ARTIFICIAL PROPAGATION OF BROOK TROUT AND RAINBOW 

 TROUT, WITH NOTES ON THREE OTHER SPECIES.^ 



Revised and enlarged by Glen C. Leach, Assistant in Charge of Fish Culture. 



CONTENTS. 



rage. 



Brook trout 2 



Description 2 



Size 5 



Food 6 



Commercial importance 6 



Range and spawning season 7 



Character of the eggs 9 



Propagation 9 



Water supply 9 



The hatcliery site 11 



Dams 12 



Water-supply intake 13 



Capacity of water pipes 14 



Aeration 16 



Hatchery equipment 17 



Field operations 1 IS 



Traps 19 



Taking the spawn 20 



I'acking the eggs for shipment 23 



Transportation of green eggs 25 



Incubation of the eggs 26 



Care of the fry 27 



Planting the fry 27 



Rearing and feeding 28 



Distribution of fingerlings 30 



Eggs from commercial hatcheries 30 



Rainbow trout 31 



Desciiption 33 



Range and variation 33 



Transplanting 33 



Size and growth 34 



Propagation 35 



Water supply 35 



Spawning ponds 37 



Taking the spawn 39 



Production of eggs 43 



Hatching troughs and trays 43 



Care of eggs and fry 47 



Rearing ponds 49 



Stocking the riffle pond 49 



Food 50 



Preparing eggs for shipment 52 



Packing eggs for shipment 52 



Distributing and planting fry and fingerlings 54 



1 .Vppendix VI to the Report of the U. S. Commissioner of Fisheries for 1923. B. F. Doc. 

 No. 955. This document represents a revision and enlargement of the chapters on "The 

 brook ti-out," " The rainbow trout," and " Minor, tronts " from A Manual of Fish Culture, 

 Based on the Methods of the United States Commission of Fish and Fisheries, with 

 Chapters on the Cultivation of Oys.ters and Frogs, revised edition, published in 1900. 



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