Northern pikeminnow
The Northern pikeminnow, Columbia River dace or colloquially Squawfish is a large member of the minnow family, Leuciscidae. This predatory freshwater fish is native to northwestern North America, ranging from the Nass River basin to the Columbia River basin. A good deal of concern has been expressed regarding the impact northern pikeminnow populations may have on salmon in Columbia and Snake River impoundments.
Naming
Until 1999, when the American Fisheries Society officially changed the common name to pikeminnow, the four species of Ptychocheilus were known as squawfish. The renaming effort was undertaken due to the word squaw being an ethnic slur for Indigenous [peoples of the Americas|Native American] women.Behavior and habitat
Northern pikeminnows can live at least 11 years, reaching up to in total length and in weight. Female northern pikeminnow reach sexual maturity at about six years, males in three to five. A mature female can lay 30,000 eggs annually. Pikeminnow are adept predators, and in the Columbia and Snake Rivers, salmon smolts comprise a large part of their diets. Their populations have flourished with the development of the Columbia River hydropower system. The reservoirs have provided excellent habitat for pikeminnow and given them an advantage over depressed salmon and steelhead populations.Diet
Like many freshwater fish that belong to the size range of the pikeminnow, they consume a wide range of food from insects to small fish. However, their diet for the fry of other game fish such as trout or salmon has led to declining populations in those species. It is estimated that Northern Pikeminnows consume up to 650,000 salmon and trout fry each year which is detrimental to those populations.While the pikeminnow are devastating to the populations of other local fish, their diet does change with age. Younger pikeminnow are seen to feast upon smaller fry and crayfish while, as they mature, the older pikeminnow are seen to consume larger fish such as salmonids, perch, sculpins, and suckers. It has been noted that salmonids are crucial to the size and population increase of northern pikeminnows since consumption rates of salmonids by pikeminnows correlates positively with the growth of mature pikeminnows.