In parts of Central Africa, a remarkable and unusual fishing technique is employed to catch a fish known as the lungfish (Protopterus). This fish possesses an extraordinary survival mechanism: during the dry season, when waterways often vanish, the lungfish buries itself deep into the mud and secretes a layer of mucus that hardens into a protective cocoon. In this state, it can survive out of water for months, or even years, by breathing air through a small mud plug, effectively entering a state of estivation, similar to hibernation. This survival strategy makes traditional net or line fishing impossible during the arid periods.

​To catch these subterranean sleepers, local fishermen resort to using spades or large digging tools. They locate the hardened mud “cocoon” of the lungfish—sometimes indicated by faint air holes or simply from knowledge of previous fishing spots—and carefully excavate the fish from its muddy crypt. The dug-up lungfish is still alive, but essentially dormant and immobile. Rather than preparing the catch immediately, fishermen often bury the fish near their homes, allowing them to keep it alive and fresh underground until they are ready to cook it, making the spade an essential tool for harvesting this unique and resilient protein source.