The Freshwater Gastropods of Missouri

The FWGNA Project is pleased to announce that a ninth region has been added to our burgeoning portfolio of online resources: The Freshwater Gastropods of Missouri, by R.T. Dillon, Martin Kohl, and Bruce Stephen.  Our coverage now extends across all or part of 23 states, from the Atlantic drainages onward into The Great Plains.

And just for fun, try entering the FWGMO site from our easy-to-use front page, freshly enhanced by our new friend Greg Nemes of Tanager Creative with a fancy clickable map, here:

FWGNA

Our survey of approximately 788 springs, streams, rivers, swamps, ponds and reservoirs across the Show-Me State yielded 1,760 records of 44 species and subspecies, eight of which are new to the FWGNA Project [1]. Fresh species pages for each of these eight brings our total coverage up to 156.  Two of the pleurocerid subspecies are new combinations, more about which in coming months.  Our database, as usual, is freely available for the asking.

The major drainage basins of Missouri, showing 788 sample sites.

We have stood on the shoulders of giants.  The giant of whom we must make special mention here is Dr. Shi-Kuei Wu, who along with Ronald Oesch and Mark Gordon published the wonderful 97-page, staple-bound report, Missouri Aquatic Snails, in 1997 [2].  We spent a very productive week working in Shi-Kui’s carefully-curated collection at the University of Colorado Museum back in 2021, ultimately yielding 1,261 (70%) of the records transmitted here.  Our new FWGMO web resource is dedicated to him.  We also owe special debts of gratitude to Leanne Elder and Hsiu-Ping Liu for hosting us graciously in the collection and in the home, respectively.

And speaking of gracious hosts.  Our colleagues Randy Sarver and Dave Michaelson were most generous with time, talent, and seven-year-old blacktop vials of macrobenthos at the Missouri Department of Natural Resources in Jefferson City [3].  Sorting through those vials, and the meticulous records that came with them, yielded another 325 (18%) of the records in the FWGMO database.

Ste. Genevieve-Modoc Ferry at low water

The remainder of our records were personally-collected by the three of us. The vastly-trapezoidal patch of the world enclosed by the boundaries of Missouri in 1821 is flat-out gorgeous, not all over but in spots, and I for one greatly enjoyed wetting a boot toe in her sparkling waters.  We concentrated our efforts on undersampled regions and habitats, especially the main Mississippi and Missouri Rivers, which we collected at historic low waters in September of 2023.

I have cousins in St. Louis and in Moberly, about an hour north of Jeff City, and had it explained to me that Missouri is not one state but two, “Mi-zoor-ree” in the northern flatlands and “Muh-zoor-rah” in the Ozark highlands of the south.  A biogeographer might point out that the Mississippi lowlands of the bootheel region could be considered a third state, at minimum.  The freshwater gastropod fauna reflects those striking physiographic, cultural, and military [4] distinctions.  See the FWGMO Discussion [link] for an elaboration.

We have also updated our Synthesis of relative abundances across the entire 127 species, 23-state fauna covered by the FWGNA project to the present date.  This new “Version 3.2” [link] has been a long time coming.  Since our previous Synthesis v3.1 (12May22), we have added the Great Plains (1,482 records) and the Gulf drainages of Georgia (650 records) as well as the 1,760 records newly collected from Missouri, for a grand total of 25,468.  The present update has (of course) resulted in an adjustment of the incidence rankings over the entire 127 species set, the less common half of the distribution, in any case.

The Gasconade River, Osage Co.

And finally.  We gratefully acknowledge and sincerely thank Mr. Greg Nemes of Tanager Creative for his skillful enhancement of the entire FWGNA site.  In addition to the keen clickable map on the front page, Greg did a tremendous job re-wiring the site to facilitate routine maintenance and update, freshening up the fonts, adding cool new analytics and hooking up an email platform with subscription boxes at the bottom of every page, to name but a few improvements.  So, remember the little red bird with the great big bag of skills, tanager.org, when clear communication matters to your nature, science, or humanities nonprofit!

Notes:

[1] The eight new species and subspecies freshly added: Amnicola stygia, Antrobia culveri, Fontigens aldrichi, F. antroecetes, F. proserpina, Leptoxis arkansensis, Pleurocera simplex ozarkensis, P. canaliculata lawrencii.

[2] Wu, S-K., Oesch, R. & Gordon, M. (1997) Missouri Aquatic Snails. Missouri Department of Conservation, Natural History Series #5. 97 pp.

[3] We posted a photo of our handsome colleagues from the Missouri DNR late last year:

• Art, science, and public policy: A dialogue in three languages [10Dec25]

[4] Infantry representing the northern half of Mi-zoor-ree shot south with rifled muskets; Muh-zoor-rah State Guard returned fire with obsolete smoothbores.