June 8, 2009
Guppies adapt quickly to new environments
U.S. scientists looking at adaptation and survival in a wild population found guppies can adapt to new surroundings in just a few years.
A research team led by Swanne Gordon from the University of California-Riverside found guppy populations introduced into new habitats developed new and advantageous traits in just a few years.
Gordon and colleagues studied 200 guppies that had been taken from the Yarra River in Trinidad and introduced into two different environments in the nearby Damier River, which previously had no guppies. One Damier environment was predator-free, while the other contained fish that occasionally snack on guppies.
Eight years after their introduction, the team found the females had altered their reproductive effort to match their surroundings. In the environment where predators were present, females produced more embryos each reproductive cycle. That makes sense, the scientists said, because where predators abound, one might not get a second chance to reproduce. In less dangerous waters, females produced fewer embryos each time, thus expending fewer resources on reproduction.
The researchers then took more guppies from the Yarra, marked them, and put them in the Damier alongside the ones that had been there for eight years. They found the adapted guppies had a significant survival advantage over the more recently introduced group.
The study appears in The American Naturalist