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Photo by John Lyons, WDNR
Gravel Chub (Erimystax x-punctata), listed as Endangered in Wisconsin, prefers the strong currents of riffles and fast runs in shallow medium to large rivers over pea-gravel substrate. Spawning occurs from mid-May to mid-June.
The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Gravel Chub (Erimystax x-punctatus). 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 | END |
| Federal Status in Wisconsin | none |
| State Rank | S1 |
| 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 ER-091.
Identification: Olive green dorsally, silvery on sides, silvery and white on belly. Large "bug" eyes. Scattered "X"-shaped markings on back and sides. Adult length: 3 inches (76 mm).
Habitat: Deep, swift waters of medium-to-large-sized rivers over pea-gravel bottom. Avoid rooted aquatic plants and larger species of algae and aquatic mosses.
State Distribution: The lower Rock River drainage, including lower Pecatonica River, lower Sugar River, the main channel of Rock River and lower Turtle Creek. A map outlining Pre-1977 and 1997 to Present Distribution is available.
Phenology: Gravel chubs spawn in early spring in swift gravel raceways or channels.
Diet: Probe under rocks and crevices for desmids, diatoms, plant debris and other vegetation.
Management Guidelines: The main reason for the gravel chub's decline is a general lack of its highly specialized habitat and increasing turbidity and siltation of existing sites resulting from agricultural run off. Specific microhabitat requirements may be beneath rocks in riffle areas where the effects of swift water are reduced, but where the current sweeps the gravel bottom clean of silt.
Click to view a larger version. Please considering donating a photo to the Natural Heritage Conservation Program for educational uses. Photo use
Side view adult.
Photo by John Lyons, WDNR.
Side view adult.
Photo by John Lyons, WDNR.
Photo by David Marshall, WDNR.
The table below lists the natural communities that are associated with Gravel Chub. Only natural communities for which Gravel Chub 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 | 3 |
The table below lists the ecological landscape association scores for Gravel Chub. 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 Landscape | Community |
|---|---|
| Southeast Glacial Plains | Warmwater streams |
| Southeast Glacial Plains | Warmwater rivers |
| Southwest Savanna | Warmwater streams |
| Southwest Savanna | Warmwater rivers |
* 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.