Saturday, 7 September 2013

New seaweed may be Hobart's Wollemi Pine


Last week I said I was tickled pink about having a new seaweed named after me. And I was. My university supervisor and in many ways mentor, Dr Gerry Kraft, named an alga Entwisleia

Bridie Smith from The Age did a lovely job explaining its significance and in the process comparing me (indirectly) to Adolf Hitler, Nelson Mendela and Sid Vicious. But I think there is more to the story. This new organism could be Hobart's Wollemi Pine. 


The new alga (or seaweed) is Entwisleia bella, classified in the family Entwisleiaceae in the order Entwisleiales. Not just a new species to science, but a new genus, family and order. The species name bella is due to the beauty of the alga, not of me, and also a reference to the Italian ancestry of one of the authors of the paper, Fiona Scott*.

You could say finding Entwisleia is like sighting the very first conifer, primate, spider or diprotodontids (kangaroo, possum, koala or possum) on Earth. Not only that but it may be almost as rare as the Wollemi Pine, now only know from a hundred or so specimens distributed between a few small populations. Entwisleia is known only from a dozen or so seasonal individuals on a few submerged rocks south of Hobart. And we don’t know how secure it is, or how it might cope with environmental change.

The Wollemi Pine (Wollemia nobilis), discovered 19 years ago near Sydney, was rightly hailed as a scientific marvel. It’s true it was already known from the fossil record and thought to be extinct, and it is unusual to find a brand new genus of tree in Australia, but it fits into an existing family, the Araucariaceae, with hoop pines and monkey puzzle trees. This family is, in turn, part of the order Pinales including all known pine trees and conifers. 


So I think this really could be considered Hobart’s Wollemi Pine. It grows closer to Hobart than the Wollemi Pine does to Sydney, and Entwisleia is more significant in an evolutionary sense and perhaps as rare. 

The discovery also goes to show how much there is still to discover in Australia’s algal flora. I got into algae myself after finding something unusual and new for Victoria in Melbourne’s Darebin Creek – it was the thrill of discovery and curiosity that hooked me. I spent my research life working on freshwater algae, and particularly on a group of freshwater red algae called Batrachospermum. This new alga looks like Batrachospermum but grows in the sea and turns out (from DNA sequencing) to be quite unrelated.


It’s estimated that in the oceans, lakes, streams and ponds of this country there are 12,000-18,000 species of algae (compared with about 25,000 vascular plants), with about 10,000 of them described so far. We know very little about the evolution, biology and ecology of any species. 

The Southern Australian coastlines support more than 1,150 species of algae (seaweeds), compared with 1,000 in the Mediterranean Sea, 900 around Japan and 900 in the Philippines. More than 60% per cent of the species in Australian waters are found nowhere else.

I should point out that ‘algae’, including many things that we call seaweeds, is a category of convenience rather than an evolutionarily distinct lineage. The red algae are closely related to the branch that leads to green plants including flowers and pines, and they are, of course, the most interesting and the prettiest. 


Notes: *Fiona Scott, who actually discovered the alga and then dived regularly to study its abundance and ecology, was supported in her work by the Winifred Violet Scott Charitable Trust. Fiona works for the Institute for Marine and Antarctic Studies at the University of Tasmania in Hobart. The paper describing the new alga will be published in November 2013: Scott, F.J, Saunders G.W. and Kraft, G.T. (2013) Entwisleia bella gen. et sp. nov., an novel marine “batrachospermaceous” red alga from southeastern Tasmania representing a new family and order in the Nemaliophycidae. European Journal of Phycology 48(4). The picture of me holding (very inappropriately) a herbarium specimen was taken by Penny Stephens from The Age. The final picture of Entwisleia was taken by Fiona Scott.

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