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False Killer Whales

About AquaFacts: AquaFacts are a resource for students who are looking for information on the animals at the Aquarium or other Aquarium-related topics. Here, we’ve compiled some of the most frequently asked questions that we’ve received about killer whales. The answers come from our biologists and from reputable sources that we reference at the end of this page. If you have a question about killer whales that’s not addressed in this page or the references below, please feel free to email our librarian.

False killer whale

Questions & Answers

What is a false killer whale? 

A false killer whale is a member of the dolphin family. While false killer whales are not closely related to killer whales, they do have superficial similarities (like cone-shaped teeth) to other members of the dolphin family (like bottlenose dolphins and Pacific white-sided dolphins).

Why are they called false killer whales? 

This name comes from the similarly shaped skulls that false killer whales have to that of killer whales (Orcinus orca). The “crassidens” in their scientific name Pseudorca crassidens means “thick tooth.” The name originated from scientists who were studying false killer whale sub-fossils (bone that has not been fully fossilized) in 1846. The first live specimens were documented in 1862.

Where can they be found? 

They are more commonly seen off the coasts of places like Hawai’i, Mexico, Costa Rica and Japan. Although they seem to prefer warmer places, they do wander into cooler waters; a few individuals have been seen as far north as Alaska and Norway.  Since there are no known populations that spend all of their time in these places they are considered “wanderers.”  

The B.C. Cetecean Sightings Network, based at the Vancouver Aquarium, collected 177 sightings over a 20-year period, likely of the same individual. In July 2014, the Vancouver Aquarium Marine Mammal Rescue team, with help from Fisheries and Oceans Canada (DFO), rescued a month-old false killer whale calf that had stranded on a beach in Tofino, Vancouver Island.

There is currently no estimate of their global population. The best studied group of false killer whales is a cluster of resident animals in Hawai’i that researchers have studied for years. 

Do they swim in groups? 

Groups of 10-50 individuals have been commonly observed, but even larger groups can form at different times of the year.  

What depth of water can they be found in? 

False killer whales do swim in shallower coastal waters, but they typically inhabit deep offshore seas of 3,000 metres (1.8 miles). To put that into perspective, that’s about 10 Eiffel Towers or 16 Space Needles stacked on top of each other.

How big are false killer whales? 

At birth, false killer whale calves are around 175 cm (5.7 feet) in length. Females can grow to 5 metres (16 feet) and males can grow to 6 metres (20 feet). Adults can weigh 1,360 kilograms (3,000 pounds).  

Do males and females look different from each other? 

There does appear to be some sexual dimorphism in false killer whales; males tend to have larger foreheads (melons) and be longer than females.    

Do false killer whales have any distinguishing markings? 

They tend to have overall solid dark grey colouration on their long, slender bodies, but some individuals have lighter grey or even white markings on their undersides and chests between their side (pectoral) flippers. Their pectoral flippers can have an ”S” shaped curve to them, and they have a small curved dorsal fin positioned centrally on their back.

What is their lifespan?

Researchers believe that false killer whales can grow to 57.5 years of age for males and 62.5 years for females. This is based on counting the rings on the teeth of dead animals. 

How fast are they? 

They have been observed reaching speeds of 5.5-11 kilometres/hour (3.4-6.8 miles/hour) and up to 18 km/hour (11 m/hour).

When does mating occur? What is their gestation period? 

Mating appears to occur at any time of the year but seems to coincide with prey availability. Females have a gestation period of 15.5 months and will nurse their young for 18-24 months.

What do they eat?

They are known to eat a wide variety of large fishes, like dolphinfish (Mahi mahi), and squid.  False killer whales are known for pulling bait and catch from fishinglonglines, which can be dangerous for the animal. Unfortunately, like other marine animals, false killer whales have also been found to have eaten plastic. 

Have false killer whales ever stranded on the shoreline? 

Most of what we know about false killer whales comes from animals that have stranded. The largest group of false killer whales to have stranded was 835 individuals near Mar del Plata, Argentina on October 10, 1946. 

Do false killer whales migrate?

Not much is known about the migration of false killer whales, but some groups seem to show preference for a particular place, like the group around Hawai’i that has been observed for the past 20 years.

Facts & References

Key Facts

  • Sexual maturity: females around 8-11 years, males slightly later than that
  • Gestation: 15.5 months
  • Weaned: 18-24 months
  • Length: males 6 m (20 feet), females 5 m (16 feet)
  • Weight: adults can reach 1,360 kg (3,000 lb)  

Did You Know?

  • False killer whales are sometimes called ”blackfish,” which refers to their dark body colouration. This term also includes:

-          killer whales

-          pilot whales (long and short-finned)

-          pygmy killer whales

-          melon-headed whales

  • False killer whales are highly energetic, acrobatic animals


  1. http://www.arkive.org/false-killer-whale/pseudorca-crassidens/image-G35822.html

  2. [Marine Mammals of British Columbia by John Ford]

  3. “Nowak, R.M. (1999) Walker's Mammals of the World: Volume 2. Johns Hopkins University Press, Baltimore, Maryland.”

  4. http://www.cms.int/reports/small_cetaceans/data/P_crassidens/p_crassidens.htm 

  5. http://www.cascadiaresearch.org/hawaii/HawaiifalsekillerwhalereviewMMC2009.pdf

  6. http://www.marinemammalscience.org/index.php?option=com_content&view=article&id=463&Itemid=299

Permission is granted by the Vancouver Aquarium Marine Science Centre for classroom teachers to make copies for non-commercial use. This permission does not extend to copying for promotional purposes, creating new collective works, or resale.


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