Tadpoles in Maine Pond Die from Ranavirus

An estimated 200,000 Wood Frog (Lithobates sylvaticus) Tadpoles in a local pond in Maine died within a few days (in 2013) from most-likely a ranavirus. A paper was recently published in Herpetological Review that is co-authored by Nathaniel Wheelwright, a biologist at Bowdoin College, along with the University of Tennessee.

“The dead tadpoles had signs of hemorrhaging in their legs and around their throats, and many had skin that was sloughing off their bodies”, Wheelwright said.

Wheelwright has monitored the pond for close to 30 years and said it was quite surprising. Usually there are 50-100,000 tadpoles and only 1000 may live to become adult frogs. But for all to die, very unusual. They did notice there were no leeches present.

There are other species who can carry the ranavirus, such as green frogs, bullfrogs, painted turtles and spotted salamanders* (*who were found in the pond and showed signs of suffering from the virus also.)

Here’s a video from Bowdoin College with biology professor, Nat Wheelwright talking about the tadpoles:

The good news is that this past Spring showed healthy tadpoles and frogs and no sign of any issues.

Do you think this was caused by pesticides and/or climate change? Too many tadpoles crowded together?
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The differences between Chyrid Fungus and Ranavirus are:

Chyrid is a fungus and infects individual frogs who suffer damage to their skin. Once infected it impairs respiration and the frog dies. It has been devastating amphibian populations around the world.

Ranaviruses infect insects, fish, amphibians and turtles and infect larvae or recently metamorphosed individuals.