The white-sided does not have the distinct white and yellow streaks on its side and is typically larger. However, the range of the Atlantic white-sided dolphin their ranges overlaps in range with the white-beaked.

Feeding

They have a diverse diet, ranging from herring, cod, and mackerel to shrimp and sandeels. Known to feed cooperatively in groups, working together to herd fish into large groupings. 

Mating and Calving

Large groups of Atlantic white-sided dolphins will gather during the breeding season (spring and summer), numbering in upwards of 50 individuals (while superpods of hundreds and even thousands have been observed!). In the fall and winter, males will travel in small groups while females, calves and juveniles will travel together. 

The average gestation period is 1 year and calves are typically born between April and September. Calves will nurse for about 18 months and will remain with their mothers’ pods until they are between 3 and 5 years old on average. 

Photo: WDC

Did you know?

  • Atlantic white-sided dolphins communicate using both vocalizations underwater and body language. Body language can include tail slapping, swimming in unison with other members of the pod, jumping in unison, and breaching.
  • In the Gulf of Maine, a satellite-tagged dolphin travelled an estimated distance of over 186 miles in 64 hours (~2.5 days) (Mate et al. 1994). In this same study, the dolphin spent most of its time underwater (89%), carrying out many short dives.

Threats to Atlantic white-sided dolphins

Learn more about Atlantic white-sided dolphins