Common Name: Melon-Headed Whale
General Description: This animal resembles the False Killer Whale Pseudorca crassidens and the Pygmy Killer Whale Feresa attenuata. Its body is elongated and usually slim. The tail stock is slender. The forehead is rounded, ending in a rounded melon shape or a very indistinct beak. The lower portion of the face is usually slightly concave. The head appears triangular from above and below. The flippers are long, and the tall dorsal fin is back-curved.
The animal is uniformly black or very dark grey on the back and sides, a little lighter on the belly. A small triangular darkening in the face that tapers toward the eyes may be seen in the field. There is a faint grey throat patch. Areas around the lips and the anal and genital regions may be light coloured.
The Melon-headed Whale is one of the species called ‘blackfish’. Others include the Killer Whale Orcinus orca, False Killer Whale Pseudorca crassidens, the Pilot Whales Globicephala macrorhynchus and G. melaena, and the Pygmy Killer Whale Feresa attenuata.
Size: The length is up to 2.7 m and the weight up to 180 kg.
Appearance At Sea: Very little is known of the Melon-headed Whale’s natural history. It normally forms groups of 20 to 30, but schools of 500 are known to occur.
The Melon-Headed Whales arch quite strongly while diving, exposing the keel on the tailstock.
They have not been seen to bowride.
Found In: The Melon-headed Whale has a preference for warm waters. It is normally a pelagic animal. Melon-headed Whales feed on squids and small fish. There are reports of these whales possibly attacking porpoises escaping from seine nets of tuna fishermen in the Pacific.
Records from India: There are few records of the Melon-headed Whale from India. It is said to be recorded from Porto Novo.
Date : 23 August 1853
Details : “Delphinus (Lagenorhynchus) fusiformis”described by Owen
from Walter Elliot’s collections made near Vizagapatam;
Skull in the British Museum (Natural History).
References : Jerdon, 1867; De Silva, 1987;
Leatherwood et al., 1991
Date : About 1888
Details : Skull from the Palk Strait, in the British Museum.
References : De Silva, 1987; Leatherwood et al., 1991
Date : [?]
Details : Sighting from Vizagapatam.
References : Leatherwood et al., 1991
Date : Before 1971
Details : Specimen from Car Nicobar Island.
References : Leatherwood et al., 1991
The Melon-headed Whale is known to have stranded in Pakistan and in the Seychelles. It has been sighted near Djibouti and the Horn of Africa. It has also been recorded from Tanzania.
World Distribution: Found in all tropical and subtropical waters of the world, the Melon-headed Whale is rare everywhere except near Cebu Island in the Philippine Sea, where it is abundant.
Could Be Confused With: At a distance, the Melon-headed Whale may be difficult to distinguish from the Bottlenose Dolphin Tursiops truncatus, but at close quarters the absence of a beak would clear up any confusion. There is a greater possibility of confusion with the Pygmy Killer Whale Feresa attenuata and the False Killer Whale Pseudorca crassidens. They can be distinguished as follows:
Species : Melon-Headed Whale
Fin : Fin up to 25 cm high, with smooth trailing edge
Flippers : Pointed flippers
Head : Narrow and curved into ‘parrot beak’
Markings : Pure black above the water, absence of patch on chin, grey throat patch, light region around the lips.
Species : Pygmy Killer Whale
Fin : Up to 40 cm high, with wavy trailing edge
Flippers : Flippers are rounded at the tips
Head : Narrow and smoothly pointed
Markings : Grey flank marking and white goatee
Species : False Killer Whale
Fin : High curved fin
Flippers : Long pointed flippers with elbow
Head : Narrow, tapered head
Markings : No markings visible
Diagnostic Features: At sea, Prominent dorsal fin, narrow head curved into a ‘parrot beak’, pointed flippers, light region around the lips.
Stranded Specimens: There are 20 to 25 pairs of small, sharply pointed teeth in the upper jaw and 22 to 24 pairs in the lower jaw.