This region, about 11,000 square kilometers (over 4000 sq miles) is dotted with playa wetlands. These are shallow, wetlands, mostly fed by rainwater. They vary in their level of permanence, some deeper ones, over a meter deep, may hold water all year. Others, shallower and more common, will hold water during the rainy seasons only, and dry up completely throughout much of the year.
Geology:Without too much detail, here is a bit of the geology: Depressions in the underlying soil layers are covered with loess (wind blown sand and clay), creating an area with many shallow basins. These fill with water seasonally. The most shallow ones dry up completely while deeper ones may retain water all year long.
When I say this landscape is dotted, I mean dotted. Originally, the estimate is that over 4000 wetlands were scattered throughout this area. Now the number is more like 400 with only 84 protected, in some fashion, by state or federal control. Thus, fewer than 10% remain, and, of those, about 20% are protected.
Environmental disaster though it is, it is still a popular bird watching spot with several hundred species living in, around, or passing through this region. Including the Sandhill and Whopping cranes.
The birds are present, though certainly not doing well by any stretch of the imagination. The number of wetlands have dwindled to a shadow of their former numbers, so the amount of habitat available to the birds has followed suit. How are the aquatic organisms doing? The knee jerk response would be, poorly. And that would be correct. But here is the thing, we hardly know what is missing because so little work has been done in the past, present, and little is expected in the future. This area has, in nearly all intents and purposes, been needed to agriculture. But we still have 84 protected areas, tiny though they may be, in comparison to the once whole, they are there.
Somewhere in those 84 wetlands lives a small, dare I say tiny, snail. This, less than 5 mm snail, goes by the name the Prairie Fossaria, Galba bulimoides. Forgive me a not too brief aside here:
Names, names, names:
Name changes have made things confusing, this snail was once placed in the genus Fossaria, thus its common name (quite silly to keep this common name since the genera has changed, how about we go with the Prairie Pondsnail). It has since been shuffled (as most members of this family of snails have; the family is the pond snails Lymnaeidae, through various genera (Lymnaeae, Stagnicola), to arrive, for now, at Galba. It was described as Lymnaeae bulimoides by Lea in 1841. This is also the same species sometimes known as Galba techella, and Galba cockerelli. And wait, is this the same species as the one known as Galba viator? How about Galba cubensis? Isn’t this name roulette fun?...more information to come, certainly, I hope. Galba bulimoides, for now. One dilemma in this whole name fiasco is that species descriptions were terse and didn’t need to follow any rules in the 1800’s. Here is Haldeman’s full description of Limneae techella (sic), which is the same species already described by Lea, but he didn’t think so.
“Surface smoother than in L. bulimoides, Lea, of Oregon, with the lines of accretion less apparent, and the labium more angular. In some individuals the shell is thick enough to be corroded.”
FYI; for those who want to study freshwater snails, my advice, get away, study something else. The taxonomy is messy, arguments of authority without evidence, machismo, and hubris often seem to rule the day (although the 2020 paper cited below may help). If you truly want to dive in and clean it up, bring your DNA, and not the mitochondrial kind, which is highly variable, even within a population, among the freshwater snails.
Back to the snail:
This species, let’s call it the Prairie Pondsnail, is found, you guessed it, in the prairie. So here we are in the prairie, in habitat that the snail has been found in before, temporary wetlands, and the snail is hardly evident. In states that have some recent survey data on freshwater snails, not that many unfortunately, only one state has a recent record of this species. And that was just a few individuals observed in three, of hundreds of sampled, wetlands. This snail is endangered.
Why endangered, and soon to be extinct:
Beyond just the loss of the wetlands, the barely hanging on wetlands, the aquatic denizens of this area face lowering groundwaters, herbicide and pesticide inundation, and dust flows from neighboring farming activity, all due to the proximity of farmland (which typically begins seven feet beyond the fenced boundary of the wetland).
Or
Is it endangered? If the “species” is not one, but 3 or 5 species (as currently named) then maybe this little snail is more widespread: But it will still go extinct in the prairie, unless.
The little snail:
Alda P, et al (19 more authors) 2020. Systematics and geographical distribution of Galba species, a group of cryptic and worldwide freshwater snails. Molecular phylogenetic and evolution. (Issue not assigned yet as this is a In Press online posting, so the year may end up being 2021).
Haldeman SS. 1867. Description of a new species of Limnea. American Journal of Conchology. 3: 194.
Lea, I. 1841. Continuation of paper on fresh water and land shells. Proceedings of the American Philosophical Society II: 30-34.