杏吧原创

AFRICAN clawed frogs are cannibals. They will willingly eat their own tadpoles聽鈥� but they like eating those of an endangered South African frog even more.

Biologists are already familiar with the fact that African clawed frogs聽(pictured above)聽will eat their own聽young. But John Measey at Stellenbosch University in South Africa and his colleagues wanted to know whether other tadpoles were on聽the frog鈥檚 menu. They were particularly concerned about the fate of tadpoles belonging to the Cape platanna, an endangered species that lives in ponds around Cape Town.

By placing African clawed frogs in聽tanks with tadpoles of their own species and those of the Cape platanna, the team found that the frogs prefer eating their endangered cousin鈥檚 tadpoles ().

Measey says the evidence suggests the African clawed frog can tell the difference between the two types of tadpole. 鈥淭hat is very bad news for the聽Cape [platanna],鈥� he says.

Partly due to their popularity as pets, African clawed frogs are now an invasive species on four continents. They don鈥檛 occur naturally around Cape Town either, having exploited urbanisation to colonise the area.

鈥淚t鈥檚 another interesting example where human alteration of the landscape has changed the playing field,鈥� says James Vonesh at Virginia Commonwealth University, a co-author of the study.

Measey thinks it may be necessary to physically remove clawed frogs from the environment to help the Cape platanna.