Ictalurus pricei

Taxonomic status of Mexican catfishes in other than the rios Yaqui-Casas Grandes basins remains unclear (USFWS 1994). Ictalurus meeki may be a synonym (Lee et al. 1980, Hendrickson et al. 1981). An undescribed catfish resembling I. pricei has been introduced and is established in the Gila River drainage (D. Propst), but its morphology, status, and overall distribution are yet to be determined (USFWS 1994). See Lundberg (1992) for a synthesis of recent work on the systematic relationships of ictalurid catfishes.

Small range in northwestern Mexico and adjacent Arizona; declining in distribution and abundance; threatened by habitat modification and interactions with non-native catfishes.

Historical range most likely included the uppermost Rio Yaqui system, Arizona, and the basins of the Rio Yaqui and Rio Casas Grandes, Sonora and Chihuahua, Mexico (USFWS 1994, Page and Burr 2011); also rios Sonora, Mayo, and Fuerte, northwestern Mexico (Miller 2005). The species is apparently extirpated in the Rio Sonora basin and in the Rio Casas Grandes, an interior drainage in Chihuahua, Mexico (Miller 2005, Varela-Romero et al. 2011). Recent range-wide surveys indicated that Ictalurus pricei is now restricted to the Yaqui, Mayo and Fuerte river basins, though the species is possibly extirpated in the Mayo drainage (Varela-Romero et al. 2011). Populations of native Ictalurus south of the Fuerte River represent a distinct, undescribed species (Miller 2005, Varela-Romero 2011).

Three small, wild populations (introduced from hatchery stock) exist in the United States: Twin Pond (San Bernardino National Wildlife Refuge) and House Pond (Slaughter Ranch), both in the Yaqui River Basin, and Big Tank (El Coronado Ranch) in the Sulphur Springs Valley drainage, all in Cochise County, Arizona (Baker et al. 2008, Varela-Romero et al. 2011). Baker et al. (2008) indicated it is fairly certain that populations in Twin Pond and Big Tank were pure I. pricei, but there was some concern as to whether the population in House Pond was contaminated by either blue catfish or channel catfish.

This species is represented by a limited number of distinct occurrences (subpopulations) (probably fewer than 20). Varela-Romero et al. (2011) surveyed the entire Mexican range and found this species in 3 sites in the Yaqui basin, 0 sites in the Mayo basin, and 2 sites in the Fuerte basin. Not more than a few small populations exist in Arizona (Varela-Romero et al. 2011). Based on pervasive threats in most occupied drainage basins, the number of distinct locations (as defined by IUCN) may not exceed five.

Current diminished distribution and abundance are due to habitat modifications such as arroyo cutting, water diversion, dam construction, excessive groundwater pumping, and chemical and sewage pollution, combined with the effects of non-native fish species, especially competition and hybridization with Ictalurus punctatus (Miller 2005). All drainages currently inhabited by I. pricei now harbor non-native blue (I. furcatus) and channel (I. punctatus) catfishes, the non-native black bullhead (Ameiurus melas) is now known from the Yaqui Basin, and the flathead catfish (Pylodictis olivaris) has been recorded anecdotally in the Yaqui Basin (Varela-Romero et al. 2011).

Extirpation in the United States resulted from ground water pumping that decreased spring flow, causing San Bernardino Creek to dry up; trampling by livestock made remaining habitat unsuitable. Geothermal leases pose a potential threat through possible lowering of groundwater levels and increased likelihood of pollution.

Threats (non-native species, new reservoirs) to the Yaqui catfish have increased in recent years, and hybridization with the channel catfish now appears widespread (Varela-Romero et al. 2011).