Classification Key to Certain Fishes
la. Body noticeably covered with scales……………………………………..............................2
lb. Scales not covering body or too small to be seen……………………….............................12
2a. Dorsal fin single…………………………………………………………………………….3
2b. Dorsal fins two or more, joined or separated…………………………………………….....6
3a. Body more than four times as long as broad (top to bottom);front edge of dorsal fin far back on body; mouth large,hinge in back of eye ………………………………………………1
3b. Body less than four times as long as broad; front edge of dorsal finabout midway between head and tail; mouth notlarge, hinge in front of eye……………………………………………5
4a. Dark lines forming netted design on body; fins not spotted……………………...Pickerel
4b. Body covered with spots; fins spotted……………………………………...Northern pike
5a. Mouth turned downward; barbels absent; dorsal fin not elongated…………White sucker
5b. Mouth not turned downward; barbels present; dorsal fin elongated…………………Carp
6a. Two dorsal fins separated, the anterior spiny and the posterior soft………………………..7
6b. Two dorsal fins united, forming an anterior
spiny portion and a posterior soft porti…...................................................................................8
7a. Top of head concave, fanning a hump in frontof dorsal fin;
dark vertical bars on body………………...............……………………………Yellow perch
7b. Top of head not concave, body sloping to dorsal………………………….Walleyed pike
fin and not forming a hump; dark blotches on body
8a. Body more than three times as long as broad………………………………………………9
8b. Body less than three times as long as broad………………………………………………10
9a. Hinge of jaws behind the eye; notch between Largemouth black bass.. spiny and soft dorsal fin deep and nearly separating into two fins………………… Largemouth black bass
9b. Hinge of jaws below the eye; notch between spiny and soft dorsal fin not nearly separating into two fins. .………………………………………………………....Smallmouthblack bass
10a. Mouth large, hinge below or behind eye…………………………………………………11
10b. Mouth small, hinge in front of eye………………………………………………Bluegill
11a. Five to seven spines in dorsal fin; dark spots……………………………. White crappie
forming broad vertical bars on sides
11b. Ten or more spines in dorsal fin; sides flecked with dark spots……Rock bass (Redeye)
12a. Body much elongated and snakelike; dorsal, caudal, and anal fins continuous………..Eel
12b. Body not elongated and snakelike; dorsal caudal, and anal fins
separate; adipose fin present………………………………………………………………….13
13a. Barbels growing from lips and top of head; head large and broad……………………....14
13b. Barbels lacking; head not large and broad………………………………………………16
14a. Caudal fin deeply forked; head tapering…………………………………………………15
14b. Caudal fin rounded or slightly indented but not forked; head blunt……Bullhead catfish
15a. Dorsal fin rounded at top; body silvery, speckled with black markings….Channel catfish
15b. Dorsal fin long and pointed at top; body bluish-gray without speckles…….Blue catfish
16a. Caudal fin deeply forked; back not mottled and with few spots………..Atlantic salmon
16b. Caudal fin square or slightly indented; back mottled or spotted………………………...17
17a. Back and caudal fin spotted; broad horizontal band along sides…………Rainbow trout
17b. Back mottled with dark lines; caudal fin not spotted;
fins edged with white…………………………………………………………..…Brook trout