How can a big fish eats a small fish, without worrying about the fishbones of the small fish? How does a big?

Question

fish digest the fish bones of the small fish?

Answer 1

more than likely it either does 1 of 2 things: eats it like an owl and regurgitates the bones or the stomach/digestinal track of the large fish can either break the bones down with the right kind of acids or the bones will not penetrate the lining of the stomach or intestinal track.

Answer 2

Fish teeth can bite right through fish bones. A baracuda, for example, has been observed to nip off a smaller baracuda hooked by a fisherman, without giving the line a tug in the process.

Some fish swallow their prey whole.

Bones are easily digestible, being calcium and phosphorus and protein.