What fish carries its young in a pouch like a kangaroo?

Yes. Almost all (but not quite all) marsupials carry their young in a pouch, and most of these are pouches on their abdomen, like the kangaroo has. All members of the kangaroo family hop upright, carrying their joeys in their abdominal pouch. These animals include wallabies, wallaroos, potoroos, bettongs and rat-kangaroos.