Mexican Goatfish

M. dentatus has a small mouth, which can be protruded. Its villiform teeth are also small, and it does not have teeth on the roof of its mouth. The snout is dull and its chin contains two sizeable barbels. Between its dorsal fins, it has six rows of scales. It is yellow throughout, except for its two blue stripes which run horizontally. Its maximum size is 40 cm (16 in). It is similar to Mulloidichthys vanicolensis, but M. dentatus has shorter pectoral fins and barbels, and lesser gill rakers and pectoral fin rays.

M. dentatus is found in the Central-Eastern Pacific Ocean, from southern California to Peru. Its range includes the Galápagos Islands and is rare north of the Baja California peninsula. It is found at depths between 2–110 m (6.6–360.9 ft). It mainly sticks to the coast and coral reefs, living in the sandy, muddy, and rocky bottoms near the shore. Despite this, its young are more fond of the open ocean. It can be found solitary, although it prefers to be in small schools. At night it can change its color to have red patches.