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Photo © Illinois Natural History Survey
Wartyback (Quadrula nodulata), listed as Threatened in Wisconsin, is found in the sand, mud, or fine gravel of large rivers. It can be locally common. Six common host fishes have been reported, including crappie, bluegill, catfish, and bass species.
The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Wartyback (Quadrula nodulata). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where occurrences of this species meet NHI data standards and is not meant as a comprehensive map of all observations.
Note: Species recently added to the NHI Working List may temporarily have blank occurrence maps.
| Summary Information | |
|---|---|
| State Status | THR |
| Federal Status in Wisconsin | none |
| State Rank | S1S2 |
| Global Rank | G4 |
| Tracked by NHI | Y |
| WWAP | SGCN |
Note: a species guidance document is not available at this time. Information below was compiled from publication PUB-ER-085-99 (now out-of-print).
Identification: Shell is brown or yellow, small, and heavy. Beak includes a few tubercles that extend onto the disc to the ventral margin in two diverging rows with no depression between them. Pseudocardinal teeth are serrated and heavy. Lateral teeth are serrated, short, heavy and straight. Nacre is pearly white and iridescent posteriorly. Anterior end is sharply rounded and the posterior end is sharply truncated, slightly winged or alate. Length to 3 inches (7.6 cm).
Habitat: Found in large rivers where it usually lives in sand or fine gravel. Juvenile shells often found on sandbars.
State Distribution: Occurs in the Mississippi and lower Wisconsin Rivers.
Phenology: Host fish for this species are known to be black crappie (Pomoxis nigromaculatus), white crappie (P.annularis), bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), and channel catfish (Ictalurus punctatus). Glochidia have been found on white crappie in September.
Management Guidelines: Habitat destruction and river pollution have resulted in mussel declines. Protection of habitat and improvements in water quality along with restriction of dredging, impoundments, sand and gravel mining, and navigational improvements would benefit this species
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Photo © Illinois Natural History Survey.
The table below lists the natural communities that are associated with Wartyback. Only natural communities for which Wartyback is "high" (score=3) or "moderate" (score=2) associated are shown. See the key to association scores for complete definitions. Please see the Wildlife Action Plan to learn how this information was developed.
| Natural community | Score |
|---|---|
| Warmwater rivers | 3 |
| Warmwater streams | 2 |
The table below lists the ecological landscape association scores for Wartyback. The scores correspond to the map (3=High, 2=Moderate, 1=Low, 0=None). For more information, please see the Wildlife Action Plan.
Ecological priorities are the combinations of natural communities and ecological landscapes that provide Wisconsin's best opportunities to conserve important habitats for a given Species of Greatest Conservation Need. The 10 highest scoring combinations are considered ecological priorities and are listed below. More than 10 combinations are listed if multiple combinations tied for 10th place. For more information, please see the Wildlife Action Plan.
* Ecological priority score is a relative measure that is not meant for comparison between species. This score does not consider socio-economical factors that may dictate protection and/or management priorities differently than those determined solely by ecological analysis. Further, a low ecological priority score does not imply that management or preservation should not occur on a site if there are important reasons for doing so locally.
Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.