Pieter Johnson of the University of Colorado Boulder and colleagues studied field data from hundreds of California ponds and found that communities with high species diversity had only about 20 percent as much transmission of the trematode parasite Ribeiroia ondatrae
, and suffered roughly half as much disease as communities with low diversity.
Johnson and colleagues visited hundreds of ponds in California, recording the types of amphibians living there as well as the number of snails infected by the pathogen Ribeiroia ondatrae
(Trematoda: Digenea) infection induces severe limb malformations in western toads (Bufo boreas).
Recent research has linked the infection of a flatworm parasite called Ribeiroia ondatrae
to amphibian malformations," says Larsen.
Johnson discovered that bodies of water with higher frequencies of abnormal frogs also teem with a trematode--or wormlike parasite (organism that lives on or inside another organism)--called Ribeiroia ondatrae
Schotthoefer (UIUC, Urbana) reported that infection with the larval trematode Ribeiroia ondatrae
could be responsible for limb malfomations in tadpoles and could explain the observed increase in the frequency of these malformations within natural frog populations.