Shoal Chub (Macrhybopsis hyostoma)

Overview

Overview

Shoal Chub (Macrhybopsis (Hybopsis) aestivalis), a fish listed as Threatened in Wisconsin, prefers fast, moderate depth water over broad sand flats. Spawning occurs from May through June, sporadic in August.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Shoal Chub (Macrhybopsis hyostoma). 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.

Species guidance

Note: a species guidance document is not available at this time. Information below was compiled from publication ER-091.

Identification: Elongate, slender body round in cross section. Protruding nose, mouth barbels and speckled body. Pale and translucent with white belly. Sides with a silvery longitudinal stripe. Adult length: 1.7-2.1 inches (45-55mm).

Habitat: Shallow riffles of large, sand-bottomed rivers and tributaries over 160 feet (50m) wide with varying turbidity.

State Distribution: The Mississippi River north to its confluence with the Chippewa River and the Wisconsin River north to Wisconsin Dells. This is the northern limit of their range. A map outlining Pre-1977 and 1997 to Present Distribution is available.

Phenology: Spawning occurs in May through June and continues sporadically into August. Spawn when water temperatures rise above 70 deg. F (21 deg. C). Eggs are dispersed along the bottom by currents and develop as they drift. Juveniles tend to be solitary. Lifespan is 1.5 years.

Diet: Adapted for bottom dwelling, speckled chubs are sedentary, resting quietly on the stream bottom when not moving about searching for immature insects (Trichoptera, Hemiptera, Odonata and Coleoptera), cyclopoid fish scales and some plant matter.

Management Guidelines: Siltation may explain Wisconsin's low populations. Population densities of other fishes and amount of space available may also be factors. See summary fish management section.

Other resources

Links to additional Shoal Chub information

Other links related to fishes

• NatureServe Explorer
• Non-game Fish Habitat Information
• Fish Identification Database [exit DNR]
• USGS Great Lakes Gap And WI-DNR Fish Mapping Application [exit DNR]

Photos/Video

Photos

Click to view a larger version. Please considering donating a photo to the Natural Heritage Conservation Program for educational uses. Photo use

Wildlife Action Plan

Natural community (habitat) associations

The table below lists the natural communities that are associated with Shoal Chub. Only natural communities for which Shoal 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.

Ecological landscape associations

The table below lists the ecological landscape association scores for Shoal Chub. The scores correspond to the map (3=High, 2=Moderate, 1=Low, 0=None). For more information, please see the Wildlife Action Plan.

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Landscape-Community combinations of highest ecological priority*

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.

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Issues/threats and conservation actions

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.

Threats/issues and conservations actions for rare animals

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