Sea stars are quit interest to watch, like paint drying, or tennis matches. Just kidding its a ocean of lovely sea stars because they are not fish at all. Nice puzzle.
I just googled "thick starfish" and I think it's a red cushion starfish. It said, "It usually has five thick, broad arms projecting from a broad cushioned disc" and comes in shades of orange, red and brown. They're so...thick!