||The Mammals of Texas -
Pygmy Sperm Whale
Cetacea : Family Physeteridae :
Kogia breviceps (Blainville)
Description. A small, toothed whale;
upperparts, top of pectoral fins, and flukes blackish;
underparts and upper lip, white; dorsal fin small,
situated posterior to the mid-point on back, the tip
pointing backwards; pectoral fin short and
"spear-shaped"; blowhole an oblique crescent
left of midline; mouth small and subterminal; snout
blunt; skull short, broad, spongy, and markedly
asymmetrical; left naris large, right one degenerate, as
in the sperm whale; front part of skull deeply
bowl-shaped; teeth small, slender, and widely spaced,
12-16 in each lower jaw; total length 2-4 m. Measurements
of one whale: total length, 3.2 m; snout to anterior edge
of dorsal fin, 1.7 m; height of dorsal fin, 76 mm; length
of pectoral fin, 495 mm. Weight of adults, more than 300
Distribution in Texas. These
whales are found in warm waters worldwide. In the western
North Atlantic they occur from Nova Scotia to Cuba and as
far westward as the Texas coast, where strandings occur
relatively frequently. These whales were once thought to
be quite rare, but stranding records indicate they may be
more common than originally believed.
Habits. This is a deep water,
pelagic species about which very little is known. They
occur in small groups of three to six individuals and
appear slow and deliberate in their actions. Low
frequency, low intensity, pulsed sounds have been
recorded from these whales, suggesting that they may be
capable of echolocation.
Their food habits are not well-known.
Stomachs that have been examined contained carapaces and
appendages of green crabs, shrimp, and beaks of squid.
Information available suggests that
mating takes place in late summer and the young are born
the following spring after a gestation period of some 9
months. The young calf stays with its mother during its
first year, as judged from records of capture of pregnant
females accompanied by offspring of the previous year.
Newborns are about 1.2 m long and weigh 54 kg. Strandings
of these whales may often be related to calving, as
females with newborn young often strand, as well as
females whose reproductive tract shows evidence of
parturition just prior to stranding.
Illustration credit: Pieter