THE BRINE SHRIMP OF GREAT SALT LAKE. IQ 



that the lake water was so salty that no life could exist in it 

 except the brine shrimp. Gilbert suggests that the presence of 

 Artemia is no mystery for its ancestors may have lived in the 

 fresh water of the basin and have transformed with the increasing 

 saltiness of the lake. Talmage observed that the little phyllopod 

 existed in great numbers in the lake, especially between the 

 months of May and October. He states having collected them 

 in the midst of winter when the temperature was far below the 

 freezing point of fresh water, and from the evaporating ponds 

 of the salt works, where the brine was near the point of saturation. 

 He was able to keep them alive for several days in various dilu- 

 tions of lakewater, and noted that they would even live for some 

 time in distilled water. He further observed that repeated 

 washings in fresh water for five minutes removed the brine so 

 completely that salt had to be added to make them a palatable 

 food. 



The adult Artemia, Plate I., has a small head carrying a 

 single black median eye (ocellus), a pair of large stalked com- 

 pound eyes, two pairs of antennae, one pair of mandibles and a 

 pair of maxillae. The second pair of antennae of the female are 

 short and pointed, while those of the male are large and broad, 

 Plate II. The thorax bears eleven pairs of legs which are leaf- 

 like in structare and serve as swimming organs and for the 

 attachment of the respiratory organs. The abdomen is long, 

 composed of eight segments without appendages. A number of 

 bristles are to be found on the terminal segment. The ovisac 

 is roughly bottle-shaped, being rather short and broad and 

 attached to the first and second abdominal segments. 



The oesophagus is short and leads to the stomach, which 

 is situated in the head. The stomach is divided into two lobes, 

 each of which receives a duct from the liver. The liver is two- 

 lobed and lies in the head anterior to the stomach. The intestine 

 is a straight tube. The division extending through the thorax 

 is twice as large as that passing through the abdomen. The 

 intestine includes a well-marked rectum, which is provided with 

 constricting circular muscles. The ovaries are located in the 

 first and second abdominal segments ventral to the intestine. 

 The testes are located in the same relative position. The heart 



