Northern pikeminnow

Common name

Northern pikeminnow

Scientific name

Ptychocheilus oregonensis 

Fish family

Cyprinidae 

Also known as

Columbia River dace, Columbia squawfish, gray sea trout, gray weakfish, northern squawfish, seatrout

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What they look like

The northern pikeminnow has a dark green or green-brown back, and a silvery white/cream abdomen. It has a long snout and a large mouth - you can usually insert 2 to 3 fingers fully into an 11-inch pikeminnow's mouth. The head is relatively long, approximately a quarter of its total length. The eyes of adults are small. Its tail is distinctly forked and fins are clear; however males display yellow/orange lower fins during spawning periods. Mature individuals generally have a rounded belly. Northern pikeminnows are similar in shape to the walleye, but a pikeminnow doesn't have the walleye's spiny dorsal fins and white-tipped tail fin. Unlike walleye, pikeminnow are native to the Columbia River system.

The pikeminnow is not the same as the threatened Colorado squawfish. They are two distinct species. Prior to 1998, the northern pikeminnows were named the northern squawfish. The American Fisheries Society officially changed the name to pikeminnow.

One of the best ways to determine the difference between a peamouth and a pikeminnow is to compare where the corner of the mouth ends. On a pikeminnow the corner of the mouth comes back to the eye, while on the peamouth, the corner of the mouth is well before the eye. The barbels at the corner of the peamouth's mouth are missing on the pikeminnow, as are the dark bars on the side.

Pikeminnow from the Columbia River are generally a bright silvery color, while those from tributaries will usually be darker and more colored.

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Where they live

In Washington, the northern pikeminnow is found in the Columbia and Snake river systems and coastal and Puget Sound drainages. The species fares well in stream, river, and lake-like habitats, and has flourished in the mainstem Columbia River and its many tributary systems. Northern pikeminnow congregate in rocky areas with fast current near dams, islands, stream mouths, points, eddies, rows of pilings, and ledges or bars in the river. Most fish are caught in 7 to 25 feet of water. Studies show there are greater concentrations of northern pikeminnow in shallow water during low-light conditions.

While historically squawfish have not been of interest commercially nor to sport anglers, Washington and Oregon state fisheries agencies and the Bonneville Power Administration have placed a bounty (reward) on them in order to reduce predation on scarce salmon stocks. A sport fishery has developed based on that bounty. Pikeminnow are native to the Columbia River. Their population has flourished with the development of the Columbia River Hydro-power System. The reservoirs have provided excellent habitat for pikeminnows and given them an advantage over depressed salmon and steelhead populations.

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What they eat

The diet of northern pikeminnow varies with their size. In the Columbia River, invertebrates dominate the diets of northern pikeminnow that are smaller than 12 inches in length, with fishes and crayfish increasing in importance as fish size increases. Salmonids, sculpins, trout perch, and suckers are common prey items of northern pikeminnow. Salmonids are generally an important diet item only for large, old northern pikeminnow, and the consumption rate of juvenile salmonids increases exponentially as the size of the northern pikeminnow increases. Consumption rates of juvenile salmonids by northern pikeminnow correlate positively with how abundant salmonids are; in other words, the more salmonids there are, the more the northern pikeminnow eat until the pikeminnow reaches satiation. During the salmon spawning season, they will also feed on eggs.

They move to find concentrations of prey. Northern pikeminnow eat millions of young salmon and steelhead in the Columbia and Snake rivers each year. Researchers believe reducing the number of these predators can greatly help the salmon and steelhead.

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Life cycle

The northern pikeminnow is a large member of the minnow family. They are large, long-lived, slow-growing predaceous minnows whose unexploited populations are typically dominated by large, older individuals. In the Columbia River, maximum fork length, weight, and age are approximately 23½ inches, 5½ pounds, and 16 years. However, the maximum age of 16 years may be an underestimate based on possible under aging.

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Spawning

Sexual maturity occurs at sizes of 8-14 inches and corresponding ages of 3–8 years, with males typically reaching initial maturity before females. Spawning generally occurs during June and July and the fish tend to gather in large numbers, and each female will spawn with more than one male. They broadcast their eggs over clean rocky substrate in slow-moving water at a range of depths in rivers, lake tributaries, lake stream outlets, and shallow and deep littoral areas. A mature female can lay 30,000 eggs annually. Northern pikeminnow eggs hatch in 7 days at 65°F water, and that the young become free swimming within 14 days.

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State Record

8 lbs. 8 oz.caught in the Snake River by angler Pamela Ramsden of Deer Park, Washington on May 16, 2008

World Record

8 lbs. 8 oz.caught in the Snake River by angler Pamela Ramsden of Deer Park, Washington on May 16, 2008

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