The Salt Lake Fairy Shrimp

THE SALT LAKE FAIRY SHRIMP By Harold L. Snow Were you ever bitten by a shrimp while taking a dip in Great Salt Lake? Probably not, because the brine shrimp, or fairy shrimp, as it is commonly called, being known to the scientists as Artemia gracilis, is so small and insignificant, as well as being absolutely harm- less, that it is usually not perceived by people who bathe in the salty water. Very little attention has been paid the fairy shrimp in the past, and descriptions of the creature, as well as reference to it, are so scarce that it has become the general opinion of the public that Utah's Left: Fairy shrimp; front and side views, (actual size from about one-third to one-half inch in length.) Right: Close up view of fairy shrimp, showing antennae, central eye and pair of compound eyes. salt sea is absolutely devoid of any form of animal life whatsoever. The absence of much literature on the subject is probably due to the fact that the fairy shrimp not only is of but little interest to those who attend the lake resorts to float on the surface of the dense salt water, but also because the creature at present is neither of any great significance as a benefit nor as a detriment to human society. In certain parts of the lake not far from the shore one can catch hundreds of salt water animals in one double handful of the brine. They swim about in the water, first in one direction and then in the other, as if they were making a violent attempt to escape. But when observed from the surface of the lake they may be seen to move about in quite the same manner right in their native habitat. Observed more closely, the fairy shrimp is seen to be from about one-third to one-half an inch in length, the male being somewhat

540 IMPROVEMENT ERA larger than the female. Many of them are colored most beautifully. Some are of a light brown or almost a yellow color, while others are bright red, orange, green, brown or even a mixture of these colors. Eleven pairs of legs, co-ordinating in a wave-like movement along a horizontal plane, propel the shrimp through the brine with a gliding motion. The delicate and slender legs and body of the creature moving so gracefully through the water may be considered ample justification for man's christening it the fairy shrimp. A large pair of claspers resembling to some extent those of a crab or lobster, are seen in the male form, whereas the opposite sex has in their stead a small second pair of antennae. A small black spot right at the top of the head may be seen easily with a low power microscope. This is a centrally placed eye. In addition to this, the fairy shrimp has a pair of compound eyes. They are relatively large and easily arrest the attention of the naked eye. Under the direction of Dr. Newton Miller, now professor of microscopic anatomy at the University of Utah, a special study of the brine shrimp was made by Albert C. Jensen in 1917, while taking out his master's degree in zoology. In describing the shrimp Mr. Jensen states that the stomach is situated in the head of the animal. Each of two lobes of the stomach receives a duct from the liver, which also lies in the head, even higher in its position than the stomach, he states. The brine shrimp's heart is in the form of a long tube extending nearly the entire length of the body. Blood is thought to enter the tubular heart through a series of valves in its sides, and to be pumped out at the two ends. Cases have been observed where the little round black eggs of the fairy shrimp laid by isolated females, have developed into mature animals without fertilization from the opposite sex, showing that the species may also reproduce partheno- genetically. However, in these cases most of the eggs developed into females. The brine shrimp is a vegetarian. Perhaps it was originally forced to this sort of diet by the absence of sufficient other small forms of animal life on which to "make out a meal." Great abundance of a certain alga exists in the water near the shores of Great Salt Lake. On this plant it is that the shrimp feeds. Some believe the alga to be the only food in the lake, on which the animal can live. At any rate the abundance of the alga near the shore helps to account for the presence of myriads of fairy shrimps in the same locality. In earlier times Indians are said to have caught large quantities of the brine shrimps for their food. First they washed them with fresh water to reduce their saltiness, it is said, and then the shrimps were dried much the same as the Indians used to dry berries and other foods for the winter's use. The fact that these shrimps are quite a palatable delicacy has been confirmed by Dr. James E. Talmage, who states that he has collected enough of the shrimps to

THE SALT LAKE FAIRY SHRIMP 541 wash, cook, season and eat, and he describes them as being "actually delicious." As far back as the time of Captain Bonneville, nearly a century ago, mention was made of what in all probability was the fairy shrimp in Great Salt Lake. Later, Fremont wrote of life in the salt water lake, and then in 1869 the fairy shrimp was given its scientific name, Artemia gracilis, by Verrill. Dr. Siebold of Munich studied this animal in 1876, and since that time a number of Americans have written on the subject, among whom were A. S. Packard, Jr., David Starr Jordan, Grove Carl Gilbert, James E. Talmage and Albert C. Jensen. The question as to how the fairy shrimp came to live in such a salty habitat is one of interest to the observer. Many years ago the shores of Great Salt Lake were as high as the present levels of the old Lake Bonneville, which are to be seen marking the foot hills around the Great Basin. At that time the lake had an outlet through rivers running into the Pacific Ocean. Constant drainage prevented the lake from becoming so salty as was its fate at a later period when outlets from the lake, other than through evaporation, were stopped off. So the salt which is now deposited in the lake, was at that time carried into the sea. Thus the ancient ancestor of Artemia gracilis must have lived at its time in practically fresh water. This assumption is confirmed by the fact that the present-day fairy shrimp can live in water with a wide variation from the exact concentration of salt which is found in the lake. This fact has been demonstrated repeatedly by different investigators. The lake is so salty that but little, if any, life other than the hardy little fairy shrimp can live in it. Thus the creature has practically no enemies, and for this reason, it is thought, the shrimp exists in the Great Salt Lake in such abundance as it does. Now the question may arise as to just what industrial value these edible salt-water shrimps might have. At the present time they are abundant enough, but their small size and the difficulty' of catch- ing and cleaning or isolating them from other substances in the lake, seem to be the principal obstacles. If a Burbank would only appear and develop a shrimp of even twice or three times the size of the largest shrimp now found in the lake, Salt Lake City might become the center of a new industry, and summer tourists who visit the lake might not entirely disregard Artemia gracilis while enjoying a float on the waters of Great Salt Lake. Salt Lake City, Utah