selfish, shellfish

Selfish or selfish means interested only in one's own wants and needs, and not interested in what others may want or need--
She is too selfish; she never wants to do what the rest of us want to do.
They are both selfish and inconsiderate; they argue a lot.

Shellfish or shellfish ( almost rhymes with selfish ) means a fish commonly eaten, with a shell, such as crab, shrimp, or lobster--
Muslims and Jews do not eat pork or shellfish.
He enjoys all kinds of shellfish, so we are going to a lobster festival.

Now that you know that, you can say--
"Don't be selfish; share your shellfish."

Note--"sell fish" ( two words ) means to exchange fish for money--
Does this store sell fish, or just meat?