This fish survives years-long droughts buried in dried mud

When its swamp dries up, the African lungfish burrows into the mud, secretes a mucus cocoon around itself, and drops its metabolism to a fraction of normal — breathing air through a small hole via a lung instead of gills. It can stay like this, in a state called estivation, for a year or more until rain refills the swamp and it digs itself out. It's one of the clearest living links to the fish that first crawled onto land.

— John R. Paxton and William N. Eschmeyer (eds.), Encyclopedia of Fishes — 2nd edition, entry on lungfishes (1998)
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