Global Range: (5000-20,000 square km (about 2000-8000 square miles)) 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). Currently the subspecies occurs in low numbers in several creeks in the Kinlichee Creek and Canyon de Chelly areas in Arizona and is restricted to three isolated populations in the upper Rio Nutria drainage in the Zuni River watershed in west-central New Mexico; the Kinlichee Creek, Canyon de Chelly, and Rio Nutria areas are completely isolated and separate from one another (see USFWS 2013).
Regularity: Regularly occurring
Type of Residency: Year-round
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: 6 - 20
Comments: This fish is currently represented by populations in several creeks in the Kinlichee Creek and Canyon de Chelly areas in Arizona and by three isolated populations in the upper Rio Nutria drainage in New Mexico (USFWS 2013).
250 - 1000 individuals
Comments: Total adult population size is uncertain 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).
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 east-central Arizona; currently occupies less than 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
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
Global Short Term Trend: Decline of 10-30%
Comments: Information on current trend was not available for this assessment, but threats and declines likely are ongoing (USFWS 2011).
Global Long Term Trend: Decline of >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). Distribution rangewide has been reduced by over 90 percent in the last 20 years (see USFWS 2013).
New Mexico: Fish surveys from 1990 to 2009 show that Zuni bluehead sucker populations in headwater springs (e.g., Aqua Remora and upper Rio Nutria) have declined significantly from numbers seen in the 1970s (USFWS 2013). In the 1990s, the population at the Zuni River confluence with Rio Nutria and Rio Pescado was declining, and the populations in the Rio Pescado and lower Zuni River were almost depleted. Zuni bluehead suckers have not been collected from the Zuni River or Rio Pescadosince 1993 (see USFWS 2013)
Degree of Threat: Very high - high
Comments: Threats to habitat include water withdrawals, logging, livestock grazing, water impoundments, road construction, subdivision development, and long-term drought. In New Mexico, water withdrawals, subdivision development, livestock grazing, road construction, logging, and drought threaten Zuni bluehead suckers and their habitat. In Arizona, water withdrawals, livestock grazing, road construction, and drought have affected the Zuni bluehead sucker. The changes in the flow regimes and loss of habitat from water withdrawals, sedimentation, and impoundments have reduced and eliminated populations of Zuni bluehead sucker in both New Mexico and Arizona. These conditions, in combination with the predicted worsening drought conditions due to climate change, will continue to degrade and eliminate Zuni bluehead suckerhabitat. Source: USFWS (2013).
Black grub (a parasite) has been documented throughout the range of the species and is known to adversely affect or kill fish. In addition, nonnative predatory fish, particularly green sunfish, have contributed to the displacement or elimination of the species throughout its range, and nonnative crayfish are likely preying upon Zuni bluehead sucker eggs. USFWS (2013) concluded that disease may be a threat to the Zuni bluehead sucker and predation is a documented threat to the species. These threats are already occurring, they affect the species throughout its range, and they result in the reduced viability of the species because of the reduced range and low population numbers rangewide (USFWS 2013)
USFWS (2013) determined that state endangered species and water withdrawal regulations, as well as the Federal Land Policy and Management Act and the National Forest Management Act are not adequate to protect the Zuni bluehead sucker or its habitat. State regulations prohibiting take of the species have been in place for decades; however, these regulations are not adequate to address the threats to habitat, particularly water withdrawals, impoundments, and the distribution and abundance of nonnative fishes. Because most of the threats to the Zuni bluehead sucker are from effects to its habitat and the introduction of nonnative, invasive species, in order to protect individuals and ensure the species' long-term conservation and survival, its habitat must be protected. Therefore, USFWS (2013) concluded that these existing regulations are inadequate to mitigate the impacts of identified threats to the species.
Currently, Zuni bluehead sucker populations are highly fragmented within small, isolated springs and stream segments, causing them to be vulnerable to stochastic events, such as wildfire and episodic drought, and to deleterious genetic effects (USFWS 2013).
"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 most of the Zuni River drainage in New Mexico (Propst et al. 2001, USFWS 2013).
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).
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).
Proposed critical habitat (USFWS 2013) included approximately 472 kilometers of stream habitat in Apache County, Arizona, and Cibola, McKinley, and San Juan counties, New Mexico, and on the Navajo Indian Reservation. The proposed designated habitat included areas outside the currently occupied distribution.
Management Requirements: "Survival of Zuni bluehead sucker without intensification and expansion of current conservation is doubtful" (Propst et al. 2001).
Relevance to Humans and Ecosystems
Stewardship Overview: Gilbert and Carman (2011) made the following conservation recommendations:
Cooperative efforts to monitor and manage Zuni bluehead sucker on tribal lands should be facilitated between tribal, State, and Federal partners.
Efforts to annually monitor Zuni bluehead sucker and identify threats for the Arizona populations should be initiated.
Coordination and cooperation among the Pueblo of Zuni, Navajo Nation, U.S. Forest Service, The Nature Conservancy, Service, NMDGF, and private landowners should continue and be formalized through the development of a Cooperative Agreement.
Cooperators should work to ensure that consideration for Zuni bluehead sucker recovery is included in all projects in the watershed. Partnerships with local State, and Federal agencies such as McKinley County and Natural Resource Conservation Service, should be sought.
Permanent legal access for monitoring and management purposes should be achieved for all current and historical habitats.
Habitat protection and restoration projects should continue across the watershed. Funding should be sought for both large multi-jurisdictional and small private projects, including through State Landowner Incentive and Tribal Landowner Incentive programs. Potential projects include: installation of ground and surface water quantity meters, such as pizometers, and repair, re-installation, or relocation of USGS gage on the Rio Nutria; installation of surface water quality meters in key habitats to monitor dissolved oxygen and temperature; physical rehabilitation or improvement of the Agua Remora; sediment transport abatement in the upper watershed, including forest restoration and sediment traps in ephemeral watercourses; restoration of historical habitat in the upper Rio Pescado.
Habitat, especially presence of wetted habitat, surveyed and monitored in the upper Rio Nutria on the TNC Rio Nutria Preserve. If perennial habitat is found, efforts to move Zuni bluehead sucker from lower in the Rio Nutria Box Canyon should be initiated.
The programs to remove nonnative species should be continued or initiated: intensive crayfish removal initiated in the Rio Nutria; removal of green sunfish in the Agua Remora.
Conservation genetic research continued to guide management decisions regarding captive holding and assisted movement of Zuni bluehead suckers in natural habitat.
Rearing investigations should be continued to assist in maintenance of a refuge population. This includes collections of additional fish from all populations, especially the Agua Remora.
Efforts to restore Zuni bluehead sucker to historical, suitable habitat should continue, particularly in the upper Rio Nutria if found perennial.
Efforts to create secure refuge populations within the natural distribution should begin.
Beaver removal and relocation efforts should be continued to lessen the impacts of stream impoundment in Zuni bluehead sucker habitat in the Rio Nutria. With increased water availability in historically occupied areas of the Rio Pescado and Zuni River, relocation of beavers into these areas may be appropriate. Water retention through beaver dams in these areas may help with retention of water in downstream reaches, potentially leading to restoration of historical Zuni bluehead sucker habitat.
See also 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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