Mammal Species of the World
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Pseudorca crassidens is found throughout the Atlantic, Pacific, and Indian Oceans. It is nearly cosmopolitan, occurring at latitudes as far north as 50 degrees north and as far south as 52 degrees south.
This species has been observed as far south as New Zealand, Peru, Argentina, South Africa, and the north Indian Ocean. They also range from Australia, the Indo-Malayan Archipelago, Philippines, and north to the Yellow Sea. They have been observed in the Sea of Japan, coastal British Columbia, coastal Maryland (USA), the Bay of Biscay, and have been discovered in the Red and Mediterranean Seas. Many pods live near the Gulf of Mexico and surrounding the Hawaiian Islands.
Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native ); mediterranean sea (Native )
Other Geographic Terms: cosmopolitan
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Widely distributed, though apparently nowhere abundant, in tropical, subtropical, and warm temperate waters throughout the world. In the U.S. they occur in Hawaii, along the entire West Coast, and from the Mid-Atlantic coastal states south.
Distribution in Egypt
Red and Mediterranean Sea.
False killer whales are black or dark gray with a white blaze on their ventral side. Some have a paler gray coloring on their head and sides. Their heads are rounded and often described as blunt and conical with a melon-shaped forehead. Their bodies are elongated. The dorsal fin is sickle-shaped and protrudes from the middle of their back, the pectoral flippers are pointed. They have a slight overbite--the upper jaw extends beyond the lower jaw. This gives them a slight beaked look to their rostrum. No subspecies have been described.
Adult males range from 3.7 to 6.1 m in length, while adult females range from 3.5 to 5 m. Adults may weigh 917 to 1842 kg. Newborns range from 1.5 to 1.9 m in length and weigh about 80 kg. The dorsal fin can grow to be 18 to 40 cm high. This species has a more slender build compared to other dolphins and they have tapering heads and flippers. Their flippers average about one-tenth of the head and body length and have a distinct hump on the leading margin of the fin. There is a definite median notch on their flukes and they are very thin with pointed tips. False killer whales also have 8 to 11 teeth on each side of their jaw.
The skulls of females range in length from 55 to 59 cm, while males are 58 to 65 cm. They have 47 to 52 vertebrae: 7 cervical, 10 thoracic, 11 lumbar, and 20 to 23 caudal vertebrae. They have 10 pairs of ribs. Their manus consists of 6 carpals, 5 metacarpals, and 14 phalanges.
This species is often mistaken for bottlenose dolphins (Tursiops truncatus), short-finned pilot whales (Globicephala macrorhynchus), or long-finned pilot whales (Globicephala melas) as they inhabit the same regions. To distinguish these species, bottlenose dolphins have beaks, and pilot whales are larger with obvious dorsal fin differences.
Range mass: 916.26 to 1841.59 kg.
Range length: 3.5 to 6.1 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger; sexes shaped differently
Length: 550 cm
Size in North America
Range: 3.7-6 m males; 3.3-5.1 m females
Average: 1,360 kg (maximum)
Catalog Number: USNM A3679
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Preparation: Partial Skull
Collector(s): Collector Unknown
Locality: Paita, Off Paita, Piura, Peru, South America, South Pacific Ocean
False killer whales are common in tropical or temperate seas. They visit coastal waters but prefer to remain in deeper waters. They are known to dive as deep as 2000 meters.
Range depth: 0 to 2000 m.
Average depth: 500 m.
Habitat Regions: temperate ; tropical ; saltwater or marine
Aquatic Biomes: pelagic ; coastal
Habitat and Ecology
Although false killer whales eat primarily fish and cephalopods, they also have been known to attack small cetaceans, humpback whales, and sperm whales. They eat some large species of fish, such as mahi-mahi (also called dorado or dolphinfish), tunas (Alonso et al. 1999) and sailfish. In Hawaiian waters observational studies suggest that large game fish (mahi-mahi, tunas, billfish) may form the majority of their diet (Baird et al. 2008).
Habitat Type: Marine
Comments: Primarily pelagic; usually not near land except around oceanic islands and coast with deep water nearby (Leatherwood and Reeves 1983).
Water temperature and chemistry ranges based on 116 samples.
Depth range (m): 0 - 0
Temperature range (°C): 1.915 - 29.248
Nitrate (umol/L): 0.048 - 23.409
Salinity (PPS): 32.029 - 37.045
Oxygen (ml/l): 4.476 - 7.572
Phosphate (umol/l): 0.070 - 1.578
Silicate (umol/l): 0.777 - 18.227
Temperature range (°C): 1.915 - 29.248
Nitrate (umol/L): 0.048 - 23.409
Salinity (PPS): 32.029 - 37.045
Oxygen (ml/l): 4.476 - 7.572
Phosphate (umol/l): 0.070 - 1.578
Silicate (umol/l): 0.777 - 18.227
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
May make seasonal migrations into northern Pacific waters during spring-summer warming (Leatherwood and Reeves 1983).
False killer whales are carnivores, eating primarily fish and squid. They mainly eat squid (Loligo) but also opportunistically take fish and occasional marine mammals, such as seals (Phocidae) or sea lions (Otariidae). Some of the fish they eat include salmon (Oncorhynchus), squid (Loligo, Berryteuthis magister, or Gonatopsis borealis), sciaenid and carangid fishes, bonito (Sarda lineolata), mahi mahi (Coryphaena hippurus), yellowfin tuna (Thunnus albacares), yellowtail (Pseudosciana manchurica), and perch (Lateolabrax japonicus). On one occasion researchers found the remains of a humpback whale Megaptera noveangliae in the stomach of a false killer whale.
This species moves quickly in order to catch fish. They have been observed catching a fish in their mouth while completely breaching the waters' surface. They have also been seen shaking their prey until the head and entrails are shaken off. They then peel the fish using their teeth and discard all the skin before eating the remains. Some mothers will hold a fish in the mouth and allow their calf to feed on the fish. This food manipulation is rare in cetaceans.
Animal Foods: mammals; fish; mollusks; other marine invertebrates
Primary Diet: carnivore (Piscivore , Molluscivore )
Comments: Diet mainly squid and large fishes (Stacey et al. 1994), including some obtained from fishing lines. May attack dolphins released from purse seines in eastern tropical Pacific (Leatherwood and Reeves 1983).
False killer whales are predators of fish and squid (Uroteuthis duvauceli), and they also eat smaller delphinids and pinnipeds (e.g., seals [Phocidae], and sea lions [Otariidae]).
One protozoan that is found in false killer whales are the parasites Bolbosoma capitatum. They are also carriers of two types of whale lice: Lsocyamus delphini and Cyamus antarcticensis.
- Lsocyamus delphini
- Cyamus antarcticensis
- Bolbosoma capitatum
Due to their harmful effects on fisheries, humans kill false killer whales. In some regions in the eastern tropical Pacific, they are hunted for meat.
- humans (Homo sapiens)
Comments: Nowhere abundant.
Gregarious, often in herds of >100 individuals; mean group size off Japan was 55; group size from 14 mass strandings (not uncommon) averaged 180 (50-835). Herds usually include both sexes and all age classes (or minus males in the late maturing stage) and appear to be socially cohesive. Often associates with other cetaceans (Leatherwood and Reeves 1983).
Life History and Behavior
Pseudorca crassidens use echolocation primarily in the frequency range of 20 yo 60 kHz. They also use higher frequencies of 100 to 130 kHz. False killer whales, like other toothed whales also use other sounds, such as whistles, squeals, or less distinct pulsating sounds. It has been noted that whenever researchers get close to a group of false killer whales, they have been able to detect the whales' piercing whistles from about 200 meters away. James Porter notes, "The noises were astonishingly diverse, much more varied than the sounds of human speech, both in pitch and intensity. Each whale seemed to be making different sounds. The cacophony gave the impression that whatever they were 'saying', they were not all 'saying' the same thing at the same time (Watson 1981)."
Communication Channels: tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; ultrasound ; echolocation ; chemical
Researchers estimate that males live an average of 57.5 years and females live an average of 62.5 years in the wild. No known age-dependent mortality rate has been discovered. Because few false killer whales are kept in captivity, captive lifespans are unknown.
Status: wild: 60 years.
Status: wild: 22.0 years.
Lifespan, longevity, and ageing
Although false killer whales breed year-round, their breeding peaks in late winter to early spring. Studies suggest they are polygynandrous.
Mating System: polygynandrous (promiscuous)
False killer whales will only have one calf per pregnancy and she carries that calf for 11 to 15.5 months. The calf stays with the mother for 18 to 24 months. Between 18 and 24 months old, the calf is gradually weaned. Sexual maturity occurs in females between 8 and 11 years of age and in males at 8 to 10 years.
In this species and a few others in the family Didelphinidae, if the female doesn't conceive after the first ovulation, she will keep ovulating until she does conceive. After giving birth, the female will not breed again for an average of 6.9 years.
Breeding interval: Females give birth every 6.9 years, on average.
Breeding season: Breeding occurs year-round, but peaks December to January and again in March.
Range number of offspring: 1 (high) .
Average number of offspring: 1.
Range gestation period: 11 to 15.5 months.
Range weaning age: 18 to 24 months.
Range age at sexual or reproductive maturity (female): 8 to 11 years.
Range age at sexual or reproductive maturity (male): 8 to 10 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; viviparous
Average number of offspring: 1.
After false killer whales calves are born, they are cared for and nursed by their mother for up to 24 months. Young are capable of swimming on their own shortly after birth. Young are likely to remain in the same social group with their mother beyond weaning.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); post-independence association with parents; extended period of juvenile learning
Protracted breeding season, reportedly with no fixed breeding or calving season, though a peak in calving in March was found off Japan. Gestation lasts about 15-16 months. Lactation lasts apparently about 18 months. Sexually mature at about 3.2-3.8 m (Leatherwood and Reeves 1983), probably at a minimum age of 8 years (IUCN 1991, Stacey et al. 1994). Off Japan, the average interval between births has been estimated at about 7 years, with females over 45 years old post-reproductive (see Stacey et al. 1994). May live several decades.
Molecular Biology and Genetics
Barcode data: Pseudorca crassidens
Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen.
Other sequences that do not yet meet barcode criteria may also be available.
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Download FASTA File
Statistics of barcoding coverage: Pseudorca crassidens
Public Records: 3
Specimens with Barcodes: 3
Species With Barcodes: 1
Although false killer whales are hunted by humans and there are annual mass strandings, populations are considered stable. There are only a few countries that hunt them for food or remove them as threats to the fisheries industry.
US Federal List: no special status
CITES: appendix ii
State of Michigan List: no special status
IUCN Red List of Threatened Species: data deficient
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Lower Risk/least concern(Baillie and Groombridge 1996)
- 1994Insufficiently Known(Groombridge 1994)
National NatureServe Conservation Status
Rounded National Status Rank: NU - Unrankable
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Reasons: Widespread in oceans, not significantly threatened.
Status in Egypt
Global Short Term Trend: Relatively stable (=10% change)
False killer whales are occasionally taken in Japan for food and in St. Vincent in the Caribbean for meat and cooking oil (Jefferson et al. 1993; Odell and McClune, 1999). Considerable numbers of false killer whales may have also been killed in a past drive fishery in the Penghu Islands of Taiwan. Their interactions with fisheries, particularly their tendency to remove desired target species from longlines and sport fishing gear, have made them the targets of culling efforts. Around Iki Island, Japan, over 900 false killer whales were killed in drive fisheries from 1965 to 1980 in an attempt to reduce interactions with the yellowtail fishery (Jefferson et al. 1993; Odell and McClune, 1999). They continue to be taken opportunistically in Japanese harpoon and drive fisheries (Kishiro and Kasuya 1993). They are also hunted at least opportunistically in Indonesia, Taiwan and the West Indies. Some of the animals caught in the Japanese and Taiwanese drive fisheries have been kept alive and sold to oceanaria (Reeves et al. 2003).
Incidental takes of small numbers of false killer whales in gill nets has occurred off northern Australia, the Andaman Islands, the southern coasts of Brazil and in tuna purse seines in the eastern tropical Pacific. Dolphin entrapment in tuna purse seine nets may be providing artificial feeding opportunities for Pseudorca on other marine mammals (Odell and McClune, 1999). Although there have not been any records of false killer whale being killed in the large-mesh pelagic driftnets off eastern Taiwan, some are likely to be caught. Yang et al. (1999) reported on by-catch rates in Chinese coastal fisheries (trawl, gill and stow net), which may number in the hundreds per year for P. crassidens alone. False killer whales are occasionally hooked in longline fisheries, presumably as they are removing fish from the hooks. Death has been observed as a result of some hookings (Forney 2006). Many of the other hookings are inside the mouth or gullet and are likely to result in the subsequent death of the animals (Forney and Kobayashi 2005). Other types of non-lethal injuries may also occur (Baird and Gorgone 2005). Such longline fisheries are found throughout the central and western tropical Pacific, and similar interactions with false killer whales occur in other regions (e.g. Mediterranean, Bearzi 2002). Observer programs to monitor bycatch are limited.
Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk
This species, like beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006).
Predicted impacts of global climate change on the marine environment may affect false killer whales, although the nature of impacts is unclear (Learmonth et al. 2006).
Degree of Threat: D : Unthreatened throughout its range, communities may be threatened in minor portions of the range or degree of variation falls within natural variation
Comments: No known major threats, though some mortality occurs as a result of direct and indirect taking associated with various fisheries (IUCN 1991). Culls have occurred in Japan in efforts to reduce perceived damage to fisheries (IUCN 1991).
This is a relatively poorly-known species which, although mostly observed over deep water, is known to strand from many coasts. Abundance estimates as well as by-catch data do not exist for most areas, nor are there detailed accounts on migratory behaviour. Clearly, more research is needed.
Relevance to Humans and Ecosystems
These whales will eat fish off of fishing lines and out of nets of commercial fishing operations.
In the eastern tropical Pacific, Pseudorca crassidens is taken for food and also to limit their consumption of tuna Osteoglossiformes and inhibit their competition with commercial fisheries.
Positive Impacts: food
Comments: Has been successfully maintained in several marine aquaria. Sometimes taken for human food and oil in mass shore drives in Japan and in small cetacean fisheries in Taiwan and the Caribbean (Leatherwood and Reeves 1983, Stacy et al. 1994). Sometimes regarded as pest by fishermen who perceive these whales as a competitor for fishes. Sometimes takes fishes hooked on fishing lines; sometimes causes significant impact on tuna long-line fishery in the tropical Pacific (IUCN 1991).
IUCN Red List Category
False killer whale
The false killer whale (Pseudorca crassidens) is a cetacean, and the third-largest member of the oceanic dolphin family (Delphinidae). It lives in temperate and tropical waters throughout the world. As its name implies, the false killer whale shares characteristics, such as appearance, with the more widely known killer whale. Like the killer whale, the false killer whale attacks and kills other cetaceans, but the two species do not belong to the same genus.
The false killer whale has not been extensively studied in the wild; much of the data about it have been derived by examining stranded animals.
The false killer whale was first described by the British paleontologist and biologist Richard Owen in his 1846 book A history of British fossil mammals and birds. He based this work on a fossil discovered in 1843 in the great fen at the neighourhood of Stamford, Lincolnshire. Owen proposed to name the cetacean Phocaena crassidens, and by comparing its characteristics and dimensions, noted a general resemblance to those of the grampus (Phocaena orca) and the round-headed porpoise (Phocaena melas).
The species was thought extinct until Johannes Reinhardt confirmed it was alive when he described a large pod at the Kiel Bay in 1861. One of these was captured, and others were found the following year, beached on the coast of Denmark.
Population and distribution
The false killer whale appears to have a widespread, if small, presence in tropical and semitropical oceanic waters. A few of these whales have been found in temperate water, but these are probably stray individuals. Their most common habitat is the open ocean, though they also frequent other areas. They have been sighted in fairly shallow waters such as the Mediterranean Sea and Red Sea, as well as the Atlantic Ocean (from Scotland to Argentina), the Indian Ocean (in coastal regions and around the Lakshadweep Islands), the Pacific Ocean (from the Sea of Japan to New Zealand and the tropical area of the eastern side), and in Hawaii.
The Hawaiian populations are the most studied groups of false killer whales. The three distinct groups in the islands are an offshore population, a northwestern Hawaiian Island group, and a small group around the main Hawaiian Islands. This last group, a unique, small, insular population, is genetically distinct from the other populations.
The false killer whale is black with a grey throat and neck. It has a slender body with an elongated, tapered head and 44 teeth. The dorsal fin is sickle-shaped and its flippers are narrow, short, and pointed. The average size is around 4.9 m (16 ft). Females can reach a maximum known size of 5.1 m (17 ft) in length and 1,200 kg (2,600 lb) in weight, while the largest males can reach 6.1 m (20 ft) and as much as 2,200 kg (4,900 lb).
False killer whales are kept in captivity and studied in the wild by scientists. Several public aquaria display them. For example, Okinawa Churaumi Aquarium in Japan displays false killer whales in the Okichan Theater.
Scientists have undertaken research to understand more about the species—including population surveys, satellite-tagged individual whales, and carcasses studies. From these studies, they determined information about habitat, range, and distinct populations. Recent study of the local population of false killer whales in Hawaii shows evidence of a dramatic decline over the last 20 years. Five years of aerial surveys from 1993 through 2003 show a steep decline in sighting rates. Group sizes of the largest groups documented prior to 1989 surveys were almost four times larger than the entire 2009 population estimate.
On 30 July 1986, a pod of 114 false killer whales became stranded at Town Beach, Augusta, in Flinders Bay, Western Australia. In a three-day operation, coordinated by the Department of Conservation and Land Management, volunteers carried 96 of the whales on trucks to more sheltered waters, and then successfully guided them out into the bay.
On 2 June 2005, up to 140 (estimates vary) false killer whales were beached at Geographe Bay, Western Australia. The main pod, which had split into four separate strandings along the length of the coast, was successfully moved back to sea, with only one death after the intervention of 1,500 volunteers, coordinated once again by the Department of Conservation and Land Management.
Just prior to sunrise on 30 May 2009, a pod of 55 false killer whales was discovered stranded on a sandy beach at Kommetjie in South Africa ( ). Despite the efforts of over 50 volunteers, most animals beached themselves again and the weather complicated further attempts. Authorities euthanized 44 whales.
As of July 2014, no record of an orphaned infant of the species surviving to adulthood after stranding has been reported, but veterinarians expressed hope about the prospects of a six-week-old male calf found on the shores of North Chesterman beach, near Tofino, British Columbia. He was found in critical condition on July 11, 2014, and received care at the Vancouver Aquarium.
The false killer whale is covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS), and the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS). The species is further included in the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU) and the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU)
In November 2012, the United States' National Oceanic and Atmospheric Administration recognized the Hawaiian population of false killer whales, which numbers around 150 individuals, as endangered.
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