What fish breathing structure is part of an alligator?

Alligators possess a structure known as a "palatal valve," which is part of their respiratory system. While alligators are reptiles and primarily breathe air through lungs, the palatal valve allows them to keep their mouths closed while submerged, preventing water from entering their lungs. Additionally, it helps them to hold prey underwater without drowning. Unlike fish gills, alligator respiration is adapted for a semi-aquatic lifestyle.