Gymnotus choco, commonly known as the cuchillo (Spanish for "knife"), is an electric knifefish.

[1] G. choco is distinguished from its cogenerate species group by a color pattern possessing pale yellow bands oriented obliquely, wherein the interband margins are wavy or even irregular; one to three Y-shaped dark bands occur on its body's posterior section; and its pale bands do not extend above the fish's lateral line on its body's anterior two-thirds.

Its scales are circular or slightly ovoid and are present on the entire postcranial portion of its body.

Its eye position is lateral, and its premaxilla contains 13–15 teeth which are disposed in a single row along the outer margin.

It lacks a lateral ethmoid bone, while its parietal is rectangular, shorter than it is wide.

It notably counts with a single hypaxial electric organ, extending along the entire ventral margin of the fish's body.

The fish counts with about 21-22 oblique pale-yellow bands on its ventrolateral surface, extending from the tip of its tail to the pectoral fin's base.