Share your observations of plants or non-game animals with the Natural Heritage Inventory
Help care for rare plants and animals by ordering an Endangered Resources plate.
Photo © Richard Lillie
Pecatonica River Mayfly (Acanthametropus pecatonica), a State Endangered species, is known only from nymphal specimens. The mature nymph is about 0.8 inch (20 mm) long, creamy white with three short tail filaments densely fringed on the margins, a small head with lateral eyes, and abdominal segments one through seven each bearing a distinctive pair of plumelike gills. Paired spines of the head, thorax, and a row of dorsal abdominal spines distinguish this nymph. There is no information known about the adult mayfly and repeated attempts to rear Wisconsin nymphs to adulthood have been unsuccessful. The species habitat requirements include sand-bottom rivers with little water pollution. The specimens found in Wisconsin have been collected from large, sand-bottomed rivers with wide channels, in water a meter or less deep. Records from Illinois are from moderately sized, fast, shallow streams with sand and rock bottoms.
The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Pecatonica River Mayfly (Acanthametropus pecatonica). 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 | G2G4 |
| 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: Known only from nymphal specimens. The mature nymph is about 0.8 inches (20 mm) long, creamy white with three short tail filaments densely fringed on the margins, a small head with lateral eyes, and abdominal segments one through seven each bearing a distinctive pair of plumelike gills. Paired spines of the head, thorax, and a row of dorsal abdominal spines distinguish this nymph. There is no information known about the adult mayfly and repeated attempts to rear Wisconsin nymphs to adulthood have been unsuccessful.
Habitat: Wisconsin specimens have been collected from large, sand-bottomed rivers with wide channels, in water a meter or less deep. Records from Illinois are from moderately sized, fast, shallow streams with sand and rock bottoms.
State Distribution: The species occurs in the Mississippi River and the Wisconsin River in Grant County, the Chippewa River in Pepin County, and the Black River in Trempealeau County.
Phenology: The Pecatonica River mayfly nymph is predaceous, the main food item thought to be Chironomids (midges). Specimens have been collected from May through early July. Presumable like other mayflies, the terrestrial adults are short-lived, nonfeeding, and spend time in reproductive activities: swarming, mating, and ovipositing.
Management Guidelines: Many species of mayflies are known to be highly susceptible to water pollution. Dredging, which slowed the rivers and created mud bottoms, undoubtedly hastened the demise of the Illinois populations of this species. Pecatonica River mayflies require sandy habitat. Activities protecting the integrity of large, clean, sand-bottom rivers will be beneficial to this mayfly.
Click to view a larger version. Please considering donating a photo to the Natural Heritage Conservation Program for educational uses. Photo use
Photo © Richard Lillie.
The table below lists the natural communities that are associated with Pecatonica River Mayfly. Only natural communities for which Pecatonica River Mayfly 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 |
The table below lists the ecological landscape association scores for Pecatonica River Mayfly. The scores correspond to the map (3=High, 2=Moderate, 1=Low, 0=None). For more information, please see the Wildlife Action Plan.
| Ecological landscape | score |
|---|---|
| Southwest Savanna | 3 |
| Western Coulee and Ridges | 3 |
| Southeast Glacial Plains | 2 |
| Central Sand Hills | 1 |
| Central Sand Plains | 1 |
| Western Prairie | 1 |
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.