Science: Shrimp in the Desert

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Bicycle Lake, near Barstow on California's Mojave Desert, is no place for canoes or water skiing. It is a shallow depression normally filled with 5,000 sq. yds. of dry, cracked mud. Once in a great while rain covers its surface with an inch or so of water, which evaporates in days. The rest of the time the "lake" is as dry as a stove lid.

Last month an unprecedented cloudburst filled Bicycle Lake to the depth of 18 inches in its deepest place. For a while the lake was a saucer of muddy water. Then, Army tank men from nearby Camp Irwin saw the water come to life, seething with millions of wiggly things. They found it swarming with four kinds of shrimp, some of which swam upside down. Others had hard, smooth shells and looked like tiny clams.

Hearing of the Miracle of Bicycle Lake, a team of zoologists from Los Angeles City and State College, led by Dr. James P. Welsh, went out to investigate. They found that the lake, which only a short time before was hard enough to serve as a playground for tanks, contained at least 4,000,000 specimens of one kind of shrimp alone. Bicycle Lake rarely holds water long enough for shrimp to grow to breeding age. One possibility: dust devils may have picked up shrimp eggs and carried them across the desert. Another guess: the shrimp may have survived, most of the time as eggs, since the period when the Mojave Desert had fairly permanent lakes.

Dr. Welsh took samples of adult shrimp back to his laboratory. He found that they were happiest in hot water (110° F.) and that they all laid eggs before they finally died. He also brought dried mud from the borders of the lake. It presumably contains shrimp eggs, and he intends to keep it dry for years, wetting samples of it from time to time to see how many of the eggs have stayed alive.