DWARF SPERM WHALE (T) 



Kogiasimus (Owen 1866) 



Other Common Names 



Rat porpoise (West Indies). 



Description 



Dwarf sperm whales reach an overall length of 

 approximately 9 feet (2.7 m). Like the other species oiKogia. 

 the pygmy sperm whale (p. 144), the dwarf sperm whales are 

 characterized by 1) a squarish head, 2) an extremely robust 

 body which tapers rapidly near the tail stock, 3) a narrow, 

 underslung lower jaw, and 4) a bracket mark or false gill on 

 the side of the head. 



The dorsal fin of this species is tall and falcate, closely 

 resembling that of the Atlantic bottlenosed dolphin, and is 

 located near the midpoint of the back. There are several 

 short, irregular creases or grooves on the throat similar to 

 those found on the sperm whale (see Figs. 60, 165). 



Dwarf sperm whales are dark steel gray on the back, 

 grading to lighter gray on the sides, and fading to dull white 

 on the belly. 



May Be Confused With 



Because of their tall, falcate dorsal fin, dwarf sperm 

 whales may be confused at a distance with any of the small 



dolphin species. Their all-black or dark steel-gray coloration 

 and the blunted head increase the likelihood that they can be 

 confused with pygmy killer whales or many-toothed 

 blackf ish . They will have to be examined at close range before 

 they can be distinguished. 



Dwarf sperm whales may also be confused with pygmy 

 sperm whales (p. 144 and Fig. 160). The two species can 

 be differentiated by the characteristics tabularized on p. 144. 



Distribution 



Since it has only recently been recognized as a species 

 distinct from the pygmy sperm whale and even more recently 

 given a common name, records of dwarf sperm whales may 

 have been confused with those of its close relatives. The 

 dwarf sperm whale has been reported from at least Georgia 

 south to St. Vincent, Lesser Antilles, and throughout the 

 eastern and northern Gulf of Mexico. It is highly likely that 

 this species, like the pygmy sperm whale, extends further to 

 the north. 



Stranded Specimens 



Because of the distinctive characteristics of the genus, 

 neither species of stranded Kogia is likely to be confused with 

 any other species. They can be distinguished from one 

 another by the characteristics tabularized on p. 144. 



Figure 164.-A dwari sperm whale stranded near St. Augustine, Fla., shown swimming in the Unk at Marineland of Florida. In this species 

 the dorsal fin is taller than that of the pygmy sperm whale and is located near the midpoint of the back (see Figs. 159 and 160). 

 (Pkoto courtesy of Marineland of Florida. ) 



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