AKTIFICIAL PROPAGATION OF WHITEFISH, ETC. 17 



to headwaters. On numerous occasions they have been observed 

 passing artificial or natural barriers that the native blackspotted 

 and rainbow trouts after repeated attempts have failed to surmount. 

 They prefer streams of a rather sluggish current and containing 

 deep pools, with sandy or gravel bottoms. In Montana streams 

 they usually spawn in a water temperature of 50 to 52° F. 



ARTIFICIAL PROPAGATION. 



Grayling were first artificially propagated in Michigan in 1874, 

 but the work was never vigorously or regularly prosecuted. It has 

 recently been taken up again by the Michigan fishery authorities. 

 The propagation of this species in Montana was not attempted until 

 1898, but it has been systematically conducted and has been attended 

 by strikingly good results. It is a noteworthy fact that the species 

 has been successfully established in many waters of the State where 

 it is not indigenous. In this connection Georgetown, Ronan, Rogers, 

 and Ashley Lakes are prominent examples, while more recently it 

 appears that plants of grayling made in waters of the Glacier and 

 Yellowstone National Parks are also yielding material results. 



The establishment of the grayling in these and other waters of the 

 State will perhaps serve as a balance against their depleted numbers 

 or entire disappearance in waters where they are indigenous, a condi- 

 tion that has been brought about by the improper methods of fishing 

 formerly permitted and possibly also by the introduction of other 

 nonindigenous fishes. 



At the present time artificial propagation of the grayling is prac- 

 tically confined to the work being done by the Montana Fish and 

 Game Commission, and the methods of culture herein described are 

 those pursued and recommended by that commission. The grayling 

 required for the work are captured in a modification of the ordinary 

 upstream trap, formed by placing a rack or barrier across a stream 

 the fish ascend for spawning, and installing, 2 rods or more down- 

 stream from that point, another rack containing one or more 

 V-shaped openings. The fish pass through these openings on their 

 upstream journey and are trapped between the racks. Pending the 

 development of the eggs and sperm, it has been found necessary to 

 hold the fish in an inclosure of this kind on a natural bottom, as 

 experience has demonstrated that grayling segregated as to sex or 

 ripeness in wooden pens similar to those used in salmon and trout 

 propagation invariably produce eggs of an inferior quality. 



COLLECTION AND INCUBATION OF EGGS. 



Unlike practically all other species of fish eggs artificially handled, 

 the eggs of the grayling produce better results when taken by the 

 wet method of fertilization, which consists in stripping the eggs into 

 a vessel containing a small amount of water. In the so-called dry 

 method of fertilization the eggs are expressed from the fish into a 

 receptacle that is moist but from which all water has previously been 

 drained. The manner of stripping the males and the females differs 

 in no way from that employed in the propagation of other species of 

 eggs artificially manipulated. A peculiarity of the Montana grayling 

 that has not been mentioned in connection with grayling propaga- 



