Prevalence of Ranavirus in Spotted Salamander (Ambystoma Maculatum) Larvae From Created Vernal Pools in West Virginia, Usa

Abstract

Ranavirosis is a disease of high concern for amphibians due to widespread documentation of its lethal and sublethal impacts and its high transmission potential across populations and species. We investigated whether spotted salamander (Ambystoma maculatum) ranavirus prevalence and viral load were associated with habitat characteristics, genetic diversity, corticosterone levels, and body size. In 2015 and 2016, we sampled 34 recently created vernal pools in the Monongahela National Forest, West Virginia, USA. We collected tail clippings from 1,128 spotted salamander larvae and waterborne hormone samples from 436 of those larvae, along with eight environmental characteristics of the pools. Over the 2-yr period, we detected ranavirus in 62% of pools, with prevalence ranging from 0% to 63% (mean, 7.68%). Spotted salamander size was positively correlated with ranavirus presence and viral load; however, we did not find associations between ranavirus prevalence or viral load and habitat characteristics, spotted salamander genetic diversity, relatedness, effective number of breeders, or corticosterone levels. The widespread occurrence of ranavirus in the vernal pools illustrates the potential for rapid natural introduction of the pathogen to created wetlands. Managers could consider monitoring local distributions of ranavirus before creation of new vernal pools to guide strategic placement of the wetlands to minimize occurrence and prevalence of this pathogen.

High ranavirus infection rates at low and extreme temperatures in the tadpoles of Japanese treefrogs (Dryophytes japonicus) that breed in rice paddies in the summer

“…For example, metamorphosing amphibians, whose Gosner development stage is approximately 44-46, are often more vulnerable to ranavirus infections (Haislip et al 2011;Kwon et al 2017). In addition, a high individual density can increase individual contact among tadpoles or frogs, resulting in an increased ranavirus infection rate (Brunner et al 2015;Millikin et al 2023;Peace et al 2019). In addition, ecological factors such as exposure to anthropogenic contaminants and extreme weather conditions could increase the possibility of ranavirus infection in amphibians (Cohen et al 2020;Daszak et al 2001;Davis et al 2020), possibly by suppressing the immune system (Carey et al 1999;Humphries et al 2022).…”