Monitoring and Marking Techniques for the Endangered Comal Springs Riffle Beetle,Heterelmis comalensisBosse, Tuff, and Brown, 1988 (Coleoptera: Elmidae)

Abstract

Abstract Two monitoring methods for the endangered Comal Springs riffle beetle, Heterelmis comalensis Bosse, Tuff, and Brown, 1988, were evaluated. The first used cotton cloth “lures” lodged within the substrate in close proximity to spring openings. The second evaluated the feasibility of marking H. comalensis with paint. During our evaluation, biofilms grew upon the lures over time, and within two weeks H. comalensis were collected. Numbers of H. comalensis (mean = 23, range = 4–53) collected from lures peaked at 10 weeks and then began to decline as the cotton cloth lures began to decompose. Three other invertebrate species, the riffle beetle Microcylloepus pusillus (LeConte, 1852), the endangered Comal Springs dryopid beetle Stygoparnus comalensis Barr and Spangler, 1992, and the endangered Peck's cave amphipod, Stygobromus pecki (Holsinger, 1967), were also collected from the lures, suggesting that this technique may have broad applicability as a passive monitoring tool for interstitial aquatic endem...