Hi,want to ask another silly question..why does that a shark or a ray have five gill slits and other fish,both actinopterygii kind or sarcopterygii only have one gill slits,or to be exact only one operculum?is there any advantage of having many gill slits?thanks and sorry if the scientific jargon are mispelled

Hi Evan,
As you suggested, bony fishes do have multiple gill slits, but they are covered by an operculum. So your real question is "why did the elasmobranchs (sharks and rays) lose their operculum". I'm not sure if anyone knows the real answer, but it could have something to do with the transition from a bony skeleton to a cartilaginous skeleton. Perhaps an operculum made of flexible cartilage just would not be as effective as one made of rigid bone. Another possibility is that the operculum had to be lost in elasmobranchs because of their unique jaw structure. I'll admit that I'm not a fish expert, so someone else with more knowledge might have some better ideas.