Anhinga dive to catch fish, then swallow them head first. Almost any reasonably sized fish will do.
And based on how wide she opened her mouth here I can see how those big fish disappear.
A few moments ago I returned from photographing some Anhinga catching fish in a marsh. With luck there should be a few new examples of just how they deal with large fish.
It’s amazing to see this bird with a mouth open this much.
Never dull out there.