stoneroller

1. A minnow (Campostoma anomalum) of the central and southern United States, having a horny ridge near the edge of the lower lip used for scraping food from the bottom of a body of water.
2. A sucker (Hypentelium nigricans) of the central and southern United States, common in swift or rocky streams.

Campostoma anomalum

FAMILY

Cyprinidae

TAXONOMY

Rutilus anomalous Rafinesque, 1820, Licking River, Kentucky, Ohio River drainage, United States.

OTHER COMMON NAMES

English: Central stoneroller, largescale stoneroller.

PHYSICAL CHARACTERISTICS

Size small to moderate, maximum 7.87 in (20 cm) in total length. Body stout and moderately compressed, with the nape

region becoming swollen and prominent in adults. Snout bluntly rounded and projecting beyond the nearly horizontal mouth. Lower jaw has spade-like extension. Scales deep, rather small, and crowed anteriorly; more or less mottled with dark background; scales in lateral line 53. Dorsal fin with 8 branched rays; anal fin with 7 branched rays. Color brownish, with a brassy luster above. Dusky vertical bar behind the opercle; dorsal and anal fins each with a dusky crossbar about half way up, the rest of the fin is olive in females and fiery red in males in spring. In the spring, the head and sometimes the entire body of males are covered with large rounded tubercles.

DISTRIBUTION

North America, widespread across most of eastern and central United States in Atlantic, Great Lakes, Mississippi River, and Hudson Bay basins from New York west to North Dakota and Wyoming and south to South Carolina and Texas; Thames River system in Canada; from Galveston Bay in Texas to Rio Grande in Mexico.

HABITAT

Moderate to high gradient streams with sandy to gravely substrate. Prefers riffle areas where riffles and pools alternate in rapid succession. However, can survive in almost any stream with a food supply.

BEHAVIOR

Shoaling species.

FEEDING ECOLOGY AND DIET

Primarily herbivorous, feeding diurnally on filamentous algae and diatoms but also taking detritus and aquatic insects from the periphyton assemblage on rock surfaces. Because of its long intestine (up to 8 times its body length), this species is incredibly efficient at digesting detritus and algae.

REPRODUCTIVE BIOLOGY

Matures in second or third summer of life. Adults spawn between March and late May, when water temperatures are from 55.4–80.6°F (13–27°C). Males dig spawning pits in shallow, swift riffles and occasionally in quiet pools by driving their heads into the gravel. They transport gravel from the pits by nudging stones out with their snouts (hence the name stoneroller) or by transporting them with their mouths. Males compete aggressively for favored spawning areas. Females remain in deeper water near the spawning pits and enter the pits individually or in groups to deposit eggs. The adhesive eggs become lodged in the gravel and are abandoned prior to hatching.

CONSERVATION STATUS

Not listed by IUCN.

SIGNIFICANCE TO HUMANS

Not sought by anglers. They do make good bait but are difficult to culture.