Identification Key to Native Freshwater Fishes of Peninsular Florida
How to Use this Key:
- Start with the first question. Decide whether the statement in the first box (1a) or the second box (1b) best describes the characteristics of the fish you are trying to identify.
- Click on the link in the row that best matches your fish. Your choice will lead you to a photo and range map for your fish or the next appropriate pair of questions.
- Work through the questions, each time choosing the characteristic that best matches your fish from the two choices. This will lead you to the final choice which identifies the fish. You can also navigate through the photos by clicking on the arrows near the left and right edges of the image.
1a) No pelvic fins; dorsal, anal, and caudal fins continuous; body snake-like in appearance | ![]() |
1b) Pelvic fins present; dorsal, anal, and caudal fins not continuous; body not snake-like in appearance | Question 2 |
2a) A gular plate present on underside of head; dorsal fin length about one-half the total length of the fish, with more than 45 rays; snout short | ![]() |
2b) No gular plate on underside of head; dorsal fins short, length always less than one-half total length and with less than 45 rays | Question 3 |
3a) Hard, armor-like scales cover an elongate body; snout very long | Question 4 |
3b) Scales do not form an armor-like covering over the body; snout moderately elongated to short | Question 5 |
5a) Snout moderately long, shaped like a duck bill; body elongate, scales very small, body feels soft and smooth; caudal fin forked | Question 6 |
5b) Snout not shaped like a duck bill | Question 7 |
7a) Both eyes located on right side of the head; body extremely flattened dorso-ventrally | ![]() |
7b) One eye on each side of head; body not flattened dorso-ventrally | Question 8 |
8a) Anus placed far forward, located between pelvic fins or closer to head, except in young; chocolate brown to gray in color | ![]() |
8b) Anus situated farther towards tail | Question 9 |
9a) Body greatly compressed laterally with keeled (often saw-edged) belly; coloration metallic silver or gold (see 10b for exception) | Question 10 |
9b) Body round in cross section, or if laterally compressed, without keeled belly | Question 12 |
10a) Last dorsal fin ray elongated, threadlike; lateral line straight; anal rays 17-35; color silvery | Question 11 |
10b) Last dorsal fin ray not elongated; lateral line strongly decurved; anal rays 13-19; adults silvery or golden with a reddish tint (juveniles silvery with a dark lateral stripe) | ![]() |
11a) Anal rays 17-25; lower jaw projecting beyond tip of snout | ![]() |
11b) Anal rays 29-35; lower jaw not projecting beyond tip of snout | ![]() |
12a) Front of head depressed, with 8 long barbels; pectoral fins with strong serrated spines; body without scales | Question 13 |
12b) Front of head not depressed, without 8 long barbels; pectoral fins lack strong, serrated spines, body scaled | Question 17 |
13a) Posterior end of adipose fin connected to caudal fin | Question 14 |
13b) Posterior end of adipose fin not connected to caudal fin | Question 15 |
14a) Dorsal, anal, and caudal fins heavily speckled; upper jaw overhangs lower jaw | ![]() |
14b) Dorsal, anal, and caudal fins not speckled, upper and lower jaws about equal in length | ![]() |
15a) Chin barbels at least partially white (no melanophores); anal rays 24-28; color generally uniform, without mottling | ![]() |
15b) Chin barbels dark (at least some sprinkling of melanophores); anal rays 18-24; color usually mottled or spotted | Question 16 |
17a) Spines absent in dorsal and anal fins | Question 18 |
17b) Spines present in dorsal and anal fins | Question 38 |
18a) Mouth upturned and protractile | Question 19 |
18b) Mouth terminal or downturned, never protractile | Question 29 |
19a) Third anal ray branched; anal fins of adult males and females rounded | Question 20 |
19b) Third anal ray unbranched; anal fin of males slender with long rays (forming a gonopodium) | Question 27 |
20a) Deep bodied: standard length less than three times maximum body depth; coloration red, white, and blue | ![]() |
20b) Less deep bodied: standard length more than three times body depth | Question 21 |
21a) An isolated, round, ocellated spot (dark spot surrounded by light ring) on caudal peduncle; body color greenish | ![]() |
21b) No isolated, round ocellated spot on caudal peduncle (may have a caudal spot connected to a lateral stripe) | Question 22 |
22a) A single broad, dark lateral stripe present along side of body, often ending in a spot on caudal peduncle | ![]() |
22b) A single broad, dark lateral stripe absent (several longitudinal streaks present in one species) | Question 23 |
23a) Scales along side of body 50 or more; 17 rays in dorsal fin; body peppered with small, black spots | ![]() |
23b) Scales along side of body less than 40; less than 14 dorsal rays | Question 24 |
24a) A dark, tear-drop marking under each eye; several longitudinal streaks or vertical bars present on side of body | ![]() |
24b) Tear-drop markings absent under eyes; body with spots or vertical bars | Question 25 |
25a) 7 pores lining inner edge of preopercle, origin of dorsal fin posterior to that of the anal fin; usually less than 12 vertical bars (in males) on side of body; gold or red spots or flecks on body | ![]() |
25b) 5 or 6 pores lining inner edge of preopercle | Question 26 |
27a) A single dark spot present on the dorsal fin (also on the anal fin of females); caudal fin clear | ![]() |
27b) Dorsal and caudal fins with numerous black flecks | Question 28 |
29a) Caudal fin rounded; a small vertical bar present at base of caudal fin | ![]() |
29b) Caudal fin forked; a spot (but no vertical bar) may be present at base of caudal fin | Question 30 |
30a) Mouth underslung with thickened, fleshy lips; 10-13 dorsal rays | ![]() |
30b) Mouth terminal, never underslung or with thickened, fleshy lips, 8-9 dorsal rays | Question 31 |
31a) Dorsal rays 9; mouth extremely oblique, situated at an angle of 35-45 degrees to the horizontal; scales along side of body thinly outlined with dark pigment to produce a cross hatch effect | ![]() |
31b) Dorsal rays 8; mouth more or less horizontal (always less than 35 degrees to horizontal); no cross hatch effect on sides | Question 32 |
32a) Anal rays usually 10 | Question 33 |
32b) Anal rays 9 or less | Question 34 |
34a) Anal rays usually 7; a small, oblong spot (continuous with the dark lateral stripe) present on caudal peduncle | ![]() |
34b) Anal rays usually 8; caudal spot variously developed or absent | Question 35 |
35a) A distinct round, dark caudal spot present on caudal peduncle and (mostly) caudal fin, not (or barely) connected to much less intense, thin lateral stripe; scales along middle and upper side of body thinly outlined by pigment giving a chained effect | ![]() |
35b) Caudal spot, if present, not round, always obviously joined to dark lateral stripe; no chained effect on sides | Question 36 |
36a) Dorsal and anal fins in adults (especially males) notably enlarged and rounded, often with heavy concentrations of black pigment in membranes; light area on snout of adults (especially males), often brilliant blue in life; horizontally oblong, intensely black spot (intensification of lateral stripe) present on caudal peduncle and caudal fin; origin of dorsal fin distinctly posterior to insertion of pelvic fins, situated at least one fourth of distance back along length of depressed pelvic fins | ![]() |
36b) Dorsal and anal fins in adults not notably enlarged and rounded; snouts of adults not blue in life; caudal spot, if present, not distinctly oblong, no intensely dark or extending onto caudal fin; origin of dorsal fin only slightly posterior to insertion of pelvic fins | Question 37 |
38a) The two dorsal fins widely separated; very elongate and slender body; dorsal surface greenish, sides silvery | ![]() |
38b) A single dorsal fin present, or two dorsal fins with a short separation | Question 39 |
39a) Two dorsal fins, with a short separation present between | Question 40 |
39b) A single dorsal fin present | Question 44 |
40a) Anal fin with three strong, graduated spines; several narrow stripes along sides | ![]() |
40b) Anal fin with two spines | Question 41 |
41a) Sides with 9 or more blotches, narrow and vertically elongate under dorsal fins; three evenly spaced dark spots at top, middle, and bottom of caudal fin base; snout sharp; midline of belly naked or with a single row of large scales | ![]() |
41b) Coloration not as above; snout more blunt than sharp; midline of belly without single row of large scales | Question 42 |
42a) “W” or “X”-shaped markings present along side of body, lateral line complete and straight | ![]() |
42b) Coloration not as shown above; lateral line sharply or moderately arched | Question 43 |
44a) Lateral line absent; adult length not exceeding 50 mm | Question 45 |
44b) Lateral line present; adult length exceeds 50 mm | Question 47 |
45a) Dorsal spines 5; dark spot on body near tip of pectoral fin; seven or more dark, vertical bars on side; males not blue in life | ![]() |
45b) Dorsal spines 3-4; no dark spot on body near tip of pectoral fin; five or less (often none) dark, vertical bars on side; males blue in life | Question 46 |
47a) Five or more anal spines | Question 48 |
47b) Three anal spines | Question 50 |
48a) Caudal fin rounded; 12 dorsal spines; four longitudinal dark stripes on head | ![]() |
48b) Caudal fin notched; 7-11 dorsal spines; longitudinal head stripes absent | Question 49 |
50a) Caudal fin rounded; a dark, vertical bar below each eye | Question 51 |
50b) Caudal fin notched; no dark, vertical bar below each eye | Question 53 |
51a) Middle dorsal fin spines noticeably longer than rear ones; front of dorsal fin dark; dark well defined, vertical bars on a gold to silver background | ![]() |
51b) Middle and rear dorsal spines about equally long; front of dorsal fin not darker than rest of fin; dark vertical bars, if present, less well defined, most often on a greenish or brownish background | Question 52 |
53a) Standard length more than three times the body depth; a deep notch between spiny and soft portions of dorsal fin | ![]() |
53b) Standard length less than three times the body depth; no deep notch between spiny and soft portions of dorsal fin | Question 54 |
54a) Mouth large, extending below the eye; color dark olive-brown with faint, darker blotches and several alternating light and dark stripes on operculum; an orange spot often present at tip of operculum | ![]() |
54b) Mouth smaller, not extending back to eye; color variable, but never as above | Question 55 |
55a) Pectoral fins long and pointed, when appressed almost reaching dorsal fin origin; if not, then a dark spot present at rear of dorsal fin | Question 56 |
55b) Pectoral fins long and pointed, when appressed falls short of dorsal fin origin; dark spot never present on rear portion of dorsal fin | Question 57 |
57a) Opercular spot with pale green margin; cheeks and belly orange with blue streaks | ![]() |
57b) Opercular spot black without orange-red margin; body spotted (black) or unspotted | Question 58 |