There are some words with similar structure: 1. 발끝 toe - 발 is "foot" and 끝 means "end" 2. 손목 wrist - 손 "hand" and 목 "neck" translates directly "the neck of hand"
Actually, raw fish is hwea. 희를 먹고 있읍니다. I'm not sure about eating an alive fish though.
To my knowledge, it's any kind of form, but not squids, octopi, and eels. There are more like sharks, and seaweed. By the way, in Korea, if it's someone's birthday, you cook seaweed soup, and the family eats it.