This fish is easily recognizable by the spatula-shaped protuberance that it has at the top of its mouth. It acts as a sensory organ since it has electroreceptors that help direct plankton into the mouth. It has hundreds of gill rakers that help it filter the water and retain the plankton that serves as food. To feed, it opens its mouth wide, so that the volume of water it can filter is greater.

This fish lacks scales, and is dark gray or blackish blue in color. The tail is forked like a shark's tail. Generally, males are larger than females.
The offspring do not enjoy parental care, so upon birth, many of them die. Males become sexually mature at 7 years of age, while females do so when they reach 9 or 10 years of age.