FALSE KILLER WHALE (T) 



Pseudorca crassidens (Owen 1846) 



Other Common Names 



Mongoose (St. Vincent). 



Description 



False killer whales in the western North Atlantic reach a 

 length of at least 18 feet (5.5 cm). Males are slightly larger 

 than females. Calves from 5 to 7 feet (1.5 to 2.1 m) may be 

 seen at any time throughout the year. 



The dorsal fin, located just behind the midpoint of the 

 back, is from 7 to 16 inches (17.8 to 40.6 cm) tall, falcate, and 

 variable to sharply pointed on the tip. The flippers are 

 characterized by a broad hump on the front margin near the 

 middle, a characteristic which is diagnostic for the species. 



The body of the species is all black except for a blaze of 

 gray on the belly between the flippers. This blaze varies from 

 barely visible to light grayish white similar to but generally 

 fainter than that of pilot whales. The body is long and slender, 

 and the head is narrow and gently tapered from the area of 

 the blowhole forward. 



Natural History Notes 



False killer whales are a social form and may occur in 

 herds of up to at least 100 individuals. They often jump clear 

 of the water and frequently ride the bow waves of vessels. 

 They are the only "blackfish" which are known to do so. False 

 killer whales feed primarily on squid and large fishes and are 

 notorious for their habit of stealing fish from the lines of 

 fishermen. The large prominent teeth may be visible on a 

 swimming animal. 



May Be Confused With 



False killer whales may be confused with killer whales, 

 pilot whales, or the smaller, poorly known pygmy killer whale 

 (p. 138) and many-toothed blackfish (p. 142). 



The characteristics distinguishing the species from the 

 killer whale are tabularized on p. 84; its differences from the 

 pilot whales are summarized on p. 92. 



At sea, false killer whales are distinguishable from the 

 other two species primarily by their larger size and 

 differences in coloration. False killer whales are up to 18 feet 

 (5.5 m) in length. Pygmy killer whales and many-toothed 

 blackfish reach only 8-9 feet (2.4-2.7 m) in length. Pygmy 

 killer whales have an extensive region of white on the belly 

 which my extend onto the sides and both pygmy killer whales 

 and many toothed blackfish have a distinctive white region 

 on the lips, usually lacking or indistinct on false killer whales. 



Neither of the smaller species of blackfish has been 

 reported to ride bow waves. 



Distribution 



False killer whales are widely distributed in the pelagic 

 tropical, subtropical, and warm temperate waters of the 

 western North Atlantic. They have been reported from off 

 Maryland south along the mainland coasts of North America, 

 in the Gulf of Mexico from Cuba and the Lesser Antilles, and 

 from the southeast Caribbean Sea. The species has been 

 reported from Venezuela. 



False killer whales do not appear to occur frequently in 

 coastal waters, sandy bays, or estuaries, though entire herds 



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Figure 92. - False killer whales at sea 600 miles (968.0 km) off northeastern Florida. Note the smoothly falcate 

 dorsal fin, pointed on the tip, and located near the midpoint of the back. Dorsal fins of this species may also be 

 rounded on the tip but all are sharply concaved on the rear margin. {Photo by H. E. Winn. ) 



