PARASITIC FLATWORM Ribeiroia ondatrae AMERICAN BULLFROG Lithobates catesbeianus After the flatworm Ribeiroia ondatrae reproduces asexually inside a snail, its larvae find a bullfrog tadpole and burrow their way through its skin, forming cysts around the frog’s developing limbs. With legs added, subtracted, or compromised, the ungainly victim is easy prey for frog-eating birds like herons. Inside the heron, the parasite reproduces sexually. Its eggs reenter the water when the bird defecates, infecting new snails to start another round.
