Filling a gap in the distribution of Batrachochytrium dendrobatidis: evidence in amphibians from northern China

Abstract

Chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) has been recognized as a major driver of amphibian declines worldwide. Central and northern Asia remain as the greatest gap in the knowledge of the global distribution of Bd. In China, Bd has recently been recorded from south and central regions, but areas in the north remain poorly surveyed. In addition, a recent increase in amphibian farming and trade has put this region at high risk for Bd introduction. To investigate this, we collected a total of 1284 non-invasive skin swabs from wild and captive anurans and caudates, including free-ranging, farmed, ornamental, and museumpreserved amphibians. Bd was detected at low prevalence (1.1%, 12 of 1073) in live wild amphibians, representing the first report of Bd infecting anurans from remote areas of northwestern China. We were unable to obtain evidence of the historical presence of Bd from museum amphibians (n = 72). Alarmingly, Bd was not detected in wild amphibians from the provinces of northeastern China (> 700 individuals tested), but was widely present (15.1%, 21 of 139) in amphibians traded in this region. We suggest that urgent implementation of measures is required to reduce the possibility of further spread or inadvertent introduction of Bd to China. It is unknown whether Bd in northern China belongs to endemic and/or exotic genotypes, and this should be the focus of future research. KEY WORDS: Chytridiomycosis · Andrias davidianus · Museum specimens · AsiaResale or republication not permitted without written consent of the publisher

Pathogenic selection promotes adaptive immune variations against serious bottlenecks in early invasions of bullfrogs

“…Bd is responsible for the decline of at least 500 amphibian species in Australia, Central America, South America, the Sierra Nevada in North America, and the Iberian Peninsula in Europe. 38 , 39 Native Asian amphibians generally show no clinical signs of chytridiomycosis and a low Bd prevalence, 28 , 40 , 41 , 42 , 43 with no declines in Asian amphibians reported. 38 , 44 The mass mortality of wild American bullfrogs at Finley Lake in the US was attributed to chytridiomycosis, and experimental evidence shows that bullfrogs were susceptible to Bd (one strain).…”

The origin of invasion of the alien Pelophylax nigromaculatus in Tibet, China

“…Our study suggests that the alien P. nigromaculatus on the TP stemmed from Chongqing. A previous study found that the amphibian chytrid fungus Batrachochytrium dendrobatidis ( Bd ) ( Zhu et al 2014 , 2016 ), which is a lethal pathogen responsible for declines in amphibians worldwide, was detected in P. nigromaculatus in Chongqing. Furthermore, Bd has been found in other regions of high elevations, such as the Andes ( Seimon et al 2007 ), the Rocky Mountains ( Pilliod et al 2010 ), and the Sierra Nevada ( Vredenburg et al 2010 ).…”

A Review of Non-Invasive Sampling in Wildlife Disease and Health Research: What’s New?

“…Skin mucus has been collected from amphibians [111,[149][150][151][152][153][154][155] and fish [156][157][158]. In amphibians, the main focus of studies utilising skin mucus has been the detection of the fungal pathogen Batrachochytrium dendrobatis [111,150,151,[153][154][155]; however, wider investigations of the skin microbiome [149] and cortisol detection [152] are further uses for this material. The sensitivity of pathogen detection in skin mucus may be limited when the intensity of infection is low [151].…”