Page "Gill" Paragraph 18

Tadpoles of amphibians have from three to five gill slits that don't contain actual gills.

There is usually no spiracle or true operculum, though many species have an operculum-like structure.

Instead of internal gills, they develop three feathery external gills that grow from the outer surface of the gill arches.

Sometimes adults retain these, but they usually disappear at metamorphosis.

Lungfish larvae also have external gills, as does the primitive ray-finned fish Polypterus, though the latter has a structure different than amphibians.