Back in Biblical days after the great flood,God speaks to Noah.
He says "Noah, now that the ark is empty, I want you to make it bigger"
Noah replies "Your wish is my command My Lord, what do you need"?
God says "Noah, I want you to add another twenty decks to the ark and fill it with fish"
Noah says "It will be done My Lord, what fish would you like"?
God says "I want it full of Kois, Noah"
Noah replies "Why just Kois,My Lord"?
God replied "Because I want a multi-storey Carp Ark"