How would being able to bring in to the gills when the mouth is closed benefit a bottom dwelling shark or ray?

Answer 1

Being able to bring water in through the gills while the mouth is closed allows bottom-dwelling sharks or rays to efficiently extract oxygen from the water without needing to open their mouths, which can be advantageous in their habitat. This adaptation helps them avoid sediment disturbance when feeding or resting on the ocean floor and allows for a more energy-efficient breathing process. Additionally, it enables them to remain stealthy and undisturbed by potential predators or prey while still ensuring adequate oxygen intake.