The diet of Cymbium glans, was studied from January 2016 to January 2018. This study was made from the stomach collected monthly on the gastropod from the industrial and artisanal marine fisheries of the EEZ. All the stomach contained prey. The vacancy coefficient (Cv) is zero. The methods of corrected occurrence frequency, numerical frequency and specific abundance were used to analyze the importance of different prey. The analyzes indicate that the Cymbium glans feeds on phytoplankton mainly diatoms (38, 2%). Zooplankton (crustacean) occupies 4%. The proportion of zooplankton increases with the size of the individual. In addition, the diet does not change, according to the marine seasons, nor according to the size of the individuals landed.