HYDE*, D.M; TRACY, C.R.; Univ. of Nevada, Reno; Univ. of Nevada, Reno: Is an ELISA Test for Mycoplasma agassizzi a Useful Diagnostic Tool for Tortoise Conservation ?

Mycoplasma agassizii is believed to be responsible for large scale population declines of the desert tortoise(Gopherus agassizii). Indeed, this disease was responsible for the emergency listing of the desert tortoise by the Fish and Wildlife Service in 1989 as a threatened species. Yet, a small, confined population of desert tortoises (n = 55), for which an ELISA test indicated exposure to Mycoplasma agassizii did not experience a population decline. That experiment indicated that exposure to Mycoplasma is not sufficient to cause a population decline. The lack of predictive value of an ELISA test, along with the possibility of change in ELISA status over a period of a year, brings into question the value of ELISA testing as a diagnostic tool in assessing the future heath of a tortoise and of tortoise populations.