Fish Culture in Inland Waters 283 



From the foregoing it is seen that the poHcy of the Commission 

 as well as views of individuals vary from time to time. It is the 

 failure of nature to maintain the supply of fish demanded today, 

 which has given rise to the question of how best to meet the 

 demand, and the difference of opinion concerning at what age the 

 young fish can best be planted. The character of the habitats or 

 places where the different stages of young fish live, as well as of 

 adults, varies with the species of fish as do their habits in relation 

 to the conditions under which they live. Nature selected the habitats 

 and they are naturally the best possible places and conditions, else 

 the species would not have survived. 



The life histories and natural habitats of some kinds of fish are 

 so well known that it is comparatively easy to decide at what age, 

 when, where and how they should be planted. But there are 

 others concerning which little or nothing is known in the direction 

 mentioned. In the latter case it is obvious that results will always 

 be uncertain until the unknown facts are learned. As remarked 

 elsewhere it is a waste of time, money and good fish to plant any 

 kinds before they have attained an age concerning the needs of 

 which there is definite knowledge. 



Aside from the question of economy in raising and transporting 

 young fish, the character of the locality to be stocked and what is 

 known concerning the life history of the fish to be planted become 

 determining factors in deciding the best age at which to plant the 

 fish. Other things being equal, the food and feeding habits of 

 young fish are of first importance. In a general way the natural 

 food of adults of the common species is known, but upon what 

 some of the same fish subsist in the earliest periods of their lives is 

 not definitely known. Although this is so, as concerns waters 

 naturally inhabited by a given species, or waters in which it has 

 become permanently established, the food for all ages of that 

 species must be present in the habitats of the fish at the respective 

 ages, or else the fish would not occur or have been established there. 

 Therefore, if the habitat of fry is known and the habitats of the 

 older young fish are unknown the logical age to plant the fish is as 

 fry, other things being favorable. So with the older fish. 



In the case of fry, if it is necessary to plant fry and the natural 

 spawning places of the species are known, it is a justifiable assump- 

 tion that, other things being equal, the best places for planting them 

 will be on those spawning places, for there is where nature plants 

 fry. If it is known that fingerlings naturally occur in certain 

 shallow water localities, or in deep water, or at the surface at a 

 distance from the shore, those would appear to be the natural places 

 in which to plant the fingerlings. Again the same may be said of 

 older fish. 



The object of planting the fish is to supplement the native supply 

 or make up for a deficiency in natural production. In this connec- 

 tion it should be borne in mind that from the time, at whatever age, 

 the fish is planted, nature takes her course, and the only advantage 

 attainable lies in the greater number reaching maturity than would 



