A New Ranavirus Isolated from Pseudacris clarkii Tadpoles in Playa Wetlands in the Southern High Plains, Texas

Abstract

Mass die-offs of amphibian populations pose a challenging problem for conservation biologists. Ranaviruses often cause systemic infections in amphibians and, in North America, are especially virulent and lethal to larvae and metamorphs. In this paper we describe a novel ranavirus isolate as well as the first recorded occurrence of ranavirus in the southern High Plains of Texas and in associated populations of the spotted chorus frog Pseudacris clarkii. The breeding sites were playas, that is, wetlands that fill via isolated thunderstorms that can occur infrequently; thus, not every playa has water or breeding amphibians annually. We did not detect ranavirus in sympatric anurans, but other reports document ranaviruses in Pseudacris spp. elsewhere. The occurrence of multiple isolates of ranavirus in a number of Pseudacris species suggests that this genus of frogs is highly susceptible to ranaviruses and may experience exceptionally high mortality rates from infection. Thus, the virus may contribute to substantial seasonal population declines and low seasonal recruitment, with negative impacts on populations of breeding adults in successive years.