The Melon-headed whale (Peponocephala electra)

Jul 19, 2015 Features / Columnists, Interesting Creatures in Guyana

The melon-headed whale (species Peponocephala electra; other names are many-toothed blackfish and electra dolphin) is a cetacean of the oceanic dolphin family (Delphinidae). It is closely related to the pygmy killer whale and pilot whale, and collectively these dolphin species are known by the common name blackfish. It is also related to the false killer whale.
The melon-headed whale is widespread throughout the world’s tropical waters, although not often seen by humans because it prefers deep water. It has a body shape rather like a torpedo. Its head is 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 relative the killer whale. When viewed in profile, its head is not as rounded as the pygmy killer whale and this may aid identification.
This whale is capable of very fast swimming, particularly when startled. In flight, it often makes short, low jumps clear of the sea surface, splashing lots of water. Melon-headed whales usually gather in large numbers (at least 100 and possibly as many as 1,000 on rare occasions) and sometimes strand together.
The melon-headed whale weighs 10–15 kg (22–33 lb) at birth and is 1 m (3.3 ft) long. An adult grows up to 3 m (9.8 ft) long and weighs over 200 kg (440 lb). The whales’ lifespans are at least 20 years and probably more than 30 years for females. Their primary diet is squid.

Melon-headed whale

Melon-headed whales are very social animals. They have been observed swimming close to each other and touching flippers. Within the large group, they usually swim in smaller groups of 10-14.
Melon-headed whales are also known to associate with Fraser’s Dolphins (Reeves, 428). Groups of the melon-headed whales will mix with groups of Fraser’s Dolphins and socialize with them. The melon-headed whale will also associate with other animals such as, the Humpback whale and Pilot whale.
Melon-headed whales tend to rest near the surface of the water. They have been observed moving toward the sound of a boat and then riding the waves created from the boat. They are not usually deterred by the sound of the boat.
When resting near the surface, melon-headed whales will create large splashes when they break the water. Several of them will rise vertically out of the water to observe their surroundings and then splash back down, a technique known as spy hopping. At the surface, melon-headed whales will also swim quickly, almost breaking the surface of the water and creating crescents ahead of them.
The melon-headed whale lives far from shore in all the world’s tropical and subtropical oceans. At the northern fringes of its range, it may also be found in temperate waters.
Although no specific data exist, the species is unlikely to be migratory, in common with animals in its subfamily.
Melon-headed whales are closely related to false killer whales, short-finned pilot whales, and pygmy killer whales. There are many marine mammals that have parasites such as Isocyamus delphinii. These parasites (also known as a whale louse) will burrow into a whale or dolphin especially if there is a wound.
In 1999, a dead, stranded melon-headed whale was discovered and a necropsy was performed on it. They discovered bite marks from smaller sharks, and in those bite marks were the parasites Isocyamus delphinii. There were twelve of the parasites in total which is a record for the number of those parasites found on a marine mammal.
(Source: Wikipedia – The Free Online Encyclopedia)