New whale makes a splash

2003-11-19 08:30

Paris - Japanese researchers say they have uncovered a previously unidentified species of whale, a discovery that is extraordinarily rare on a planet where more and more large mammal species are at risk of extinction.

The 12-metre-long creature joins the elite club of baleen whales, or Balaenopterae in Latin - whales that use a comb, or baleen, to trap small particles of food, as opposed to the other branch of the family, the toothed whales.

The newcomer has been dubbed Balaenoptera omurai in honour of Hideo Omura, one of the top names in Japanese whale research in the 1960s and 70s.

Reporting in the British science weekly Nature, a team lead by Shiro Wada of the National Research Institute of Fisheries Science in Yokohama, say the story behind the exciting find dates back more than two decades.

In the late 1970s, Japanese research vessels, operating in southern latitudes on the border between Pacific and Indian oceans, caught eight specimens of a baleen whale that left experts baffled as to their identity.

Identity check

Then, in 1998, a similar kind of whale washed up dead on Tsunoshima, a Japanese island on the Sea of Japan.

The advent of biotechnology gave Wada's team the chance to do a DNA identity check against known whale species and make a close comparison of its skeleton and other body parts.

Their conclusion: B omurai is a different species. Not only is its molecular ID unique, its cranial structure is distinct from other whales, and it notably has a smaller number of baleen plates.

The DNA work has thrown up another discovery - that two outwardly similar baleens, the Bryde's whale and the Eden's whale, are in genetic terms so different that they deserve to be considered different species.

If this suggestion is accepted internationally, that would boost the number of known living baleen species, also called rorquals, from six to eight.

More to discover

The other five are the blue whale, which is the world's largest mammal, as well as the humpback whale, fin whale, sei whale and minke whale.

Further details about B omurai remain obscure: its habitat, eating habits, reproductive cycle and so on remain largely unknown, although Wada believes that more specimens will come to light when museums start to look more closely at their collections.

The find reflects how little of the world's flora and fauna has been documented, even as the number of species that are extinct or heading that way, especially mammals, rises each year.

According to US scientist Peter Raven, director of the Missouri Botanical Garden, of the estimated 10 million species alive today, only 1.5 million have been recognised and named scientifically. The biggest knowledge gaps are in microscopic species, especially fungi.

- AFP