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Brook Silverside

Brook silverside


Dorsal scales are outlined with black specks, the sides are silvery with a bright silver horizontal stripe and the belly is silvery white, very slender and translucent, flattened head with beaklike snout and lower jaw, always found in the upper three feet of water.


Brook silverside Distribution

Common in pools 9 - 13 of the Mississippi River also found commonly downstream and in the Maquoketa and Cedar Rivers.


Aquatic and terrestrial insects cladocera, copepods and other small crustaceans.

State Record

 Grows to 2-4 in. State Records are not documented for non-species game.

Expert Tip



The Brook Silverside is commonly collected in pools 9 through 13 of the Mississippi River and is occasionally observed in downstream pools. It also has been collected in the Maquoketa and Cedar rivers. Recent collections in central Iowa rivers have not documented this species. Habitat preference for Brook Silversides is clear, warm waters having little current.

Brook silverside is a very slender, elongate and translucent fish. The head is flattened with a beak-like snout and a lower jaw that slightly projects toward the front. Upper and lower jaws have minute, needle like teeth. The long, sickle-shaped anal fin has one spine and 20 to 26 rays. Two dorsal fins are located on the posterior half of the back. The first dorsal has 4 spines, and the second has one spine and 5 rays. Scales are small and cycloid with 75 to 84 scales along the lateral line. General body color is pale green. The dorsal scales are outlined with black specks, the sides are silvery with a bright silver horizontal stripe, and the belly is silvery white. The fins are plain, except for a spinous dorsal fin and pigmentation near the tip. Adults usually average 2 to 4 inches in length.

Spawning takes place over shallow, gravel bottoms or sites with submerged vegetation, from late May to early August. The eggs are extruded singly as a spawning pair moves at an angle from the surface to the bottom. Each egg has an adhesive filament that attaches to the first item it contacts. At a temperature of 77 degrees F the eggs hatch in about 8 days. The brook silverside matures, spawns and dies by the end of its second summer of life.


Present in these Iowa water bodies: