The body is dark blue. Along the back are white to turquoise splotches. Usually starting near the upper lip, while others run along the top of the back. From the eye back through the caudal fin is a similar bar. The other fins are dark blue. Females are similar in coloration, but are smaller and don't have the egg-spots that males have. Depending on location and conditions, M. vermivorus eats loose algae, filamentous algae, benthic invertebrates, zooplankton, and phytoplankton. Because of his highly aggressive behavior, especially with male fish, it is recommended to provide at least one retreat for each fish. Keep one male with several females.