Captive Care Notes: California Roach (Hesperoleucus, Family Cyprinidae)
I have one word of advice for any amateur aquarist wanting to keep California minnows -- don't. It is effectively illegal to collect fishes for home aquaria in California without a scientific collecting permit. Certain species of baitfish may be collected and transported within some districts, but may only be used as bait. It's not that California's code is intentionally discriminating against amateur aquarists. Instead, as in other states, lawmakers simply did not take into consideration that people might want to study fishes in aquaria or keep them as pets. One way around the law is to set up and maintain aquaria for schools and nature centers. In some instances, the California Department of Fish and Game may issue scientific collecting permits for educational purposes.
Should you be issued such a permit, then keeping California's minnows should pose no special challenges other than accommodating their potentially large size. The most suitable resident for aquarium display is the California Roach (Hesperoleucus symmetricus), which seldom exceeds four inches. Writing in the NANFA publication American Currents, David L. Hall reported that roach he collected (presumably before California's stricter collecting regulations were in effect) were active in the aquarium and prone to jump out if not kept covered.