They use a internal pouch which is named swim bladder.
Explanation; Oxygen will enter a fish’s mouth, and passes through their gills. The oxygen will be taken and gets carried by hemoglobin through their bloodstream. Hemoglobin will take out some of the oxygen into their swim bladder. The amount of oxygen will show if they will sink or rise. Your question is how do they rise. If he goes up too much, the meaning of this is when the gas diffuses into their blood and out the gills.
Got this from a writing, but rephrased it.
As far as I know it should be D. A dolor flare as it may harm satellite and aircraft flying near poles
The last one...the species is unable to reproduce in any habitat beyond a population of 300 individuals
D.8 should be the correct answer
