Status of Arkansas darter, Etheostoma cragini, and least darter, E-microperca, in Arkansas

摘要

In a 1983 survey of 50 spring-runs in northwestern Arkansas, Etheostoma cragini and E. microperca were each represented by only 5 populations. In summer and autumn 1997, we surveyed localities with historically documented populations and several additional spring-runs for presence of E. cragini and E. microperca to assess the current status of these species in Arkansas. Additionally, we documented local habitat attributes of each sample locality. We estimated population size of persistent populations in our surveys by mark-recapture method. Two populations of E. cragini had 546 (+/-214) and 79 (+/-60) individuals, and 2 populations of E. microperca had 1,341 (+/-349) and 129 (+/-56) individuals. Both darters inhabited small spring-run habitats with sand and silt substrate and some aquatic vegetation. These species are at risk of extirpation in Arkansas and should be considered for protection.