http://www.nature.com/nsu/020506/020506-12.html

Ultraviolet lights guppies' fire
Fish use ultraviolet vision to choose mates.

VIRGINIA GEWIN

To truly appreciate guppy beauty takes vision. Ultraviolet vision. Because scientists and conservationists lack this ability, they may not have fully understood what makes some fish sexy to others, until now. Two species of South American fish, the guppy1 and the amarillo2 , use ultraviolet vision to choose mates, two recent studies have found. Females of both species prefer males that they've seen in ultraviolet to those spied when ultraviolet is filtered out. Reflective body stripes and gill covers probably attract the females only when the sun glints off them, suggests the leader of the amarillo study, Constantino Macias Garcia of the Institute of Ecology at the Universidad Nacional Autonoma de Mexico. "We have been missing out on a whole channel of communication in the animal world," says Macias Garcia. * Smith, E. J. et al. Ultraviolet vision and mate choice in the guppy (Poecilia reticulata). Behavioral Ecology, 13, 11 - 19, (2002). * Garcia, C. M. & de Perera, T. B. Ultraviolet-based female preferences in a viviparous fish. Behavioral Ecology and Sociobiology, doi:10.11007/s00265-002-0482-2 (2002). Š Nature News Service / Macmillan Magazines Ltd 2002