Fish Culture in Inland Waters 2S5 



These facts have been long- recognized by those who have given 

 the matter of fish culture any intelhgent thought. But it is remark- 

 able how little attention has been given to the food of fishes. In a 

 general way the food of the adults of the commoner species is fairly 

 well known, but very little is definitely known concerning the food 

 of the young of many even common forms. Over forty years ago, 

 a " pioneer fish culturist," Seth Green, said that one of the principal 

 precautions to be regarded in stocking streams was not to put in 

 too many fish, and that the food supply of the fish must be con- 

 sidered. Again, one year later, he stated that the secret of success- 

 ful stocking of waters with fish was in putting the right kinds in 

 waters suited to them. These facts are now as emphatically true as 

 they were so many years ago, although they have always been more 

 or less disregarded. It is not such a simple thing as it might seem 

 to determine to what species of fish a given body of water is best 

 suited, but in a general way, certain conditions being known, it may 

 be inferred that the water will or will not support certain kinds of 

 fishes. However, in fish cultural practices of the past, such infer- 

 ences have been based largely upon conditions pertaining to adult 

 fish, and little or no attention was given to the matter of food supply 

 of young fish after they left the hatcheries, and even today too 

 little consideration is given that point in stocking and restocking 

 natural waters. For years there has been much discussion concern- 

 ing places in which to plant, the season in which fish should be 

 planted, and the food of young fish in the hatcheries. 



It seems to have been assumed that the young fish could find its 

 natural food abundant anywhere at one or another season of the 

 year, but until comparatively recently no investigation was made 

 to ascertain what constituted the natural food for various ages of 

 the dififerent species, or whether suitable natural food at any time 

 was sufficiently abundant to supply the nvmiber of fish planted. The 

 number planted often depended upon the amount of stock on hand 

 and the " pull " of the applicant. 



It has been generally assumed that youngest stages of most 

 carnivorous fishes subsist upon the minute organisms, such as water 

 fleas, etc. This assumption is based upon observation of a few 

 species only. It is now known that the food of some species 

 consists of such minute life. A few scientists have made a specialty 

 of the qualitative and quantitative study of the lakes and ponds of 

 various localities. 



Although much data pertaining to these subjects have been 

 accumulated and published, usually in technical form, with few 

 exceptions they have been correlated with the habits of young fishes 

 only in a very general way. This fact is due to the lack of trained 

 investigators able to devote themselves to such work. Those who 

 have contributed to the knowledge in this direction have usually 

 been college professors and students who have done so with little 

 or no pecuniary remuneration. 



Plantings. The foregoing pertains to planting fish in waters 



