Biodiversity researchers from Denmark and Australia believe they have solved one of the great mysteries of the sea – where did the sea skaters come from?
Sea skaters are small, flightless creatures which are the only insects in the world to permanently live on the high seas. The five known species spend all their lives on the ocean wave, skating on the surface of the Indian and Pacific Oceans throughout the tropics.
There has been a great deal of speculation among scientists about where sea skaters first originated, and how they evolved to live their unique lifestyles. Sea skaters are thought to be related to freshwater insects called water-striders, but until now the connection between the two types of insects has remained a mystery.
Now an insect collected last year on Queensland’s Cape York by biodiversity researcher Paul Zborowski has been identified as the sought-after missing link. The Australian insect is a kind of half-way point between the two types of animal.
Danish biodiversity researcher Dr Nils Andersen, from the Zoological Museum at the University of Copenhagen, and CSIRO researcher Tom Weir have given the new species a scientific name, Austrobates rivularis, publishing their findings in the international scientific journal Invertebrate Taxonomy.
"The Cape York skater is a freshwater insect, but it’s also closely related to the sea-faring skaters," Dr Andersen said. "We think the new Australian insect must be very close to how the sea skaters’ ancestors looked. Probably about 60 million years ago water-striders living in coastal creeks in what is now northern Australia took to the sea. Australia is probably the original home for all the sea skaters in the world."
"It shows just how rich Australia is in natural biodiversity, and how much we can learn about the evolution of life on Earth from studying Australia’s biodiversity; its flora and fauna. It is estimated that there are about 140,000 species of insects in Australia alone – many thousands of these still await discovery and study. Who knows what part they play in the world’s environment?"
Biological diversity (or "biodiversity") means simply the variety of life on Earth. It includes three levels – genetic variation within a species, variation between different species and variation between different ecosystems. The International Convention on Biodiversity, which Australia and more than 50 other countries have now ratified, came into force around the world on December 29 last year.
By David Mussared. Department of the Environment and Water Resources. May 12, 1994.