422 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



transferred until they bad passed the fry or hirval stage. Of course 

 it is not practical to treat whitefish, shad, &c., the same as carp, nor to 

 rear the young in large numbers m ponds, but the adult fish could easily 

 be transferred from native to new waters. In this way I believe that 

 more than half the inland lakes and small waters of the Northern States 

 could be stocked with whitefish, lake trout, or lake herring, or perhaps 

 with all of these and other varieties. Elizabeth Lake, Oakland County, 

 was formerly well stocked with whitefish, resulting from a plant of about 

 100 adult fish upwards of thirty years ago, which were hauled to the lake 

 in casks from Lake Saint Clair by Mr. A. Whitehead, of Pontiac* 

 NoRTHViLLE, MiCH., October 31, 1885. 



133.— PliANTIIVCl U^niTEFISH AND OTHER SATMOIVOaOS Ii\ IiVI,AN» 



i.ake:$$. 



By MARTIIV METCALF. 



All the salmonoids, including the brook trout, grayling, &c., breed in 

 sheltered, rapidly-running water of low and even temperature (or the 

 equivalent of these conditions), the eggs being deposited and fertilized 

 near the head springs or at such i^oints as will secure the conditions 

 named and not subject the eggs to freezing, as a slight frosting, or even 

 a sudden change of a few degrees in temperature, is sufficient for their 

 destruction. So, also, exposure to the direct rays of the sun, or in 

 water at rest for but a short time, will destroy the eggs. 



Most of this family of fishes spawn in late autumn and early winter, 

 while only a few, such as the grayling, California mountain trout, &c., 

 cast their ova in early spring. The spawn of the last-mentioned varie- 

 ties will endure a somewhat higher temperature, but is still more sus- 

 ceptible to sudden change and less tenacious of life than the fall 

 spawners. 



It will thus be seen that the expectation of the successful natural 

 reproduction of the salmonoids in lakes having no considerable visible 

 iidet or outlet must meet with disappointment. Adult trout may sur- 

 vive for a time along with pickerel and bass, but their successful repro- 

 duction aiid the growth of the fry is impossible, as the perch, pickerel, 

 bass, and other predaceous shallow- water fish would quickly devour 

 the fry. There are whitefish in some of the deep inland lakes of Michi- 

 gan, and the species has been there beyond memory, but this is be- 

 (;ause the whitefish is a deep-water fish and thus escapes from his pred- 

 atory neighbors. 



The promiscuous planting of any kinds of fishes in all sorts of waters, 

 in Michigan as well as elsewhere, has been and must always be without 



* The Michigan llsli conimission 7th bienuial report, December 1, 1884, to December 

 1, 1886, j). 70, Hlatos that whitefish were about (exterminated tliere in 1881. 



