New branches on the zoanthid family tree
19 November 2010
New specimens discovered on the CReefs expedition to Heron Island may a result in a major overhaul of the taxonomy of several groups of marine animals, according to Associate Professor James Reimer, of Japan's University of the Ryukyus.
Professor Reimer is studying zoanthids, an order of colonial animals that are found in oceans around the world. He and several of his graduate students have discovered a tiny, undescribed species of zoanthid in the waters around Okinawa in Japan, and have found several specimens of the same species both at Ningaloo Reef in Western Australia and here at Heron Island.
The discovery of this and several other unusual groups of zoanthids may see the classification of the order revised dramatically.
"The existing family tree assumes zoanthids are a neat group, clearly divided from related orders such as anemones – but a few groups of zoanthids have been found recently that are really very different from what we already knew. They are part of the tree, but they fit on branches quite far out either side of the main group," Professor Reimer explains.
"DNA sequencing of these specimens suggests that the order is much more genetically diverse than we thought. The general idea of zoanthids is correct, but our understanding of the scope that they encompass is definitely going to change," he says.
"At the same time, scientists are also finding anemones that have somewhat similar behaviour to zoanthids, so we may also find that these two groups are much closer than we imagined," he says.
Professor Reimer is collecting specimens and establishing the diversity of zoanthids in the waters around Heron Island during the CReefs field expedition this month. He will compare these with the existing taxonomy of zoanthids found around Australia, in Japan, Singapore and elsewhere.
He is also collecting specimens of small crustaceans of the order Amphipoda for study by one of the post-doctoral researchers in his laboratory in Japan.