Released guppies go wild

According to new research by Dr Amy Deacon and Professor Anne Magurran of the School of Biology, in collaboration with Professor Indar Ramnarine of the University of the West Indies, a single released ornamental female guppy can generate an entire new population in the wild even with no male present. Dr Deacon explains that “female guppies can store sperm in their reproductive tracts for many months after mating, and this enables single fish to establish populations, even when no males are present”.

The guppy, whose native home is Trinidad and the north-eastern fringe of South America, is now present in over 70 countries worldwide, and has earned a reputation as one of the world’s most invasive fish. The two most important routes of guppies finding their way into the wild are the escapes of ornamental fish, and deliberate introductions designed to control the larvae of mosquitoes that spread malaria. Although self-contained at first, heavy rains and flooding mean that the fish eventually find their way to streams and rivers where they come into contact with native fish, which can ultimately contribute to the reduction of biodiversity in these freshwater habitats. [full article]