How big is a fish stomach?

Fish stomachs vary greatly in size depending on the species. Some fish, such as the ocean sunfish, have stomachs that can hold up to 50% of their body weight in food. Other fish, such as the blacktip shark, have stomachs that can hold up to 25% of their body weight in food. On average, most fish stomachs can hold between 10-20% of their body weight in food.