Never heard of bigeye shiners -- cute fish! I guess the first thing to do would be to 1) make sure that a 20 gal would house it long-term and then figure out its habitat and compatability and see if you can find fish that go with it. Also is it a shoaling fish?
Bigeye Shiner in Alabama
"Bigeye Shiner
Notropis boops Gilbert (Plate 12)
Description: Large eye. High, sharply pointed dorsal fin. Dark band
around snout, from eye to eye, crossing lips. Dusky streak along
middle of sides, ending in small spot at base of tail fin. Scales on
back large and sharply outlined, no streak along midline of back.
No bright breeding colors. Anal fin with eight rays.
Size: The Bigeye Shiner grows to a length of 9 cm (33^ inches).
Habitat: In Kansas, this fish is
common in the Spring River sys-
tem in Cherokee County, and in
the Verdigris and Caney rivers in
the southern Flint Hills. It is ab-
sent from the Neosho. The Big-
eye Shiner prefers clear upland
streams with high gradients and rocky bottoms.
Reproduction: This species spawns from June through August at water
temperatures of 26°C (80°F) or higher.
Food: The Bigeye Shiner eats small insects. "
From:
Full text of "Fishes in Kansas"