|The Mammals of Texas -
Cetacea : Family Delphinidae : Peponocephala
Description. Melon-headed whales are
about the same size as pygmy killer whales (Feresa
attenuata), with adult males up to 2.7 m and adult
females up to 2.6 m in length. Maximum weight is about
225 kg. The profile of the melon-headed whale is not
unlike that of the pygmy killer whale; however, while the
pygmy killer whale has a totally rounded, bulbous head,
that of the melon-headed whale is rounded in profile and
on the top, flat below, and seen from bottom or top,
forms a distinct triangle between the eyes and the tip of
the snout. The dorsal fin is distinct and falcate, and
located at the middle of the back. The flippers are long
and, unlike those of the pygmy killer whale, pointed at
the tips. Each upper jaw has 20-25 sharp-pointed teeth,
while there are 22-24 in each lower jaw. This is about
twice the number found in the pygmy killer whale and the false killer whale (Pseudorca crassidens), and is a firm
identification mark for even decomposed animals.
Coloration is black except on the belly
and around the mouth, with the white lips resembling
those of pygmy killer whales. Although the belly may be
very white, it is usually a light gray and not as
distinct as the white belly patch of the pygmy killer
Distribution in Texas. Worldwide
in tropical and subtropical waters but most numerous in
the Philippine sea. They appear to favor warm, pelagic
waters and rarely stray over the continental shelf. Known
in Texas on the basis of one animal that stranded alive
on Matagorda Peninsula in June, 1990. Previously, the
nearest record of occurrence was from the island of St.
Vincents in the Caribbean.
Habits. Melon-headed whales
travel in groups of 100-1,000, although even larger
groups have been reported. In the tropical Atlantic,
Pacific, and Indian Ocean they have been reported
traveling with Frasers dolphin (Lagenodelphis
hosei) and with spinner and spotted dolphins (Stenella spp.).
Little is known about their
reproductive habits. Calving appears to peak in early
spring in the low latitudes of both hemispheres. The
length of gestation is not known, but is probably about
12 months. Migration is unknown, and strandings occur
year round in tropical and subtropical waters.
Melon-headed whales feed mainly on squid and fish.
Illustration credit: Pieter