Mermaids are mythical creatures that are said to live in water, so their mythical diet likely consists of seafood. Lobster, fish, crabs, shrimp, oysters and clams are protein sources.
Seaweed may be another food they would eat. Because mermaids live in the water, they are often depicted dwelling in caves or mythical sunken castles. Their food choices are probably determined by the sea life native to their living area, although many authors who write about mermaids never reveal what they eat.
These half-human and half-fish creatures are thought to be dark entities who enjoy being deceitful; however, some people think they are innocent and fun loving. Mermaids are mystical beings, so each person can use their imagination to determine what mermaids eat and how they live.