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False Killer Whale (Pseudorca crassidens)



The false killer whale, or pseudorca, was named because it has a similar skull shape and size, shape and number of teeth as the orca or killer whale. Despite their name, they are members of the dolphin family.

Description:

The false killer whale is a dark colored whale - their body is black or dark gray, and they also have a white blaze marking between their flippers along with a white stripe down their belly and around their genital area.

They have a slender body, rounded dorsal fin, small, rounded head without a prominent beak, and flippers with an S-shape along one edge.

The false killer whale grows to a maximum length of about 20 feet (the maximum length documented for a false killer whale, according to the Society for Marine Mammalogy, was 5.96 meters, or 19.55 feet). They weigh about 1,500 pounds.

Classification:
  • Kingdom:Animalia
  • Phylum:Chordata
  • Subphylum: Vertebrata
  • Superclass: Gnathostomata, Tetrapoda
  • Class: Mammalia
  • Subclass: Theria
  • Order: Cetartiodactyla
  • Suborder: Cetancodonta
  • Infraorder: Cetacea
  • Suborder: Odontoceti
  • Superfamily: Odontoceti
  • Family: Delphinidae
  • Genus: Pseudorca
  • Species: crassidens

Habitat and Distribution:

False killer whales are found in warm, tropical and sub-tropical waters in all the world's oceans. They are a pelagic species that prefers water more than 3,300 feet deep. When false killer whales swim close to shore it is usually near oceanic islands.

False killer whales may ride in the bow waves of ships, and may exhibit aerial activity.

Feeding:

False killer whales, like other toothed whales, are social animals that travel and feed in groups. The groups generally number around 10-20 whales, although groups may be as large as several hundred. Within these groups, they will cooperatively feed on fast-moving fish such as tuna, swordfish and squid. Individuals may also pass prey back and forth, a behavior thought possibly to help build trust between hunting partners.

Like other odontocetes, false killer whales find prey, communicate and navigate using echolocation, a process in which the whale emits high-frequency sounds using an organ in their head called the melon. The sounds bounce off objects around the whale, and then are received in the whale's lower jaw and interpreted. In one study, it was determined that false killer whales find their prey at a distance of 984 feet (Source: Discovery of Sound in the Sea).

Reproduction:

Females become sexually mature around 8-10 years of age, and males become sexually mature in their late teens. Like other cetaceans, false killer whales reproduce sexually with internal fertilization. A single calf about 5-6 feet long is born after a gestation period of about 15 months. False killer whales reproduce slowly - the average time between calf may be about 7 years.

These whales are thought to live at least 60 years.

Communication:

False killer whales may communicate using whistles, pulses and echolocation clicks. The false killer whale's whistles are distinct to their species. You can click here to visit the Discovery of Sound in the Sea web site to hear false killer whale sounds.

Conservation:

False killer whales are listed as endangered under the U.S. Endangered Species Act. They are listed as "data deficient" on the IUCN Red List due to the lack of abundance and trend data for the species.

Since they are a social species that travels in groups, false killer whales may mass strand, with sometimes hundreds of individuals stranding at once.

Other natural and human threats to false killer whales include their slowness in reproduction, and the presence of small, genetically-isolated populations which may be vulnerable to threats. Pollution is a threat to these whales as they are active predators who may accumulate high amounts of pollutants from their prey. They are also threatened by manmade noise (e.g., military sonar and seismic surveys), interaction with fishing gear such as longlines. False killer whales have also been hunted in drive fisheries (which sold some false killer whales for displays in aquariumds in the 1990's) and by harpoons.

They may be preyed-upon by sharks and orcas.

References and Further Information:
  • Baird, R. False Killer whale (P. crassidens). Society for Marine Mammalogy Fact Sheet. Accessed September 30, 2013.
  • NOAA Fisheries, Office of Protected Resources. False Killer Whale (Pseudorca crassidens). Accessed September 30, 2013.
  • Perrin, W. 2013. Pseudorca crassidens (Owen, 1846). In: Perrin, W.F. (2013) World Cetacea Database. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137104. Accessed September 30, 2013.
  • Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. 2008. Pseudorca crassidens. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. www.iucnredlist.org, Accessed September 30, 2013.
  • The Pacific WildLife Foundation. False Killer Whale. Accessed September 30, 2013.

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