Found only in the Santa Ana River, the San Gabriel River, and Big Tujunga Creek, the federally threatened Santa Ana sucker (Catostomus santaanae) is one of two fish species protected by the western Riverside County MSHCP.  The other fish is the arroyo chub.

Measuring just 3-4 inches long at maturity, this little fish is sensitive to habitat degradation and loss, drought, wildfires, and invasive species. Protecting the Santa Ana sucker has been a priority for many southern California conservation agencies.

The Santa Ana sucker uses its mouth to feed and attach itself to the ground and structures around it. The sucker typically has a dark gray upper body with a lighter underside. Due to its small size, the Santa Ana sucker is easy prey for others. They primarily feed on algae, diatoms, and detritus that it sucks it from the ground or rocks. They also feed on small insects.

After reaching maturity, the sucker can lay between 4,000 and 16,000 eggs. Having twins and triplets may seem like a lot to us humans, but the Santa Ana sucker takes the trophy for the amount offspring it can produce! The abundance of offspring has a purpose, though, helping to quickly repopulate rivers and streams that have been affected by the boom-and-bust cycles of drought and flooding.

Living in shallow streams, the Santa Ana sucker can be found just a few centimeters in depth but also use deep pools for habitat. They like to be around course gravel, rubble, and boulders where water is clean, and calm. They often use algae and other vegetation for cover.

The MSHCP is conserving habitat along the Santa Ana River and its tributaries. While the vast majority of the habitat is currently in conservation, it continues to be threatened. To help this little sucker thrive, RCA is improving wildlife connectivity, removing invasive species from its habitats, and preventing habitat degradation. Under the MSHCP, projects such as the Hammer Avenue Bridge Replacement, I-15 Express Lanes, and the Van Buren Boulevard Interchange were streamlined by providing take coverage for the Santa Ana Sucker and the Santa Ana River habitat.