The Melon-headed Whale (Peponocephala electra) is a cetacean of the oceanic dolphin family (Delphinidae). It is closely related to the Pygmy Killer Whale and the Pilot Whales, and collectively these dolphin species are known by the common name blackfish. The Melon-headed Whale is widespread throughout the world's tropical waters, although not often seen by humans on account of its preference for deep water.
On account of its inaccessibility (most scientific data has come from mass strandings), this species is poorly understood. Until 1966 it was classified in the genus Lagenorhynchus. Scientists then reclassified the creature into its own genus, Peponocephala. It his 1998 survey of all cetacean species Dale Rice points out that pepo is actually Latin for pumpkin not melon as the namers had intended. The strict translation of the scientific name is therefore Pumpkin-headed Whale. This name is never used by cetologists or whale enthusiasts.
The Melon-headed Whale has a body shape rather like a torpedo - its head shaped like a rounded cone giving the animal its common name. The body is more or less uniformly light grey except for a dark grey face - sometimes called the "mask". The flippers are long and pointed. The dorsal fin is tall with a pointed tip - reminiscent of its cousin the Orca. When viewed in profile the head is not as rounded as the Pygmy Killer and this may be an aid to identification.
This whale is capable of swimming very quickly, particularly when startled. When doing so it often makes short low jumps clear of the sea surface, causing lots of splash. Melon-heads usually gather in large numbers (at least 100 and possible as many as 1000 on rare occasions) and sometimes strand together.
The Melon-head weighs about 10-15kg at birth and is 1m long. An adult grows upto 3m long and weighs in excess of 200kg. The whales' lifespan is at least 20 years and probably more than 30 years for females.
Their primary diet is squid.
Population and distribution:
The Melon-headed Whale lives well off-shore in all the world's tropical and sub-tropical oceans. At the northern fringes of its range it may also be found in the warm currents of temperate waters, for example they has been the odd sighting off the southern coast of Ireland. Ordinarily however the Melon-head is found beyond the continental shelf between 20° s and 20° n. Hawaii and the Cebu, Philippines are good sights for the seeing the whale as the continental shelf is narrow. Although no specific date exists, the species is unlikely to be migratory in common with animals in its subfamily.
National Audubon Society: Guide to Marine Mammals of the World.
Encyclopedia of Marine Mammals.