ECOS Guide to the Ecology of the Northern Rockies

Name: Rhinichthys cataractae - Longnose Dace

Family: Cyprinidae (Minnows)

Order: Cypriniformes (Suckers and Minnows)

Class: Osteichthyes (Bony Fishes)

Abundance: Patchy

Origin: Native.

Active Season: Year Round

Size:

average: 10in
largest: 22in

Colors: red-orange (upper side), yellow (upper side, under side), red-brown (upper side), black (upper side), white-gray (underside)

General Description: Adults 4” to 6”. Color black to light-olive on back and upper side, shading to silver or yellowish on belly. Faint to pronounced mottling over body. Dark lateral stripe and a dark stripe on nose in front of the eye, especially in juveniles. Spawning males have red on head, body, and fins. Snout projects far beyond the mouth. Mouth ventral with thick lips. Small barbels at angles of jaws. Caudal fin moderately forked.

Similar Species: Juvenile Suckers ( Castostomus ) do not have barbels in corners of mouth and the anal fin of suckers is further back on the body. Suckers also do not have the dark lateral stripe, but they can have a similar mottling coloration.

Life History: Becomes sexually mature in about 3 years. Spawns in late spring to early summer. Spawn in shallow riffles over gravel. Large numbers of fry occur in backwaters in july and august.

Distribution: Widely distributed in northern North America and Montana.

Habitat Description:Riffle areas of streams and rivers, less often in lakes.

Feeding Habits: Feeds primarily on immature aquatic insects (immature mayflies, midges, stoneflies, and blackflies), which it picks off rocks. Also known to eat fish eggs and algae.

Enemies & Diseases: Because golden trout live at high elevation sites, predation is primarily by man, but ospreys, herons, minks, or other fish predators would certainly eat golden trout where their ranges overlap.

Did You Know: Longnose dace are commonly captured in riffles of rivers in Montana. They are important as forage for other fishes. Larger Longnose Dace tend to move into faster flowing riffles because they can hold in faster water.

Glossary:

Barbels: slender, flexible projections on the mouth or chin used for touch or taste.

Keywords: Longnose, dace, rhinichthys, minnow

References:

Holton, G. D. and H. E. Johnson. 2003. A Field Guide to Montana Fishes, Third Edition. Montana Fish, Wildlife & Parks, Helena, MT.

Contributor:

Allison Greene


Home Plant Guide Insect Guide Bird Guide Mammal Guide Geology Guide Fish Guide Fish by Name Fish by Family Fish by Order Glossary of Fish Terms Amphibian Guide Reptile Guide Habitats Descriptions Maps Contributors ECOS Home		Physical Characteristics - General Description - Similar Species - Life History - Distribution - Habitat - Feeding Habits - Did You Know - Glossary - References Name: Rhinichthys cataractae - Longnose Dace Family: Cyprinidae (Minnows) Order: Cypriniformes (Suckers and Minnows) Class: Osteichthyes (Bony Fishes) Abundance: Patchy Origin: Native. Active Season: Year Round Size: average: 10in largest: 22in Colors: red-orange (upper side), yellow (upper side, under side), red-brown (upper side), black (upper side), white-gray (underside) General Description: Adults 4” to 6”. Color black to light-olive on back and upper side, shading to silver or yellowish on belly. Faint to pronounced mottling over body. Dark lateral stripe and a dark stripe on nose in front of the eye, especially in juveniles. Spawning males have red on head, body, and fins. Snout projects far beyond the mouth. Mouth ventral with thick lips. Small barbels at angles of jaws. Caudal fin moderately forked. Similar Species: Juvenile Suckers ( Castostomus ) do not have barbels in corners of mouth and the anal fin of suckers is further back on the body. Suckers also do not have the dark lateral stripe, but they can have a similar mottling coloration. Life History: Becomes sexually mature in about 3 years. Spawns in late spring to early summer. Spawn in shallow riffles over gravel. Large numbers of fry occur in backwaters in july and august. Distribution: Widely distributed in northern North America and Montana. Habitat Description:Riffle areas of streams and rivers, less often in lakes. Feeding Habits: Feeds primarily on immature aquatic insects (immature mayflies, midges, stoneflies, and blackflies), which it picks off rocks. Also known to eat fish eggs and algae. Enemies & Diseases: Because golden trout live at high elevation sites, predation is primarily by man, but ospreys, herons, minks, or other fish predators would certainly eat golden trout where their ranges overlap. Did You Know: Longnose dace are commonly captured in riffles of rivers in Montana. They are important as forage for other fishes. Larger Longnose Dace tend to move into faster flowing riffles because they can hold in faster water. Glossary: Barbels: slender, flexible projections on the mouth or chin used for touch or taste. Keywords: Longnose, dace, rhinichthys, minnow References: Holton, G. D. and H. E. Johnson. 2003. A Field Guide to Montana Fishes, Third Edition. Montana Fish, Wildlife & Parks, Helena, MT. Contributor: Allison Greene