Female jumping spiders get turned on by 'sexy' ultraviolet rays

Washington, May 2 : They might be invisible to the human eye, but for the female Chinese jumping spider, ultraviolet B (UVB) rays come handy when it comes to mating, says a new study.

The study by National University of Singapore researchers provides the first evidence of an animal using ultraviolet B (UVB) rays to communicate with other members of its species.

In a series of mate choice experiments with the Chinese jumping spider (Phintella vittata), the researchers found that female spiders would rather mate with males that reflect UVB than those that do not.

" It has long been recognized that solar UVB has direct deleterious effects on a wide range of living organisms; for example, it can cause skin cancer and damage the retinal tissues of the eyes of mammals," said Daiqin Li of National University of Singapore, who is also an Adjunct Professor in Hubei University, China.

"Thus, it has generally been assumed that animals are unable to sense the presumably deleterious UVB wavelengths," Li said.

Many arthropods and vertebrates were known to have body parts that reflect in UV and photopigments that are sensitive to UV, the researchers said, but previous studies have considered primarily the UVA spectral region.

Indeed, UVA vision is known to function in animal communication, particularly in the assessment of potential mates.

Now, the researchers find the same can go for UVB.

Male spiders held the attention of females more successfully when they weren't behind a filter that blocked UVB, the researchers found.

Females also more often "chose" males that reflected UVB.

The research team confirmed that the difference in the mating behavior was not influenced by the overall brightness or by UVA.

Jumping spiders are known to have uniquely complex eyes and acute eyesight, as well as UVA-sensitive photoreceptors in their principal eyes, the researchers said. owever, it remains unclear how their eyes detect UVB. Indeed, scientists had conventionally thought that the absorbance of proteins within the UVB range would preclude UVB vision, they noted.

The study is published in the journal Current Biology, a publication of Cell Press.

ANI