EXPERIMENTS IN THE ARTIFICIAL REARING OF FRESH- 

 WATER MUSSELS IN TROUGHS UNDER 

 CONDITIONS OF CONTROL. 



By F. H. Reuling, 



United States Bureau of Fisheries, 



Fairport, Iowa. 



The rapid depletion of the fresh-water mussels of the streams of 

 the United States is a subject too well known to be dwelt on here. 

 Persons directly, or indirectly, concerned with this swift exhaustion 

 of a natural resource which furnishes the raw material for the 

 support of such a large and typically American industry as the 

 manufacture of fresh- water pearl buttons, are quite familiar with 

 the steps that the United States Bureau of Fisheries has taken 

 for some years past to artificially propagate these mussels on a 

 commensurably large scale. 



This work, which involves the collection of fishes on a large 

 scale, infecting them with glochidia of suitable species of mussels 

 and liberating them again in suitable waters, is described in 

 publications of the United States Bureau of Fisheries.* While this 

 work is undoubtedly effective and beneficial results are apparent, 

 the desirability of improving the work, so that definite and local 

 plants can be made with young mussels that have passed at least 

 one growing season of independent life, has been cogently realized; 

 a method of rearing young mussels in quantities under conditions 

 of control and making definite plants on particular and suitable 

 bottom areas. 



With these facts in mind and as a part of a general plan, the 

 writer was assigned the problem of rearing mussels in troughs 

 with running water, by Mr. A. F. Shira, Director of the United 

 States Fisheries Biological Station, Fairport, Iowa. The experi- 

 ments were commenced in July, 1917, and continued for three 

 summers. 



Prior to the time these trough experiments were inaugurated, 

 but few young mussels had been artificially reared under conditions 



* "The Fairport Fisheries Biological Station, etc.," by R. E. Coker, 

 U. S. Bureau of Fisheries Document No. 829, 1916. 



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