Monday, May 10, 2010

Your Gonads Are Located Where?

A new family of jellyfish discovered off Tasmania. Photo courtesy: CSIRO (Commonwealth Scientific and Industrial Research Organisation)

There has been a staggering number of new species found recently proving that we have only scratched the surface of what Gaia still has to offer us.

Just this month, there have been many new species of jellyfish discovered in Australia - one being of particular interest.

Ironically, this discovery was made off the jetty of a wharf belonging to Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Hobart, Tasmania with a specially-designed plankton net. Short of the jellyfish leaping onto the wharf, collection doesn't get much easier than this. The jellyfish has been given the name Csiromedusa medeopolis and is not just a new species; but, an entirely new family.

Researchers from the Queen Victoria Museum and Gallery in Launceston and the South Australian Museum didn't know what they had until they put their catch under the microscope.

"There it was, just waiting to be discovered," said jellyfish researcher Lisa-Ann Gershwin.

What the microscope revealed was a tiny 1-2 mm (.04-.08") jellyfish that was shaped like a flying saucer. Protruding from a hole in the top of its head are its gonads (testicles and ovaries) looking like teensy skyscrapers. This became a feature of its name: csiromedusa means "jellyfish from CSIRO" and andmedeopolis means "city of gonads". A bit of research humour here?

The discovery of a new family of any kind is extremely rare. "A discovery of a whole new family like this is an uncommon occurrence," said Lisa-Ann. How apropos that this discovery was made in the International Year of Biodiversity.

The researchers found many new species of jellyfish in the samples collected from marinas, wharfs, jetties and boat ramps around Tasmania. However, this new family of jellyfish stand out because they have a structure that has never been seen before in the jellyfish world.

This new family belongs to the narcomedusa group of jellyfish that are only found in deep water. So how was it caught just off a wharf? Jellyfish have two life stages in their life cycle. As polyps, they are small cylindrical creatures that are either free-floating or attached to the ocean floor, rocks, or even small clumps of algae. These microscopic polyps have tiny tentacles at the top to catch food.

When the polyps mature, the jellyfish or medusa drifts away on the ocean currents. Mature jellyfish release sperm and eggs into the water so fertilization is a completely random affair occurring outside the body of most species. It will be interesting to see what kind of life cycle the Csiromedusa medeopolis has.

Via Wildlife Extra News

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