Warner Sucker

Catostomus warnerensis

Catostomidae · freshwater water fish

4 minute read · Species guide

Warner Sucker field guide illustration

About Warner Sucker

The Warner sucker (Catostomus warnerensis) is a rare species of freshwater ray-finned fish in the family Catostomidae. Native to Oregon in the United States and found only in the Warner Basin, its distribution extends just into Nevada and California. It is a federally listed threatened species. Its other common name is redhorse. The International Union for Conservation of Nature has rated this fish as an endangered species because of its small extent of occurrence, the small number of locations in which it is found, and the extreme fluctuations in area of occupancy resulting from drought and water abstraction. Conservation efforts have been put in place.

Description

This sucker is up to about 15 + 3 ⁄ 4 inches (40 cm) in length. It has a dark back and sides and a white belly. The male and some females take on a bright red wash along the sides during the spawning season. The fish spawns in the creeks when they are full in the spring, as well as in canals and on lakeshores. The fish can reach the age of twenty. It becomes sexually mature at three or four.

Distribution

This fish is native to shallow lakes and associated marshes and intermittent lakes and creeks in the Warner Valley of Lake County, Oregon. It has been seen in Twelvemile Creek just over the border in Nevada and West Barrel Creek within California state lines. It was historically quite abundant in the valley. There is only one metapopulation of the fish, made up of several subpopulations. There are two morphs, one that lives in the lakes and one that stays in stream habitat past spawning time. The lake-dwelling morph is generally larger in size. The stream morph may be the only one that is now experiencing recruitment.

Status

Threats to the species include the many dams which have been installed in the local creeks to divert water for agriculture. These impoundments prevent fish migration and reduce the stream flows. The spawning grounds may be polluted and loaded with excessive silt. The introduced crappie (Pomoxis spp.) may be a predator on the juvenile sucker. Drought is also a current threat. The drought conditions are then made worse with increased irrigation demands on the dwindling water supply. The International Union for Conservation of Nature has rated this fish as an endangered species because of its small extent of occurrence, the small number of locations in which it is found, and the extreme fluctuations in area of occupancy resulting from changes in the amount of available habitat.

Conservation efforts include the restoration of riparian vegetation and the construction of a fishway at a dam on a major creek. Individuals have been transplanted to Summer Lake Wildlife Management Area when they were threatened by drought conditions; these fish died but not before successfully reproducing in their new habitat. Conservation activities in the area have been shown to benefit the Great Basin redband trout (Oncorhynchus mykiss newberrii) as well as the sucker.

Article text: Wikipedia contributors, Warner sucker (source revision). Licensed under CC BY-SA 4.0. Retrieved 2026-10-11.

Diet and feeding

The FishTraits compilation records these diet categories for this species: algae or phytoplankton; detritus or unidentified plant material; invertebrates or larval fish. These are broad categories, not a claim that every individual consumes every example in a category.

Reported feeding positions include bottom feeding. The compilation combines published observations; diets can vary with age, locality, and available food.

Habitat preferences

Reported habitat associations include creeks, still-water habitats, springs or subterranean waters.

The source records associations with sand, gravel. An association indicates reported use, rather than an exclusive requirement.

Reproduction and parental care

The compilation reports a representative maturity age of 3.5 years. Its maturity field summarizes mean, median, or modal estimates, usually for females; male estimates can be used when female data are unavailable. It is not a fixed age at which every fish first breeds.

Recorded spawning months are Mar, Apr, May for the source’s reporting region (OR). This is a regional calendar, not a range-wide schedule.

The reproductive-guild classification includes spawning on open substrates without guarding the brood.

Size and recorded longevity

FishTraits reports a maximum total length of 35 centimetres. Some entries use an estimated asymptotic length; this value should not be treated as a certified record catch.

Recorded longevity in the compilation is 9 years. Wild observations were preferred, but captive records were accepted where wild records were unavailable, and unspecified records were assumed wild. The value is not a guaranteed wild lifespan or an aquarium life expectancy.

Spawning movements

The compilation records significant spawning-related movement. Its combined migration flag covers movements within fresh water as well as between rivers and the sea; this flag alone does not establish which migration pattern applies.

Range

Where it lives

Share of 44 GBIF observation records with a state location, across 2 states.
0%
97.7%
Share of 44 GBIF observation records with a state location, across 2 states.

Share of records by state

Habitat

Water and movement

Water
WoRMS records this species in fresh water.
Migration
Migratory
Pattern

Classification

Taxonomy

Kingdom
Animalia
Phylum
Chordata
Superclass
Actinopterygii
Class
Teleostei
Order
Cypriniformes
Genus
Catostomus
Species
Catostomus warnerensis
ITIS TSN
163915
WoRMS AphiaID
1018044
GBIF key
2359059

Common questions about Warner Sucker

What is the scientific name of Warner Sucker?
The scientific name is Catostomus warnerensis, in the family Catostomidae. Classification follows ITIS.
Does Warner Sucker live in fresh water or salt water?
WoRMS records this species in fresh water.
Where has Warner Sucker been recorded in the United States?
GBIF has observations in 2 states, with the most records in Oregon, California. The map shows observation records, which do not establish the complete natural range.

Closest relatives

Other Catostomus species

Same family

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All 67 species in Catostomidae