Science: Champion Laggard

Last December a lungfish from a pond in British East Africa was placed in a large tin can filled with wet mud. This creature, something like a catfish, something like a small eel, struggled through the mud to the top of the can occasionally to breathe air; but as the mud dried and hardened, the lungfish was held fast at the bottom. Six months later, the can reached its destination, a biological supply house in Chicago. The can was opened, the cylindrical mold of dried mud delicately picked away, the lungfish removed. It was alive. The fish, gaunt from its fast, made a sort of barking noise by rapidly expelling air from its lungs. When placed in a tank it soon became spry as ever.

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Lungfish are evolutionary survivors of the Devonian period (300-400 million years ago) when many forward-looking fish were experimenting with lungs. The lungfish are related to those intrepid pioneers which crawled up on land to become ancestors of reptiles, mammals and birds; also to the Coelacanths, which had fins like rudimentary limbs and which were thought by scientists to have been extinct for 50,000,000 years—until last year, when an astonishing live Coelacanth was brought up in a fishing net off the South African coast (TIME, April 3). The lungfish of today are evolutionary laggards. By coming to the surface periodically for air, they can live in stagnant, oxygen-deficient water; when the water disappears during dry spells, they can survive for long periods buried in the mud, not eating, hardly breathing. Physiologist Homer William Smith of New York University, recounting in Natural History last week the case of the canned lungfish shipped to Chicago, said that lungfish have been observed to live four years without food—the longest authentic fast known to scientists in all the animal kingdom.

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