A Creeper Mussel with Marsupial Gills? Seriously.
The South Carolina Department of Natural Resources (SCDNR), the Southern Carolina Department of Environmental Services (SCDES) and the U.S. Fish and Wildlife Service (FWS) recently joined us for a freshwater mussel survey of Thompson Creek at the Southern 8ths Field Station. A total of 11 people joined us, filled with passionate knowledge and expertise of mussels and aquatic animals!
The day began with the visitors gathering at the Learning Center to discuss a quick game plan. We then set out for Thompson Creek. The first survey site is a place we like to call Kayak Put-in. Just down a couple of stairs is a beautiful creek bed filled with all different shapes and sizes of rocks. The water was flowing at a nice steady pace, the ripples it created gave us wonderful background music to listen to while surveying. Here is where we found two mussels of the Elliptio complanata species commonly known as the Eastern Elliptio. After 20 minutes of surveying, we packed up and trailed onto the next site.
Our next site was on the floodplain forest side of Thompson Creek. We each took bathyscopes, which eliminate water surface glare and allow underwater viewing, and formed a line across the creek waiting to hear that magic word “begin”. And there we go, searching the rocky bottom for any mussels or shells.
At this site we found one mussel of the Strophitus undulatus species, commonly known as the Creeper mussel. Fun fact, this female mussel was brooding which means she was holding larvae in the gill pouches of her marsupial gills. That was surprising given that researchers in S.C. typically collect them brooding in the spring. That was the highlight of our day because this species is of concern and has a State Wildlife Action Plan (SWAP) ranking of imperiled to vulnerable (S2S3) with moderate conservation priority. Because of this ranking and the unusual timing in the breeding cycle, she was taken back to the US Fish and Wildlife breeding facility in hope of reproducing her offspring.
Our last site of the day and we had no luck. But we did find shells of Elliptio icterina common name Variable Spike, and Venustichonca constricta common name Notched Rainbow. The Venustichonca constricta is also a species of concern and its SWAP ranking is critically imperiled (S1). It has the highest conservation priority.
As we finished at our third and final site, we packed up our equipment, exchanged contacts and wished everyone safe travels. Overall, it was a very successful day surveying the amazing Thompson Creek for mussels. This is just a fraction of aquatic animals who depend on this creek to thrive.
Author: Anna Anderson
