“Pescetarianism is the practice of adhering to a diet that incorporates seafood as the only source of meat in an otherwise vegetarian diet. Most pescetarians are ovo-lacto vegetarians who eat seafood along with dairy products and eggs.”
“A common reason for adoption of pescetarianism is perceived health, such as fish consumption increasing intake of omega-3 fatty acids which are associated with reduced risk of cerebrovascular disease. Fish and plant food consumption are parts of the Mediterranean diet which is associated with lowered risk of cardiovascular diseases. In one review, pescetarians had relatively low all-cause mortality among dietary groups.” (Wikipedia)