Pygmy Right whale

(Caperea marginata)

The Pygmy Right whale is the smallest and least known of all the baleen whales. It has been rarely seen and most confirmed sightings have been limited to stranding reports from South Australia, Tasmania, New Zealand, South Africa and one from South America.

This whale is similar in appearance to the Minke whale (Balaenoptera acutorostrata) but can be distinguished from it by its strongly arched jawline and the lack of Minke-like white flipper bands. Although the Pygmy Right whale shares the arched mouth with the larger Right whale (Eubalaena australis) the Pygmy has a dorsal fin, different flipper shape and a more streamlined body.

Suborder: Mysticeti

Family: Neobalaenidae

Other Names: No other names

The head of this species is about 1/4 of its body size and the female is larger than the male. Their lengths range between 5 and 6.4 meters (16 to 21 feet) and they can weigh between 3 and 3.5 tonnes. As the Pygmy Right whale is a baleen whale it has no teeth. Its lower jaw is highly modified - bowed and slightly projecting beyond its strongly arched upper jaw. The line of the mouth extends behind and below the eye. Attached to the upper jaw, on each side, are 230 baleen plates pale grey or white in colour with dark outside edges. Although the tongue and the inside of the whale's mouth are white, often, when the mouth is open only the white band of the baleen gums can be seen. There are two indistinct longitudinal furrows on the throat.

The Pygmy Right whale's back is grey or dark grey, with variable pale streaks extending to the shoulder and dark streaks from the eye to the flipper, lightening on the sides to white on the belly and lower jaw. The flanks and pectoral flippers are also grey or dark grey and contrast the lighter color of the sides.

The flippers are small and narrow with slightly rounded tips. The dorsal fin is small, sickle-shaped and two-thirds along the back. The tail flukes are broad and distinctly notched.

Although never seen feeding the Pygmy Right whale is believed to eat copepods. It is inconspicuous at sea and only surfaces for a few seconds at a time. It has not been observed breaching or lobtailing but it will throw its snout out of the water. Its flukes never lift clear of the water and sometimes its back and dorsal fin remain hidden for view.

None of these whales have been found in the Northern Hemisphere. Distribution appears limited by the surface water temperature as they are almost always found in 5° to 20°C (41° to 68°F) temperature water. This excludes the whales presence south of the Antarctic Convergence and the cold waters of the Antarctic. Population numbers are unknown as it is easily confused with the Minke whale but Pygmy Right whales may be more common than the limited sightings suggest.