How to Identify Fantail Darter

To identify Fantail Darter (Etheostoma flabellare), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Generally olive to brownish-yellow dorsally, fading to a lighter ventral surface. Sides often have 8-12 dark, vertical bars or blotches. Males in breeding condition develop striking dark bands on their fins, particularly the dorsal and caudal fins, and their bodies become darker, sometimes almost black, with iridescent blue or green flecks.

Scale type

ctenoid

Mouth position

subterminal

Distinctive features

First dorsal fin with 7-10 spines, often with fleshy knobs on the tips of the spines in breeding males., Second dorsal fin with 11-14 soft rays., Caudal fin rounded or slightly emarginate, often with dark bands., Lateral line incomplete, typically with 35-50 scales., Snout blunt, mouth subterminal.

Dorsal fin

Two dorsal fins; the first spiny, the second soft-rayed. Breeding males develop distinctive fleshy knobs on the tips of the first dorsal fin spines.

Tail fin

Rounded to slightly emarginate, often with dark vertical bands, especially prominent in breeding males during fanning displays.

Pectoral fin

Large and fan-like, used for propulsion and maintaining position on the substrate.

Distinctive fins

The fleshy knobs on the first dorsal fin spines of breeding males are a key diagnostic feature. The fanning behavior of the caudal fin during courtship is also highly characteristic.

Identification Tips

1. 1

   Body Shape and Size

   Small, slender, and elongated fish, typically 5-8 cm (2-3 inches) in length, rarely exceeding 10 cm (4 inches).

2. 2

   Coloration and Markings

   Olive to brownish-yellow with 8-12 dark vertical bars on the sides. Breeding males are much darker, often nearly black, with iridescent blue or green highlights and prominent dark bands on fins.

3. 3

   Dorsal Fin Spines

   Look for the fleshy, bulbous knobs on the tips of the first dorsal fin spines, especially in breeding males. This is a definitive characteristic.

4. 4

   Caudal Fin

   The caudal fin is rounded or slightly emarginate and often displays dark banding, particularly during breeding.

5. 5

   Lateral Line

   The lateral line is incomplete, ending before the caudal fin.

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