Santa Ana sucker

Taxobox
name = Santa Ana sucker
status = VU
status_system = iucn2.3
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Cypriniformes
familia = Catostomidae
genus = "Catostomus"
species = "C. santaanae"
binomial = "Catostomus santaanae"
binomial_authority = (Snyder, 1908)

The Santa Ana sucker, "Catostomus santaanae", is a sucker found only in a handful of rivers in southern California.

They are closely related to mountain suckers, and quite similar in appearance. Color is dark grey above and silvery-white below; the sides have a faint pattern of darker blotches and stripes. There are distinct notches where the upper and lower lips meet, and the lower lip is narrower in the middle, with only 3 or 4 rows of e at that point. The dorsal fins have 9 to 11 rays, while the pelvic fins have 8 to 10 rays. The caudal peduncle is somewhat longish. In contrast to the mountain sucker, the membrane between the rays of the tail fin is pigmented. Length has been recorded up to 25 cm, but less than 16 cm is more typical.

Also like mountain suckers, they feed on diatoms, other kinds of algae, and detritus, which they get by scraping surfaces such as rocks. They also eat the occasional insect larva, with larger fish observed to consume insects more frequently.

These suckers live in smaller (under 7 m wide) permanent streams, with depths from a few cm to over a m. The water must be cool, but the flow may be variable; they seem to prefer clear water, but tolerate turbidity. Not surprisingly given their feeding method, they prefer gravel, rubble, and boulder substrates.

Their 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 the upper portion of the Los Angeles and San Gabriel drainages, and the lower part of the Santa Ana River, especially areas with additional water effluent from sewage treatment plants. Although some stretches of the rivers are protected by being in the Angeles National Forest, the coincidence of this fish's range with the Los Angeles metropolitan area means that it is vulnerable to extinction.

References

* Listed as Vulnerable (VU B1+2c, D2 v2.3)
*
* Peter B. Moyle, "Inland Fishes of California" (University of California Press, 2002), pp. 182-185
*