of Higgins' Eye (Lampsilis higginsii),
a endangered freshwater mussel in the Mississippi River
The Higgins' Eye Pearlymussel, Lampsilis higginsii, is a Federally endangered species, which is in jeopardy of extinction throughout its range, the Upper Mississippi River (UMR) and several associated tributaries. The primary threat is infestation by the alien zebra mussel (Dreissena polymorpha), which has colonized and spread throughout much of the UMR. Plans for recovery of this species include a Relocation Plan submitted by the St. Paul District (MVP), Army Corps of Engineers (COE), to augment and/or create L. higginsii populations throughout its range. The Relocation Plan includes relocation of adult individuals and a propagation program. Information on the genetic characteristics of L. higginsii populations is needed to make scientifically sound decisions regarding the numbers, localities, and logistical concerns of proposed relocations. If genetic variability is high, then a large number of individuals should be relocated to adequately preserve the genetic variation of the species. Likewise, if genetic variability if high, then a large number of females should be used as sources for propagation projects. If populations differ from one another genetically, then animals should be relocated to areas that contain similar genetic profiles.
We obtained samples of L. higginsii from seven localities: (1) St. Croix River, near Hudson, WI (River Mile [RM] 16); (2) Wisconsin River near Sauk City, WI (RM 89-92); (3) Mississippi River at Whiskey Rock near Lansing, IA (RM 661); (4) East Channel near Prairie du Chien, WI (RM 635); (5) McMillan Island near Guttenberg, IA (RM 618); (6) Cassville, WI (RM 606); and (7) Cordova, IL (RM 504). We extracted DNA and amplified segments of the mitochondrial DNA genes cytochrome b (cyt b), 16S ribosomal RNA (16S), and cytochrome oxidase subunit I (COI). We successfully sequenced all three gene segments for 124 individuals: 23-30 individuals from each of Hudson, Lansing, Cassville, and Cordova; 4-7 individuals from East Channel, McMillan Island, and Wisconsin River. We are in the process of conducting statistical analyses on the sequence data. Preliminary analysis for two gene segments (cyt b and 16S) indicates that each sampling location contained several DNA forms (haplotypes) and most haplotypes were found in several localities. These data indicate that Lampsilis higginsii does not contain genetically distinct populations in the portions of the St. Croix and Mississippi Rivers that we studied. The level of genetic variation is high in L. higginsii, compared with other Endangered Species.
This research is supported by the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service.
Bowen, B. S., and W. Richardson. 2000. Genetic characterization of Lampsilis higginsii. Final Report submitted to USFWS.
Additional information about Lampsilis higginsii can be found at the following links:
USFWS species profile on Endangered L. higginsii.
USFWS report on conservation plan for L. higginsii.
US Army Corps of Engineers story on mussel conservation
Lampsilis higginsii propagation update--2002.
Public Radio story on conservation of mussels, including L. higginsii.