Physa progress

F. C. Baker called Physa heterostropha “the most misunderstood mollusk in America.” Without question, the entire family Physidae has been a source of considerable frustration to me personally, since I collected my first batch as a child 30-40 years ago. The doggone things are everywhere, and all 40+ nominal species of American Physa pretty much look identical.

Now I’m happy to report that progress is being made. In the most recent issue of Invertebrate Biology, Amy Wethington, two undergraduates and I report that the most common species of Physa in North America is Physa acuta. Here’s the reference:

Dillon, R.T. Jr., A.R. Wethington, J.M. Rhett & T.P. Smith (2002) Populations of the European freshwater pulmonate Physa acuta are not reproductively isolated from American Physa heterostropha or Physa integra. Invert. Biol. 121:226-234. [PDF]

Yes, it appears that the most misunderstood mollusk in America, together with its more northern cognate, is not different from a Physa discovered in southern France in 1805 - a Physa which has since spread throughout the Old World, down to South Africa and out to Japan. Although it seems fairly clear that Physa acuta is a North American native, it was apparently first described in Europe. I think P. acuta may be the most common freshwater mollusk in the world.

This is the but the first salvo in an all-out frontal assault on the bastion of the Physidae. This spring Chuck Lydeard, Ellen Strong and I have been awarded a $400k three-year grant from the NSF to review the systematics of the entire family. Chuck and Amy will focus on a big sequencing effort, Ellen will work on the anatomy, and I’ll keep cranking out the breeding studies.

We’ve already collected almost a year of data on crosses involving the other major group of physids, those that Burch puts in the subgenus Physella. (Physa acuta, integra, and heterostropha are in the subgenus Costatella.) We’ve got good results from Physa gyrina gyrina, Physa gyrina aurea, Physa microstriata, Physa utahensis, and a population from Zion National Park. We’ve also piddled with Physa parkeri and Physa ancillaria in the past year. Just this spring we’ve begun new experiments with the Costatella group, including Physa virgata and P. hendersoni. You’ll hear more about all this research in Charleston next month.

So what’s the bottom line? The number of biological species of physids has probably been overestimated by an order-of-magnitude. The critters show tremendous phenotypic plasticity, in shell, life history, and any other respect you could name. The Charleston meeting will feature several talks focusing on phenotypic plasticity in pulmonate snails as well. We’ll keep you posted as this research progresses.

P.S. - You will notice that we do not use “Physella” as a genus. Jack Burch (1992) has moved Physella back down to subgenus rank, and we agree. See Burch & Jung’s “Freshwater Snails of the University of Michigan Biological Station Area” (Walkerana 6:85) for more.

Freshwater Gastropod Pests, Continued...

My 5/23 message on the subject of pest snails brought an interesting response from David Richards, research ecologist with EcoAnalysts Inc and Ph.D. student at Montana State. He called my attention to a really impressive Potamopyrgus web site being developed at MSU - Bozeman. The site is "70% ready for public use" according to David (as of late May), but many of the resources are already spectacular. Check out the "Mudsnail Maps" at: http://www.esg.montana.edu/aim/mollusca/nzms/

Potamopyrgus antipodarium is not, alas, on the draft list of pest gastropods currently being circulated by Rob Cowie, the AMS Conservation chair. You may recall the allusion I made last month to a collaboration between the USDA and the AMS aimed at identifying "America's Least Wanted Mollusks." Not only is it difficult to document an economic impact for Potamopyrgus, it's also probably too late to do much about it.

But there are certainly many other pest gastropods whose introduction to North America may yet be prevented, including a couple freshwater groups. The message from Rob Cowie appended below is self-explanatory. Please consider responding to him. Or meet him, and the rest of the Pest Mollusk Committee, and David Richards, here at AMS 2002 in August!


--------- [Begin message from cowie@hawaii.edu] ---------

To all Researchers interested in the impacts of alien species:

I am sending this message out in the hope of getting feedback from people not only in the USA, but also from throughout the world.

The United States Department of Agriculture (USDA) has asked me (through the American Malacological Society) to create a list of 15 non-marine molluscan taxa that the USA should consider of paramount quarantine importance. That is, these are taxa either not yet in the USA or if they are in the USA they are confined, as yet, to only a few localities where it may be possible to eradicate them or at least to prevent them from spreading further afield. The list will eventually be accompanied by "factsheets" on each taxon in an American Malacological Society report to the USDA*.

The first step is to create the list. Working together, David Robinson, Rob Dillon and I (with Jim Smith of USDA providing guidance) have come up with the following list. We decided it was not possible to come up with just 15 species (the initial USDA request), so we have come up with groups of species belonging to 15 families. These taxa were selected based on 13 criteria that in general are thought to correlate with potential invasiveness. These criteria include biological features of the taxa (e.g., reproductive rate, body size) as well as features reflecting their interaction with humans (e.g., pest status elsewhere, frequency of interception by quarantine officials). Our method of scoring each taxon against the criteria is as yet very rudimentary.

I would very much welcome comments about this list, especially regarding any glaring omissions of taxa that you know to be serious invasive pests elsewhere in the world? [But remember, there are many pest species that are not on this list because they are already widespread in the USA.] Here's the list, with the most important taxa first:

• Veronicellidae - especially Sarasinula plebeia and Veronicella cubensis, but also Laevicaulis alte and Diplosolenoides occidentalis. Agricultural pests.
• Ampullariidae - especially Pomacea species (except Pomacea bridgesii), but also Pila species and Marisa species. Rice (and other aquatic plant) pests, and likely environmental pests damaging native aquatic vegetation.
• Helicidae - especially Theba pisana and Eobania vermiculata, but also Cantareus apertus, Otala punctata, and perhaps Helix species (remember Helix aspersa - or whatever genus you consider it to be in now - is already widespread in the USA). Agricultural and garden pests.
• Achatinidae - especially Achatina fulica, but also Archachatina marginata, and perhaps Achatina achatina. Agricultural and garden pests and general nuisances; also, as with many snail species on this list, can vector serious human parasites.
• Hygromiidae - especially Cernuella species, Cochlicella species, and Xerolenta obvia. Agricultural pests.
• Planorbidae - especially Indoplanorbis exustus, and to a lesser extent Biomphalaria species. Vectors of animal schistosomes not yet in the USA.
• Milacidae - Tandonia budapestensis and Tandonia sowerbyi, and to a lesser extent, T. rustica. Crop pests.
• Enidae - various species. Vectors of livestock diseases.
• Succineidae - Succinea tenella/horticola, possibly also non-US Calcisuccinea species. Agricultural/horticultural pests. Contaminants of horticultural products.
• Pleurodontidae - Zachrysia provisoria. Agricultural pest.
• Helicarionidae - Ovachlamys fulgens and Parmarion martensi. Pest potential not fully appreciated, but contaminants of horticultural products and spreading very rapidly around the world.
• Arionidae - Arion lusitanicus. Agricultural pest, general nuisance.
• Urocyclidae - Elisolimax flavescens.
• Bradybaenidae - Acusta touranensis.
• Spiraxidae - Euglandina species (except E. rosea, which is native to the south-east USA). Predators of native snails.

Many thanks for any input you care to offer. Your help will be duly acknowledged in the final product.

Robert Cowie
Center for Conservation Research and Training
University of Hawaii
3050 Maile Way,
Gilmore 408
Honolulu, Hawaii 96822 USA


*Historical Note:
The paper for which this survey was compiled in 2002 was ultimately published in 2009:

Cowie, R. H., R. T. Dillon, D. G. Robinson and J. W. Smith (2009) Alien non-marine snails and slugs of priority quarantine importance in the United States: A preliminary risk assessment. American Malacological Bulletin. 27: 113-132. [PDF]

Freshwater Gastropod Pests

As this year's president of the AMS, I've become involved with a USDA initiative to identify mollusks (of all sorts) that have the potential to become pests*. Although most of the critters falling into this category are land snails and slugs, occasionally freshwater gastropods receive some attention.

The following news item was called to my attention by Jim Smith, a scientist at in the USDA's Animal and Plant Health Inspection Service whom I've recently had the pleasure to work with. It comes from a web site that's new to me - NAPPO, the North American Plant Protection Organization. http://www.pestalert.org/pestnews.cfm

Subject: Mollusk from New Zealand expands range in US
Date posted: 04/23/02
Source: US Geological Survey

The New Zealand mudsnail, Potamopyrgus antipodarum, first recorded from North America in Idaho's Snake River watershed in 1987, has added Arizona to its US distribution. Through the 1990's, the mudsnail spread to the waters of Montana, Wyoming, and California, including public lands such as Yellowstone National Park. In the eastern US, P. antipodarum is found in Lake Ontario, where a population was discovered in 1991. While widely distributed through Australia, Asia, and Europe, this species, as it name suggests, is native to freshwater lakes and streams of New Zealand. The snail is capable of rapid population growth, reproducing parthenogenically,and in Yellowstone, localized infestations can reach a density of 28,000 individuals per square foot. In the United Kingdom, P. antipodarum is reported to eat watercress; however, the main concern in the US is that the mudsnail will out compete algae-feeding aquatic insects, the main food source of trout.

The NAPPO web site also has a nice write-up on Pomacea canaliculata in the "Pest Alert" section, with a 14-page data sheet. Go to their website and submit "Mollusks" on the Pest Alert page, if you're curious.

We're anticipating several talks on the subject of molluscan pests at the Charleston meeting this August, including contributions by Jim Smith and by Rob Cowie, the chair of the AMS Committee spearheading this effort. Registration for that meeting will continue until June 30.


*Historical Note:
This paper was ultimately published in 2009:
Cowie, R. H., R. T. Dillon, D. G. Robinson and J. W. Smith (2009) Alien non-marine snails and slugs of priority quarantine importance in the United States: A preliminary risk assessment. American Malacological Bulletin. 27: 113-132. [PDF]

Charleston Symposium

To the FWGNA group,

The Charleston meeting is shaping up very nicely. Here's the current list of participants in our featured symposium, "The Biology and Conservation of Freshwater Gastropods." Their titles are, in many cases, tentative:

• John Alderman - Evolution of aquatic habitat conservation in North Carolina.
• Art Bogan and M. Raley - The conservation status of the Magnificent Ramshorn (Planorbella magnifica).
• Ken Brown - A general review of the conservation status of North American freshwater gastropods.
• Matthias Glaubrecht - Leopold von Buch's legacy: Treating species as dynamic natural entities, or Why geography matters.
• Rob Guralnick - Tying together bioinformatics and molecular approaches to discover conservation units.
• Paul Johnson - TBA.
• Steve Johnson - Spatial patterns of genetic structure, armature and coloration in Mexipyrgus churinceanus.
• Eileen Jokinen - TBA.
• Chuck Lydeard - The Phylogenetic Species Concept and its application in the conservation of freshwater mollusks.
• Bob McMahon - TBA.
• Elizabeth Milhalcik & Fred Thompson - The "Elimia" curvicostata species complex.
• Doug Shelton - The Freshwater Gastropods of Mississippi: Pioneer Survey Efforts in the 21st Century.
• Tim Stewart - Distribution and status of the freshwater gastropods of Virginia.
• Jon Todd - Species diversity assessment, sediment impact and point endemism: Problems in conservation assessment for highly speciose rift-lake endemics.
• Amy Wethington - Conservation issues in the Physa gyrina group.

And as if this weren't enough, that hard-working Amy Wethington has organized a special session entitled "Pulmonate Gastropods In The Laboratory" promising to provide a lot of additional insight into the biology of our favorite group!

• Susan Bandoni - TBA.
• Ken Brown - What can radio-isotope methods tell us about grazing in Physa?
• Thom DeWitt and Brian Langerhans - I. Overgeneralized cues induce maladaptive phenotypic plasticity in a pulmonate snail. Also II. Multivariate selection and emergent impacts of multiple predators in a freshwater snail-fish-crayfish system.
• Vasiliki Flari - Reproductive endocrinology of terrestrial pulmonates, mainly Deroceras reticulatum, Arion subfuscus, & Helix aspersa.
• Tom McCarthy - TBA
• Tom Smith & Rob Dillon - "Social facilitation" accelerates self-fertilization in Physa.
• Andy Turner - Nonlethal effects of predators on behavior and growth of Physa integra: comparing mesocosm and field experiments.
• Amy Wethington - Divergence and reproductive isolation in physids among populations of the gyrina group.

Many additional talks and posters dealing with diverse aspects of freshwater snail biology will be contributed. You won't want to miss this meeting! The deadline for early registration (and paper/poster submission) is May 15. Go to the website: http://dillonr.people.cofc.edu/AMS2002.htm

See you here!
Rob

Do the Charleston?

To the FWGNA group,

Please accept my invitation to attend the 68th annual meeting of the American Malacological Society here in Charleston, August 3 - 7, 2002. See the website:
http://www.fwgna.org/dillonr/AMS2002.htm

Our featured symposium will be "The Biology and Conservation of Freshwater Gastropods." I've lassoed a galaxy of malacological stars to make presentations, and the entire FWGNA group will get together to formulate project strategy for the future.

There will, of course, be the usual contributed paper and poster sessions, evening programs, an endowment auction, and a dinner cruise on Charleston Harbor. Field trips will be available for every taste, featuring historic tours, a fossil trip, and a boat trip to pristine Bull Island.

Housing will be available at modest cost in dormitory facilities at the College of Charleston. Lodging is also available at the Westin Francis Marion Hotel, located adjacent to the meeting facilities.

This afternoon I've placed brochures in the snail-mail to those of you for whom I have addresses. Registration materials and a call for papers should go out in February or March. But mark your calendars today! And I'll see you in Charleston next summer.

Season's Greetings,
Rob

FWGNA Edcomm

To the FWGNA group,

I am pleased to report that Dr. Rob Guralnick has agreed to join the Editorial Committee for our project. He succeeds Bob Hershler, who resigned as the Pacific regional coordinator last month, citing other commitments.

Rob is a 1999 Ph.D. from Dave Lindberg's lab at Berkeley. He is so skilled, both with molecules and with computers, that he went straight from grad school to win Shi-Kuei Wu's old post at the University of Colorado Museum.

It occurs to me that quite a few of you have joined this list since the EdComm was established 8/99, and may not know who these folks are or what they do. The EdComm is a group of eight malacologists, organized regionally, who provide oversight and guidance to the FWGNA project. They served as "Principal Investigators" for the NSF proposals we submitted in 1999 and 2000, and will edit the final products (both print and electronic) when we get to that stage (still quite a few years down the road.) Names and contact info follow:

• Steve Ahlstedt - Eastern Mississippi. USGS Knoxville, ahlstedt@usgs.gov
• Ken Brown - Western Mississippi. Louisiana State University, kmbrown@lsu.edu
• Rob Dillon - Southern Atlantic. College of Charleston, dillonr@cofc.edu
• Rob Guralnick - Pacific. University of Colorado, guralnic@spot.colorado.edu
• Paul Johnson - Eastern Gulf. Southeast Aquatic Research Institute, pdj@sari.org
• Eileen Jokinen - Great Lakes. Sault Ste. Marie, ejokinen@sault.com
• Bob McMahon - Western Gulf. U. Texas Arlington, r.mcmahon@uta.edu
• Dave Strayer - Northern Atlantic. Inst. Ecosystem Studies, strayerd@ecostudies.org

Rob Guralnick brings a lot of strengths to a project already quite obviously bulging with scientific talent. Join me in welcoming him to the Edcomm.

And keep in touch!
Rob

Report From Vienna

To the FWGNA group:

The American Malacological Society met with Unitas Malacologia in Vienna, Austria, August 19 - 25 in what might fairly be counted as the second "World Congress of Malacology." The following is a brief recap, from the special standpoint of the Freshwater Gastropods of North America project.

I understand that The Congress attracted somewhere around 400 - 500 registrants, and that a roughly equivalent number of papers and posters were presented. The North American turnout was a bit light (perhaps only 70 - 80) almost certainly due to the lateness of the season - school starts in late August for many of us on this side of the Atlantic. But I enjoyed meeting the host of workers from South America, Asia, and Africa, whom one would ordinarily not encounter at functions in the USA.

The five symposia organized for this meeting included one that will be of particular interest to the members of our group. Ian Killeen (Felixtowe, UK) and Mary Seddon (National Museum of Wales) organized a session entitled "Molluscan Conservation & Biodiversity" that included a keynote address, seven 20-minute symposium presentations, and twenty 15-minute "satellite" talks distributed over three days.

The keynote was offered by Mr. Tony Whitten, Senior Biodiversity Specialist for the World Bank, who asked rhetorically, "Malacologists: What are your priorities?" His premises were that (1) there is a global biodiversity crisis, and that (2) there has never been more money available for biodiversity conservation from governments, foundations, conservation NGOs, multi-lateral agencies, and even the private sector. He then asked, "Where is the Snail Defense League? Where are the expeditions to undercollected areas? Where is the development of human resources in the malacologically-richest countries? Where are the coordinated efforts to get funds?" The implication seemed to be that we malacologists are all too busy making phylogenetic trees to notice that those little bags of character states or DNA we're trying to classifying are disappearing before our eyes.

Mr. Whitten's remarks were good-natured, and sweetened with lots of humor, and I don't think anybody in the room took offense. He does have a point. However, I take this opportunity to call Mr. Whitten's attention to the Freshwater Mollusk Conservation Society: http://ellipse.inhs.uiuc.edu/FMCS/ and to the 110 members of its "Snail Defense League" listed above. We've been "developing human resources" and mounting "coordinated efforts to get funds" for "expeditions to undercollected areas" since 1998, and have yet to find a single dollar of support. Perhaps this is my failing. Might Mr. Whitten be available to consult?

The main symposium presentations were as follows:

• Winston Ponder - The research vs. conservation dilemma (Australian examples)
• R.A.D. Cameron - Species/area in land snails
• Philippe Bouchet - Marine Indo-Pacific diversity
• Rob Cowie - Alien invasions (focus on Pacific island land snails)
• Dick Neves - Propagation of North American unionids
• Joe Heller - Using GIS on land snails in Israel
• Thierry Backeljau - Genetics & conservation

These talks were followed by a general discussion session, during which both Dick Neves and I offered advertisements for the Freshwater Mollusk Conservation Society. Although primarily North American at this point, the FMCS does in fact solicit a worldwide membership. I had a couple inquiries later.

The primary concern, both in the main symposium presentations and in the "satellite" sessions that followed, seemed to be land snail conservation, with the unionaceans (especially Margaritifera) running a respectable second and marine faunas third. Freshwater gastropods came to the fore only in a presentation by Ioan Sirbu (Lucian Blaga University, Romania) on the severe human impacts suffered by the freshwaters of Transylvania and Banat. Among 51 gastropod and 22 bivalve species, 25 appear on the author's personal "Red List."

I don't intend to fuss about the relative absence of freshwater gastropods from this particular part of the Vienna program. I think the symposium as organized by Killeen and Seddon offered a fair reflection of world conservation consciousness as it flickers briefly upon the Mollusca.

There were plenty of papers and posters dealing with freshwater gastropods in the general sessions*. The symposium on the endemic molluscan faunas of the ancient lakes organized by Frank Wesselingh and Ellinor Michel was excellent. The program for the entire congress may be viewed at: http://www.univie.ac.at/WCM2001/ All the abstracts will also be published at the address above, organized alphabetically by author. (Currently authors A - E are on line, others "will follow in a few days.")

Thanks are due to the organizers of The Congress, especially Gerhard Steiner and Luitfried Salvini-Plawen of the University of Vienna, for their efforts in bringing a marvelous conference to fruition.

Keep in touch,
Rob

*However, I think Amy Wethington and I offered the only two presentations specifically featuring North American freshwater gastropods. We reported that Physa heterostropha, Physa integra, and Physa acuta are all the same species. Our manuscript is currently in review at Invertebrate Biology.