Endangered Resources Program Species Information
Blue Sucker (Cycleptus elongatus)

Overview

Species Overview

Blue Sucker (Cycleptus elongatus), a fish listed as Threatened in Wisconsin, prefers large, deep rivers with moderate to strong currents over substrates of gravel or cobble. Spawning occurs from late April through early May.

Status and NHI Documented Occurrences in Wisconsin

The table below provides information about the protected status (State and Federal Status) and the rank (S and G Ranks) for Blue Sucker (Cycleptus elongatus). See the Working List Key for more information about the abbreviations used. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. For invertebrates, dots depict locations from the "Invertebrate Atlas," a database with occurrences of rare and common aquatic and select terrestrial invertebrate species found in Wisconsin and adjacent areas. While the invertebrate atlas is a quality assured database, not all records have been verified. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Summary Information State Status: THR Federal Status in Wisconsin: none State Rank: S2 Global Rank: G3G4 Tracked by NHI: Y Species of Greatest Conservation Need: Y

Detailed Information

Identification: Elongate body with small head. Snout pointed, slightly bulbous at tip. Back and sides blue to blue black, belly whitish. Adult length: 2 feet (61cm).

Habitat: Prefer large, deep rivers and deeper zones of reservoirs, moderate to swift currents of narrow channels with gravel or rubble bottom.

Natural Community Associations: The Wildlife Action Plan lists the natural community associations for this species.

State Distribution: Mississippi River drainage basin, lower St. Croix, Red Cedar, Chippewa, Black, LaCrosse and Wisconsin Rivers. Generally found as far upstream as the first dam. A map outlining Pre-1977 and 1997 to Present Distribution is available.

Phenology: Spawn from late April to early May at water temperatures of 50-60o F (10-15o C). Newly hatched young frequent shallow waters and are preyed on by fish-eating birds.

Diet: A gregarious fish, blue suckers are bottom feeders. Eat insects, insect larvae, crustaceans, plant material and algae.

Management Guidance: Wisconsin populations of blue sucker represent some of the largest remaining in the upper Mississippi River basin, and therefore merit careful management. This species is intolerant to turbidity and pollution, so sources of pollution discharge and soil runoff within its range should be monitored and minimized.

Information compiled from publication ER-091.

Photos

Click on a photo to view a larger version. Please considering donating your photos to the Endangered Resources Program for educational uses. See also information regarding use of photos

Side view adult. Photo by John Lyons, WDNR.

Side view adult. Photo by John Lyons, WDNR.

Side view adult. Photo by John Lyons, WDNR.

Top view adult. Photo by John Lyons, WDNR.

Bottom view adult. Photo by John Lyons, WDNR.

Head-on view adult. Photo by John Lyons, WDNR.

Close-up flank. Photo by John Lyons, WDNR.

Close-up head. Photo by John Lyons, WDNR.

Close-up mouth and snout. Photo by John Lyons, WDNR.

Close-up tail. Photo by John Lyons, WDNR.

Close-up dorsal fin. Photo by John Lyons, WDNR.

Close-up anal fin. Photo by John Lyons, WDNR.

Close-up pectoral fin. Photo by John Lyons, WDNR.

Close-up pelvic fin. Photo by John Lyons, WDNR.

Juveniles are similar to adults, but lower lobe of caudal fin is darker. Photo by John Lyons, WDNR.

Breeders develop numerous turbercles and a dark color on their bodies; specimen held by Kyle Piller. Photo by John Lyons, WDNR.

Breeders develop numerous turbercles on their heads. Photo by John Lyons, WDNR.

Breeders develop numerous turbercles on their fins and bodies. Photo by John Lyons, WDNR.

Breeders develop numerous turbercles on tail and scales. Photo by John Lyons, WDNR.

Side view of the largest confirmed specimen from Wisconsin (weight 7.5 kg). Photo by John Lyons, WDNR.

The body shape is elongated and fusiform, the color is bluish; there are 53-58 lateral line scales and 28-33 dorsal rays. Photo by John Lyons, WDNR.

Close-up dorsal fin: There are 28-33 dorsal rays with anterior rays being elongated. Photo by John Lyons, WDNR.

Close-up head: The mouth is inferior. Photo by John Lyons, WDNR.

Close-up mouth/snout: The lips are fleshy and papilose. Photo by John Lyons, WDNR.

Related Links

Links to Additional Blue Sucker Information

There are currently no additional links for this species.

Other Links Related to Fishes

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