Modoc Sucker (Catostomus microps)
Modoc suckers are small, usually less than 6 inches (16 cm) standard length, with short heads and small eyes (Moyle 2002). Maximum size is 11 inches (28 cm). Lateral line scales number 73-91. Scales above the lateral line number usually number 15 (range = 14-19); those below the lateral line number 9-12. Dorsal fin rays number 9-12; anal fin rays 7; pelvic fins 8-10 (Kettratad 2001, Moyle 2002). The lower lip is deeply notched, with only one of the 5-6 rows of papillae connecting the two haves (Moyle 2002). The non-breeding color of both sexes is greenish-brown through bluish to deep-grey and olive, and the sides are lighter with generalized mottling and usually with 3-4 darker blotches, and is similar to Sacramento suckers of similar size. The belly is white to cream or yellowish and unmarked. Breeding males have a reddish-orange lateral band, and orange fins; tubercles develop on fins and body.
- States/US Territories in which the Modoc Sucker, Wherever found is known to or is believed to occur: California , Oregon
- US Counties in which the Modoc Sucker, Wherever found is known to or is believed to occur: View All
- Countries in which the the Modoc Sucker, Wherever found is known to occur: United States
|Status||Date Listed||Lead Region||Where Listed|
|1985-06-11||California/Nevada Region (Region 8)||Wherever found|
» Federal Register Documents
|Date||Title||Plan Action Status||Plan Status|
|1984-05-08||Action Plan for Recovery of the Modoc Sucker (Catostomus microps)||View Implementation Progress||Conservation Strategy|
|Date||Citation Page||Title||Document Type|
|2015-12-08||80 FR 76235 76249||Removal of the Modoc Sucker From the Federal List of Endangered and Threatened Wildlife; Final Rule||
|2014-02-13||79 FR 8656 8667||Proposed rule to Delist the Modoc Sucker and 12-month petition finding and notice of availability of draft post-delisting monitoring plan.||
|2006-03-22||71 FR 14538 14542||Initiation of 5-Year Reviews of 56 Species in California and Nevada: Notice of review.||
|2010-05-21||75 FR 28636 28642||Initiation of 5-Year Reviews of 34 Species in California and Nevada; Availability of 96 Completed 5-Year Reviews in California and Nevada||
|2009-08-17||Modoc Sucker 5-Year Review|
|2015-08-03||Modoc sucker (Catostomus microps) Post-Delisting Monitoring Plan|
|2014-02-14||Modoc sucker (Catostomus microps) Draft Post-Delisting Monitoring Plan|
» Critical Habitat
|Date||Citation Page||Title||Document Type||Status|
|1985-06-11||50 FR 24526 24530||Determination of End. Status & Crit. Hab. for Modoc Sucker; 50 FR 24526- 24530||Final Rule||Final designated|
|1984-01-31||49 FR 3892 3895||Proposed End. Status & Crit. Hab. for Modoc Sucker (Catostomus microps); 49 FR 3892-3895||Proposed Rule||Not Required|
To learn more about critical habitat please see http://ecos.fws.gov/crithab
» Conservation Plans
No conservation plans have been created for Modoc Sucker.
» Life History
Modoc suckers are primarily found in mud and rock bottom pools in small streams and occupy an intermediate zone between the high-gradient and higher elevation, coldwater trout zone and the low-gradient and low elevation, warm-water fish zone (Reid 2008). The elevational range of the Modoc sucker is from about 4,200 to 5,000 feet in the upper Pit River drainage (Ash and Turner Creeks) and from about 4,700 to 5,800 feet in the Goose Lake sub-basin (Reid 2008). Cover consists of overhanging banks, larger rocks, woody debris, and aquatic rooted vegetation or filamentous algae. Larvae occupy shallow, vegetated margins and juveniles tend to remain free-swimming in the shallows of large pools, particularly near vegetated areas, while larger juveniles and adults remain mostly on, or close to, the bottom (Moyle and Marciochi 1975).
Modoc suckers feed on algae, aquatic insects, and small crustaceans found in mud or in algal filaments (Moyle 2002). Chironomid (midge) larvae may be especially important in the diet, but the jaw structure suggests specializations for scraping algae from rocks.
Movement / Home Range
Modoc suckers likely do not move large distances but do move upstream to spawn and move downstream when water levels drop in summer.
Both sexes mature in their third year at a length of about 5 inches (12 cm; Moyle 2002). Spawning occurs in gravel at the lower end of pools or in riffles in small tributaries, including those that are intermittent, from mid-April to early June when water temperatures are 56 to 61°F (13-16 °C). Several males position themselves on each side of the female and eggs and sperm are released. The fertilized eggs fall into the gaps in the gravel. Females produce up to 12,000 eggs per season (Moyle 2002).
A greater understanding of the genetic relationships and natural gene flow between the Modoc sucker and Sacramento sucker has reduced concerns over hybridization between the two species (Reid 2008; USFWS 2009). The most significant threat to the Modoc sucker is nonnative predatory fish, especially largemouth bass and brown trout.
» Other Resources
NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.