- Page, L.M. and B.M. Burr 1991 A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p. (Ref. 5723) http://www.fishbase.org/references/FBRefSummary.php?id=5723&speccode=2590
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: This sucker is native to headwater streams of the Little Colorado River in east-central Arizona and west-central New Mexico (Propst et al. 2001), at elevations of 2,000-6,760 feet (610-2060 meters) (Arizona Game and Fish Department 2002). Historically occupied areas include the Zuni River, Río Nutria, Agua Remora, Tampico Draw, Tampico Spring, and Río Pescado (see Carman 2004). Based on surveys through 2001, the current range in New Mexico is limited to the upper Río Nutria drainage, including the mouth of Río Nutria box canyon, upper Río Nutria, confluence of Tampico Draw and Río Nutria, Tampico Spring, and Agua Remora (Propst et al. 2001, Carman 2004). As of the early 1980s, the range in Arizona apparently was reduced to only Kin Li Chee Creek (occupancy confirmed in 2000 when fish were collected for genetic evaluation) (Arizona Game and Fish Department 2002). Genetic and morphological relationship of the bluehead suckers in Arizona to the Zuni bluehead sucker is under investigation (S. Carman, pers. comm., 2004).
Habitat Type: Freshwater
Comments: Habitat is generally low-velocity pools and pool-runs with seasonally dense perilithic and periphytic algae (Propst et al. 2001), particularly shady, cobble/boulder/bedrock substrates in streams with frequent runs and pools (New Mexico Department of Game and Fish, recovery meeting announcement, 2004; Carman 2004). Occupied pools often are edged by emergent aquatic vascular plants (e.g., willows, cattail) (Arizona Game and Fish Department 2002). Fry and young prefer shallow areas in backwaters or near the shore line (Arizona Game and Fish Department 2002). Spawning substrate is not known but is presumed to be the spaces among cobbles on pool bottoms (Arizona Game and Fish Department 2002).
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Seasonally dry channels and low waterfalls limit movement among headwaters (Propst et al. 2001).
This fish appears to be sedentary. Larvae may move a short distance downstream, and adults may stay in or near one pool throughout their adult life, only moving several meters upstream to spawn (D. Propst, NMDGF, pers. comm., cited by Carman 2004).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 1 - 20
Comments: This fish is currently represented in New Mexico by five semi-isolated, "stable" populations (Carman 2004), plus perhaps another population in Arizona. Populations in other areas are either declining (confluence of ríos Pescado and Nutria) or depleted (Zuni River, lower Río Nutria or Río Pescado) (see Carman 2004).
250 - 1000 individuals
Comments: Total adult population size may be only several hundred in the five "stable" populations (see Carman 2004).
Life History and Behavior
In the Zuni River drainage, this sucker spawned in April-early June when water temperature was 6-13 C; some individuals matured at age 1 and most were mature by age 2; few survived to age 4 (Propst et al. 2001).
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: T1 - Critically Imperiled
Reasons: Very small, reduced range in headwater streams of the Little Colorado River in west-central New Mexico and possibly east-central Arizona where taxonomic questions obscure status; currently occupies only about 10 percent of the historical range; total adult population size may be only several hundred; threatened by elevated siltation and sedimentation, decreases in habitat from reduction in groundwater and surface water flows, and interactions with non-native species.
Intrinsic Vulnerability: Moderately vulnerable
Global Short Term Trend: Unknown
Comments: Information on current trend was not available for this assessment.
Global Long Term Trend: Decline of 70 to >90%
Comments: Only about 10% of the historical range is currently occupied (Carman 2004). The subspecies declined significantly between 1980 and the 1990s (S. Albert, pers. comm., 1999).
Degree of Threat: High
Comments: Past land use practices in the watershed, including dam construction, stream channelization, deforestation, and livestock grazing, and the introduction of nonnative fishes and crayfishes, have contributed to the current imperiled status of the species (New Mexico Department of Game & Fish, recovery plan meeting announcement, 2004; Carman 2004).
"Primary threats are elevated siltation and sedimentation and decreases in run and run-pools. These threats may be exacerbated with increased development in the area, which may impact groundwater and surface water flows. Zuni bluehead sucker populations are also threatened by competition, predation, and hybridization with non-native species." [Carman 2004]
Logging, road construction, over-grazing, reservoir/irrigation construction, and stocking of exotic fishes are primary threats (Arizona Game and Fish Department 2002).
Fish eradication efforts in the 1960s and 1970s in the middle and lower Río Nutria and Río Pescado eliminated populations from portions of the Zuni River drainage in New Mexico (Propst et al. 2001).
In the Zuni River drainage, populations persist where channel incision and sedimentation are limited and non-native fishes (especially Lepomis cyanellus) are rare or absent (Propst et al. 2001). Few, if any, Zuni bluehead suckers are found in the lower Zuni River drainage where non-native species are common (Carman 2004).
Water withdrawals for irrigation and human consumption led to decreased surface discharge in the system (Carman 2004). Dam construction has inundated habitat, blocked fish movements, reduced stream flows, and caused downstream erosion; streams and riparian areas have been degraded by stream channelization, vegetation clearing, expansion of saltcedar, poor grazing management, and impacts of exotic fishes (S. Albert, pers. comm., 1999). Designation of Nutria Canyon as a wilderness area plus habitat restoration efforts have reduced these threats (S. Albert, pers. comm., 1999).
A fenced section of the Agua Remora has exhibited marked improvement of riparian vegatation but, currently, the fence is often in disrepair, and legal access difficulties preclude its maintenance. The USFS and adjacent private landowners are attempting to redefine access rights to property to aid in better management of the habitat (Carman 2004).
- IUCN 2006 2006 IUCN red list of threatened species. www.iucnredlist.org. Downloaded July 2006. http://www.fishbase.org/references/FBRefSummary.php?id=57073
Management Requirements: "Survival of Zuni bluehead sucker without intensification and expansion of current conservation is doubtful" (Propst et al. 2001).
Global Protection: Few (1-3) occurrences appropriately protected and managed
Comments: Land ownership in the upper Zuni River watershed is a checkerboard of USFS (Cibola National Forest) and private lands, including TNC's Río Nutria Preserve. The upper Río Nutria is primarily privately owned. The U.S. Forest Service and private landowners alternately own the uppermost sections containing Agua Remora and Tampico Draw. All the lower courses of the ríos Nutria and Pescado and the Zuni River to the New Mexico border are within the Zuni Indian Reservation. [Source: Carman 2004]
In Arizona, extant populations if present are on the Navajo Nation; possibly on U.S. Forest Service (Apache-Sitgreaves NF) and private lands (Arizona Game and Fish Department 2002).
Relevance to Humans and Ecosystems
Stewardship Overview: See recovery plan (Carman 2004).
Zuni Bluehead Sucker
The Zuni bluehead sucker has a slender fusiform body with a subterminal mouth. The fish’s mouth contains fleshy lips and protuberances, mainly on the lower lips. Both lips are notched laterally, and the middle separation of the lips extends all the way to the fish’s anterior margin. The position of the lips is unique to this species.  A Zuni bluehead sucker has a generally thick caudal penduncle. For coloration, young Zuni bluehead suckers are dark gray-green dorsally and cream-white ventrally; while adults are slate-gray, being almost black dorsally and cream-white ventrally. Males develop a distinct coloration during spawning season; instead of being slate-gray, they become intense black with a bright red lateral band.  Most individuals are 200 mm (7.87 in) at most, although few were found at 250 mm.
The Zuni bluehead sucker can be found in East Central Arizona, and most recently found in four small streams in 1966. Several specimens were collected from East Clear Creek and from Kin Li Chee Creek, but populations decreased in the early 1980s. However, the presence of the Zuni bluehead suckers was confirmed in 1987 and 2000 when individuals were collected again for genetic evaluation. 
Zuni bluehead suckers are found in stream habitats with shade and lots of substrates like bedrock, boulders, and cobble. Pools are often edged by emergent aquatic vascular plants. 
Zuni bluehead suckers eat algae and invertebrates off of rocks with the cartilaginous scraper in their mouths.
Zuni bluehead suckers spawn in April through late May, when water temperature reaches 10-15°C (50-59⁰ F). Females are usually larger than males, and produce about 200-300 eggs (larger females can produce more than 450).
Due to poor watershed management, the populations of the Zuni bluehead sucker decreased 90% in the last 20 years. These fish are now only found in fragmented, semi-isolated stretches of their historic range.
- Froese, Rainer and Pauly, Daniel, eds. (2014). "Catostomus discobolus+jarrovii" in FishBase. April 2014 version.
- Sublette, J.E., M.D. Hatch, and M. Sublette. 1990. The Fishes of New Mexico. University of New Mexico Press, Albuquerque, New Mexico
- Propst, D.L. and A.L. Hobbs. 1996. Distribution, Status, and Notes on the Biology on the Zuni Bluehead sucker, Catostomus discobolus yarrowi, in the Zuni River Drainage, New Mexico. Conservation Services Division, New Mexico Department of Game and Fish, Santa Fe, New Mexico
- Crabtree, C.B. and D.G. Buth. 1987. Biochemical systems of the catostomid genus Catostomus: assessment of C. clarki, C. plebius, and C. discobolus including the Zuni sucker, C.d. yarrowi. Copia 1987: 843-854)
- Arizona Game and Fish Department. 2002. Catostomus discobolus yarrowi. Unpublished abstract compiled and edited by the Heritage Data Management System, Arizona Game and Fish Department, Phoenix, AZ. 5 pp.
Names and Taxonomy
Comments: This sucker has been regarded as a product of introgressive hybridization between C. discobolus and C. plebius, but it shows evidence of genetic differentiation from other C. discobolus irrespective of localized effects of hybridization (see Propst et al. 2001 for a brief literature review); recognition at the species level may be warranted (Starnes 1995).
Subspecific name formerly was spelled "yarrowi," and some recent literature uses this spelling, but the original and hence proper spelling is jarrovii (Sublette et al. 1990, Starnes 1995).
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