American Crown Conch

The shell of this species is extremely variable in terms of the degree of spiny ornamentation. Some shells are much smoother than others. These snails can be as large as about 5 in (12 cm) long, and are mostly dark brown with irregular bands of white or cream, but an overall light-color yellow form, without banding, is also known. There are small spines on the largest whorl of the smoother forms: the most spiny forms have several rows of spines. The aperture of the shell can be closed at will with an operculum.

This snail is a predator; it eats other mollusks, including scallops. M. corona is a significant scavenger and detects food using chemical stimuli. It has been recorded feeding on dead horseshoe crabs and on fish scraps. The banded tulip snail, Cinctura hunteria, is commonly eaten by M. corona. Live oysters are a component of the diet of M. corona, but it is not a major oyster predator. M. corona feeds on oysters by inserting its proboscis between the valves of the oyster shell. M. corona also feeds on the common solitary sea squirts Styela plicata and Molgula occidentalis.