Torrence Shannon M, Green D Earl, Benson Catherine J, Ip Hon S, Smith Loren M, McMurry Scott T
Department of Natural Resources, Texas Tech University, Lubbock, Texas 79409, USA.
J Aquat Anim Health. 2010 Jun;22(2):65-72. doi: 10.1577/H09-035.1.
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.
两栖动物种群的大规模死亡给保护生物学家带来了一个具有挑战性的问题。蛙病毒通常会在两栖动物中引发全身性感染，在北美，这种病毒对幼体和变态期个体尤其具有毒性和致命性。在本文中，我们描述了一种新型蛙病毒分离株，以及首次记录到的蛙病毒在得克萨斯州南部高平原地区和相关的斑点合唱蛙（Pseudacris clarkii）种群中的出现情况。繁殖地点是季节性湖泊，即通过偶尔发生的孤立雷暴形成积水的湿地；因此，并非每个季节性湖泊每年都有水或繁殖两栖动物。我们在同域分布的无尾目动物中未检测到蛙病毒，但其他报告记录了在其他地方的Pseudacris属物种中存在蛙病毒。在多个Pseudacris物种中出现多种蛙病毒分离株，表明这种蛙类对蛙病毒高度易感，可能因感染而经历极高的死亡率。因此，该病毒可能导致季节性种群大幅减少和季节性补充率降低，对连续多年的繁殖成年个体种群产生负面影响。
