Home Archived April 13, 2016
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Southeast Ecological Science Center


Key to Species

       1a. Dorsal fin long, with a stout, saw-toothed, spine-like ray anteriorly, followed by 13 or more branched rays (fig. 1A); anal fin also preceded by a stout, spine-like ray [Note: Spine-like rays preceded by one or a few short or rudimentary rays] ... Go to 2

       1b. Dorsal fin short, with 12 or fewer branched rays (fig. 1B); dorsal and anal fins without stout, saw-toothed spine-like ray ... Go to 4

Figure 1. Examples of nonindigenous cyprinids having (A) a long dorsal fin with 13 or more branched rays, and (B) a short dorsal fin with 12 or fewer branched rays.

Figure 1. Examples of nonindigenous cyprinids having (A) a long dorsal fin with 13
or more branched rays, and (B) a short dorsal fin with 12 or fewer branched rays.

       2a. One pair of fleshy barbels on each side of the head, located near corner of mouth on upper jaw, the anterior barbel slightly shorter (fig. 2); pharyngeal teeth molariform, in 3 rows (1,1,3-3,1,1; fig. 3A); color brassy to yellowish, with lower fins often yellow-orange; ornamental varieties may range in color from bright orange, red, black, to white or some combination of these; some genetic strains with only a few large scales (“mirror carp”) or lack scales entirely (“leather carp”). ... Common Carp (Cyprinus carpio)

Figure 2. Head of Common Carp, showing two fleshy barbels near corner of jaw.

Figure 2. Head of Common Carp,
showing two fleshy barbels near corner of jaw.

       2b. No barbels around the mouth; pharyngeal teeth in one row (0,4-4,0; fig. 3B); body relatively deep and compressed (except in some stunted forms that are relatively elongate or in certain ornamental forms exhibiting bizarre body shapes). ... Go to 3

Figure 3. Pharyngeal teeth: (A) Common Carp [1,1,3-3,1,1], and (B) Goldfish [0,4-4,0].

Figure 3. Pharyngeal teeth: (A) Common Carp [1,1,3-3,1,1], and (B) Goldfish [0,4-4,0].

     3a. Upper margin of dorsal fin straight or slightly concave (fig. 4A); caudal fin deeply emarginate; rakers on first gill arch 37-52; spine-like ray of dorsal fin deeply serrated on posterior margin with 10-11 teeth (denticles) becoming markedly larger towards tip of ray; lining of abdominal cavity (peritoneum) darkly pigmented; no dark spot at base of caudal fin; color of wild types typically olivaceous or olive bronze, but cultured varieties may be white, silver, pink, gold, brassy gold, orange, or blotched orange, black, or a combination of these colors. ... Goldfish (Carassius auratus)

       3b. Dorsal-fin margin slightly convex (fig. 4B); caudal fin slightly emarginate; rakers on first gill arch 22-33; spine-like ray of dorsal fin serrated on posterior margin, typically with 28-29 teeth (denticles) of about the same size; lining of abdominal cavity (peritoneum) light; a dark spot at the base of the caudal fin, more evident in juveniles but sometimes also present on adults; color typically coppery-gold but may be silvery-white. ... Crucian Carp (Carassius carassius)

Figure 4. Concave dorsal fin of (A) Goldfish, and convex dorsal fin of (B) Crucian Carp.

Figure 4. Concave dorsal fin of (A) Goldfish, and convex dorsal fin of (B) Crucian Carp.

       4a. Scales small, 70 or more in lateral line ... Go to 5

       4b. Scales large, fewer than 65 in lateral line ... Go to 7

       5a. A single small, thin barbel on each side of the head, on upper jaw near corner of mouth (fig. 5); belly rounded, without keel on venter; posterior margin of caudal fin straight or slightly forked; color of body variable, dark brown to black, to dark green or greenish yellow, often bronze or yellow below; one variety (“Golden Tench”) uniformly golden yellow with dark blotches. ... Tench (Tinca tinca)

       5b. No barbels around the mouth; keel present, either along entire midline of belly or posterior to pelvic fin base; caudal fin distinctly forked; body color generally gray or silver above and white or cream below. ... Go to 6

Figure 5. Head of Tench, showing single barbel near corner of jaw.

Figure 5. Head of Tench, showing
single barbel near corner of jaw.

       6a. Body color on sides generally uniformly gray or silver, without scattered irregularly shaped dark blotches; ventral keel long, extending along midline of belly from anus forward almost to junction of gill membranes (fig. 6A); rakers on first gill arch fused into a sponge-like structure (fig. 7A); when apressed, pectoral fin does not extend to base of pelvic fin. ... Silver Carp (Hypophthalmichthys molitrix)

       6b. Body color on sides gray or silver with numerous small, irregularly shaped dark blotches; ventral keel relatively short, extending from anus forward to near origin of pelvic fins (fig. 6B); rakers on first gill arch long and slender, comb-like, not fused into a sponge-like structure (fig. 7B); when apressed, pectoral fin extends beyond pelvic fin origin. ... Bighead Carp (Hypophthalmichthys nobilis)

       7a. Lateral-line scales fewer than 50 ... Go to 8

     7b. Lateral-line scales 55-63 ... Ide (Leuciscus idus)

Figure 6. Ventral keels: (A) Silver Carp, and (B) Bighead Carp.

Figure 6. Ventral keels: (A) Silver Carp, and (B) Bighead Carp.

Figure 7. Gill rakers: (A) fused, sponge-like gill rakers of Silver Carp, and (B) slender, comblike rakers of Bighead Carp. (Gill raker photographs courtesy of David Ostendorf, Missouri Department of Conservation.)

Figure 7. Gill rakers: (A) fused, sponge-like gill rakers of Silver Carp,
and (B) slender, comblike rakers of Bighead Carp. (Gill raker photographs
courtesy of David Ostendorf, Missouri Department of Conservation.)

       8a. Keel present on belly between anus and base of pelvic fins (fig. 8). ... Rudd (Scardinius erythrophthalmus)

8b. No keel on belly ... Go to 9

Figure 8. Keel of Rudd. Note: The native morphologically similar Golden Shiner has a similar keel (see fig. 49).

Figure 8. Keel of Rudd. Note: The native
morphologically similar Golden Shiner
has a similar keel (see fig. 49).

     9a. Pored scales in lateral line 35-45; origin of anal fin posterior to dorsal fin base; membranes of dorsal and anal fin of adults without red pigment; midlateral stripe on caudal peduncle absent; body cylindrical; adults often over 1 m TL ... Go to 10

       9b. Pored scales in lateral line fewer than 12; origin of anal fin beneath dorsal fin base; membranes of dorsal and anal fins of adults with red pigment; distinct midlateral stripe present on caudal peduncle; body compressed, deep; adults rarely over 11 cm TL. ... Bitterling (Rhodeus sericeus)

       10a. Pharyngeal teeth elongate, with prominent grooves or serrations on grinding surfaces, hooks sometimes present, teeth typically 2,5-4,2 (fig. 9A); body typically olivaceous or silvery-white, may be olive-brown above and silver to white below; most fins only lightly pigmented (dusky), never black; lining of body cavity (peritoneum) silvery with dark mottling, large areas may be darkly pigmented (fig. 10A); 12-16 rakers on first gill arch. ... Grass Carp (Ctenopharyngodon idella)

       10b. Pharyngeal teeth massive, molar-like, without hooks, generally smooth (not serrated or grooved), with wide masticatory surfaces, teeth typically in a single row with four or five on each side (fig. 9B), but two rows present in some individuals (in which case the outer row usually consists of a single small tooth, or very rarely two); body usually dark, often blue-gray or black, white or cream below; fins darkly pigmented, almost black; lining of body cavity (peritoneum) typically black (fig. 10B); 14-23 (usually 18-21) rakers on the first gill arch. ... Black Carp (Mylopharyngodon piceus)

Figure 9. Pharyngeal teeth: (A) Grass Carp, and (B) Black Carp.

Figure 9. Pharyngeal teeth: (A) Grass Carp, and (B) Black Carp.

Figure 10. Body cavity linings: (A) Grass Carp, and (B) Black Carp.

Figure 10. Body cavity linings: (A) Grass Carp, and (B) Black Carp.

Table of Characters
[TL, total length; cm, centimeter; m, meter]

Table of Characters - click to enlarge

Continued

Table of Characters continued - click to enlarge

Anglers fishing for Carp and Goldfish in Beijing Canal, Peoples Republic of China, 2004. (Photo by Leo G. Nico.)

Anglers fishing for Carp and Goldfish in Beijing Canal, Peoples
Republic of China, 2004. (Photo by Leo G. Nico.)


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