62 



U. S. BUREAU OF FISHERIES. 



Future work looking to an increase in the output of the pond fishes 

 must lie along the line of more intensive cultural methods. The 

 proper steps to be taken in this direction are as yet more or less 

 of an unsolved problem, but such studies as have been made would 

 indicate that the problems are subject to satisfactoiy and practical 

 solution. To the practical fish-culturist the deductions formed by 

 observation of the results obtained from a certain pond giving most 

 excellent results are sometimes seemingly contradicted by the results 

 from another pond where conditions, from the generally accepted 

 theories, are more favorable. Further investigations and studies of 

 these interesting and important problems are urged as being abso- 

 lutely essential. 



Another point in connection with the operation of the pond sta- 

 tions is to determine the most suitable and effective way to distribute 

 the output. The very young fry can not be successfully handled. 

 Even the transfer of such fry to rearing ponds usually meets with 

 a very heavy mortality. On the other hand, if they are retained 

 in the spawning ponds with the adults the first fry appearing are 

 sure to prey to a large extent on the progeny of the later spawners 

 and will themselves fall a prey to the adults. The loss of young 

 fish from cannibalism is large in an artificial pond under the best 

 of conditions. Perhaps the most suitable time to effect the trans- 

 fer to rearing ponds or to distribute the fish in them is in the ad- 

 vanced fry or No. 1 fingerling stage. At this time they are hardy 

 enough to withstand careful handling, and, being still under the 

 guardianshi|5 of the male parent, may easily be taken in a net as they 

 school along the shores of the pond. 



SUMMARY OF OUTPUT. 



The output of the stations devoted to the culture of the so-called 

 warm-water or pond fishes during the fiscal year 1921 aggregated 

 2,473,711, as opposed to a production of 1,837,598 the preceding 

 year. The seven stations included in the pond fish-cultural group 

 are given in the table below, with the figures of the aggregate out- 

 put of each for the fiscal years 1920 and 1921. The Edenton (N. C.) 

 station, though listed with the pond fish-cultural stations, also does 

 important work with the shad and glut herring, mention of which 

 is made on pages 42 and 44 in this report. 



Output of Pond Fish-Cultural Stations, Fiscal Years 1920 and 1921. 



