Trichomycterus maracaiboensis is a species of freshwater ray-finned fish belonging to the family Trichomycteridae, the pencil and parasitic catfishes. This catfish is endemic to Venezuela, where it occurs in the San Juan river, a tributary to the Motatán river in the Lake Maracaibo basin. This species reaches a maximum length of in the wild; in aquaria, it may grow up to TL.