Nurse shark resting on sandy ocean floor moving it's gills to absorb oxygen

nurse shark elasmobranch fish shark sharks ginglymostoma cirratum ginglymostomatidae threatened species vulnerable night dive night diving noctural night feeder night reef fish fishes maldives indian ocean pacific ocean atlantic ocean underwater under sea tropical diving tropical ocean aquatic aquatic animal undersea ocean life reef life sea life marine animal marine creature marine species breathing gills