Longnose Dace (Rhinichthys cataractae)

A member of the Cyprinidae family of minnows and carp, the longnose dace has many valuable functions. Easily obtainable, small, and extremely hardy, it is prized as exceptional bait and is especially significant for bass fishing. Primarily feeding on blackfly larvae, it is also valued for its control of the blackfly population. And, like many small minnows, it provides excellent forage for predator fish, especially bass and trout. It is not sought by anglers but may be netted for use as bait.

Identification

The longnose dace is a distinctive minnow with a long fleshy snout, a subterminal mouth, and a deep caudal peduncle. The head and the nape slope downward from its cylindrical body, giving this minnow a streamlined appearance. Pigmentation is widely variable; the dorsum can be greenish, brown, or reddish purple, and the lower sides and the venter may be silvery, white, or yellow.

The sides are sometimes marked by darkened scales, a lateral stripe, and a blotch near the tail. The longnose dace can quickly be distinguished from most other minnows by the presence of a frenum, a small fleshy bridge between the snout and the upper jaw. It can be distinguished from other species of Rhinichthys by its long snout.


Other characteristics of the longnose dace are small barbels in the corner of the mouth, small scales, a complete lateral line with 48 to 76 scales, and eyes that are situated near the top of the head. A breeding male has red coloration on the head and the fins and develops small tubercles on the head, the body, and the ventral fins.

Size/Age

Adults can reach lengths exceeding 6 inches, but most are less than 4 inches long. They have been known to live up to 5 years.

Spawning behavior

Longnose dace mature within 2 years but may live up to 5 years. Females often grow larger and live longer than do males. Reproduction occurs between the late spring and the early summer. Interestingly, an eastern subspecies spawns during the day, whereas a western subspecies spawns at night.

Longnose dace are categorized as broadcast spawners, scattering their eggs in shallow, fast-flowing areas and over chub nests. Males aggressively defend spawning areas, but more than one male may line up next to the female during spawning. Spawning occurs on the stream bottom and may result in the burial of eggs within the substrate. The female deposits between 200 and 1,200 eggs during spawning.

Food and feeding habits

Longnose dace feed on aquatic insects (especially midges and blackfly larvae), worms, small crustaceans, mites, algae, and plants. They have taste buds on their ventral fins, lower heads, lips, and snouts, which may enable them to find food along the stream bottom.

Other Names

dace; French: naseux de rapide.

Distribution

The longnose dace has the widest distribution of any minnow in North America and is an important forage species where it is abundant. Several subspecies are recognized, but further study may reveal the occurrence of unique populations or additional subspecies.

The distribution of the longnose dace spans the entire continent, ranging throughout the southern half of Canada and the northern United States. It extends southward to Georgia within the southern Appalachian Mountains and into northern Mexico through the Rocky Mountains. Its northern limit is the Mackenzie River drainage, Canada, which lies within the Arctic Circle.

Habitat

Longnose dace occur in a wide variety of habitats. They are found in the riffles, runs, and pools of creeks, streams, and rivers. Within lakes, they usually prefer areas around rocky shorelines. These streamlined fish are well adapted to fast-moving waters.

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