PYGMY KILLER WHALE (T) 



Feresa attenuata Gray 1874 



Other Common Names 



Slender blackfish, slender pilot whale. 



Description 



Pygmy killer whales reach a length of about 8-9 feet 

 (2.4-2.7 m). They are usually relatively slender-bodied with a 

 rounded head, an underslung jaw, and no beak. 



The falcate dorsal fin, located about the center of the back, 

 is usually between 8 and 12 inches (20.3 and 30.1 cm) tall 

 (though it may reach 15 inches [38 cm] in some individuals), is 

 sometimes very distinctive, and resembles that of the 

 Atlantic bottlenosed dolphin. The flippers are slightly 

 rounded on the tips. 



The color has been described as dark gray or black on the 

 back, often lighter on the sides, extending higher in front of 

 the dorsal; fin and with a small zone of white on the 

 underside, often a lighter gray area on the sides, and 

 distinctive white regions around the lips. The chin may be 

 completely white. This white zone on the chin, described as 

 a "goatee," is often clearly visible in swimming animals. 



May Be Confused With 



The pygmy killer whale resembles the false killer whale 

 but is much smaller and can be distinguished at close range by 

 the zones of white coloration. False killer whales are almost 

 all black and reach a length of up to at least 18 feet (5.5 m). 

 Pygmy killer whales are dark gray on the back, often lighter 

 on the sides, and show a region of white on the belly which 

 may extend so high up onto the sides that it is visible on a 

 swimming animal. Further, they reach only 8-9 feet (2.4- 

 2.7 m). 



Pygmy killer whales may also be confused with the 

 similarly sized and colored many-toothed blackfish. So little is 

 known of the two species' appearance and behavior at sea that 

 it is doubtful that they can be successfully distinguished, 

 though many-toothed blackfish apparently lack the white 

 region often seen on the sides of pygmy killer whales. 

 Further, pygmy killer whales have rounded flippers and 

 smoothly tapered heads, while those of the many-toothed 



blackfish are pointed on the tip and more sharpely pointed 

 (often described as a parrot beak). 



Distribution 



Pygmy killer whales are probably distributed in the 

 tropical and subtropical waters of the western North 

 Atlantic. They have been reported from Texas, the Atlantic 

 coast of Florida, and St. Vincent Island, Lesser Antilles. 

 Records of the species from the other oceans of the world 

 suggest that its distribution is limited to tropical and 

 subtropical waters. 



Stranded Specimens 



Stranded pygmy killer whales can be clearly distinguish- 

 ed from both the false killer whale and the many toothed 

 blackfish. In addition to the differences discussed above, the 

 following are key differences between the pygmy and false 

 killer whales: 



Pygmy Killer Whale 



False KiUer Whale 



TEETH 



10-13 in each side of upper 

 and lower jaws; lower teeth 

 smaller. 



8-11 per jaw 

 prominent. 



per 



side. 



VENTRAL COLORATION 



White from anus to under tail 

 stock, white may extend up 

 sides. 



Dark from anus to tail stock; 

 lighter pale gray area for- 

 ward between flippers. 



FLIPPERS 



Smoothly rounded. 



Characteristic hump on for- 

 ward margin. 



Pygmy killer whales can be distinguished from many- 

 toothed blackfish on the basis of the second species" larger 

 number of teeth. (Many-toothed blackfish have from 22 to 25 

 teeth in the upper jaw and from 21 to 24 in the lower jaw.) 



Figure 152. — Pygmy killer whales at sea northwest of Hawaii (top) off the island of 

 Oahu, Hawaii (middle), and from southeastern Florida in the tank at the W'ometco 

 Miami Seaquarium (bottom). When swimming rapidly, pygmy killer whales may 

 closely resemble the much larger false killer whales. In addition to their much smaller 

 size, rarely exceeding 9 feet (2.7 m), however, pygmy killer whales can be 

 distinguished by their more rounded head, the white coloration of the lips and chin, and 

 the white zone on the belly, sometimes extending up the sides. [Photos by S. Ohsumi 

 [top]; J. Naughton, Natvoruil Marine Fisheries Service and courtesy of E. Shallenberger, 

 Sea Life Park \middle]: and courtesy of Wometco Miami Seaquarium [bottom].) 



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