What is the controbution of the Plentimaws to the development in the story? What does that indicate to the nature of the story ?

In Chapter Five, a group of Angel Fish comes to the surface. They are “as big as sharks” with “literally dozens of mouths.” Butt tells Haroun that these are Plentimaw Fishes (named because “they have plenty of maws, i.e., mouths”). These fish are always in pairs with their faithful partners for life. They look very sick because of the pollution. The fish swallow the stories in the sea and then miracles occur in their innards; “a little bit of one story joins on to an idea from another...when they spew the stories out they are not old tales but new ones.” Iff tells Haroun, “No story comes from nowhere; new stories are born from old--it is the new combinations that make them new.”