Winged Floater (Anodonta nuttalliana) - species status statement

Publication Type:

Report

Authors:

Utah Division of Wildlife Resources

Source:

Utah Division of Wildlife Resources (2020)

Call Number:

U20UWR01IDUS

URL:

https://wildlife.utah.gov/pdf/sensitive_species/inverts_winged_floater_2020.pdf

Keywords:

Anodonta californiensis, Anodonta nuttalliana, California floater, Winged Floater

Abstract:

Uncertainty regarding the taxonomy of winged floater (Anodonta nuttalliana) and California floater (Anodonta californiensis), two morphologically similar species of freshwater mussel, has been a confounding issue during past surveys and subsequent publications throughout their overlapping distributions. The species are also so genetically similar that some taxonomists (Chong et al. 2008; Jepsen et al. 2009) recommend grouping them into the same clade (while also suggesting up to five deep genetic divisions within that grouping).
Unfortunately, this taxonomic uncertainty has muddied our understanding of the distribution of A. nuttalliana/californiensis. Regionally, surveyors have reported one or the other putative species in Arizona, California, Idaho, Oregon, Utah, Washington and Wyoming (Jepsen et al. 2009). In Utah, the clade has been documented (as A. californiensis) throughout much of the Bonneville Basin including the Bear River, Salt Creek, Redden Springs, Burraston Ponds, Pruess Lake, Piute Reservoir and Otter Creek Reservoir (Mock et al. 2010). Oliver and Bosworth (1999), while acknowledging the past confusion in taxonomy, listed historical occurrences (of A. nuttalliana) in Salt Lake, Davis, Utah and Piute Counties. Efforts are ongoing to attempt to further clarify these species’ distribution via eDNA testing (Rodgers and Mock 2018). For now, we choose to group them, and use the name Anodonta nuttalliana […].