It’s one thing to not eat a single subspecies of mammal when there’s so much to choose from, the Dagonians are basically every form of sea life ranging from sharks to mollusks. That’s a titanic range of food to suddenly be off limits because of evolutionary squeamishness.
Too tired to search out a proper link, but yes, monkeys and apes eat other primates.
And Ms. Fortune’s gang is called the ‘Fishbone Gang’, hence the skeleton. It’s not necessarily a food reference.
But wow, really? I honestly took the “Dislikes: Sushi” bit as more of a reference to her and her gang being chopped up rather than a distaste for fish in general. Would make sense though seeing as how all her friends aaaare a kind of fish people ha.