In search of deformed frogs

A CU-Boulder research team, led by Professor Pieter Johnson, spent three years visiting hundreds of ponds in California in search of amphibian deformations and the parasites that cause them. The researchers discovered that amphibians living in ponds with greater biodiversity had greater protection against parasitic infection. The findings are published in the journal Nature and shed light on how biodiversity may dampen disease transmission in a variety of ecosystems.

A northern leopard frog with limb deformities caused by a parasitic flatworm. Photo courtesy of Dave Herasimtschuk / Freshwaters Illustrated.

CU-Boulder researchers collect recently metamorphosed amphibians from a pond in the Bay Area of California to check them for malformations. Photo courtesy of Dave Herasimtschuk / Freshwaters Illustrated.

A northern red-legged frog with limb deformities in an urban pond near Portland, Ore. Photo courtesy of Dave Herasimtschuk / Freshwaters Illustrated.

CU-Boulder researchers in California pond

CU-Boulder researchers search for malformed amphibians in a pond in the Bay Area of California. Photo courtesy of Dave Herasimtschuk / Freshwaters Illustrated.

A Pacific tree frog with limb deformities caused by a parasitic flatworm. Photo courtesy of Dave Herasimtschuk / Freshwaters Illustrated.

CU-Boulder's Pieter Johnson collects snails from an urban pond in Portland, Ore., to test whether they are infected Ribeiroia ondatrae, a parasitic flatworm that causes malformations in amphibians. Photo courtesy of Dave Herasimtschuk / Freshwaters Illustrated.