Santa Ana sucker

Species of fish

The Santa Ana sucker (Catostomus santaanae) is a freshwater ray finned fish, endemic to California. It is closely related to the mountain sucker and has dark grey upper parts and silvery underparts. It grows to a maximum length of , but most adults are much smaller than this. It feeds on algae, diatoms and detritus on the floor of shallow streams with sand, gravel or cobble bottoms. It is found in only a few streams in southern California, and many of these in the Greater Los Angeles metropolitan area have been restricted to concrete channels. Because of its small area of occupancy and vulnerability, the International Union for Conservation of Nature has rated this fish as "endangered". The breading habits of Santa Ana Suckers do not differ from other species of suckers as the female fish are attended by at least 2 male fishes during mating seasons. A female sucker can release between 4,000 and 16,000 eggs amongst her gradual breeding process. Not surprisingly, given their feeding method, they prefer gravel, rubble, and boulder substrates.

The Catostomus santaanae range is extremely restricted; they are native only to the Los Angeles, San Gabriel, Santa Ana, and Santa Clara River systems in Southern California. Populations have been lost from several parts of the rivers, so that they now only live in Big Tujunga Creek in the Los Angeles River Basin, the headwaters of the San Gabriel River in the San Gabriel Mountains in Angeles National Forest in Los Angeles County, parts of the Santa Clara River system in Los Angeles and Ventura counties, and the lower part of the Santa Ana River in Orange County, especially areas with additional water effluent from sewage treatment plants. A substantial fish population can also be found in a research monitored project in Los Angeles County of Haines Creek.

Since Santa Ana suckers were first listed as a federally threatened species (effective May 2000 Watershed conservation efforts are key in saving these suckers as their biggest threat posed is of habitat loss where it is recorded that they currently have lost over 95% of their natural habitat. Although some stretches of the rivers are 'wild' and protected by being within the Angeles National Forest area of the San Gabriel Mountains, the coincidence of this fish's range and the Greater Los Angeles metropolitan area, and flowing in concrete lined flood control channels, means that it is a species vulnerable to extinction. The International Union for Conservation of Nature has rated this fish as an "endangered species" because of its decreasing area of occupancy and declining population.