CSIRO harbours new jellyfish
A spectacular new jellyfish has recently been found off the CSIRO wharf at
Battery Point in Hobart, Tasmania, and has been given the name
Csiromedusa medeopolis. This newly
discovered life form is full of surprises, as it represents not only a new
species but also a new family.
The jellyfish was discovered by researchers from the Queen Victoria Museum and
Gallery in Launceston and the South Australian Museum. They used a
specially-designed plankton net to catch the jellyfish off the CSIRO wharf. When
they pulled up the net and looked at what they had caught under a microscope
they found an amazing and unique jellyfish that had never been seen before.
"There it was, just waiting to be discovered," said jellyfish researcher
Lisa-Ann Gershwin.
What they saw was a small 1?2 mm jellyfish, shaped like a flying saucer with a
hole in the top of its head with its gonads (reproductive organs such as
testicles and ovaries) sticking out, looking like tiny skyscrapers. Hence its
name, csiromedusa meaning 'jellyfish
from CSIRO' and medeopolis meaning ?city
of gonads?.
Well timed in the international year of biodiversity, the discovery of a new
family is rare. "A discovery of a whole new family like this is an uncommon
occurrence," said Lisa-Ann.
The researchers took samples from marinas, wharfs, jetties and boat ramps around
Tasmania. Many new species of jellyfish were found in these samples but this
jellyfish stood out from the crowd because it had a structure that was
completely without parallel in the whole jellyfish world.
It belongs to the narcomedusa group of jellyfish that are found in deep water.
Most jellyfish have two stages in their life cycle. They start as polyps - small
cylinders that can either be free-floating or attached to the ocean floor, rocks
or small clumps of algae. These polyps have tiny tentacles at the top to catch
food.
From the polyp stage comes the jellyfish, or medusa, that drifts away in the
ocean currents. The mature jellyfish then release sperm and eggs into the water,
and these are fertilized outside the jellyfish in most species. More research is
needed, however, to find out if Csiromedusa
medeopolis has a similar life cycle as little is known about this new
discovery.
