PYGMY SPERM WHALE (T) 



Kogia breviceps (Blainville 1838) 



Other Common Names 



None known. 



Description 



Pygmy sperm whales reach a length of at least 11 feet (3.4 

 m). They are characterized by 1) an extremely robust body 

 that rapidly tapers near the tail, 2) a squarish head, and 3) a 

 narrow, underslung lower jaw which is located well behind 

 the tip of the snout. Along the side of the head, in 

 approximately the same position where gill slits would be 

 located on a fish of comparable size, there is a crescent- 

 shaped bracket mark, often called a false gill. 



The flippers, which are smoothly curved on the forward 

 margin and may reach a length of 18 inches (45.7 cm) or more 

 on an adult specimen, are located well forward on the body, 

 just below and behind the bracket mark. 



The dorsal fin is very small, falcate, and located in the 

 latter half of the back. 



Though coloration can be described only from stranded 

 specimens and a few encounters with living animals, pygmy 

 sperm whales appear to be dark steel gray on the back, 

 shading to a lighter gray on the sides, and gradually fading to 

 a dull white on the belly. The outer surface of the flippers and 

 the upper surface of the tail flukes are also steel gray. 



Natural History Notes 



From the few accounts, the following may be summarized 

 about the behavior of pygmy sperm whales at sea: They 

 reportedly usually rise slowly to the surface to breathe, 

 produce a blow that is inconspicuous, and do not normally roll 

 aggressively at the surface like most other species of small 

 whales. They reportedly fold their flippers flat against their 

 bodies when swimming. They have been reported to lie 

 motionless in the water with the back of the head on the 

 surface and the tail hanging loosely down in the water. (A 

 similar behavior in sperm whales has made them a minor 

 hazard to shipping, since it has resulted in some collisions 

 with ships. ) When they are startled in this posture, they may 

 defecate, issuing a cloud of reddish brown to rust-colored 

 fece. Beached pygmy sperm whales have also been observed 

 to defecate a fine chocolate feces. 



Pygmy sperm whales apparently feed primarily on squid, 

 but do take fish as well. 



the name implies, have elongated "dolphinlike" beaks and are 

 considerably larger. At sea, pygmy sperm whales are most 

 likely to be confused with their cousins the dwarf sperm 

 whales (p. 148 and Fig. 160). The two species can be dis- 

 tinguished as follows: 



Pygmy Sperm Whale 



Dwarf Sperm Whale 



To 11 feet (3.4 m) 



MAXIMUM SIZE 



To 9 feet (2.7 m) 



DORSAL FIN 



Small to 8 inches (20.3 cm), 

 falcate; located in latter third 

 of back. 



Taller, more like that of 

 bottlenosed dolphins; locat- 

 ed near the midpoint of the 

 back. 



COLORATION 



Both species are dark steel g^ay on the back, grading to 

 lighter on the belly. 



Distribution 



Because they have been rarely observed at sea, normal 

 ranges for this species are not known. Based on stranding 

 records, however, the following can be stated. In the western 

 North Atlantic, pygmy sperm whales have been found as far 

 north as Sable Island, Halifax, Nova Scotia, as far south as 

 Cuba, and as far west as Texas in the Gulf of Mexico. They are 

 frequently found stranded along the Atlantic coast of Florida 

 and throughout the eastern and northern Gulf of Mexico. 



Stranded Specimens 



Because of the distinctive characters of the genus, 

 stranded pygmy and dwarf sperm whales are unlikely to be 

 confused with any other species of cetacean, though the 

 rather narrow underslung jaw and the blunted head may 

 result in their casual dismissal by some beach walkers as 

 stranded sharks. The two species of Kogia may be 

 distinguished by the following: 



Pygmy Sperm Whale 



Dwarf Sperm Whale 



May Be Confused With 



In general, when they can be examined at close range, 

 pygmy sperm whales are so distinctive that they are unlikely 

 to be confused with any other species except perhaps the 

 dwarf sperm whales. At a distance, they might be confused 

 with small individuals of any of the beaked-whale species 

 (p. 78) that also have a relatively small, falcate dorsal fin 

 located in the latter third of the back. Closer examination 

 should permit easy separation, however, since the pygmy 

 sperm whale has a blunted head, while the beaked whales, as 



TEETH 



12-16 (rarely 10-11) in lower 

 jaw are larger; no teeth in 

 upper. 



8-11 (rarely 13) small and 

 extremely sharp teeth in 

 lower jaw; sometimes have 

 up to 3 teeth in each upper 

 jaw. 



THROAT 



No creases or grooves on 

 throat. 



Several short irregular creas- 

 es or grooves on throat. 



144 



