Backyard Snailing Revisited
By Harry G. Lee
Daedalochila avara (Say, 1818) Florida Liptooth

    Early in November, 2001, impelled by the recent interest expressed in the pastime of “snail-trapping” on the Internet (specifically on the shellers’ list-serve called “Conch-L”) and at the urging of shutterbug/snailer Bill Frank, I brought my quarter-century-old “snail-trap” out of retirement.  This device is nothing more than a 4 ft. by 5 ft. by 5/8 in. (formerly; now edited by the depredations of termites, etc.) plywood.  Despite languishing in a shed for about 20 years, the “trap” produced results in only ten minutes!  Bill got about 78 shots of the White Snaggletooth, Depressed Glass, Minute Gem, Florida Liptooth (top left), and Southern Flatcoil (bottom left) - all actively crawling on the undersurface when we flipped over the board.

Polygyra cereolus (Mühlfeld, 1816) Southern Flatcoil     I live on the bank of a small river, and the water table is not far below the surface of the back yard.  Early that afternoon, as is not unusual, the lawn was still a little moist with dew, which percolates slowly into the sodden ground.  Things were approximately the same in 1977, when I routinely placed this board on the grass and examined its underside every morning or so - after the sprinkler had wet the lawn down at night.  No baiting was involved; any use of beer, etc. was limited to consumption by the investigator.  The program was prosperous indeed - I saw over 100,000 snails and harvested most of them (to conservation-inclined readers, this is about 1/100,000 the decimation produced by one application of insecticide, which I, natch, have avoided).  Of course most species are tiny - in the case of the Blade Vertigo, I weighed 446 shells at 0.1273 grams or 0.285 mg. per shell, which means it would take about a billion to match the world record Tridacna gigas in mass).  The following are the species (in "systematic order" and with links to images) I found:

Pupoides modicus (Gould, 1848)    That's 27 species, nearly 40% known from our region of Florida (see Northeast Florida Terrestrial Mollusk Checklist), many by the hundreds of individuals, some by the tens of thousands.  With this kind of return, you're bound to learn things.  Two species, a Striate Vertigo and a Florida Liptooth, were represented by hundreds of specimens including a single perfect sinistral individual of each.  Some readers might have note the anachronistic "1981" in the litany above.  That's because Dryachloa dauca Thompson and Lee, 1981, the Carrot Glass, wasn't named until after the 1977 snail trapping campaign.  In fact, the species was described based on "trapped" specimens, and the plywood is/was arguably the type locality!

A few weeks later, on Thanksgiving Day, while attempting to busy myself with yard work (in forced exile from my wife's kitchen), I noticed a line of drifted wrack along the riverbank in back of my house - just a few feet from where the snail-trapping device had been deployed earlier.  Following instincts shared by many of us, I harvested the stuff (about a pint), sifted it, and spread it out under the microscope.  Shortly before sitting down for the annual feast, I had extracted the following empty shells from among the Styrofoam nuggets, insect parts, stems, seeds, and other plant debris:

Gastrocopta rupicola (Say, 1821) Tapered Snaggletooth (7 shells)
Gastrocopta tappaniana (C. B. Adams, 1842) White Snaggletooth (5 shells)
        Pupoides modicus (Gould, 1848) Island Dagger (1 shell)
Vertigo ovata Say, 1822 Ovate Vertigo (7 shells)
        Vertigo oralis Sterki, 1898 Palmetto Vertigo (2 shells)
Strobilops texasianus Pilsbry and Ferriss, 1906 Southern Pinecone (1 shell)
Succinea unicolor Tryon, 1866 Squatty Ambersnail (2 shells)
Hawaiia minuscula (Binney, 1841) Minute Gem (1 shell)
Nesovitrea dalliana (Pilsbry and Simpson, 1888) Depressed Glass (1 shell)
        Ventridens demissus (A. Binney, 1843) Perforate Dome (2 shells)
Polygyra cereolus (Mühlfeld, 1816) Southern Flatcoil (29 shells)
Allopeas gracile (Hutton, 1834) Graceful Awlsnail (1 shell)
        Huttonella bicolor (Hutton, 1834) Two-tone Gullela (1 shell)
 plus the one shell of each of these two aquatic species:
Rangia cuneata (G. B. Sowerby I, 1831) Atlantic Rangia
Mytilopsis leucophaeata (Conrad, 1831) Dark Falsemussel

     I have indented the names of 4 of the total 13 landsnail species because they not only were they never found among the 27 species/100,000 individuals (list above) found clinging to my snail trap, they had never before been found in my yard at all.  What a surprise!

    But maybe not so shocking.  Landsnails can live very close to freshwater, but when swept into such watercourses are often doomed to perish by drowning.  Both living and dead landsnails tend to float, and the abundance of this material in freshwater "drift" is legendary among collectors (see Dream Stream Stems Teem With Stenotremes).  Thus I cashed in on a method to expand the diversity of my yard collections.  Here are some factors relating to my catching the "new" species:

 (1) Pupoides modicus likes disturbed, dry habitats not found in my yard.  There is, however, a railroad cut  (right down to the river) just a few hundred yards from my place, and I've found this species very close to the river along the railroad tracks.

(2) Vertigo oralis is a "swamp beast," occurring on palmettos and in very damp leaf litter in swamplands typically along rivers around here. That habitat is not present in my yard but is visible a few hundred yards away.

(3) Ventridens demissus is a special critter.  I and a few other collectors have witnessed this native species actually extending its range through northeast Florida over the last quarter century.  It reached Duval Co. in the last decade (about the same time as the Eurasian Turtle Dove), and it has a penchant for disturbed habitat (like P. modicus).  It may be in the process of colonizing my back yard by rafting in.

(4) Huttonella bicolor is a non-indigenous species (like Allopeas gracile above); the dynamics of its appearance are likely similar to V. demissus.

     As I reflect on my good fortune, I see a moral for collectors located almost anywhere in the world, of almost any age and level of experience:

(1) You can enjoy collecting with thrift and simplicity.
(2) There will always be something "new under the sun."
(3) The wisdom of the Yogi Berra-style aphorism "shells are where you find them," is again demonstrated.