Overview
The Shortnose Sucker (Chasmistes brevirostris) is an imperiled, long-lived freshwater fish endemic to the Upper Klamath River Basin of southern Oregon and northern California. Known to the indigenous Klamath and Modoc peoples as ‘c’waam’, this midwater-adapted lake sucker has lived in the Klamath Basin for millennia, serving as a primary cultural symbol and ecological barometer of upper basin water quality.
Biology and Physical Characteristics
The Shortnose Sucker is characterized by a stocky cylindrical body, a short blunt snout with a prominent dorsal hump, and an oblique, terminal mouth with thin, weakly papillose lips. Its coloration is dark greenish-brown to slate on the dorsum, with yellowish-silver sides and a white belly. Inside its gills, closely spaced, branched gill rakers allow it to capture zooplankton as well as benthic insect larvae.
Behavior and Ecology
Shortnose Suckers spend the vast majority of their multi-decade lives inhabiting open lake waters. In April and May, adults migrate into the Williamson and Sprague rivers or congregate near freshwater shoreline springs to spawn over coarse gravel riffles, scattering adhesive eggs that hatch in approximately one to two weeks.
Conservation and Human Impact
Listed as Endangered by the IUCN and protected under the US Endangered Species Act since 1988, the Shortnose Sucker faces severe survival challenges in Upper Klamath Lake. Major threats include poor water quality driven by agricultural runoff, massive toxic summer blue-green cyanobacteria blooms, low dissolved oxygen, and fish passage barriers.
Interesting Factoid
The Shortnose Sucker can live for more than 33 years in Upper Klamath Lake, but adult fish must navigate water with almost zero oxygen during summer algae blooms to survive.