Dr. Rob Dillon, Coordinator

Friday, December 19, 2003

FMCS Gastropod Workshop

To The FWGNA Group:

Registration is now open for the Freshwater Mollusk Conservation Society's Gastropod Workshop, to be held in conjunction with a water quality conference at the University of Alabama this March. The Water Quality conference is scheduled for March 15 - 16, with the gastropod workshop to follow on March 17 - 18. A single registration fee gets you into both events!

We'll review the freshwater gastropod families systematically on Wednesday the 17th, with a team of fresh young scientists as our guides (and Jack Burch, as well!) On Thursday we'll turn to the biology and conservation of our favorite critters, wrapping up with a discussion of the nascent "National Strategy" for freshwater gastropod conservation and recovery.

The conference chair is Dr. Paul Johnson and the local arrangements contact is Chuck Lydeard .

See you all there!

Wednesday, October 29, 2003

Invasive Viviparids in South Carolina

Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2019d)  Invasive viviparids in South Carolina.  Pp 1 – 5 in The Freshwater Gastropods of North America Volume 4, essays on Ecology and Biogeography.  FWGNA Press, Charleston.

Several weeks ago I had an opportunity to revisit the shores of Lake Marion, a large impoundment of the Santee River about 50 - 60 miles west of Charleston. I was stunned to discover the sandy beaches covered by wracks composed almost entirely of millions of viviparid shells (figure at left). The shells were a striking mixture of approximately 95% Viviparus subpurpureus and 5% V. georgianus. This is, to my knowledge, the first report of V. subpurpureus in an Atlantic drainage, as well as the first report that this species can be invasive.

Lake Marion and its sister, Lake Moultrie, were impounded for hydroelectric purposes in the early 1940s. I have visited them casually every couple years since the early 1980s, and had no observations of viviparids through the mid-1990s. I first noticed Viviparus georgianus in Lake Moultrie in 1997, but didn't think too much about it. Georgianus is a fairly well known invader, distributed from Florida up to Quebec according to Clench & Fuller (in Burch), but "mainly in the Mississippi River system."

Viviparus subpurpureus is a similar animal, although its shell has more flatly-sided whorls and appears more triangular in outline than globose. Subpurpureus is very rarely banded, while the shell of V. georgianus almost always bears color bands. Shells of the two species are compared at right. Burch quotes Clench & Fuller's range for V. subpurpureus as including the Mississippi River system north to Iowa, plus several river systems in Texas, Louisiana & Mississippi.

The co-occurrence of both viviparid species in a single lake is rather spectacular. Mr. Larry Woodward of the USFWS Santee National Wildlife Refuge on the north shore of Lake Marion is a native of the area, and does not recall seeing snails (of any sort) until the lakes suffered record low water in the summer of 2002. At that point, living snails were very common on exposed aquatic vegetation. Large volumes of dead shell only began materializing on the beaches this summer, apparently related to the rise in water level that has occurred over the last 12 months. Mr. Mike Spivey, the Manager of Santee State Park on the south shore of Lake Marion, also first noticed snails in the summer of 2002, and similarly attributes the current abundance of dead shell to the rise in lake levels.

Although most individuals in the small sample of V. georgianus I collected in 1997 were around 30 mm standard shell height, essentially all the beach shells I observed earlier this month, of both species, were in the 13 - 20 mm range. This seems consistent with a year of growth. All were quite clean and beginning to bleach a bit, apparently dead for several months. Both Lakes Marion and Moultrie have suffered serious aquatic weed problems in the recent past. Hydrilla was first discovered in the 1980s, and by the mid-1990s covered more than 40,000 acres of the 156,000 lake system. I think the best hypothesis is that viviparids may have been introduced to the lakes along with the weeds in the early to mid-1990s, but that their population densities remained below detection. Some aspect of the severe drought of 2002, followed by the high waters of 2003, caused viviparid populations to explode to the point that they have called attention to themselves.

To be complete, I should also mention that the large viviparid Bellamya japonica has also been reported in South Carolina recently. My colleague Jim Glover of the SC Department of Health & Environmental Control sent me a specimen collected in June from Lake Greenwood, an impoundment of the Saluda River about 40 miles west of Columbia. Although this was my first record of Bellamya in SC, Jay Cordeiro has called my attention to a 1996 record from the Jonesville Reservoir near Spartanburg.

Bellamya (above, 64.5 mm) reaches a much larger adult size than Viviparus and is another famous invader, native to the orient and apparently spread by "water garden" hobbyists. It is often referred to the genus "Cipangopaludina," but I agree with Doug Smith [Nautilus 114: 31-37] that Bellamya has priority.

I don't know of any obvious adverse environmental consequences attributable to viviparid invasion, and it's tempting to write off big impoundments like Lakes Marion and Moultrie as disturbed environments in any case. But I would be curious to hear from any of my colleagues regarding your observations on invasive viviparids in other regions of the country, especially any other records of V. subpurpureus invasion.

Friday, July 25, 2003

Leptoxis plicata Release

To the FWGNA Group,

As many of you are aware, Paul Johnson (current chairman of the FMCS Gastropod Committee) has been working for several years to artificially propagate Leptoxis plicata, the federally endangered pleurocerid snail endemic to Alabama's Black Warrior drainage. Earlier this week he wrote to inform us of the successful release of almost 5,000 yearlings back to the wild. He suggests that this may be the first release of an artificially cultured endangered freshwater snail in the United States. I think it may be the first anywhere in the world, ever. Congratulations, Paul!

Paul sent us an article from the Sunday edition of the Birmingham (AL) News which offers a pretty good overview of the project and is mostly accurate. [Paul's notations are in brackets.] We join him in thanking Paul Hartfield of the USFWS and Stan Cook of AL-DCNR for making this small but important step possible.

Keep the faith!

---------[Birmingham News 07/20/03]----------

At a Snail's Place
Scientists release critters to breed in Locust Fork
JERRY BAKER News staff writer

Hoping to reverse a trend that began decades ago, research scientists released 4,876 snails Saturday into the Locust Fork of the Black Warrior River near Kimberly. It was the first of five annual releases planned in hopes of restoring the population of a federally endangered species. Though small, the plicate rocksnail is a cornerstone species upon which all the other animals living in the river depend, said Paul Johnson, a research scientist with the Tennessee Aquarium Research Institute. The snail lives beneath large, flat rocks and eats algae and organic matter; it is food for turtles and fish.

Sixty years ago, the half-inch-long snail was so plentiful in the Locust Fork that a person standing anywhere in the river's shoals would have a couple dozen snails under each foot, Johnson said. Now those snails are almost gone, victims of pollution and sediment washed into the river. Once found along the entire length of the river, their numbers have diminished so much that they are found in only a few shoals along a 20-mile stretch between Interstate 65 and U.S. 78, about 2 percent of their original habitat.

Johnson and several assistants carried the snails to the river in three one-gallon buckets in a cooler. He let the buckets sit for a while in shallow water to adjust their water temperature, then sprinkled the snails in an area where the water was a couple of inches deep. The released snails are the offspring of 100 he collected from the river in March 2002 from shoals near Sayre. Saturday's release is a result of five years of research and development, Johnson said. "This is aimed at trying to develop the techniques for restoring freshwater snails, especially in the Mobile River Basin," Johnson said. The Warrior River is a part of the Mobile River Basin. The basin is one of the most biodiverse in the world, Johnson said. It also is one of the most troubled. Of the 60 species of freshwater snails that have become extinct in North America, 42 of them are from the Mobile River Basin.

Eleven snail species are listed by the U.S. Fish and Wildlife Service as threatened or endangered, and eight of them are from the Mobile River Basin, he said [clarification - 11 listed species in AL only]. Sediment from development and strip mining along the rivers has washed into the streams and covered up the snails' habitat. Pesticides and herbicides also have contributed to snails' dwindling numbers, he said. The release site near Kimberly was chosen because Johnson said he knows snails can survive there. He found one snail after a couple of hours of searching a couple of months ago but came across none in a search last week.

Johnson will visit the river several times a year to monitor the snails. Each is marked with a one-millimeter tag affixed with dental cement, he said. The tags help researchers monitor the progress of the snails and ensure the same ones won't be used for breeding stock every time [clarification - adult broodstock was tagged, not the juveniles]. This fall he will release the 97 survivors of the original 100 he removed last year as breeding stock. He will put those back where they came from near Sayre [error - this was completed last year, and no adult mortality has been associated with 2003 propagation efforts].

Johnson plans to collect more each spring, and later in the summer he will release more. Johnson hopes to improve his technique so that about 10,000 1-and 2-year-old snails will be released each summer.

With conditions along the river improving, Johnson hopes his repopulation efforts will give the snail the boost it needs to survive. "They can take themselves out from the brink of extinction," Johnson said. "We've just got to give them a chance.


Wednesday, April 23, 2003

How To Study and Collect Freshwater Gastropods

Some of you may be familiar with the classic AMU publication, "How To Study and Collect Shells." That 100-page booklet, last published (in its fourth edition) in 1974, was very popular among hobbyists and collectors of all backgrounds for years. It featured a nice little chapter on freshwater snails written by F. C. Baker in 1941.

Three years ago Charlie Sturm (of the Carnegie Museum) accepted the task of editing a new, completely updated version of the old chestnut. I was honored to be asked to contribute the freshwater snail chapter, following in the footsteps of one of my heros. I put together about ten pages of general background information on the biology, ecology, and conservation of our favorite animals, with tips on collecting and keeping them in aquaria, all aimed at a very general audience.

Alas, publication of this promising resource has been delayed for several years*. In the interim I have received many requests for information on freshwater gastropods from the public at large, and have occasionally furnished manuscript versions of my chapter to the outreach offices of various natural resources agencies, public school teachers, and so forth. So I've decided (with Charlie's permission) that the time has come to make the chapter generally available.

Dillon, R. T. (in press) Freshwater Gastropods. In Sturm, C.F., T.A. Pierce & A. Valdes (eds.), The Mollusks: A Guide to Their Study, Collection and Preservation. American Malacological Society, Pittsburgh, PA. [PDF]

Feel free to copy and circulate this document wherever it can do some good. It is citable as a chapter from a forthcoming AMS publication. I'll let you all know* when the actual booklet finally hits the presses.

*PS - Ultimately published in 2006:
The Mollusks: A Guide to Their Study, Collection and Preservation

Thursday, March 20, 2003

Report from RTP

As many of you are aware, we enjoyed a marvelous three days in Raleigh-Durham at the FMCS meeting. I'm pleased to report that our plan to hold a freshwater gastropod workshop in 2004 has been approved by the FMCS Board. Almost all of the discussion at our gastropod committee meeting lunchtime Monday was devoted to kicking around ideas and plans for this most important event. We did squeeze in a bit of time to elect Paul Johnson as the new chair of the committee, and re-elect Ken Brown as co-chair. Congratulations Paul and Ken!

The following message from Paul is self-explanatory. Please send any feedback to Paul and/or me at your earliest convenience!

Dear FMCS Gastropod Committee Members,

My thanks to John Alderman, Judith Radcliff, the folks at NC-State for the terrific job hosting the 2003 FMCS Symposium. The NC State/DOT/DWRC staff did an outstanding job! I believe the final attendance for the meeting was about 250 people (a terrific total in times of tight state and federal budgets). In regards to the 2004 FMCS Gastropod Workshop, I am sending you this brief communication to obtain your feedback for the final location and program design. Please keep in mind the final program will vary, depending on where we eventually agree to hold the meeting. I need feedback as rapidly as possible, so that we can make the final arrangements. If we are required to hold the meeting in a hotel, we'll need as much time as possible make the reservations / arrangements (in fact, we're already behind the curve on this).

The basic format:
  • A 1-1.5 day session on the identification of NA freshwater gastropods. This would cover the basic identification of NA freshwater gastropods to family and genus (excluding the Hydrobiidae). This would also tentatively include a session on soft anatomy.
  • A half day session on the basic topics (biology, conservation, genetics, ecology etc. 30 min sessions).
  • A session on a draft of the National Strategy for the Conservation of Freshwater Gastropods (30 min presentation - 1 - 2 hour discussion and comment period).
  • Katherine Perez also offered to host a short (beginners) session on terrestrial gastropods.
Location. We have had five very kind offers to host the meeting - LET ME KNOW WHICH YOU PREFER. (1) Marshall University in Huntington, West Virginia. (2) Kevin Roe has offered to host the workshop at the Delaware State Museum, Wilmington, DE (about 1 hours drive from Philadelphia). (3) Libby Hartfield has offered use of the Mississippi State Natural History Museum in Jackson, Mississippi. (4) Chuck Lydeard has offered to host the meeting at the Univ. of Alabama conference center in Tuscaloosa, AL. (5) US Fish and Wildlife Service, NCTC, Sheperdstown, West Virginia.

Date: TENTATIVELY SET FOR MARCH 2004. If we hold the meeting at NCTC, the dates must be March 2-4, 2004. However, there are not enough rooms at the NCTC so attendees would be required to stay off-site. We will have to arrange the specific date depending on who host's the meeting.

Chuck Lydeard has told me that if we hold the meeting at the Univ. of Alabama - the participants will also be able to receive a "primer" course (pun intended) on phylogenetic sequencing and analysis with a little demonstration. Additionally, the folks at U of A will be happy to show us the computer morphometric analysis they are now using. Additionally a field trip to the Cahaba River could be planned, where you can see several federally listed snail spp. "in action". For several reasons, the U of A offer has my support, but I want to hear from you.

Thanks to all for your participation and input.

Paul D. Johnson
Research Scientist I
Tennessee Aquarium Research Institute
5385 Red Clay Road
Cohutta, GA 30710
Phone (706) 694-4419
Fax (706) 694-3957

Tuesday, February 25, 2003


To the FWGNA group,

I recently received an updated Gastropod Committee roster from Rita Villella Bumgardner, the secretary of the Freshwater Mollusk Conservation Society, and was pleased to note seven new names. Welcome all. This brings the total size of the FWGNA group up to 131.

I'm often asked about the relationship between the Freshwater Gastropods of North America Project (FWGNA), the Freshwater Mollusk Conservation Society (FMCS), and the American Malacological Society (AMS). And it occurs to me that this might be a good time to review.

The FWGNA project was born at an informal meeting of the AMS in Washington DC in July of 1998. I don't think any of us present at the Washington meeting realized that, just four months previously, the National Native Mussel Coordinating Committee had voted to form a society, the Freshwater Mollusk Conservation Society, and to broaden its interests to include gastropod conservation. In November of 1998 an FMCS group drafted bylaws which included a Gastropod Committee, with yours truly as Chairman pro tem. The FWGNA project then became an activity of the FMCS.

Our group has met twice with the FMCS (Chattanooga 1999 and Pittsburgh 2001) and again with the AMS this summer in Charleston, during my term as AMS President.

Here's the bottom line. You are not required to belong to any society or pay any dues to join the FWGNA group. Membership in the FWGNA is completely free. But if you want to go to the FWGNA meetings, practically speaking, you'll need to pay some dues somewhere.

The FMCS would certainly be a good choice! Approximately 37% of our 131 members belong to the FMCS, receive the (really first-rate) newsletter Ellipsaria, and look forward to a regular cycle of symposia and workshops. And as all of you should be aware, the next FMCS symposium is right around the corner, March 16 - 19, at the Sheraton Hotel in Durham, NC. Our FWGNA meeting is scheduled for noon on Monday the 17th.

Let me conclude with a bit of additional bookkeeping. Three folks on the recipient list of this message are not actually new members, but rather old members who changed email addresses and fell off my list. Another five of you are receiving this message at a new address. (That is, the address on my fresh FMCS roster looked more current than the one in my address book, so I changed it.) So please email me directly if you want to change your email address - my updates from the FMCS Secretary are annual at best.

Keep in touch, and I hope to see lots of you in Durham,

P.S. - I couldn't help but notice that a batch of you are a year (or more) behind in your FMCS dues! Come on, ladies and gentlemen, pay up! Email me if you're unsure of your status.