Families represented here: Petromyzontidae, Acipenseridae, Hiodontidae, Osmeridae, Catostomidae, Cyprinidae, Salmonidae, Esocidae, Percopsidae, Lotidae, Percidae, Gasterosteidae, Cottidae

1a) Seven pairs of small, separate, gill openings no opercle, no paired fins; mouth an open disc with horn-like teeth but without jaws . . . . . . Petromyzontidae, Sea lamprey (Petromyzon marinus)

1b) A single, large, gill opening on each side of head, covered by opercle; paired fins present, mouth with moveable jaws; teeth of dentine and enamel . . . . . . . . . . . . . . Gnathostomes, 2

2a) Caudal fin forked with upper lobe much larger or stronger in adults; snout triangular in dorsal view, with ventral barbels; mouth tubular; 5 rows of large plates along back and sides; gill area not enlarged . . . . . . . . . Acipenseridae, lake sturgeon

2b) Caudal fin rounded or forked with nearly equal lobes; snout without flattened extension of snout and ventral barbels . . . 3

3a) Fangs on tongue, large teeth on roof of mouth--larger than teeth on the jaws . . . . . . . . . . . . . . . . . . . . . . . 4

3b) Teeth on tongue and roof of mouth similar in size to jaw teeth, or teeth absent . . . . . . . . . . . . . . . . . . . . 5

4a) Snout blunt and shorter than eye diameter, no adipose fin . . . . . . . . . . . . . . . . Hiodontidae, Hiodon tergisus, mooneye

4b) Snout sharp, longer than eye diameter, adipose fin present. . . . . . . . . . . . . . Osmeridae, Osmerus mordax, rainbow smelt

5a) Adipose fin present . . . . . . . . . . . . . . . . . . . 6

5b) Adipose fin absent . . . . . . . . . . . . . . . . . . . . 7

6a) Origin of pelvic fins well behind pectoral fins; jaws with basic single row of teeth; smooth scale edges, no spines . . . . . . . Salmonidae, whitefish, grayling, trout, and salmon

6b) Origin of pelvic fins forward under center of pectoral fins; jaws with wide bands of small teeth; posterior edge of scales ctenoid, weak spines in dorsal, anal, and pelvic fins . . . . . . . . . . . . . . Percopsidae, troutperch, (Percopsis omiscomaycus)

7a) Jaws with no teeth; dorsal fin positioned mostly over pelvic fins; second dorsal fin absent; head and cheeks with no scales. . . . .. . Cypriniformes 8

7b) Jaws with teeth, soft dorsal mostly over anal fin, less over pelvic fins . . . . . . . . . . . . . . . . . . . . . . . . . . 9

8a) Lips fleshy, with visible sensory papillae or ridges, mouth ventral or subterminal; principal caudal rays 18; more than 17 pharyngeal teeth on each arch . . . . . . . Catostomidae, suckers

8b) Lips without visible sensory structures, mouth usually terminal or subterminal; principal caudal rays 19; fewer than 7 pharyngeal teeth on each arch . . . . . . . . Cyprinidae, minnows

9a) Pelvic fins abdominal (nearer anal fin than pectoral fin); blade-like teeth in jaws and roof of mouth . . . Esocidae, pikes

9b) Pelvic fins under pectoral fin; pelvics with 1 spine; dorsal and anal spines present (flexible in burbot and sculpins) . . 10

10a) Chin barbel present, dorsal fins with more than 45 rays . . . . . . . . . . . . . . . . . . . . Lotidae, burbot, (Lota lota)

10b) Chin barbel absent, dorsal with fewer than 45 rays . . . 11

11a) Back with 3-9 unconnected dorsal spines ahead of soft dorsal fin, caudal peduncle slender . . . Gasterosteidae, sticklebacks

11b) First dorsal fin with spines (sometimes flexible) connected by membranes . . . . . . . . . . . . . . . . . . . . . . . . 12

12a) First dorsal fin with soft spines, head wider than deep, pectoral fin large, eyes dorsal; 1-4 stout spines on cheek bone (preopercular) . . . . . . . Cottidae, sculpins

12b) Dorsal spines hard and sharp, head not wider than deep, eyes lateral; cheek bones smooth or with serrations, not spines . . . . . . . . . . . . . . . Percidae, perch, walleye, sauger, darters

KEY TO 11 SPECIES OF FAR NORTHERN MINNOWS, CYPRINIDAE Brassy minnow (Hybognathus hankinsoni) Emerald shiner (Notropis atherinoides) Spottail shiner (Notropis hudsonius) Northern redbelly dace (Phoxinus eos) Finescale dace (Phoxinus neogaeus) Fathead minnow (Pimephales promelas) Blacknose dace (Rhinichthys atratulus) Longnose dace (Rhinichthys cataractae) Creek chub (Semotilus atromaculatus)

1a) scales small, more than 50 diagonal rows along sides . . . 2

1b) scales large, fewer than 50 diagonal rows along sides . . 8

2a) barbel present corner of mouth or end of upper lip . . . . 3

2b) no barbel present on mouth or lip . . . . . . . . . . . . 5

3a) barbel at corner of mouth . . . . . . . . . . . . lake chub

3b) barbel ahead of corner of mouth, in fold of upper lip . . 4

4a) dark spot in anterior corner of dorsal fin, upper lip slightly expanded in front . . . . . . . . . northern creek chub

4b) no dark spot in dorsal, upper lip not expanded .. pearl dace

5a) mouth oblique, two dark stripes on upper sides sides, lateral scales more than 70 . . . . . . . . . . . . . Phoxinus, 6

5b) mouth small and subterminal or ventral, body uniformly dark above, lateral scales fewer than 70 . . . . . . . Rhinichthys, 7

6a) intestine short, with 1 loop, 2 distinct stripes . . . . . . . . . . . . . . . . . . . . . . . . . . . northern redbelly dace

6b) intestine long, with 3 loops, 1 distinct lateral stripe, 1 faint dorsolateral stripe . . . . . . . . . . . . finescale dace

7a) mouth ventral, long snout, bridge of skin across center of upper lip (frenum) . . . . . . . . . . . . . . . . longnose dace

7b) mouth subterminal, short snout, no frenum . . blacknose dace

8a) first principal (long) dorsal ray preceded by short separate ray, predorsal scales smaller and crowded . . . . fathead minnow

8b) first principle dorsal ray preceded by a short ray tightly pressed to it, scales of back and sides similar in size . . . . 9

9a) distinct spot at caudal base . . . . . . . . spottail shiner

9b) snout short, its length subequal to eye and contained more . . . . . . . . . . . . . . . . . . . . . . . . . . emerald shiner

KEY TO NORTHERN SUCKERS, CATOSTOMIDAE

1a) scales large, in 65 or more lateral rows . . . . . . . . . . . . . . . . . . . . . . . . white sucker, (Catostomus commersoni)

1b) scales small, mor than 80 lateral rows . . . . . . . . . . . . . . . . . . . . . . . longnose sucker, (Catostomus catostomus)

KEY TO WHITEFISH, GRAYLING, TROUTS, AND SALMONS OF MICHIGAN Round whitefish (Prosopium cylindraceum) Lake whitefish (Coregonus clupeaformis) Lake herring (Coregonus artedii) Bloater (Coregonus hoyi) Arctic grayling (Thymallus arcticus) Brook trout (Salvelinus fontinalis) Lake trout (Salvelinus namaycush) Atlantic salmon (Salmo salar) Brown trout (Salmo trutta) Rainbow trout, steelhead (Oncorhynchus mykiss) Coho salmon (Oncorhynchus kisutch) Chinook salmon (Oncorhynchus tshawytscha) Pink salmon (Oncorhynchus gorbuscha)

1a) Teeth absent from maxilla, minute on other jaw bones, scales large, fewer than 95 in lateral line (whitefishes) . . . . . . 2

1b) Teeth present on maxilla, prominent on other jaw bones, scales small, more than 100 in lateral line (trout, salmon, grayling) . . . . . . . . . . . . . . . . 9

2a) Single flap between the 2 nostrils on each side, gill rakers fewer than 20 (Prosopium) . . . . . . . . . . . . . . . . . . 3

2b) Double flap between nostrils, gill rakers more than 23 (Coregonus) . . . . . . . . . . . . . . . . . . . . . . . . . 4

3a) Lateral line scales 56-66 . . . . . . . Prosopium coulteri

3b) Lateral line scales 83-96 . . . . . .Prosopium cylindraceum

4a) Mouth overhung by blunt snout; gill rakers <32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coregonus clupeaformis

4b) Mouth terminal, snout angular; gill rakers 32+ (ciscoes)...5

5a) Lower jaw projects, with symphyseal knob; subopercle depth= 1/4 its length (hoyi, kiyi) . . . . . . . . . . . . . . . . . . 6

5b) Jaws subequal, no symphyseal knob, subopercle depth =1/3 its length . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6a) Gill rakers usually 36-41, fins dark, fall spawner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coregonus kiyi

6b) Gill rakers usually 41-44, fins light, spring spawner . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coregonus hoyi

7a) Gill rakers 46-51, first row long (lake herring and tullibee*) . . . . . . . . . . . . . . . . . . Coregonus artedii [*herring have basibranchial teeth; tullibee do not]

7b) Gill rakers usually 34-42, short . . . . . . . . . . . . . 8

8a) Gill rakers usually 34-38; snout short; fins short, spring spawner . . . . . . . . . . . . . . . . . . . Coregonus reighardi

8b) Gill rakers usually 38-44; snout long; fins medium, fall spawner . . . . . . . . . . . . . . . . . . Coregonus zenithicus

9a) Dorsal fin with more than 17 rays, its base longer than head length . . . . . . . . . . . . . . . . . . . Thymallus arcticus

9b) Dorsal fin with fewer than 17 rays, its base shorter than head length (chars, trouts, salmons) . . . . . . . . . . . . 10

10a) Light spots on dark background on back (chars) . . . . 11

10b) Dark spots on light background on back (trouts, salmons) 12

11a) Lower fins with black stripe, caudal square . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Salvelinus fontinalis

11b) Lower fins without black stripe, caudal forked . . . . . . . . . . . . . . . . . . . . . . . . . . . . Salvelinus namaycush

12a) No rows of spots on caudal fin; background color tan or silver, spots black or red, with halos; no gap between vomerine and palatine teeth; postorbital bones short; lacrymal groove extends in front of line with nostril (Salmo) . . . . . . . . 13

12b) Rows of spots present on at least some of caudal fin; color silver or reddish; spots small, black, never reddish; gap between vomer and palatine teeth; postorbital bones extend more than half way to preopercle; lacrymal groove stops below nostril (Oncorhynchus) . . . . . . . . . . . . . . . . . . . . . . . . 14

13a) Caudal fin square; 120-130 lateral line scales; 16-19 gill rakers; 12-14 dorsal rays; vomerine teeth 2-6 in adults, 10-18 in young; adipose fin with orange markings in young . . Salmo trutta

13b) Caudal fin forked; 109-121 lateral line scales; 19-21 gill rakers; 10-12 dorsal rays; vomerine teeth 0-2 in adults, 1-8 in young; adipose fin without orange markings in young...Salmo salar

14a) Anal rays <13; back and caudal fin covered with small spots . . . . . . . . . . . . . . . . . . . . Oncorhynchus mykiss

14b) Anal rays 13 or more, back and caudal fin with large spots or caudal incompletely spotted . . . . . . . . . . . . . . . 15

15a) Gill rakers 16-24, fewer than 150 rows of scales; caudal fin with small spots . . . . . . . . . . . . . . . . . . . . 16

15b) Gill rakers 26-34; more than 150 rows of scales; spots on back and tail larger than pupil . . . . . Oncorhynchus gorbuscha

16a) Caudal fin spotted on both lobes; black gums at base of lower teeth; anal rays usually 15+; pyloric caecae 140-185 . . . . . . . Oncorhynchus tshawytscha

16b) Caudal fin spotted on upper lobe; white or blotchy gums; anal rays usually <15; pyloric caecae 45-80 . . . . . . . . . . . . Oncorhynchus kisutch

PERCIDAE, PERCH, WALLEYES, DARTERS Rainbow darter (Etheostoma caeruleum) Iowa darter (Etheostoma exile) Johnny darter (Etheostoma nigrum) Yellow perch (Perca flavescens) Logperch (Percina caprodes) Sauger (Stizostedion canadense) Walleye (Stizostedion vitreum)

1a) Preopercle serrated, mouth extends below eye, size large...2

1b) Preopercle with smooth border, mouth not reaching below eye, size small ... 4

2a) Anal rays 6-8, no canine teeth . . . . . . . . yellow perch

2b) Anal rays 12-13; canine teeth present . . . . . . . . . . 3

3a) A large black spot in posterior part of spiny dorsal fin; dorsal fins with dusky mottlings, not rows of small black spots . . . . . . . walleye

3b) No large black spot in posterior part of spiny dorsal fin; dorsal fins with rows of round spots . . . . . . . sauger

4a) 15-25 vertical bands, snout extended . . . . . . . logperch

4b) no long vertical bands, snout pointed or blunt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Etheostoma, 5

5a) snout blunt, . . . . . . . . . . . . . . . . . johnny darter

5b) snout pointed, . . . . . . . . . . . . . . . . . . . . . 6

6a) Cheeks with scales; dorsal rays 9-11 . . . . . Iowa darter

6b) Cheeks scaleless; dorsal rays 12-14 . . . . rainbow darter

STICKLEBACKS

5 dorsal spines . . . . . . Brook stickleback (Culaea inconstans)

3 dorsal spines...Threespine stickleback (Gasterosteus aculeatus)

9 dorsal spines . . . Ninespine stickleback (Pungitius pungitius)

SCULPINS

1a) gill membranes separate from isthmus, dorsal fins separated, . . . . . . . . . . Deepwater sculpin (Myoxocephalus thompsoni)

1b) gill membranes connected to isthmus, dorsal fins connected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2a) lateral line complete, head spatulate . . . . . . . . . . . . . . . . . . . . . . . . . . . Spoonhead sculpin (Cottus ricei)

2b) lateral line ends under second dorsal, head broadly rounded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3a) pelvic rays usually 4, palatine teeth usually present . . . . . . . . . . . . . . . . . . . Mottled sculpin (Cottus bairdi)

3b) pelvic rays usually 3, palatine teeth usually absent . . . . . . . . . . . . . . . . . . . . Slimy sculpin (Cottus cognatus)