History of the Mohave tui Chub

Background Information:

The Mohave tui Chub is the only fish native to the Mojave River watershed in California. Its population declined after sport fishermen introduced theArroyo Chub (Gila orcutti) in the 1930s as live bait.

Picture credit http://www.dfg.ca.gov/hcpb/cgi-bin/read_one.asp?specy=fish&idNum=23

The Recovery Plan explains that the Arroyo Chub hybridized with the Mohave tui Chub, leading to its extirpation. But viability of the hybrids has not been demonstrated and genetic studies have shown only pure strains (May et al., 1997). Mohave tui Chub also declined after headwater reservoirs altered natural flow regimes and provided more favorable habitat for non-native species. A relic population of genetically pure Mohave tui Chub survived isolated in MC Spring (a.k.a. Mohave Chub Spring) that is now part of Mojave National Preserve. MC Spring appears to be the only true refugium or nature refuge this endangered fish has in nature. The fragmented character of the Mojave River basin is both the very reason for the continued existence of Mohave tui Chub and a fundamental impediment to natural recovery of the species.

[This information was taken from "Report on a Workshop to Revisit the Mohave tui Chub Recovery Plan, September 3-4, 2003 at Zzyzx, California, Mojave National Preserve"]

Current Distribution:

The Mohave tui Chub's current distribution is secluded to three established refuges. They are believed to no longer be present in the Mojave River itself. This is due to the hybridization of the Mohave tui Chub with the Arroyo Chub. Reintroduction of the Mohave tui Chub back into the river is unrealistic at this time because of the existence of the Arroyo Chub. However, if we could some how remove the Arroyo from the river, it might be possible to introduce the Chub.