2007-11-15 09:42:10 · 3 answers · asked by MJ 1 in Science & Mathematics ➔ Biology
Most species have to move to breath so the water can go in to their gills and mouth so they can take out the oxygen. Imagine trying to sleep while swimming, sharks get around that by only deeply resting so there still open to escape from potential predators like killer whales. That also effects why they can't really be kept in captivity because they need so much space to swim while they rest. So yes or else they die.
2007-11-15 22:31:57 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Otherwise they cannot breathe -- at least not most species. They have to keep moving so that fresh water is forced through their open mouths and over their gills.
2007-11-15 17:50:12 · answer #2 · answered by Randy G 7 · 0⤊ 0⤋
Well I'm only 9,so what do I know,but I DO know this:They have to keep swimming in order to FLOAT.
2007-11-15 17:45:56 · answer #3 · answered by Anonymous · 0⤊ 1⤋