An Evaluation of Visible Implant Elastomer for Marking the Federally Listed Fountain Darter and the San Marcos Salamander

Abstract

Visible marks can aid in population studies but, depending on the type of mark used, may result in poor retention and increased mortality. Visible implant elastomer (VIE) was evaluated as a marking technique for two species listed as endangered or threatened under the federal Endangered Species Act: The fountain darter Etheostoma fonticola and the San Marcos salamander Eurycea nana. We compared VIE with acrylic latex paint (ALP) marks in the fountain darter and found that VIE marks exhibited greater retention than ALP marks (88% versus 23% at 244 d). Fountain darter survival and growth were not affected by mark type. In the San Marcos salamander, the use of VIE marks did not affect survival or growth. For both species, mark placement (dorsally versus ventrally) did not affect retention. Visible implant elastomer marks would be the preferred method for population studies of these listed species.