Answer:
付 FU , tsu(ku) - attach, belong
養 YOU, yashina(u) - rear, support, adopt
参 SAN, mai(ru) - three, visit, come
庸 YOU - mediocre, ordinary
勹+e The "Tsutsumigamae" radical - to wrap / Alphabet "E"
They all take the "fish" radical (魚 GYO, sakana, uo - fish) to become other characters.
鮒 funa - a type of carp
鱶 fuka - a type of shark
鰺 aji - horse mackerel
鱅 konoshiro - a kind of tench
鮑 awabi - abalone