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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Unionid Ecology
COLLECTION OF UNIONID GLOCHIDIA THROUGH THE USE OF ARTIFICIAL SUBSTRATES.
M.L. Shema. Department of Environmental Science, Allegheny College, Meadville, Pennsylvania, USA
This project aimed to develop three variations of maintenance-free artificial substrates that could be set in place to collect benthic macroinvertebrates and freshwater mussel glochidia. The substrates were constructed from plastic crates encased with 1-mm window screen and partially filled with industrial glass beads. One design was a plain, screened top with no additional structure, a second design added 4’’ corrugated pipe to provide fish hiding places, and the third design simulated a weed bed constructed of polypropylene strapping material. The habitats were designed to congregate fish above the substrates so that the glochidia the fish may be carrying had a better chance of falling directly into the tops of the substrates. The substrates worked under the premise that organisms entered the enclosure through the screen then grew to a size larger than 1mm, becoming trapped. A total of 36 substrates were placed at two sites in the Ohio River (RM 15 & 16) and two sites in French Creek at Cambridge Springs, PA. During the 18 weeks of submersion the substrates were colonized by numerous species of macroinvertebrates and Asiatic clams (Corbicula fluminea), zebra mussels (Dreissena polymorpha), Paper pondshells (Utterbackia imbecillis) up to 43 mm, and a Pink heelsplitter (Potamilus alatus) 44 mm in length.
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