Habitat
Habitat includes rocky pools of headwaters, creeks, and small to medium rivers (Page and Burr 2011). This species is a habitat generalist; usually it is found in small, warm, intermittent tributaries to larger streams, but it also occurs in cold trout streams, human-modified habitats, and in the main channels of rivers (Moyle et al. 1989); dense populations are often in isolated, well-shaded pools. It is most abundant in mid-elevation streams in the Sierra foothills (Moyle 1976). It is capable of withstanding extreme environmental conditions. In the Clear Lake region, habitats range from cool headwater streams to lower warmwater reaches; most abundant in pools and slow waters of the low to mid-elevation streams with high pH, conductivity, and temperature and with little cover or canopy (Taylor et al. 1982). Spawning occurs in shallow flowing areas with a substrate of small rocks. Adhesive eggs stick to rocks. Newly hatched fry stay in rock crevices or vegetation until large enough to move around actively (Moyle 1976).
Reproduction
Spawns in schools, mainly March-June. Adhesive eggs hatch in 2-3 days. Sexually mature by about the second year, probably earlier in some populations. Lifespan usually 3 years or less.