The introduction of an invasive snail (Melanoides tuberculata) to spring ecosystems of the Bonneville Basin, Utah

Melanoides tuberculata is an invasive tropical prosobranch snail that was first introduced to the Bonneville Basin, Utah, sometime in the 1960's. During 2001 and 2002 we searched 276 sites/habitat types (limnocrenes, rheocrenes, and helocrenes) in 124 springs, nested in 14 valleys distributed throughout the Bonneville Basin and found this snail abundant in 17 of the 124 springs and occurring in four of the 14 valleys. In five to eight years after initially colonizing two springheads in a large spring complex, M tuberculata became one of the most abundant species (numbers and biomass) in 15 springs across the entire complex. Melanoides tuberculata can rapidly reach high densities because it is long lived, iteroparous, parthenogenetic, and viviparous. However, our results confirm previous observations that M tuberculata appears restricted to standing or slow-flowing waters between 18 and 30 C. It has caused the decline and local extirpation of other snail species outside its native range and potentially constitutes a threat to native snails in Utah, many of which are endemic to the Bonneville Basin. Melanoides tuberculata is also an intermediate host and transmission vector for trematode parasites dangerous to humans, livestock, and wild animals, including threatened endemic fishes and amphibians of the Bonneville Basin.