American Bullfrog found in Ebro 'huge threat' to native species
American Bullfrog found in Ebro 'huge threat' to native species
A HIGHLY-AGGRESSIVE species of frog native to North America has been found in the wild in Spain for the first time, leading to concern among biologists.
The American Bullfrog (Rana Catesbeianus), so-named because of its very loud noise which sounds like a bull's roaring, is the most predatory type of frog on earth and eats any small creatures it can overpower and swallow in one.
This makes them a major threat to native aquatic flora, according to the Institute of Evolutionary Biology, part of the High Council of Scientific Research (CSIC).
Four suspected American Bullfrog tadpoles were found in the lagoons of the river Ebro delta in the province of Tarragona, the southernmost in Catalunya, on the east coast of mainland Spain.
These were taken straight to the Institute for genetic testing to confirm they were indeed examples of this perilous species, one of the top 100 most dangerous invasive creatures on the planet.
If they were to breed in the Ebro, they would effectively wipe out all other fauna in its waters, except for bigger creatures which they cannot overpower and eat, as they are voracious and have no natural predators.
One-off sightings of adult American Bullfrogs were found in Collserola, Catalunya in 1999 and in the Ebro delta in 2012, and were 'controlled', says the CSIC, but this is the first time infant varieties in numbers higher than one have been found in the country.
It is believed adult Bullfrogs or tadpoles may have been dumped in the water course by humans, despite national legislation banning their possession, transporting, trading or releasing.
Their natural habitats are found in the Atlantic coast of the USA and Canada and sometimes as far west as Oklahoma and Kansas, but they have been introduced artificially into western Canada and the Caribbean – mostly Cuba and Jamaica – as well as South America, specifically Venezuela, Brazil, Colombia, Argentina and Uruguay, plus Asian countries such as Japan, China and South Korea.
In Europe, they have only been found in The Netherlands, France and Italy.
Outside their natural environment, American Bullfrogs are normally only released or bred intentionally as pets, food or to control certain other species of aquatic fauna.
They are bred in the USA and Canada for food, although sometimes kept in homes in an aquarium in the same way as fish or turtles often are in the western world and young crocodiles are in parts of their native countries, such as in Nile regions of Egypt.
