Body clock controls glow-worms' light
Sydney, Aug 19 : Tasmanian cave glow-worms are energy conservationists, which switch
off lights at night-time, according to a discovery made by Queensland University
researcher.
The study revealed the glow-worm's prey-luring light output is governed by circadian
rhythms, regardless of ambient light levels.
It aimed to investigate the physiology and behaviours of cave dwelling glow-worms,
which are actually immature or larval stage of a mosquito-like fly found in parts of
Australia and New Zealand.
David Merritt, who led the study, said unlike their rainforest dwelling counterparts,
the cave-dwelling glow-worm can detect the time of day, even from the deepest stretches of
their caves.
"In the rainforest, exposure to light during the day causes them to switch off, but in
caves there is no light to cause that to happen, however they switch off of their own
accord and they do it in synchrony," Merritt said.
"The most unexpected result of the study was they are out of sync with their surface
relatives: they glow most brightly when it is daylight outside the cave."
Merritt suggested this discovery could strengthen the Queensland and Tasmanian insect
eco-tourism industries and ensure the glow-worms can continue to do what they do best -
shine.
"The more we know about the factors that influence the glow intensity the better off
managers of these sites will be in ensuring that the display is as attractive as possible
while maintaining the long-term health of the glow-worm colonies," he said.
Merritt's research could also help safeguard the species against climate change, by
providing insight into their predatory behaviours and the impact of seasonal rhythms and
human activity on the caves and their fauna.
--IANS
