Gray, 1875 - Pygmy killer whale
Distinctive Characteristics
The pygmy killer whale is often confused with the false killer whale and melon-headed whale. The best field character for distinguishing among these species is the flipper shape (rounded tips in the pygmy killer whale, pointed tips in the melon-headed whale, and humps on the leading edge in the false killer whale). The body of the pygmy killer whale is somewhat slender; the head is rounded and has no beak.
The colour of the body is dark grey to black, with a prominent narrow cape that dips only slightly below the dorsal fin, and a white to light grey ventral band that widens around the genitals. Also, the lips and snout tip are sometimes white.
The upper jaw contains 8 to 11 pairs of teeth, and the lower jaw has 11 to 13 pairs.
Can be confused with
Pygmy killer whales are most easily confused with melon-headed whales, and less easily with false killer whales. Flipper shape, head shape, and the contour of the cape are the best features to use in distinguishing pygmy killer and melon-headed whales.
Size
Newborns are about 80 cm long, adults up to 2.6 m. Males are slightly larger than females. Maximum known weight is 225 kg.
Geographical Distribution
This is a tropical and subtropical species that inhabits oceanic waters around the globe, generally not ranging north of 40°N or south of 35°S.
Biology and Behaviour
There is little known of the biology of the pygmy killer whale. Groups generally contain 50 or fewer individuals, although herds of up to several hundred have been seen. It is slow and lethargic compared to the similar-appearing melon-headed whale.
Not much is known of the reproductive biology of this species.
Pygmy killer whales eat mostly fish and squid, although they occasionally attack other dolphins, at least when those dolphins are involved in tuna fishery interactions in the eastern tropical Pacific.
Exploitation
A few individuals are known to be taken in drives and in driftnets in various regions, most notably Japan and Sri Lanka. Small incidental catches are known in fisheries in other areas.
IUCN Status
Insufficiently known.