[5] The spines on the pectoral and dorsal fins are shorter than those of a channel catfish (Ictalurus punctatus) of similar size.

[8] A small population of 350 fish has been reintroduced into the Rio Yaqui on the northernmost portion of the San Bernardino National Wildlife Refuge in November 1997.

[9] Streams flow intermittently in the dry season, and the catfish seeks refuge in permanent, often spring fed pools.

[10] The catfish were introduced in 1899 into the Santa Cruz River system (in a reservoir fed by Monkey Spring), where they persisted until the 1950s.

Threats: aquifer pumping, reduction in stream flows, water diversion, drought, hybridization, and competition and predation by non-native fishes Management needs: protect San Bernardino aquifers, and Leslie Creek and Black Draw watersheds to ensure adequate perennial flow, ameliorate effects of non-native fishes, reintroduce into suitable habitats within historical range, stabilize and protect populations in Mexico