Central Stoneroller

Central Stoneroller, photo by Lance Merry

Central Stoneroller, photo by Lance Merry

Central Stoneroller (Campostoma anomalum)

North American Native Fishes Association; photo by Lance Merry

The Central Stoneroller is a small minnow 3-5 inches in length with a blunt snout and relatively small eyes. It is widespread in Kansas as well as most of the eastern and central United States. It prefers freshwater streams of mid to high gradients with riffles. It is active in the mid to bottom level of streams where it feeds predominantly on algae scraped from rocks with the cartilaginous ridge on its lower jaw. It will also consume rotifers, diatoms and microcrustacea plus the occasional aquatic insect. They may feed in schools and can often be seen leaping above the surface of the water. They in turn are part of the diet of smallmouth & largemouth bass, herons and bitterns. Adult males and females are similar in appearance, having a dark, olive colored dorsal surface fading to a white ventral surface. Randomly distributed dark spots are scattered along the length of the body. Fins are pale or nearly colorless. Breeding males are further distinguished by orange and black splashes on their fins and large pointed tubercles on their head (see photo above) with smaller one along the dorsal and lateral part of the body. In preparation for spawning, these fish may need to migrate upstream to calmer waters where breeding males build nests in late winter throughout midsummer. They excavate depressions in the stony bottom of calm waters using their noses to roll pebbles and stones out of the way. Females roam the available nests occupied by larger males. Eggs are attached by an adhesive substance to pebbles and hatch in less than 72 hours. Their population suffers with both aquatic and riparian habitat fragmentation, fluctuating stream flows, siltation, and excessive aquatic vegetation.