The SRALP and the SRNLP: Physa acuta were found

Editor’s Note: This is the second essay in a fresh series on the Snake River Physa controversy, prompted by the 2021 publication of new genetic data by M. K. Young and colleagues [1].  If this is your first visit to the FWGNA blog, I would suggest that you back up to last month’s post at minimum [14May24].  And if you have a serious interest in the subject, from last month’s essay you can follow links to six previous posts on Physa natricina and the Snake River, 2008 – 2013.

Located 35 miles south of Boise on the Snake River at River Mile (RM) 458, the Swan Falls Dam is something of a museum piece.  It was constructed in 1901 by local mining companies as a demonstration of the potential for waterpower to drive industry in a land that was just beginning to assert its potential.  That dam and its generating plant were consolidated into the newly incorporated Idaho Power Company, IPC, in 1916.

Swan Falls Dam

Physa natricina, described in 1988 from the Snake River upstream at RM525 – RM571 [2], was entered onto the federal endangered species list in 1992 [3].  And at that point, alas, IPC found itself in the Physa business, as well as in the power business.  IPC biologists initiated a comprehensive Physa survey and monitoring program in 1995, beginning way downstream at the Oregon border (RM 340) extending upstream to the Lower Salmon Falls Dam (RM 573), using a broad range of sampling techniques, including Venturi loop dredging apparatus operated by tethered divers in deeper and more rapid waters.  By 2007, over 1,500 Physa specimens had been collected from these 233 miles of river, identified to genus (only) and deposited in the Orma J. Smith Museum of Natural History (ALBRCIDA) in Caldwell, Idaho.

In 2007, our colleagues Christopher Rogers and Amy Wethington examined this gigantic collection of preserved gastropods and compared them, critically and completely, to the type specimens of Physa natricina deposited by Dwight Taylor in connection with his 1988 description [4].  They found no individual snail matching all eight of Taylor’s diagnostic characters completely.  Indeed, none of Taylor’s paratypes matched all eight characters of his holotype.  Taylor’s “diagnostic characters” were variable.  And that variation extended seamlessly from his holotype Physa natricina to merge with the (extremely variable) North American invasive species Physa acuta, which is what the great majority of those 1,500 snails collected between RM 340 and RM 573 between 1995 and 2007 appeared to be.

Rogers and Wethington synonymized Dwight Taylor’s narrowly endemic P. natricina under the cosmopolitan P. acuta, suggesting as they did that the stunted morphology and unusually large body whorl demonstrated by individuals sampled from stones in exposed environments in the middle of the Snake River might be an ecophenotypic response to life in rapid currents.

Our scene now shifts to the Minidoka Dam, way upstream at RM 675, a hundred miles above any place that Dwight Taylor or IPC ever surveyed for Physa.  The Minidoka Dam is also a museum piece, built by the brand new US Bureau of Reclamation in 1906 to supply water for irrigation.  In 2005 the USBR contracted with a pair of biologists from Montana State University, Kiza Gates and Billie Kerans, “to thoroughly survey the USBR P. natricina recovery area from RM 663-675 and determine if any P. natricina populations or colonies exist” [5].  These surveys, conducted by tethered divers operating Venturi suction dredges, extended through the field seasons of 2006 – 2008. 

Gates & Kerans ultimately recovered 274 physids with shell morphology matching the description of Physa natricina in at least some respects, of which roughly 15 were sequenced for two mtDNA genes by two different laboratories.  Concatenated, these sequences averaged 17% different from a set of reference Physa acuta fished from GenBank.  The gray literature report of Gates & Kerans [5], released in 2010, “confirmed the original description of P. natricina as a distinct species and the existence of a population below Minidoka Dam.”

The Snake River, modified from Fig 3 of Gates et al [6]

My concern, stated forcefully at a meeting convened by the USBR in Boise in September of 2010 [2Apr13], was that the physids Gates & Kerans were identifying as Physa natricina must be compared to the Snake River acuta-like Physa (“SRALP”) common as cockroaches in the shallows of the river downstream, not to random Physa acuta fished from GenBank, none sampled closer than Wyoming, on the other side of the continental divide.  My cries fell on deaf ears [6].

I might also have objected that the physids Gates & Kerans were identifying as “Physa natricina” must also be compared to bona fide Physa natricina sampled from the type range, RM 525 – 571, but I did not realize the significance of that problem until much more recently [14May24].  In retrospect, the Physa that Gates & Kerans did sample below the Minidoka Dam are best referred to as Snake River natricina-like Physa (SRNLP), just as the Physa they did not sample downstream were SRALP.

Setting all such pretty distinctions aside, however, sailing 215 river miles back downstream to the Swan Falls Dam, and picking up the story as told by Idaho Power in a 2011 gray literature report to the FWS [7]:

“Verified specimens of Snake River physa were very rare until recently, when the USBR discovered them in the upper Snake River (Gates and Kerans 2010). These new collections of Snake River Physa prompted IPC to re-evaluate specimens identified as Physidae from samples collected throughout the Middle and Lower Snake River from 1995–2003. John Keebaugh of the Orma J. Smith Museum of Natural History at the College of Idaho in Caldwell, Idaho, identified 51 (live when captured) Snake River Physa from 19,426 specimens identified as Physidae (Keebaugh 2008) (Table 2). These Snake River Physa were collected between Bliss Dam (RM 559.3) downstream to a site near the mouth of the Payette River (RM 367.9). Of the 51 Snake River Physa Keebaugh identified from IPC’s samples, 37 were collected in the (Swan Falls) Action Area (RM344 – RM469).”

The IPC went on to report that anatomical and genetic studies “conducted by Montana State University” had confirmed the Keebaugh identifications.  Those genetic results (from the laboratory of Steven Kalinowski) were dubiously transmitted in 2013 [6] and never vouchered.  But the bottom line is this.  A physid population morphologically indistinguishable from Physa natricina inhabits the rapids downstream from the Swan Falls Dam (RM 458).  This is a factual observation, with which all parties, Christopher Rogers, Amy Wethington, John Keebaugh, Gates, Kerans, and (most importantly) the U.S. Fish and Wildlife Service will all most certainly concur.

IPC biologists collecting suction dredge samples [8]

So, on the basis of what would seem to be universal scientific consensus, in 2011 the FWS required IPC to re-apply for its license to operate the Swan Falls Hydroelectric Project.  That new license, approved on September 28, 2012, contained an article that required a “snail protection plan focusing on Snake River Physa (Physa natricina),” directly analogous to the study that the US Bureau of Reclamation had undertaken in the tailwaters of the Minidoka Dam seven years earlier.  And in 2013 an elaborate five-year plan was approved [9], coauthored by IPC biologists Michael Stephenson [10] and Barry Bean.

But wait.  Because all the Physa populations inhabiting the length of the Snake River in Idaho have been the focus of intense legal and regulatory controversy for over 30 years now, exceptional rigor is demanded throughout.  And again, I must remind all parties that Dwight Taylor stated in his 1988 description that Physa natricina is “restricted to the Snake River from the vicinity of Bliss to Hammett, Idaho,” generally taken to range from RM 525 – 571.  So, the term we coined last month [14May24], “Snake River natricina-like Physa” (SRNLP) is the most appropriate name for both the stunted populations of Physa bearing shells with unusually large body whorls above that range, in the tailwaters of the Minidoka Dam at RM 675, and the stunted populations of Physa bearing shells with unusually large body whorls below that range, in the tailwaters of the Swan Falls Dam at RM 458.

Now moving forward.  The dawn of the 2014 field season saw IPC scuba divers, tethered to boats in the roaring Snake River rapids, sampling rocks and cobbles with Venturi power jet suction dredges at five selected sites between RM 400 and RM 445.  The total of 105 individual physids ultimately recovered [11] were sent to our good friend Hsiu-Ping Liu at the Metropolitan State University of Denver, who was able to obtain 16S mtDNA sequences from 59 of them [12].  The maximum sequence divergence across the entire set of 59 was just 3.6%.  Alas, Hsiu-Ping did not upload her sequences to GenBank or otherwise make them publicly available.  But comparing her big Swan Falls sample to an equally large sample of physids fished from GenBank, Hsiu-Ping concluded, “Based on the genetic evidence presented here, Idaho Power samples clustered with P. acuta.”  Physa acuta were found.

Idaho Power biologists used an identical tethered-diver technique in the 2015 field season, shifting their five sample sites to some extent, ultimately recovering another 59 individual Physa [13].  In 2016 they experimented with three new approaches, however: drift nets, sturgeon egg mats, and multiplate artificial (“Hester-Dendy”) substrate samplers [15].  Just two Physa were recovered in the nets, and just six in the mats, but promising results with the multiplate samplers [16] suggested a shift to that approach in subsequent years.  The 2016 field season was not subsequently counted among the five study years of the contracted project.

SRNLP from Swan Falls tailwaters [14]

In 2017, 2018, and 2019 IPC biologists deployed a two-part artificial substrate sampler of unusual design: a basket of large cobbles hooked to a multiplate Hester-Dendy apparatus [17].  Thirty such samplers were anchored at various spots in the Snake River rapids downstream of the Swan Falls Dam for two periods of five weeks, for each of the three study years remaining.  A total of 132 + 344 + 633 = 1,109 individual physids were recovered from the samplers, a subset of which [19] were sent to the laboratory of a fish guy named Michael K. (Mike) Young, bless his heart, at the USFS Rocky Mountain Research Station for mtDNA sequencing.

Mike and his colleagues [1] ultimately obtained CO1 sequences for 181 physids sampled from the Snake River rapids between RM 420 and RM 449.  These sequences were all fully reported and properly vouchered.  Eight sequences ultimately matched P. gyrina; let’s set those aside.  Then the maximum sequence divergence across the set of 173 that remained was just 4.82% [20].  This is the single largest survey of mtDNA sequence variation ever published for a population of pulmonate snails.

The sequence similarity between the downstream-most sample (SRP051 = OK510624) from RM 420 and the upstream-most sample (SRP182 = OK510755) from RM449 was 100%.  Let’s pick the longer of these two identical sequences, OK510624, as typical for SRALP in the Swan Fall tailwaters.

Mike Young is a hard worker and was very patient with me over several weeks of incessant pestering, and he did his best with the tools the Good Lord packed in his tool box, bless his heart.  He dumped his block of 173 CO1 sequences from Snake River miles 420 – 449 into a gigantic cauldron of 920 physid CO1 sequences downloaded from every database you can imagine, from everywhere around the world, stirred it twice, and pushed the button on a stupendous, smoke-belching, oil-spewing, gear-grinding, tree-making machine.  Shoveled in some coal and gave her a kick.

Cobble Basket / Hester-Dendy sampler [18]

Carelessly tossed into the bubbling Cauldron O’sequences and piped into the Stupendous Tree-Making Machine was one sequence that actually mattered, AY282589, a CO1 sequence from the type locality of P. acuta in the River Garonne, France.  The sequence divergence between OK510624 and AY282589 was 2.4%.  Good, thank you Jesus, finally!  The Snake River acuta-like Physa, the SRALP, is indeed Physa acuta.  At least in the Swan Falls tailwaters, RM 420 – 449.  After all these years of Sturm und Drang. Why was that so hard?

In summary.  As of 2020, the Idaho Power Company had spent six years and millions of dollars for 105 + 59 + 8 + 132 + 344 + 633 = 1,281 Physa acuta, the world’s most cosmopolitan freshwater gastropod, the cockroach of malacology, invasive on five continents.  That is all – that is the complete yield for six years of intense (and sometimes dangerous) effort by a large, well-equipped team of dedicated biologists – with a smattering of P. gyrina easily set aside.

This screaming, flailing 1,281-trash-snail bellyflop will not have been a complete, utter, tragic, waste of time, effort, money and skin if we learn from it.  So, pay attention now.

If (1) A physid population morphologically indistinguishable from Physa natricina inhabits the Snake River rapids downstream from the Swan Falls Dam, and if (2) all the physids inhabiting the Snake River rapids downstream from the Swan Falls Dam are Physa acuta, then (3) the evidence at Swan Falls supports the Rogers and Wethington hypothesis that Physa natricina is a junior synonym of Physa acuta.  Well, to be as precise and rigorous as I can be, The SRNLP is Physa acuta at RM 420 – 449.

But to be clear.  Also dumped into Mike Young’s bubbling Cauldron O’sequences were all nine of the (qualified) CO1 sequences uploaded by Gates, Kerans, and colleagues for the SRNLP sampled from the Minidoka tailwaters 220 miles upstream [6], plus three Minidoka sequences Young and colleagues developed themselves.  Those 12 are (indeed) quite strikingly different from the 173 Physa acuta sampled from Swan Falls, and all other sequences in the worldwide Physa database.  So, the identity of the SRNLP at RM 675 remains unconfirmed.

Halfway between Swan Falls and Minidoka is the actual type range of bona fide Physa natricina, RM 525 - 571.  Does the stunted population of Physa bearing shells with unusually large body whorls in the roaring rapids of the Snake River where it actually matters genetically match the SRNLP population at Minidoka 675, or the P. acuta population at Swan Falls 449?  Or?  Tune in next time.

Notes

[1] Young, M.K., R. Smith K.L. Pilgrim, and M.K. Schwartz (2021)  Molecular species delimitation refines the taxonomy of native and nonnative physinine snails in North America.  Scientific Reports 11: 21739. https://doi.org/10.1038/s41598-021-01197-3

[2] Taylor, D. W. (1988) New species of Physa (Gastropoda: Hygrophila) from the western United States. Malacological Review 21: 43-79.

[3] US Fish & Wildlife Service (1992). Endangered and threatened wildlife and plants; Determination of endangered or threatened status for five aquatic snails in south central Idaho. 50 CFR Part 17. Federal Register 57(240)59244-57. (December 14, 1992)

[4] Rogers, D. C. & A. R. Wethington (2007) Physa natricina Taylor 1988, junior synonym of Physa acuta Draparnaud, 1805 (Pulmonata: Physidae). Zootaxa 1662: 45-51.  For a review, see:

• Red Flags, Water Resources, and Physa natricina [12Mar08]

[5] Gates, K. K., and B. L. Kerans (2010) Snake River Physa, Physa (Haitia) natricina, Survey and Study.  Report to the US Bureau of Reclamation under agreement 1425-06FC1S202.  87 pp.  For a review of this report, see:

• The Mystery of the SRALP: A bidding… [5Feb13]
• The Mystery of the SRALP: A twofold quest! [1Mar13]
• The Mystery of the SRALP: Dixie Cup showdown! [2Apr13]

[6] Gates, K. K., B. L. Kerans, J. L. Keebaugh, S. K. Kalinowski & N. Vu (2013) Taxonomic identity of the endangered Snake River physa, Physa natricina (Pulmonata: Physidae) combining traditional and molecular techniques.  Conserv. Genet. 14: 159-169.  [html]  For a review, see:

• The Mystery of the SRALP: No Physa acuta were found [2May13]

[7] Bean, B., and M. Stephenson (2011) Swan Falls Biological Assessment for the Snake River Physa.  (Swan Falls, FERC Project No. 503).  Idaho Power Company, Boise. 30 pp.

[8] “From left to right: Nick Gastelecutto, Michael Stephenson, and Dain Bates.”  This is Figure 2 from the IPC report of the 2014 results [11].

[9] Stephenson, M., and B. Bean (2013) Swan Falls Snake River Physa Protection Plan.  (Compliance Report, Swan Falls FERC Project No. 503, Article 405) Idaho Power Company, Boise.  78 pp.

[10] Michael Stephenson was at the forefront of the Swan Falls Physa project from its beginnings back in 2011 to the present day, designing the studies, spending long days in the field, and writing the reports.  He was tremendously helpful and forthcoming with me in the research for this blog post.  On the Altar of Science in the Temple of Public Policy, Michael’s his sacrifice has been heroic.  Good job, Old Buddy, and thanks.

[11] Bean, B. (2015)  Swan Falls Article 405 Snake River Physa Monitoring Report: 2014 Results.  (Compliance Report, Swan Falls FERC Project No. 503) Idaho Power Company, Boise. 32 pp.

[12] Liu, H-P. (2016) Report on taxonomic identity of the Snake River Physa using molecular techniques.  Appendix 4 (pp 65 – 73) in IPC report of 2015 results [13].

[13] Bean, B. (2016) Swan Falls article 405 Snake River Physa monitoring report: 2015 results.  (Compliance Report, Swan Falls FERC Project No. 503) Idaho Power Company, Boise. 80 pp.

[14] These images come from Appendix 3 of the IPC Report of the 2015 results [13].  Shell lengths (left to right) were given as 1.41 mm, 1.71 mm, 3.64 mm.

[15] Bean, B. (2017) 2016 Snake River Physa Studies in the Swan Falls Reach. (Compliance Report, Swan Falls FERC Project No. 503, Article 405)  Idaho Power Company, Boise. 16 pp.

[16] In 2016, IPC biologists actually deployed their experimental multiplate artificial substrate samplers way upstream at RM 674, below the Minidoka Dam, yielding “2 confirmed Physa natricina, as well as one putative Physa natricina,” which were returned to the river.

[17] Bean, B. (2018) Swan Falls Article 405 Snake River Monitoring Report: 2017 Results.  (Compliance Report, Swan Falls FERC Project No. 503) Idaho Power Company, Boise. 14 pp.

[18] This is Figure 2 of the IPC Report of the 2017 results [17].  Full caption: “Photo of gravel basket and Hester-Dendy artificial substrate samplers.”

[19] As a rule of thumb, the IPC selected individual physids “with a shell length/width ratio of less than 1.5” to forward on for genetic analysis.  I’m not sure where this rule came from.

[20] The team did not formally publish any statistics for their impressive block of 173 sequences.  Mike Young communicated the maximum sequence divergence value of 4.82% to me in personal correspondence.

The SRALP and the SRNLP: A New Hope

This is the first installment of a fresh three-part series on the Snake River Physa controversy, prompted by the 2021 publication of new research on the subject by a fish guy named Michael K. Young and colleagues at the National Genomics Center for Wildlife and Fish Conservation in Missoula [1].

And because I look at the world through the eyes of a college professor, my first instinct is to assign homework.  I have previously posted six essays on Physa natricina: an introduction to the controversy in 2008, a broadening in 2010, and my four-part series on the “SRALP” (Snake River acuta-like Physa) in 2013, by the end of which I was so frustrated with the willful ignorance, professional malpractice, and borderline fraud perpetrated by our colleagues in the environmental community of the arid West I wrote, “I am done with it.”  But research published more recently has given me cause for new hope.

Figure 2.1 of Gates & Kerans [7]

So if you, dear reader, are seriously interested in the Snake River Physa controversy, I would (indeed!) encourage you to visit footnote [2] at the bottom of this essay and review my six previous essays on the subject before reading further into this, the seventh.  Then feel free to skip the next seven paragraphs and resume this month’s essay at the topic sentence, “And from that basement, the situation deteriorated.” But for the benefit of the rest of you, more casually interested, let me summarize, as briefly as I can.

We entered the Snake River Physa controversy, way back in 2005, with our eyes wide open.  We knew that Dwight Taylor’s (1988) description of Physa natricina [3], “Shell ovoid, solid, with broadly rounded anterior end and acute spire,” “length 5.4 – 6.9 mm,” found only “on boulders in the deepest accessible portion of the Snake River near rapid margins” [4] in Gooding, Elmore, and Owyhee Counties, Idaho, was motivated by water resource politics, cynically calculated to stop an impoundment project planned by the Idaho Power Company (IPC).  The concept of “endangerment” is entirely political, not testable by science.  One might argue that science is sullied by association with controversies of this sort.  I certainly did, in my essay of [12Mar08].

But as of 2010, when an email arrived on my desktop at the College of Charleston, calling me into a deeper involvement with the Snake River Physa controversy, I was still naïve enough to believe that the world of science, in which I live, might be compatible with the world of public policy, in which laws are made and regulations enforced.  No, I did not imagine that science could be brought to bear on questions of any political relevance.  I am not a Democrat.  But maybe, I thought back in 2010, science can piggyback on the public dole without becoming corrupted by it.  Just because we know the reason that Dwight Taylor described Physa natricina in 1988, doesn’t mean that he was wrong, does it?  Might the massive resources of the federal government and private industry be directed toward testing an hypothesis of purely scientific interest without entanglement, corruption, self-dealing and bias?

Is that weirdly shaped little physid population hugging those rocks in the raging torrents of the Snake River indeed a valid biological species, narrowly endemic to three counties of Idaho?  Or is it conspecific with the cosmopolitan Physa acuta, invasive on five continents, as suggested by Rogers and Wethington in 2007 [6]?  Or might those enigmatic little snails be neither?  A regional endemic, locally common in the shallow margins of the river, perhaps?  That was the “Hypothesis #2 of 3” I advanced in [14Sept10].

My faithful readership may remember a four-part series I posted in 2013 detailing my 2010 invitation to review a report filed by Kiza Gates & Billie Kerans on a Physa study conducted at the Minidoka Dam [7], one hundred river miles upstream from the type range of P. natricina [5Feb13], my field experiences hunting Physa in the shadow of that dam with Dr. J. B. Burch, with subsequent solo tour of the waters downstream [1Mar13], and our confrontation at a meeting convened by the US Bureau of Reclamation in Boise [2Apr13].

All I could find in the Snake River shallows as far upstream as the Minidoka Dam in September of 2010 was a sparse population of Physa gyrina, a rather different animal that really does not bear on the Physa natricina controversy at all, but keeps gumming up the works, somehow.  Further downstream, however, and for several hundred miles across the bottom of Idaho, I was able to confirm that the shallows of the Snake River are infested with Physa indistinguishable to my eyes from trash Physa acuta.  These snails I began calling SRALP, “Snake River acuta-like Physa.”

The Snake River, modified from Fig 3 of Gates et al [8]

In 2010 I was trying to test, or (rather) trying to spur Gates, Kerans, and the team of scientists who had been expressly contracted by the U.S. Bureau of Reclamation for these purposes to test, the 2007 Rogers and Wethington hypothesis that the stunted, oddly shaped little physids inhabiting rocks in the middle of the Snake River, identified by Dwight Taylor as Physa natricina, might genetically match the SRALP.  My hosts had already collected a fair sample of snails that they had identified as “Physa natricina” from the waters below the Minidoka Dam at RM 675 and sequenced a subset for two mtDNA genes [7].  These turned out to be genetically distinctive from Snake River P. gyrina, which is completely irrelevant, and from P. acuta sampled across the continental divide in Wyoming, which is just a little bit less irrelevant.  So, I brought with me a live sample of acuta-like SRALP Physa I collected fresh from the Snake River at RM 600 to the meeting of the Bureau of Reclamation in Boise and challenged – nay, begged – my hosts to sequence them.  And waited three years.

And in 2013, my hopes were dashed [2May13].  Gates, Kerans and their colleagues [8] blithely reported that “No Physa acuta were found,” refusing to sequence my SRALP samples or any Physa of any acuta-like morphology from anywhere down the length of the Snake River, cynically ginning up an elaborate process to avoid testing any hypothesis that might challenge the specific status of Physa natricina.  I was beyond disappointed – I was furious.

And from that basement, the situation deteriorated.  In their 2013 paper, Gates and Kerans, together with John Keebaugh of the Orma J. Smith Museum at The College of Idaho (ALBRCIDA), and  S. K. Kalinowski of Montana State University, reported the confirmation of snails that they identified as “Physa natricina” all the way down the length of the Snake River in Idaho, beyond Boise to the Oregon border.  This result is not surprising, on the face of it.  Dwight Taylor recorded all his modern collections “from the vicinity of Bliss to Hammett, Idaho,” roughly halfway between Minidoka and Boise, RM 525 – 571.

And indeed, the ALBRCIDA collection, where all Snake River physid samples have been deposited for many years, does hold many small-bodied Physa with inflated apertures, matching Taylor’s 1988 holotype as well as any of his paratypes, collected throughout most of the length of the Snake River in Idaho.  Quoting the 2013 paper by Gates, Kerans and colleagues verbatim: “Fifty-two specimens matching P. natricina shell characteristics were found in ALBRCIDA samples.  The furthest downstream P. natricina was collected at RK 592 (RM 367) in 2001 and the furthest upstream from RK 900 (RM 559) in 2002 (Fig. 3).”  Fine.

The problem is in the reporting of the sequence data.  There is an irregularity hidden so deeply in the paper by Gates, Kerans and colleagues [8] that I missed it entirely in my 2013 review, and only spotted it quite recently, as I was trying to correlate their results with the 2021 results of Mike Young and colleagues [1].  Watch this closely.

Gates, Kerans & colleagues selected N = 15 physids matching the P. natricina phenotype from the Minidoka Dam tailwaters for sequencing, which they listed in their Table 1, 15 physids matching the P. natricina phenotype from museum collections further downstream, which they listed in their Table 2, and 5 Physa gyrina, for a total of 35 individuals.  Here is how they reported their results, verbatim [9]:

“Only two of the five molecular markers surveyed produced amplicons suitable for sequencing, CO1 and mitochondrial ribosomal subunit 16S.  Twenty specimens produced readable sequences at the 16S locus with an aligned sequence length of 375 base pairs (bp) (GenBank Accession # GU830927 – GU830941 and JF806430 – JF806434). Only 16 out of 35 samples produced readable sequences at the CO1 locus with an aligned sequence length of 634 bp (GenBank Accession # GU830942 – GU830952 and JF806435 – JF806439).”

So, visiting GenBank today, we find that the JF sequences are the five for Physa gyrina.  The 15 GU accessions for 16S and the 11 accessions for CO1 are all Table 1 sequences, sampled from the Minidoka tailwaters (RM 670 – 674).  And no sequences whatsoever were uploaded for any alleged “Physa natricina” collected at any point further downstream, as listed on Table 2.  Apparently, none of the Table 2 physids yielded any “readable sequences.”  This is a significant irregularity, which the authors should have addressed forthrightly, rather than sweeping under the rug.  As a consequence, the Minidoka sequences have never been compared to bona fide Physa natricina sampled from the type range (RM 525 – 571).

Here I find it necessary to introduce a new term, “Snake River natricina-like Physa,” or SRNLP for short.  Until those stunted, oddly shaped little Physa recovered from the roiling tailwaters of the Minidoka Dam upstream at RM 670 – 674 can be matched genetically to the stunted, oddly shaped little Physa inhabiting the rapids of the Snake River in their RM 525 – 571 type range, the Minidoka Physa cannot, at the level of rigor demanded by this situation, be identified as Physa natricina.  They are SRNLP.

So now, the stage is set for some fresh data – those published by Mike Young and colleagues in 2021.   Does the SRNLP match the SRALP?  What policy implications might emerge from a match, or lack thereof?  Stay tuned!

Notes:

[1] Young, M.K., R. Smith K.L. Pilgrim, and M.K. Schwartz (2021)  Molecular species delimitation refines the taxonomy of native and nonnative physinine snails in North America.  Scientific Reports 11: 21739. https://doi.org/10.1038/s41598-021-01197-3

[2] Previous essays on the Physa natricina controversy:

• Red flags, water resources, and Physa natricina [12Mar08]
• Valvata utahensis and hypothesis #2 (of 3) [14Sept10]
• The mystery of the SRALP: A bidding… [5Feb13]
• The mystery of the SRALP: A twofold quest! [1Mar13]
• The mystery of the SRALP: Dixie-Cup showdown! [2Apr13]
• The mystery of the SRALP: “No Physa acuta were found.” [2May13]

If you are looking for something citable, all of these essays were subsequently published in Dillon, R.T., Jr. (2019d) Essays on Ecology and Biogeography.  Freshwater Gastropods of North America, Volume 4.  FWGNA Press, Charleston, SC.  257 pp.  [FWGNA Publications]

[3] Taylor, D. W. (1988) New species of Physa (Gastropoda: Hygrophila) from the western United States. Malacological Review 21: 43-79.

[4] The “deepest accessible” quote comes from the USFWS [5].  Taylor did not offer any habitat notes in his original 1988 description.

[5] US Fish & Wildlife Service (1992). Endangered and threatened wildlife and plants; Determination of endangered or threatened status for five aquatic snails in south central Idaho. 50 CFR Part 17. Federal Register 57(240)59244-57. (December 14, 1992)

[6] Rogers, D. C. & A. R. Wethington (2007) Physa natricina Taylor 1988, junior synonym of Physa acuta Draparnaud, 1805 (Pulmonata: Physidae). Zootaxa 1662: 45-51.

[7] Gates, K.K.,  & B.L. Kerans (2010)  Snake River Physa, Physa (Haitia) natricina, survey and study.  Unpublished report to the US Bureau of Reclamation, Boise, Idaho.  87 pp.

[8] Gates, K. K., B. L. Kerans, J. L. Keebaugh, S. K. Kalinowski & N. Vu (2013) Taxonomic identity of the endangered Snake River physa, Physa natricina (Pulmonata: Physidae) combining traditional and molecular techniques.  Conserv. Genet. 14: 159-169.

[9] I have corrected a pair of typographic errors in one of the accession numbers as published in [8].  Not "JF80634" but rather JF806434.

The Freshwater Gastropods of The Great Plains

We are pleased to announce a major expansion of the FWGNA Project, now extending our coverage westward to include the prairie states of Kansas, Nebraska, South Dakota, and North Dakota.  The Freshwater Gastropods of the Great Plains, by Bruce J. Stephen, Robert T. Dillon, Jr, and Martin Kohl is now online and available for reference!  Check it out:

Visit the FWGGP

In this important new web resource, we report the results of an original survey of 795 rivers, streams, lakes, and ponds across a big slice of the American heartland, documenting 33 gastropod species.  For each species we provide range maps and ecological notes, with a photo gallery and a dichotomous key for easy identification.

Although in areal extent our 308,000 square mile Great Plains study area is the largest of the eight regions thus far covered by the FWGNA Project, by freshwater gastropod species richness it is the smallest.  We suggest two historical factors to account for the relative poverty of the Great Plains malacofauna: the absence of landform diversity, and the absence of time sufficient for a regionally adapted fauna to evolve.  The effects of Pleistocene glaciation, if any, seem to have been to increase species richness.  State subtotals were 16 species in Kansas, 18 in Nebraska, 19 in South Dakota, and 23 in North Dakota.

We also document reductions in species richness for three of the four Great Plains states when compared to expectation from the published literature.  Kansas seems to have lost 4 species, South Dakota 6 and Nebraska 14.  The freshwater gastropod species apparently missing from each state typically become more common further north.  Although some of this phenomenon is certainly due to sampling error, we think it likely that climate change may have been a factor in the decreased species richness of The Great Plains.

Lymnaea (Galba) cockerelli, Number 15.

Bengt Hubendick [1] recognized 13 valid species of lymnaeid snails in North America [2], setting aside the patelliform genus Lanx, which he did not treat.  To that tally should be added L. auricularia, introduced to this continent more recently, and L. caperata, which Hubendick mistakenly synonymized under L. humilis.  Oh, and subtract emarginata from Hubendick’s list, a junior synonym of L. catascopium.  Is that the complete continental fauna?  To Hubendick’s canonical list of 13 + 2 – 1 = 14 species of Lymnaea inhabiting the waters of North America, might be added a Number 15?

Yes.  Last month [13Feb24] we reviewed the long and tortured history of Isaac Lea’s [3] nomen Lymnaea bulimoides, recognized as distinct by Hubendick but much confused by many other authorities with another of Hubendick’s canonical species, Lymnaea cubensis.  We reproduced images of 23 shells in that overly long essay.  I have subtracted the twelve images of L. cubensis/viator and other miscellaneous lymnaeids and re-reproduced the remaining eleven images as thumbnails in a single montage below, adding five images of related taxa I mentioned in passing last month but didn’t figure.

See footnote [4] for complete caption.

Does that set of thumbnail figures look homogeneous to you?  Or, just on the basis of those 16 shell images, knowing nothing about the biology of the snails that bore them, could you divide the set above into two distinct subsets [24]?  Let’s back up 118 years and get a fresh start at that question.

It will be remembered from last month’s essay that in 1906 Henry Pilsbry and James Ferriss [8] recognized four subspecies of Lymnaea bulimoides.  The typical form, originally described from the Oregon Territory in 1841, is depicted in thumbnails A, B, C, K, and M.  The (essentially indistinguishable) techella form, described from Texas in 1867, is depicted in thumbnails D, E, I, and O.  To these Pilsbry and Ferriss added a sonomaensis form (G, P) from California, and their own brand new cockerelli (F, J, L, N), from New Mexico, Colorado, Nebraska and South Dakota.  Quoting Pilsbry verbatim:

“This form (cockerelli) differs from L. bulimoides and L. techella by its more globose shape and shorter spire, and so far as we have seen is readily separable from both.”

In 1909 Pilsbry’s disciple, Frank Collins Baker [13], raised sonomaensis to the full species level and described a new Lymnaea hendersoni from Colorado, “at first thought to be sonomaensis” but “differing in the form of the spire and aperture.”  And in 1911 Baker [14] published his landmark monograph on the “Lymnaeidae of North America, Recent and Fossil,” cataloging and reviewing 103 species and subspecies in 15 genera, subgenera, and groups [15], including all five of the lymnaeid taxa listed above in exhaustive detail.

The figure below is a concatenation of Baker’s [16] plate XXVII (figs 20 – 35) and plate XXVIII (figs 1 – 19).  Figures 20 – 29 are Galba bulimoides (ss), figure 25 being the holotype, the same shell as figure A above.  Baker identified figures 1 – 3, 8, and 30 – 35 as Galba bulimoides techella, figures 4 -  7 as G. bulimoides cockerelli, figures 9 – 11 as a new form G. bulimoides cassi, figs 12 – 14 as G. sonomaensis, figs 15 – 18 as his G. hendersoni, and fig 19 as Galba perpolita, more about which anon.

To my eye, this montage of 35 shells is as naturally and easily divisible into two sets as the montage of 16 thumbnails that opened this essay.  I distinguish a set that looks like the bulimoides holotype (#25), which includes all those Baker identified as techella and cassi, and a subset with a much larger, more inflated body whorl, identified by Baker as cockerelli, sonomaensis, hendersoni, and perpolita.

Focus with me now on figs 4 – 7, depicting G. bulimoides cockerelli (three populations), and try to compare that subset of four shells with all the other (N = 23) images of shells borne by all the other subspecies of bulimoides: 1 – 3, 8 – 11, 20 – 35.  I know that’s a challenge, but humor me, OK?  Those two subsets clearly belong to different sets, can you see what I am saying?  Why in the world would splitters as practiced in their art as Pilsbry and Baker identify the snails bearing all 27 of those shells as a single species?  Especially when they split out figs 12 – 14 as a separate species sonomaensis?  And figs 15 – 18 as a separate species hendersoni?

Baker [14] plates 27, 28.  See [16] for scale.

The answer lies in the subset of five shells boxed in red.  This is a sample collected from the rural community of Bardsdale in Ventura County, CA, that weighed heavily in Baker’s calculations.  He wrote, in the “Remarks” section of his treatment of cockerelli, that  “Specimens from Ventura County, California, show a tendency to vary toward the techella form of shell, clearly showing that the cockerelli race is an offshoot of techella.”  That sentence is phrased as though he wanted to identify the entire Bardsdale population as cockerelli, but when the time came to his assemble plates, Baker split five specimens from Bardsdale three-and-two.

Well, dang my hide.  I reckon if there’s any splittin’ to be done around these parts, Sheriff Dwight Taylor is the man for the job.  In 1960 Taylor teamed up with vertebrate paleontologist Claude W. Hibbard on a 223-page monograph [17] of “two late Pleistocene faunas from southwestern Kansas.”  Hibbard & Taylor identified nine species of lymnaeids in the prehistoric fauna of the Great Plains, including Lymnaea stagnalis, six nominal species of Stagnicola, and two nominal species of Fossaria.  And as they sorted out the Stagnicola [18], Hibbard and Taylor observed, “from a review of previous literature and on examination of specimens it appears that Stagnicola bulimoides cockerelli is specifically distinct from S. bulimoides and S. bulimoides techella.”

Taylor further observed that the geographic ranges of bulimoides and cockerelli are different (although overlapping), cockerelli being the only species to extend through the northern Great Plains, and that the “apparent lack of intergradation” where bulimoides and cockerelli do overlap (in the Southwest, for example) might be viewed with special significance.  Here the young Dwight W. Taylor of 1960 seems almost to flirt with the biological species concept [19].  Taylor went on to re-identify the red-box population of cockerelli that Baker figured from Bardsdale as bulimoides techella in its entirety, and to synonymize Baker’s (1911) hendersoni under cockerelli.

And in 1973, Joe Bequaert  & Walter Miller brought Taylor’s point home [20].  In their landmark “Mollusks of the Arid Southwest with an Arizona Check list,” Bequaert & Miller relayed the following report:

“R. H. Russell informs us that he found in 1969 thriving colonies of S. b. techella and S. cockerelli living together (sympatric) in the same pond at two stations in Navajo Co. (O’Haco Farm and Sitting Bull Trading Post), without transitional specimens or other evidence of interbreeding in nature.”

And indeed.  Returning a second time to F. C. Baker’s red-box sample from Bardsdale.  I do not agree with Taylor that the snails bearing all five of the shells boxed in red above are best identified as L. bulimoides techella.  To my eye, it appears that Baker’s original identifications distinguished two distinct biological species: Figs 6 and 7 L. cockerelli and Figs. 33 – 35 L. bulimoides.  The Bardsdale collection appears to have been made from a site where a pair of reproductively isolated species co-occur, just as in Arizona.

In conclusion.  Lymnaea cockerelli Pilsbry and Ferriss 1906 is a distinct and valid biological species, reproductively isolated from L. bulimoides Lea 1841 and all 13 other North American species of lymnaeids.  Junior synonyms of L. cockerelli include sonomaensis Hemphill 1906 and hendersoni Baker 1909.  Lymnaea perpolita Dall 1905 may be a senior synonym.

Yes, dang my hide, again.  Look back with me at Figure 19 on the plate of shells I concatenated from Baker [14] above.  That is an image that Baker borrowed from William Healy Dall’s 1905 monograph on the land and freshwater mollusks collected by the 1899 Harriman Expedition to Alaska [21].  On his pages 78 – 79 Dall described a single “small, translucent, dark amber color” shell collected at Nushagak, Bristol Bay, Alaska as Lymnaea (Stagnicola?) perpolita n. sp.  It really looks to me like Dall may have scooped Pilsbry and Ferriss by one year.

But as far as I can tell, Dall’s nomen perpolita has almost never [22] been applied to any other population of snails ever collected again, while Pilsbry and Ferriss’ cockerelli has seen wide use throughout western North America.  Forget that you read these last two paragraphs.  I never wrote them.

So to summarize, over last month’s essay and this month’s as well.  Isaac Lea’s (1841) nomen Lymnaea bulimoides has been applied to populations of at least three distinct biological species, including cubensis/viator and cockerelli as well to as to the bona fide bulimoides of “Oregon” as originally described.  The eastern extent of the L. bulimoides range has been overstated.  My buddy Bruce Stephen and I have not been able to confirm populations of bona fide L. bulimoides anywhere in Kansas, Nebraska, or The Dakotas.  Populations of both L. cubensis/viator and L. cockerelli are not uncommon in those states, however.

Then opening the Burch Bible [12] to pages 172 – 174 we find five (full) species listed under Fossaria (Bakerilymnaea), the subgenus set aside for crappy little amphibious lymnaeids with bicuspid first laterals.  Under the first of those species, Fossaria (Bakerilymnaea) bulimoides, we find six subspecies.  In the table above I have listed those 12 taxa together with our modern FWGNA understanding of their identities.  For the time being.  Additional data would be most welcome.

Notes:

[1] Hubendick, B. (1951)  Recent Lymnaeidae.  Their variation, morphology, taxonomy, nomenclature and distribution.  Kungliga Svenska Vetenskapsakademiens Handlingar Fjarde Serien 3: 1 - 223.

[2] Hubendick listed three species as Holarctic: stagnalis, truncatula, and “palustris,” by which he was referring to populations better identified as elodes here.  As unique to North America, he listed ten: humilis, cubensis, bulimoides, catascopium, emarginata, columella, megasoma, haldemani, arctica and “utahensis (?)”  I would add a second question mark behind utahensis.  In fact, I’m not 100% sold on haldemani.

[3] Lea, Isaac (1841) On fresh water and land shells (continued).  Proceedings of the American Philosophical Society 2(17): 30 – 34.

[4] Original identification and authority for the 16 shells depicted, with standard length if it is known or can be estimated:  (A) Lea’s bulimoides holotype 9.3 mm, (B) bulimoides from Haldeman [5], (C) bulimoides from Binney [6], (D) techella from Haldeman [7], (E) techella from Pilsbry [8] 13.0 mm, (F) cockerelli from Pilsbry [8] 10.0 mm, (G) sonomaensis from Pilsbry [8] 10.0 mm, (H) vancouverensis from Baker [9] 18.5 mm, (I) techella from Clarke [10] 10.6 mm, (J) cockerelli from Clarke [10] 5.5 mm, (K) bulimoides from Clarke [10] 12.0 mm, (L) cockerelli from Leonard [11], (M) bulimoides from Burch [12] 13.8 mm, (N) cockerelli from Burch [12] 13.8 mm, (O) techella from Burch [13] 13.1 mm, (P) sonomaensis from Burch [12] 6.9 mm.

[5] Haldeman, S.S. (1844) A monograph of the freshwater univalve Mollusca of the United States, Number 7  Philadelphia: Cary & Hart, Dobson, and Pennington. 32 pp, 4 plates.

[6] Binney, W.G. (1865) Land and fresh water shells of North America Part II, Pulmonata Limnophila and Thalassophila. Smithsonian Miscellaneous Collections 143: 1 – 161.

[7] Haldeman, S.S. 1867  Description of a new species of Limnaea.  American Journal of Conchology 3: 194.

[8] Pilsbry, H.A. and J.H. Ferriss (1906)  Mollusca of the southwestern states II.  Proceedings of the Academy of Natural Sciences of Philadelphia 58: 123 – 175.

[9] F. C. Baker’s brief (1939) description of Stagnicola bulimoides vancouverensis nov. var. was published in The Nautilus 52(4): 144.  The figure reproduced above followed in Nautilus 53(1) plate 7.

[10] Clarke, A. (1973) The freshwater molluscs of the Canadian Interior Basin. Malacologia, 13, 1-509.

[11] Leonard, A.B. (1959) Handbook of Gastropods in Kansas. Miscellaneous Publications of the University of Kansas Museum of Natural History 20: 1 – 224.

[12] This is a difficult work to cite.  J. B. Burch's North American Freshwater Snails was published in three different ways.  It was initially commissioned as an identification manual by the US EPA and published by that agency in 1982.  It was also serially published in the journal Walkerana (1980, 1982, 1988) and finally as stand-alone volume in 1989 (Malacological Publications, Hamburg, MI).

[13] Baker, F.C. (1909) A new species of Lymnaea.  The Nautilus 22: 140 – 141.

[14] Baker, F.C. (1911) The Lymnaeidae of North and Middle America, Recent and Fossil.  Chicago Academy of Sciences, Special Publication Number 3.  539 pp.

[15] Note that the number of genera, subgenera, and other higher-level "groups" recognized by Baker in the North American Lymnaeidae is exactly the number of valid biological species.  This is not a coincidence.

[16] Quoting the caption to Plate XXVII, Figs 20 – 35 were “enlarged about two diameters” at their reproduction, and on that basis I have added the red scale bar.  Figs 1 – 19 were mostly “enlarged 2 diameters” on their original plate XXVIII, with the exceptions of figs 12 – 14 “enlarged about three diameters,” and fig 19, “1.5 diameters.”

[17] Hibbard, C.W. and D.W. Taylor (1960) Two late Pleistocene faunas from southwestern Kansas.  Contributions from the Museum of Paleontology, University of Michigan 16(1): 1 – 223.

[18]  Yes, Dwight Taylor considered L. bulimoides to be a little Stagnicola, not a big Galba/Fossaria.  F.C. Baker made exactly the same judgement call in 1939, see footnote #17 of last month’s essay.  This is yet further support, if any is needed, for Hubendick’s [1] opinion that there is insufficient morphological basis for the recognition of genera within the family Lymnaeidae.  The FWGNA follows Hubendick in assigning all North American lymnaeids (except the patelliform genus Lanx) to the typical genus Lymnaea, adding (subgenera) for their indexing function alone.  We do not assign Lea’s bulimoides to Lymnaea (Galba) to transmit any hypothesis of evolutionary relationship whatsoever, but only because “Galba” seems to connect with the greatest fraction of the recent literature.

[19] I never met the reclusive millionaire Dwight Taylor, but the dark shadow he cast over freshwater and terrestrial malacology extended far beyond the American West.  Well, even a sundial facing west will be right once a day.

[20] Bequaert, J. & W. Miller (1973) The Mollusks of the Arid Southwest, with an Arizona Check List.  Tucson: University of Arizona Press.  

[21] Dall, W. H. (1905)  Land and fresh water mollusks of Alaska and adjoining regions.  Smithsonian Institution Harriman Alaska Series 13: 1 – 171.

[22] My search of the iDigBio database [23] for family = Lymnaeidae and species = perpolita returned 12 hits in the USNM from Alaska and two hits in the University of Alaska Museum from Iceland.  Very little data on any of the 14 – not even dates of collection for the USNM records.

[23] For more about iDigBio, see:

• 20 Years of Progress in the Museums [22May19]

[24] For those of you who cannot wait until the end of the story.  The six lymnaeid shells depicted in images F, G, J, L, N, and P, showing the large, inflated body whorl, belonged to individual Lymnaea (Galba) cockerelli.  The other ten shells belonged to L. bulimoides.

What is Lymnaea bulimoides?

Thomas Nuttall (1786 – 1859) was a pioneering naturalist on the American frontier, most famous as a botanist but with interests in geology, ornithology, and yes, malacology as well.  In 1834 he resigned his professorship at Harvard and joined an expedition up the newly-opening [1] Oregon Trail.  Nuttall spent most of the next two years in the Pacific Northwest, interrupted by an exursion to Hawaii, returning to a position at the Academy of Natural Sciences of Philadelphia in 1836.

In 1841 our old buddy Isaac Lea [2] published a brief, Latinate description of Lymnaea bulimoides [3], which he followed with an English translation in 1844, as follows [4]:

"Shell ovately conical, rather thin, smooth, shining, diaphanous, brownish yellow, slightly perforate; spire rather short; sutures small; whorls five, slightly convex; aperture ovate. Hab. Oregon, Prof. Nuttall."

Alas, Lea never published a figure of his Lymnaea bulimoides.  And the “Oregon” from which Prof. Nuttall had just fetched that first sample was a vast territory that included all of the modern states of Washington and Idaho, parts of Montana and Wyoming and most of British Columbia [5].

By the blessings of Divine Providence, however, Lea’s type lot has been preserved, even unto the present day.  Both Haldeman [6] and Binney [7] published little 1:1 figures of “authentic specimens,” as reproduced below.  Prof. Haldeman [8] added a very similar looking Limnea techella from Texas to the literature in 1867 as “surface smoother than in L. bulimoides, of Oregon, with the lines of accretion less apparent, and the labium more angular.”  His little 1:1 figure of L. techella is also reproduced below.

Hald. [6] Binney [7] Hald. [8]

Now I feel quite confident that a significant fraction of my (admittedly rather specialized) readership will be at least passingly familiar with the crappy little lymnaeids we find crawling around on the muddy margins of our rivers, ditches, and ponds here in the American East.  You all listen up.  None of you would ever confuse a population of lymnaeids bearing shells such as those depicted above with Lymnaea (Galba) cubensis/viator, am I right?  The body whorl is way too big.  And – good grief – look at the scale bar on that holotype!  Adult L. bulimoides often reach double-digit shell lengths, whereas none of our crappy little Galba-type lymnaeids on this side of the Mississippi River ever really do.

Nevertheless, in 1891 Henry Pilsbry became the first in a long line of professional malacologists to confuse L. bulimoides with L. cubensis, in a survey of the malacofauna of the Yucatan peninsula [9].  He began by synonymizing L. umbilicata C.B. Adams 1840 under L. cubensis Pfeiffer 1839.  Then he wrote:

"The typical cubensis ranges at least as far west as the Mississippi River and eastern Texas.  West and southwest of this it gives place to L. techella Hald., and L. bulimoides Lea.  The last form may be considered a geographic race or subspecies of the cubensis.  L. techella Hald. is nearly identical with umbilicata."

Pilsbry corrected himself, however, in a survey of the Mollusca of the southwestern states he published with J. H. Ferriss in 1906 [10]:

“Lymnaea techella was formerly considered by one of us to be a synonym or race of L. cubensis Pfr, and L. bulimoides was treated as a variety of the same species.  They are certainly very similar, but cubensis has a more triangular and less broadly developed columellar expansion.”

Then going beyond a simple resurrection of Isaac Lea’s L. bulimoides, Pilsbry and Ferriss went on to recognize three subspecies underneath it: Haldeman’s techella from Texas, New Mexico and Arizona, Hemphill’s sonomaensis from California, and their own new cockerelli, widespread in New Mexico, Colorado, Nebraska and South Dakota.

Everybody look with me now at the three Pilsbry & Ferriss figures I have reproduced below.  They’re all significantly larger than our crappy amphibious lymnaeids here in The East, right?  The shell lengths reported by Pilsbry for all (N = 16) specimens he measured of all subspecies ranged from 8 mm up to a whopping 14 mm, with mean = 10.2 mm, good grief!  Very, very clearly not L. cubensis.

From Pilsbry & Ferriss [10]

Pilsbry’s 1906 dabbling with the obscure little lymnaeids of the American West did not take place in isolation, of course.  Indeed, the flood of pulmonate gastropod descriptions that washed across North America in the mid-nineteenth century became a torrent in the early twentieth, our hero Frank Collins Baker surfing high upon its crest.  In 1909, Baker [11] raised Hemphill’s sonomaensis to the full species level and described Lymnaea hendersoni from Colorado, a new species “at first thought to be Lymnaea sonomaensis,” but “differing in the form of the spire and aperture.”

And in 1911 he published his landmark “Lymnaeidae of North America, Recent and Fossil [12],” placing his own contributions, and those of his mentor Pilsbry [13], into a continental framework.  Baker recognized four subspecies of Galba bulimoides: the typical form restricted to the West Coast (BC, WA, OR, CA), Haldeman’s techella ranging from California through the desert southwest to Texas, Oklahoma, and Kansas, and Pilsbry’s cockerelli overlapping both, while extending further north into Nebraska and The Dakotas.  To these he added a new subspecies L. bulimoides cassi from California, utterly indistinguishable from techella in all respects, as well as the full species sonomaensis and hendersoni, both indistinguishable from cockerelli.

Although Baker carefully noted radula morphology when any observations were available to him throughout his 1911 monograph, he did not begin to draw a distinction between species bearing bicuspid first laterals and tricuspid first laterals until 1928 [14].  He did note that the radula of G. bulimoides cockerelli bore bicuspid first lateral teeth, “similar to that of cubensis” in 1911, and that hendersoni also bore bicuspid first laterals “similar to those of techella,” but offered no observations on any of the other taxa mentioned above, including (oddly) techella.

There is no evidence that F.C. Baker ever confused L. bulimoides, or any of the bulimoides-related taxa, with L. cubensis, or any cubensis-related taxa, at any point in his illustrious career.  He was keenly alert to even the finest distinctions in phenotype, and ever ready to recognize new species and subspecies on that basis.  In 1919 he described a Galba alberta from western Canada, to my eye looking like a dwarfed elodes, with bicuspid first laterals [15].  In 1929 he teamed up with Junius Henderson to describe a Fossaria perplexa from Washington state [16].  And in 1939 he added a fresh subspecies Stagnicola [17] bulimoides vancouverensis, distinguishing a strikingly large-bodied population from British Columbia [18].

From Leonard [19] Plate 1

In 1959 A. Byron Leonard published a thorough and influential review of the entire gastropod fauna of Kansas [19].  And I feel certain that he must have had a copy of Baker’s 1911 monograph on his desk, showing the range of both G. bulimoides techella and G. bulimoides cockerelli extending through the Jayhawk State.  In fact, Baker listed five localities for techella in Kansas, although none for cockerelli.  Remember that.  Baker also (of course) included Kansas within the ranges of G. humilis and G. obrussa [20], both of which he considered elements of the continental fauna broadly, but did not consider that the range of G. cubensis extended as far north as Kansas.

So, Byron Leonard can be excused for identifying L. bulimoides techella in Kansas, and not identifying L. cubensis.  His Plate 1 is reproduced above, showing what appears to be an unusually large [21] L. cubensis/viator shell identified as “L. bulimoides techella.”   This seems to be a fresh re-emergence of the bulimoides/cubensis confusion independent of Pilsbry’s 1891 error.

A third, independent confusion of bulimoides and cubensis also has its roots in the soil of F.C. Baker but germinated much further north.  Baker provided neither figure nor radular observations for the Fossaria perplexa he described with Junius Henderson from Washington state in 1929 [16].  But his description (“resembles both parva and dalli … larger than dalli and smaller than parva”) strongly suggests a synonym of either L. humilis or L. cubensis/viator.  In 1973, however, Arthur Clarke [22] reported the discovery of a population of crappy little amphibious lymnaeids in Alberta bearing shells “identical with type specimens of F. perplexa” on their backs and radulas with bicuspid first laterals in their mouths.  Since he considered L. cubensis “subtropical and tropical” in its distribution, Clarke reasoned that perplexa must be “a hitherto unrecognized morph of the highly variable Lymnaea bulimoides.”

And if the shell morphology of L. bulimoides is variable enough to include a population that looks like L. perplexa, surely we might also include populations that look like L. alberta, yes?  Clarke did not have any original observations to add in 1973, but on the basis of Baker’s original description of the radula [15], lowered L. alberta to the status of “morph” under L. bulimoides as well [23].

Clarke's [22] "morphs" of L. bulimoides

With the advent of the 1980s came Jack Burch’s “North American Freshwater Snails,” destined to enter the holy canon of American malacology [24].  Burch recognized seven subspecies of Fossaria (Bakerilymnaea) bulimoides: the three of Pilsbry (bulimoides ss, techella, cockerelli), the two added by Clarke (alberta, perplexa), the vancouverensis added by Baker, and Baker’s hendersoni, which had heretofore been considered specifically distinct.  Burch followed Baker in recognizing sonomaensis at the species level, but clean forgot Baker's cassi, no big loss.  Only techella, cockerelli, and the typical subspecies were figured for bulimoides in the Burch Bible, plus sonomaensis as a separate species.

And so it came to pass that in January of 2022 I rendezvoused with our good friend Bruce Stephen in Lawrence, KS, to review the extensive freshwater gastropod holdings of the Kansas Biological Survey 1971 – 1981.  You might remember Bruce from the comprehensive survey of historic freshwater gastropod records from Nebraska [25] he published back in 2015.  Bruce defended his dissertation, a modern survey of freshwater gastropods across Nebraska and South Dakota, in 2018.

Bruce and I spent the week pulling vials of snails out of metal cabinets on the fourth floor of Haworth Hall on the campus of the University of Kansas, ultimately reviewing an impressive 642 lots, identifying 14 samples of Lymnaea humilis, 15 samples of L. cubensis/viator, and zero samples L. bulimoides demonstrating the typical (or “techella”) morphology.  I feel confident that, sitting in these same precincts back in 1959, Byron Leonard [19] confused L. cubensis/viator with L. bulimoides techella.

Indeed, Bruce has never confirmed a population of typical L. bulimoides in Nebraska, or South Dakota, or North Dakota, for that matter.  It would appear that the range of L. bulimoides has been greatly exaggerated, almost certainly by confusion with L. cubensis.

From Bruce's camera 1/22

Bruce and I did confirm 5 lymnaeid populations bearing shells of the cockerelli form in Kansas, with similar populations scattered through Nebraska and The Dakotas as well.  Did F. C. Baker [12] confuse L. bulimoides techella with L. bulimoides cockerelli?  We’ll come back to that question next month.

But returning to the bulimoides/cubensis confusion, and shifting one state south, to Oklahoma.  GenBank holds just two pair of sequences labeled “bulimoides:” a 16S/CO1 pair from E. A. Remigio [26, 27] and a 16S/CO1 pair from Wethington & Lydeard [28].  The former pair (AF485657 and AY227367, respectively), from an individual collected in “Oklahoma” (no further information), are both 99% similar to the big body of sequence data for Galba cubensis/viator that has accumulated in GenBank over many years.

The Remigio sequences were swept up into the 2011 study of Correa et al. [29] and the influential 2021 study of Alda et al. [30], prompting both of those sets of authors, and me myself a sinner [31], to hypothesize that bulimoides might be a junior synonym of cubensis/viator in a pair of posts on this very blog.  Writing here today, I feel quite certain that sequences AF485657 and AY227367 were misidentified at their deposition.  And I have added red-font retractions to the bottoms of my blog posts of [7Aug12] and [6July21].

The pair of 16S/CO1 sequences uploaded by Wethington & Lydeard, EU038315 and EU038362 respectively, are 8.9% and 16.5% different from the Remigio sequences, respectively, and hence did not get swept up into the big worldwide surveys of Correa and Alda.  Blasting them against GenBank, however, both return close matches to sequences obtained from a topotypic population of Lymnaea (Stagnicola) caperata, deposited by Morningstar et al [32]: 98 – 99% for 16S and 96-97% for CO1.  The only conclusion I think it is safe to make at present from the negligible DNA data available for bulimoides is that I am not going any further down this rabbit hole [33].

So let us now set the record straight, for all time.  Lymnaea (Galba) bulimoides is a distinct, valid biological species, not to be confused with Lymnaea (Galba) cubensis/viator.  Fossaria perplexa Baker & Henderson 1929 is not a subspecies, synonym or morph of bulimoides, nor is Galba alberta Baker 1919.

And in conclusion, Brothers and Sisters, I rise to the pulpit.  The confusion and misunderstanding that has historically surrounded the crappy little amphibious lymnaeids of western North America is but an extension of a greater darkness that benights international malacology across five continents, Old World and New.  The figure below is from the 2011 review of neotropical lymnaeids published by Ana Correa and her colleagues [35], as reproduced in my review of [7June21].

From Correa et al. [33]

Populations of crappy little amphibious lymnaeids identified as “Galba cousini (Jousseaume, 1887)” are common and widespread in muddy ditches and ponds on the Pacific side of South America, primarily in Ecuador and Colombia.  Where have you seen snails bearing shells looking like that before?

All the lymnaeid populations we have discussed in this overly long essay, and all of those depicted in Ana Correa’s figure above, are potential hosts for the livestock fluke, Fasciola.  In Central and South America, huge international teams of malacologists and parasitologists have published mountains of research on the evolutionary relationships among truncatula, “schirazensis,” cubensis/viator and – yes – cousini.  A quick search of GenBank returns 35 hits for G. cousini alone.

Meanwhile here in the USA, the richest country on earth, the leader of the free world, we have zero authentic sequences for any population of our own Lymnaea (Galba) bulimoides, known to be an important host of livestock fluke across the Pacific Northwest since 1929 [36].  We have four spurious mtDNA sequences from two crappy snails, both of which I think were misidentified.

United States malacology had a two-generation head start on South American malacology.  Lea (1841) trumps Jousseaume (1887) by 46 years.  I do not know how we have fallen so far behind the rest of the world today, but I do know a continent-scale mess when I see it, and international embarrassment when I feel it.  Malacologists of America, we must do better.

Notes:

[1] Although pioneered for foot traffic as early as 1811, the Oregon Trail did not become passable by wagon until the 1830s.

[2] For a brief biography of “The Nestor of American Naturalists,” see:

• Isaac Lea Drives Me Nuts [5Nov19]

[3] Lea, I (1841) On fresh water and land shells (continued).  Proceedings of the American Philosophical Society 2(17): 30 – 34.

[4] Lea, I. (1844/46) Continuation of Mr. Lea’s paper on fresh water and land shells.  Transactions of the American Philosophical Society 9(1): 1 – 31.

[5] The U.S. / Canadian boundary in the Pacific Northwest was not established until 1846.

[6] Haldeman, S.S. (1844) A monograph of the freshwater univalve Mollusca of the United States, Number 7  Philadelphia: Cary & Hart, Dobson, and Pennington. 32 pp, 4 plates.

[7] Binney, W.G. (1865) Land and fresh water shells of North America Part II, Pulmonata Limnophila and Thalassophila. Smithsonian Miscellaneous Collections 143: 1 – 161.

[8] Haldeman, S.S. 1867  Description of a new species of Limnaea.  American Journal of Conchology 3: 194.

[9] Pilsbry, H.A. 1891 Land and Fresh-water mollusks collected in Yucatan and Mexico.  Proceedings of the Academy of Natural Sciences of Philadelphia 43: 310 – 334.

[10] Pilsbry, H.A. and J.H. Ferriss (1906)  Mollusca of the southwestern states II.  Proceedings of the Academy of Natural Sciences of Philadelphia 58: 123 – 175.

[11] Baker, F.C. (1909) A new species of Lymnaea.  The Nautilus 22: 140 – 141.

[12] Baker, F.C. (1911) The Lymnaeidae of North and Middle America, Recent and Fossil.  Chicago Academy of Sciences, Special Publication Number 3.  539 pp.  For a brief biography of our hero, see:

• The Legacy of Frank Collins Baker [20Nov06]

[13] For an exploration of the relationship between Frank Collins Baker and Emperor Henry Augustus Pilsbry, see:

• The Emperor, the Non-child, and the Not-short Duct [9Feb21]
• Dr. Henry A. Pilsbry was a jackass [26Jan21]

[14] Baker, F.C. (1928) Freshwater Mollusca of Wisconsin, Part I, Gastropoda. Bull. Wisc. Geol. Natur. Hist. Survey, no. 70. Madison: University of Wisconsin Press.  Baker proposed Nasonia as a subgenus to distinguish species of Fossaria with bicuspid lateral teeth, but alas, that name was preoccupied.  The German malacologist W. K. Weyrauch proposed the name “Bakerilymnaea” as a substitute in 1964.

[15] Baker, F.C. (1919) Fresh-water mollusca from Colorado and Alberta.  Bulletin of the American Museum of Natural History 41(13): 527 – 539.

[16] Baker, F.C. and J. Henderson (1929) Fossaria perplexa F. C. Baker and Junius Henderson.  Nautilus 42(3): 103-104.

[17] That's right, F. C. Baker himself transferred bulimoides from the genus Galba/Fossaria to the genus Stagnicola, simply because he discovered a population that was unusually large-bodied.  There is absolutely no biological basis for recognizing genus (let alone subgenus) divisions in the worldwide Lymnaeidae.  None.  The FWGNA follows Hubendick in assigning essentially all lymnaeids to a single vanilla genus Lymnaea.  We add subgenera for their indexing function only - just to help the Google machine find our research.  For more, see:

• The Classification of the Lymnaeidae [28Dec06]  

[18] Baker, F.C. (1939) Stagnicola bulimoides vancouverensis nov. var. The Nautilus 52(4): 144.

[19] Leonard, A.B. (1959) Handbook of Gastropods in Kansas. Miscellaneous Publications of the University of Kansas Museum of Natural History 20: 1 – 224.

[20] Lymnaea (Galba) obrussa Say 1825 is a junior synonym of Lymnaea humilis Say 1822.  See:

• Exactly 3ish American Galba [6July21]

[21] The scale on Leonard’s entire Plate 1 is dubious.  He stated, “figures enlarged approximately 2 times natural size,” but I do not know the original size of the printed page.  I’m working from a pdf.

[22] Clarke, A. (1973) The freshwater molluscs of the Canadian Interior Basin. Malacologia, 13, 1-509

[23] The radula of Lymnaea (Stagnicola) elodes also bears bicuspid first marginals.  I do not agree with Clarke about the synonymy of L. alberta, but am loathe to digress further.  It clearly is not bulimoides.  That's the point.

[24] This is a difficult work to cite.  J. B. Burch's North American Freshwater Snails was published in three different ways.  It was initially commissioned as an identification manual by the US EPA and published by that agency in 1982.  It was also serially published in the journal Walkerana (1980, 1982, 1988) and finally as stand-alone volume in 1989 (Malacological Publications, Hamburg, MI).

[25] Stephen, B. J. (2015)  Species composition of Nebraska’s freshwater gastropod fauna: A review of historical records.  American Malacological Bulletin 33: 61 – 71.  For a review, see:

• Cornhusker Freshwater Gastropods [11May15]

[26] Remigio, E.A. and Hebert, P.D. (2003) Testing the utility of partial COI sequences for phylogenetic estimates of gastropod relationships.  Mol. Phylogenet. Evol. 29 (3), 641-647.

[27] Remigio,E.A. (2002) Molecular phylogenetic relationships in the aquatic snail genus Lymnaea, the intermediate host of the causative agent of fascioliasis: insights from broader taxon sampling, Parasitol. Res. 88 (7), 687-696

[28] Wethington, A.R., & C. Lydeard (2007) A molecular phylogeny of Physidae (Gastropoda: Basommatophora) based on mitochondrial DNA sequences.  Journal of Molluscan Studies 73: 241 - 257.

[29] Correa, A.C., J.S. Escobar, O. Noya, L.E. Velasquez, C. Gonzalez-Ramirez, S. Hurtrez-Bousses & J-P. Pointier (2011)  Morphological and molecular characterization of Neotropic Lymnaeidae (Gastropoda: Lymnaeoidea), vectors of fasciolosis.  Infection, Genetics and Evolution 11: 1978-1988.  I reviewed that paper in my post:

• The Lymnaeidae 2012: Fossarine Football [7Aug12]

[30] Alda, Pilar, M. Lounnas, A.Vázquez, R. Ayaqui, M. Calvopiña, M. Celi-Erazo, R.T. Dillon Jr., L. González Ramírez,  E. Loker, J. Muzzio-Aroca, A. Nárvaez, O. Noya, A. Pereira, L. Robles, R. Rodríguez-Hidalgo, N. Uribe, P. David, P. Jarne, J-P. Pointier, & S. Hurtrez-Boussès (2021) Systematics and geographical distribution of Galba species, a group of cryptic and world-wide freshwater snails.  Molecular Phylogenetics and Evolution 157: 107035. [pdf] [html]  I reviewed that paper in my post:

• Exactly 3ish American Galba [6July21]

[31] I speculated that L. bulimoides might be a junior synonym of L. cubensis/viator in both of the blog posts cited above.  But in my own defense, see my footnote #11 of 6July21: “I am quite certain, however, that the single 16S sequence uploaded to GenBank by Remigio, labeled “Fossaria bulimoides” but collected 2,000 miles from the bulimoides type locality in Oregon, is weak evidence, indeed.”

[32] Morningstar,C.R., Inoue,K., Lang,B.K. and Berg,D.J.  (2018) A comprehensive status, phylogenetic, and anatomical review of Stagnicola caperata (Say, 1829) in the south-west United States.  Aquatic Conservation 28 (3), 527-534.

[33] OK, maybe a little further.  Our good friend Amy Wethington tells me that she got her sequences from Rob Guralnick, who got them from a Mesa County, Colorado sample identified as Lymnaea bulimoides by Shi-Kuei Wu.  Shi-Kuei was a careful worker, and thumbing through his (admirable) Colorado Inventory [34] I find no evidence that he was confused about the identity of L. bulimoides.  I have no idea what happened here.  Classic GenBank SNAFU.

[34] Wu, S-K. (1989) Colorado Freshwater Mollusks. Natural History Inventory of Colorado, no. 11. Boulder: Univ. Colorado Museum.

[35] Correa, A.C., J.S. Escobar, O. Noya, L.E. Velasquez, C. Gonzalez-Ramirez, S. Hurtrez-Bousses & J-P. Pointier (2011)  Morphological and molecular characterization of Neotropic Lymnaeidae (Gastropoda: Lymnaeoidea), vectors of fasciolosis.  Infection, Genetics and Evolution 11: 1978-1988.

[36] Shaw, J.N. and Simms, B.T. 1929. Galba bulimoides Lea an intermediate host of Fasciola hepatica in Oregon.  Science 69: 357.