Since the time of Call (1884) there has been much confusion regarding the taxonomic status of this and other floaters (Anodonta) of western North America. Call (1884) considered Anodonta nuttalliana to include, as synonyms, Anodonta wahlametensis, Anodonta oregonensis, and Anodonta californiensis, but no other authors who have published on the floaters of Utah have followed such an arrangement.
Burch (1975) recognized Anodonta californiensis, Anodonta nuttalliana, and Anodonta oregonensis as valid species and listed all three as occurring in Utah; he did not recognize Anodonta wahlametensis as a species. Similarly, Turgeon et al. (1988) recognized Anodonta californiensis, Anodonta nuttalliana, and Anodonta oregonensis as valid species but did not recognize Anodonta wahlametensis; they unfortunately misspelled the specific epithet of Anodonta nuttalliana as "nuttaliana" [sic], and this error has recently been proliferated in the literature as a result of others following this standard reference. Turgeon et al. (1998) corrected the earlier misspelling.
Chamberlin and Jones (1929) applied the common name "Nuttal's [sic] High -winged Floater" to this species and, in so doing, misspelled Thomas Nuttall's name in the same way that Turgeon et al. (1988) later misspelled the specific epithet.
The subspecies of this species that occurs in Utah is presumed to be the type (or nominate) race, Anodonta nuttalliana nuttalliana, if the recognition of subspecies is in fact warranted in this species at all.
Status in Utah
Approximately 6 (or more) historical occurrences are known in Utah. It has been reported historically from Davis, Salt Lake, Utah, and Piute counties (Henderson 1924, Chamberlin and Jones 1929, and Jones 1940a). Although there are other historical Utah records of floaters (Anodonta) that may pertain to this species (e.g., Call 1884, Chamberlin and Jones 1929, Jones 1940a, Woolstenhulme 1942a), since they would add little or nothing to our knowledge of the Utah distribution of Anodonta nuttalliana and since there is doubt regarding their assignment to species, they are not considered here.
Call (1884) wrote of this species: "It is somewhat common in fresh-water streams near Salt Lake City." However, Call (1884) was including 3 other nominal species of floaters (Anodonta), 2 of these still recognized as valid by most authors (see, for example, Burch 1975 and Turgeon et al. 1988) and all three known from Utah, within his concept of Anodonta nuttalliana. Thus, it is not possible to determine whether his comment on the historical abundance of Anodonta actually applied to this species at all.
Jones (1940a) listed at least 7 Utah specimens but did not mention whether any of them were alive or even fresh when collected.
This species has not been reported in Utah since 1940 (Jones 1940a). Threats are believed to have included dewatering and alteration (i.e., degradation) of aquatic habitats. It is believed that this species is declining rapidly in Utah, if it is not already extirpated in the state. It is no longer extant at some of the historical localities (e.g., Utah Lake).
Inventory is needed throughout central Utah, especially along the Wasatch Front in areas of its former occurrence, to determine whether this species is extant in Utah.
Habitats Utilized in Utah
Chamberlin and Jones (1929), discussing this species in Utah, mentioned a shallow lake (viz., Utah Lake) and "in an old trout pond". Although Call (1884) wrote that the species occurred "in fresh-water streams near Salt Lake City" and that "specimens were dredged in Utah Lake", his concept of the species included other currently recognized species of floaters that occur in Utah, and thus his comments cannot be considered to refer only to this species.