A frican lungfish (Protopterus spp.) live in water for part of each year.During yearly dry seasons, though, they dig into mud, curl up, and secrete staggering amounts of mucus that then hardens to ...

the bichir is especially adapted to life in dry environments. Instead of a regular swim bladder it has a pair of modified "lungs," like those of the lungfish, which enable it to survive out of ...