But progress came at the expense of mollusks that were found only in that area and nowhere else in the world.
"Their habitat was destroyed in huge chunks," Foighil said. The result: 47 of 139 endemic mollusk species were lost, representing a full one-third of all known freshwater mollusk extinctions worldwide.
Then, about 20 years ago, thanks to increased interest in and funding for conservation projects, biologists began searching patches of the drainage that weren't affected by damming, trying to find remnants of the original, rich fauna and save whatever still could be saved. At the Alabama Aquatic Biodiversity Center (AABC), a former catfish experimental research station has been converted into a captive breeding facility, with the aim of breeding survivors of the mass extinction and reintroducing them into unaffected parts of the watershed.
It was through those efforts that AABC director Paul Johnson discovered the surviving population of what he thought might be Rhodacmea filosa. But how does one definitively identify a species that hasn't been seen in decades? There are no other living members of the group with which to compare specimens.
That's where the U-M Museum of Zoology collection comes in. It just so happens that 100 years ago, biologists collected multitudes of mollusks from the Mobile River Basin---never envisioning the habitat destruction and resulting extinctions that were to come---and those specimens ended up in the U-M collection. Coincidentally, the mollusk portion of that collection was largely established by Bryant Walker, an early authority on---you guessed it---the limpet genus Rhodacmea. Furthermore, the last person to study Rhodacmea was a U-M graduate student, some 50 years ago.
Using century-old reference specimens, Foighil, professor emeritus John Burch, graduate
|Contact: Nancy Ross-Flanigan|
University of Michigan