Mantis blurb.

[Letmegrow]

Article.

LONDON (Reuters) - A giant shrimp living on Australia's Great Barrier Reef can see a world beyond the rainbow that is invisible to other animals, scientists said on Wednesday.

Mantis shrimps, dubbed "thumb splitters" by divers because of their vicious claws, have the most complex eyes in the animal kingdom, capable of seeing colours from the ultraviolet to the infrared, as well as detecting other subtle variations in light.

They view the world in up to 12 primary colours -- four times as many as humans -- and can measure six different kinds of light polarisation, Swiss and Australian researchers reported.

Polarisation is the direction of oscillation in light waves.

Just why Gonodactylus smithii needs this level of rarefied vision is unclear, although the researchers suspect it is to do with food and sex.

"Some of the animals they like to eat are transparent and quite hard to see in sea-water, except they're packed full of polarising sugars. I suspect they light up like Christmas trees as far as these shrimp are concerned," said Andrew White of the University of Queensland.

And the shrimps probably use tiny changes in colour and polarisation to send sexual signals between males and females, the researchers believe.

Their findings were published online in the Public Library of Science journal PLoS ONE, at http://www.plosone.org/doi/pone.0002190

(Reporting by Ben Hirschler, edited by Richard Meares)

 

[Letmegrow]

Polarisation = polarization.

That bugged the hell out of me.

 

[JxMetal]

yeah was bugging me too the second time they wrote it.

 

[Letmegrow]

Canadian zoo investigates puzzling stingray deaths

CALGARY, Alberta (Reuters) - Officials at the Calgary Zoo remained baffled on Tuesday as they tried to puzzle out just why 34 of their stingrays suddenly died.

The juvenile cownose stingrays, about the size of a dinner plate, were kept in a "petting" tank where visitors were able to touch them, a common feature in a number of North American zoos and aquariums, according to the zoo officials in the Western Canadian city.

On Sunday, within a few hours of opening, the normally voracious fish lost their appetites, became discoloured and started dying, with 34 of the 43 rays quickly succumbing to an ailment or cause that has yet to be diagnosed.

"It was a very acute onset of something, a very sudden change," said Cathy Gaviller, director of conservation, research and education for the Calgary Zoo. "It was high mortality in a very short period of time."

The zoo, as yet, has no real idea of what happened to the rays, which are common in the waters off North America's east coast.

Water tests show there were no problems with the tank or its filtration system, though the zoo has also sent off samples for independent testing.

Gaviller said that because of the speed of the deaths, disease or parasites were unlikely causes, but nothing is being ruled out. However results from tissue and toxicology tests won't soon be ready.

"It's unfortunate that we have very few facts," she said. "But the No. 1 likelihood is that something in the water changed suddenly."

She added that there were no signs that a zoo visitor caused the rays' deaths.

The incident is the latest in a number of animal deaths at the zoo that have sparked criticism of the facility.

A hippopotamus being moved to Calgary from Denver, Colorado, died in October. As well, a baby gorilla died in August after other gorilla disrupted the mother's nursing routine.

(Reporting by Scott Haggett; editing by Rob Wilson)