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 blackfish. 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].