This study investigates the general morphology and the ultrastructure of teeth types in adults of 2 fish species (the baracouda, Sphyraena barracuda, and the Nile Tilapia, Oreochromis niloticus). Also, it investigates the relationship between teeth types in fish and its feeding habits, where tilapia is an herbivore while barracuda is a carnivore. The present work has applied the anatomy of barracuda and tilapia and analyzed the types of teeth and how they work. The teeth were investigated by binocular microscope and scanning electron microscopy to determine the shape of teeth in both barracuda and tilapia and determine the method of using these teeth in feeding. The results indicated that there is a difference between barracuda and tilapia teeth in structural morphology and type. This difference was demonstrated by virtual and microscopic examination, and this is due to the different feeding habits of both barracuda and tilapia.