David King, age 11, of Oak Hill, W. Va., for his question:
WHAT IS AN ARTEMIA?
The artemia is at home in salty or extra salty water, which may be cool, warm or boiling hot. He looks like a busy little whisk broom about as big as your fingernail. Though a saltwater creature, he is not found in the sea. And he can survive such a wide range of hardships that surely he deserves an award for endurance.
His more common name is the brine shrimp, and he can live in super salty water where no other creatures can survive. Though he’s only half an inch long, his cousins include the leggy lobsters and the crusty crabs. Artemia, the brine shrimp, looks like a glassy whiskbroom—with a pair of turreted eyes on his head. You may not notice, but there is a third eye in the middle of his forehead.His body is a long skinny streak.
His brushes are nine pairs of whiskery legs, attached to his upper half and spreading like fluffy fans on either side. When trawling for food, he swims on his back catching floating morsels in his whiskers and sweeping them up into his mouth.
In most cases, the brine shrimp can survive in sea water and sometimes in almost fresh water. But he prefers water that is saltier than the sea, perhaps because predators cannot survive there. We find,him in saltwater springs and ponds and in drying lakes that become saltier than the sea. Brine shrimp are very much at home in the extra salty water"of Utah's Great Salt Lake. Some types survive in water that is 10 times saltier than the sea.
Some brine shrimp are quite at home in salt springs where the steaming water reaches boiling point. And their eggs can survive even tougher conditions. In most cases the parents mate, but certain females produce fertile eggs without mating. Usually the female carries the eggs and young larva in a pouch on her body, releasing them when conditions are favorable.
The tiny eggs are encased in super tough shells, which enable them to survive through many years of drought. Lab experiments have proved that brine shrimp eggs can be totally dried out in a hot vacuum. When cooled and returned to salt water, they hatch. A few will survive after being boiled for a couple of hours.
Artemia, the brine shrimp, may look like a whispy feather from fairyland, but actually he is one of the most durable creatures on earth. Usually, wherever he lives he thrives in multitudes safe from predators who cannot abide his saltwater home. Billions of brine shrimp are gathered to feed aquarium fishes. Their eggs are sold in packages, hatched in salt water and used to feed more fishes.