Both sexes seem to have a white band on the anterior surface of the snout. This white band could be considered a feeding behavioral characteristic, because it is so contrasted by the dark coloration of the snout and upper jaw, and becomes very prominent when the upper jaw is protruded. Probably under low light this white band may be more visible. This band might also be related to recognition of other individuals of the same species. The megamouth has approximately fifty rows of very small and relatively numerous teeth on each jaw, but only three rows are functional.
Females seem to present fewer teeth rows than males.
A difference between the upper and lower teeth was recognized on a female specimen. There are many pigment cells on the dorsal side, but none on the ventral side. Behavior Only two observations of megamouth provide information about this species behavior. The male specimen, with 494cm in total length, was tagged and tracked for two days. One of the conclusions of these observations is that megamouth is probably a vertical migrator on a diel cycle spending the daytime in deep waters and ascending to midwater depths at night.