ARTIFICIAL PROPAGATION OF WHITEFISH, GRAYLING, AND 



LAKE TROUT/ 



By Glen C. Leach, Assistant in Charge of Fish Culture. 



CONTENTS. 



rage. 



The whiteflsh 1 



Range 1 



Description 1 



Common names 8 



Habits 3 



Commercial value 3 



Spawning habits 4 



Destnu'tion of wbitefisli spawn in 



nature 4 



Artificial propagation 4 



Collection and incubation of 



eggs 5 



Penning wild fish 7 



Hatching methods and equip- 

 ment 8 



Care and planting of fry 12 



Rearing in ponds 13 



The graylings 14 



Range 14 



Description 14 



Size IB 



Spawning habits 16 



Page. 

 The graylings — Continued. 



Artificial propagation 17 



Collection and incubation of 



eggs 17 



Fry and their distribution 18 



The lake or Mackinaw trout 18 



Range 18 



Description 20 



Influence of environment 20 



Food 20 



Enemies 21 



Commercial value and abundance- 21 



Spawning habits 22 



Artificial propagation 22 



Collection and incubation of 



eggs 22 



Shipping eggs to the hatchery . 23 



Mortality of lake-trout eggs 25 



Hatchery equipment 26 



Care of eggs and fry 27 



Distribution of fry 29 



Packing eyed eggs for shipment- 30 



Feeding and rearing 31 



THE WHITEFISH. 



RANGE. 



The common whitefish {Coregonus clupeaformis) is eminently a 

 lake fish. It exists throughout the Great Lakes region and is espe- 

 cially abundant in Lakes Erie, Huron, Michigan, and Superior. The 

 eastern limit of its range is Lake Champlain, and it is found in Lake 

 Winnipeg, and possibly farther west. It is landlocked in Otsego 

 Lake, N. Y. Efforts to introduce it into new waters in the States of 

 the Pacific coast have not been successful. It has been established in 

 Flathead Lake, Mont., Lake Coeur d'Alene, Idaho, and possibly 

 other waters in the Kocky Mountains. 



DESCRIPTION. 



Tlie body of the common whitefish is rather long and compressed, 

 and the back, especially in adults, is arched in front; the greatest 

 depth is about one-fourth the body length. The head is small and 



> Appendix III to the Report of the U. S. Commissioner of Fisheries ,for 1923. B. F. 

 Doc. No. 949. This document represents a revision and enlargement of the chapters on 

 "The Whitefish," "The Graylings," and "The Lake or Mackinaw Trout" from A Manual 

 of Fish-Culture, Based on the Methods of the I'nited States Commission of Fieh and 

 Fisheries, with Chapters on the Cultivation of Oysters and Frogs, revised edition, pub- 

 lished in 1900. 



