Sacramento Pikeminnows, formerly known as “Squawfish”, are typically found in clear low to mid-elevation streams and rivers. Pikeminnows favor streams with deep pools and slow runs that have cover in the form of undercut banks or aquatic vegetation. While pikeminnows are often found in association with native fishes in slightly disturbed streams, they are rarely found in highly polluted rivers or sharing habitat with centrarchids in lakes. They are found where water temperatures are usually in the range of 18-28°C, though they are capable of withstanding extremes up to 38°C and salinities as high as 8 ppt. Pikeminnows grow most rapidly in the first five years of life, especially in the summer months. Fish in larger warmer waters tend to grow faster and bigger than fish found in smaller cooler waters. Younger fish feed and forage during the day, while adults tend to reside in deeper pools during the day and move into riffles to feed during dawn and dusk. Juveniles may feed on aquatic insects and change the focus of their diet to crustaceans and fish as they grow bigger. Large adults are voracious opportunistic predators and may take prey anywhere at anytime. In addition to fish, prey items may include: frogs, lamprey ammocoetes, large stoneflies, and even small rodents. At age 3-4 Sacramento Pikeminnows become sexually mature and begin spawning in April – May. Ideal spawning grounds are riffles and pool tails with gravel substrate. Residents of small streams might only move to a nearby riffle whereas residents of lakes and large rivers usually move up into a small tributary stream. Male Pikeminnows arrive at spawning grounds before female fish when water temperatures reach a range of 15-20°C. Spawning may occur annually or less frequently when adverse conditions exist. Females measuring 31-65 cm SL produce an average of 15,000 to 40,000 eggs each. The eggs hatch in a week or less (4-7 days) under favorable conditions. Young fish gradually spread out into small schools and move into deeper water with time, often occupying protected riffles and fast water. Pikeminnows grow and develop slowly but may reach great lengths, and ages in excess of 16 years.
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