Key Identifying Characters by Genus: Minnow ID Guidelines
Citations include Peterson Field Guide, Freshwater Fishes of VA, AL, MS, TN, OH and Wisconsin and Carson et al 2010
-261 native “minnows” and 10 introduced species, formerly all in the family Cyprinidae, now spread between Leucicidae and Cyprinidae (Most North American Minnows now fall in the family Leucicidae).
-Minnows adapted to a wide array of conditions across North America.
Non-Native Minnows
Black (Mylopharyngodon) and Grass Carp (Ctenopharyngodon)
Large ark-edged scales, terminal mouth, thick caudal peduncle, pointed snout.
Attain lengths exceeding 5 feet.
Black carp vs. grass carp: black with pelvic fin origin behind dorsal origin, dark fins, generally
more slender build than grass carp(grass with pelvin origin in line with dorsal origin).
Hypophthalmichthys
Silver and Bighead Carp.
Eye sitting below middle of the head.
Large terminal mouth, small scales.
Keeled belly.
No other fishes found in US possess this combination of traits.
Carrassius and Cyprinus
Goldfish(Carrassius) and Carps (Cyprinus).
Large scales, large serrated spine on dorsal and anal fin.
Carrassius similar to Cyprinus (Common Carp and Koi) but has more terminal mouth, lacks barbels on the corners of the mouth, smaller maximum size.
Ornamental and Wild type forms found in both Genera.
Leuciscus
Ide.
Rounded snout, reddish to pink paired fins, terminal mouth, superficially similar to Rudd and Golden Shiner, but with fleshier lips.
Predatory in nature when adults.
Pelvic fin origin slightly ahead of dorsal origin.
Not likely established outside of it’s native range of Eurasia, but incidentally encountered across US.
Tinca
Tench.
Small scales, thick caudal peduncle, yellowish to olive body coloration.
Rounded fins, slightly concave caudal peduncle.
Often with reddish eyes.
Prominent barbel in corner of terminal mouth.
Introduced from Eurasia, localized and uncommon in NY, MD, CT, CO, BC, WA and CA.
Scardinius
Rudd (introduced).
Deep laterally compressed body, reddish to bright red fins, keeled belly sheathed in scales (diagnostic in telling them apart from Golden Shiners).
Falcate dorsal and anal fin.
Terminal Mouth.
Lateral Line Scales 36-45, dorsal rays 9-11, anal rays 10-11.
Larger maximum size than Golden Shiner.
Western Minnows
Dionda
The Roundnose Minnows.
Minnows with rounded snouts and black lateral stripes.
Generally, with restricted ranges, characteristic round snouts should make them easy to identify
with co-occurring minnows.
Lavinia
Hitch.
Deep bodied laterally compressed similar to Golden Shiner, but lacks belly keel.
Dorsal fin origin positioned slightly behind pelvic fin origin.
Lateral line with strong curve, straight through caudal peduncle.
Pogonichthys
Splittails.
California endemics.
Similar in superficial appearance to Whitefish, but lack adipose fin.
Falcate Dorsal Fin, in line with anal fin origin.
Name derived from the telltale caudal fin which has a larger upper caudal fin lobe than lower.
Hesperoleucus
California Roach.
Telltale short rounded snout, slightly subterminal mouth.
Dorsal fin origin slightly behind pelvic fin origin.
Grey-greyish blue above, white below.
Nuptial Males with reddish coloration on chin, operculum, and lower fins.
7-10 dorsal rays.
Ptychocheilus
Pikeminnows, largest native minnows in NA.
Long head, large terminal mouth typical of many predatory fish across world.
Head flattened between eyes on top.
Mouth extending to or beyond edge of eye.
Slender, round body (almost circular in cross section, slightly compressed).
Elongate narrow caudal peduncle, deeply forked caudal fins.
Species easily narrowed down by range, since no two species co-occur.
Mylopharodon
Hardhead.
Diagnostic premaxillary frenum present on upper lip.
Long, pointed snout with large, terminal mouth.
Dorsal fin origin positioned behind pelvic fin origin.
Silver sides, brownish to bronze on top.
Orthodon
Sacramento Blackfish.
Small scales, wide head, with a flat surface along the top.
Falcate dorsal and anal fins.
Narrow caudal peduncle.
9-11 dorsal rays.
Mylocheilus
Peamouth.
Narrow rounded snout, single short barbel in corners of mouth.
Two distinct stripes visible on sides.
Axillary process present at base of pelvic fins.
8 dorsal and anal rays.
Acrocheilus
Chiselmouth.
Name derived from plate on lower lip, giving flat appearance across leading edge when viewed from below.
mouth small and notably angular from side.
black peritoneum.
body deepest in front of dorsal.
dorsal origin positioned in line with pelvic fin origin.
Richardsonius
The Redside Shiners
Dorsal origin positioned behind pelvic fin origin.
Namesake red stripe above pectoral fin on mature individuals.
Short snout, deeply forked caudal fin.
Complete lateral line.
Gila (This genus is a mess with lots of variation in the group, and not much to be said about unifying characters within the genus. Perhaps guiding people on individual species in the group is best
Western Chubs.
Unifying characters for this genus hard to distinguish in field, easier to treat members of this fish
as different subgroups.
Siphatales
Tui Chub and allies.
Notably highly variable phenotypically.
Small terminal to slightly subterminal mouth.
Dorsal fin origin over pelvic fin origin.
Deep caudal peduncle.
Small fins, rounded in shape.
Deepbodied, laterally compressed.
7-8 dorsal rays, 7-8 anal fin rays.
Can attain a max size of around 18 inches.
Agosia
Small scales.
Small barbel located on mouth corners.
Herbivorous diet evident by long coiled gut, black peritoneum.
Mouth slightly subterminal, snout short and rounded.
7 anal fin rays.
Dorsal fin large, anal fin enlarged and elongate in females.
Dorsal fin origin in line with pelvic fin origin.
Moapa
The Moapa Dace.
Telltale small, embedded scales across body.
Large black spot at base of caudal fin.
Long rounded snout, slightly subterminal mouth.
7-8 anal fin rays.
Relictus
The Relict Dace.
Round, chubby build.
Soft bodied, tissue not as firm as other minnows.
Small rounded fins.
Lateral line incomplete, pored scales reaching below dorsal fin.
Eremichthys
Similar to the Relict Dace, but often complete lateral line, sheath on upper and lower jaw, slightly subterminal mouth, sometimes 8 anal fin rays.
Iotichthys
The Least Chub.
Upturned mouth.
Large Eye.
Snout short and rounded.
Lacks lateral line, occasionally 1-2 pored scales.
Dorsal fin origin behind pelvic fin origin.
Slender caudal peduncle.
Black specks covering back and sides.
8 anal fin rays.
Oregonichthys
The Oregon and Umpqua Chubs.
Deep body, deepest at dorsal origin.
Narrow caudal peduncle.
Salt and Pepper appearance over back and sides.
Small barbel present(sometimes absent) at corners of mouth.
Snout rounded in shape.
Fully scaled chest between pectoral fins(unscaled in Umpqua).
7 anal fin rays.
Complete lateral line.
Lepidomeda
Spinedaces.
Characteristic large black-grayish blotches on body.
2 large spines on dorsal fin.
7 pelvic fin rays, unique to this genus.
Complete lateral line.
Meda
Spikedace.
One of only 2 North American minnows lacking scales.
Differs from Woundfin in lacking a barrel.
Plagopterus
Similar to Spikedace, but has barbel in corner of mouth.
Eastern Minnows
Notemigonus
Golden Shiner(native).
Similar to Rudd, but with belly keel not sheathed in scales, 7-9 dorsal rays(overlap at 9), 11-14.
anal rays(overlap at 11).
Red fins limited to southern populations.
Gill raker differences between species not easily counted in field situations.
Clinostomus
Rosyside and Redside Daces.
Large, oblique, pointed snouts.
Large, forked caudal fins.
Small scales.
Mature fish with bright red sides, body covered in tubercles.
9 anal fin rays.
Chrosomus
The Redbelly Daces (otherwise known as the Fine scale Daces).
Characterized by miniscule scales, barely visible to the naked eye.
Terminal mouths.
Nuptial fish with red pigment present on body, some species with yellow/orangeish to neon yellow fins.
8 dorsal rays, 7 to eight anal fin rays.
Partial to absent lateral line.
Hemitremia
The Flame Chub.
Round bodied, chubby build.
Short head, very short rounded snout.
Similar to Chrosomus, but has noticeably larger scales.
Semotilus
Creek Chub and Allies.
Large rounded heads, with large terminal mouths.
Barbels at corners of mouths.
Round bodied.
Compressed nape scales.
Generally 8 anal fin rays.
Nuptial males with large tubercles around snout and eyes, orange-reddish coloration on face
and chest.
Margariscus
The Pearl Daces.
Flaplike barbel, sometimes missing on one or both sides of the mouth.
Cylindrical body shape.
Terminal mouth(some say slightly subterminal), rounded snout.
Small scales, but larger than Chrosomus.
Dorsal fin origin behind pelvic fin origin.
Black lateral stripe.
8 dorsal and anal fin rays.
Allegheny Pearl Dace has larger scales than Northern Pearl Dace.
Couesius
The Lake Chub.
Large mouth, slightly subterminal.
Barbels present at mouth corners.
Snout moderately pointed.
Large eye on a head flattened on top and bottom.
Slender build, moderately compressed body.
Dorsal fin origin in line with pelvic fin origin.
Lateral Line complete.
Nocomis
The River Chubs.
Stout bodied minnows, bronze in color.
Similar to Semotilus, but with larger scales and no crowded scales on the nape.
Large mouths, terminal to slightly subterminal.
Dorsal fin origin varying between both sides of dorsal origin.
7 anal fin rays.
Complete lateral line.
Males with swollen heads, ranging in color from blue, to red, to purplish.
Campostoma
The Stonerollers.
Mouth subterminal.
Tan-ish/brownish coloration across body.
Unique to this species, cartilaginous lips present that give mouth the shape of a horseshoe when viewed from below. Used to graze biofilm from smooth rocky surfaces.
Breeding males with white lips.
Large individuals with irregular blotchy black scales.
Exceedingly long coiled gut.
Phenacobius
The Suckermouth Minnows.
Elongate cylindrical bodies.
Subterminal mouths, rounded snouts.
Complete, straight lateral lines.
Often confused with Erimystax and small suckers.
Exoglossum
The Cutlips and Tongietied Minnow.
Range can determine which Exoglossum you’ve caught.
Genus characterized by lower lip made up of a central boney plate, bordered on either side by fleshy lobes.
No other minnows in NA possess the unique mouth seen in this genus.
Rhinichthys
North American Daces.
Streamlined bodies adapted for headwaters.
Bodies deepest at nape.
Small scales.
Subterminal mouths.
Coloration highly variable within and between species but often with speckled black markings on sides.
Snouts rounded and narrow.
Small barbels usually present on mouth corners.
Lateral Lines complete.
Platygobio
Flathead Chub.
Characterized by broad, flat head that terminates in a pointed narrow snout.
Large subterminal mouth, barbel in each corner.
Falcate dorsal fin, with first ray extending beyond dorsal fin base when depressed against body.
Pectoral fins equally falcate/sickle shaped.
Small eyes.
1 Dorsal fin origin either in line or slightly in front of pelvic fin origin.
Not likely to be confused with other native species.
Macrhybopsis
Speckled Chub and Allies.
Usually large single barbel (some species a smaller second barbel present on mouth corners (Silver Chub exception).
Snout overhanging mouth, creating subterminal positioning.
Other than silver chub, body covered in black speckling.
Erimystax
The Streamline Chubs.
Overall slender built sleek fish, adapted to fast flowing runs.
Members of this genus with distinctive markings on sides, from blotches to “x” shaped markings.
Flattened across belly of fish.
Barbel situated in mouth corners.
Dorsal fin origin in front of pelvic fin origin.
Large, horizontally opening pectoral fins.
Hybognathus
The Silvery Minnows.
Minnows that are rather non-descript in general appearance.
Long coiled guts, black peritoneum.
Knob like projection just inside mouth on lower lip diagnostic for members of this Genus.
Dorsal fin origin in front of pelvic fin origin.
Eastern, Western, Mississippi Silver and Plains Minnow are very similar, and must be determined by the basioccipital process on the chest.
Range can help narrow down which species are possible in a given location.
Luxilus
Striped Shiner and Allies.
Scales large, generally larger than most other Leucicids.
Scales along lateral line generally much taller than wide towards front half of body.
Large terminal mouths.
Males with numerous hooked tubercles, often spectacular breeding colors.
Dorsal fin origin origin in line or slightly behind pelvic origin.
36-46 lateral line scales.
Lythurus
Redfin Shiner and Allies.
Small crowded nape scales.
Silver body.
Dorsal fin origin behind pelvic fin origin.
Large, terminal oblique mouths.
9-12 anal fin rays.
Nuptial Males with tubercles from head down to caudal peduncle.
Red pigment in varying degrees present in nuptial males.
Pteronotropis
Flagfin Shiner and Allies.
Characterized by narrow to broad blue/black stripe laterally.
Deep compressed bodies.
Dorsal fin origin positioned behind pelvic fin origin.
Lateral line complete.
Often with colorful, enlarged fins in nuptial males.
Cyprinella
The Satinfin Shiners.
Most notably characterized by scales that appear diamond-shaped.
Narrow pointed snouts.
Males with iridescent fins, often colorful bodies to match.
Often hybridize where members of this genus co-occur.
A few species with barbels present at corners of mouth.
Pimephales
Fathead Minnow and Allies.
Small, crowded nape scales much smaller than elsewhere on body.
First couple dorsal rays much shorter than the rest.
Nuptial males with spongey pad on back, tubercles in rows on typically blunt, rounded snout.
Notropis
Houses multiple species complexes likely warranting elevation into different genera
Hard to generalize this genus, due to the large number of likely unrelated sub groups within this genus
Members typically with 8 anal fin rays
Many exceptions, such as N. stramineous with 7
Scales typically rounded on rear edge
Usually small, silvery in appearance
Often with dark base to dorsal and anal fin.
Scales silvery, sometimes easily dislodged from fish from simply handling.
Terminal to subterminal mouths.
Scales ranging from pigmentless to edged in dark pigment
Ericymba
The Silverjaw Minnows
A contested genus, bouncing back and forth between valid and not valid.
Members of this genus characterized by the pearl organs under their eye along the upper jaw line
These pearl organs appear as metallic, cube like organs readily visible to the naked eye upon close inspection.
Hybopsis
Bigeye Chub and Allies
Superficially similar to Notropis minnows
Eyes positioned facing upward
Long overhanging snout
Subterminal mouth
Pallid shiners as the exception, members of this genus with barbels in corners of the mouth.
By Zach Alley
