6 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



had been reduced to 528 by fish of prey, thieves, and other causes, but 

 had increased in weight, the total number of 90,000 beautiful young 

 carp had originated in this time. There was, of course, not a single 

 pike in the pond, and nothing whatever was brought up in the nets 

 with the fish but a number of frogs, water-beetles, and sticklebacks. 

 These three last mentioned are notorious enemies of the roe of the car]), 

 and we were destined to learn on the following day how dangerous they 

 may become to the roe. 



Wonderfully rich as was the result from the Maxa-pond, it was 

 hardly the original intention that it should be so, for all these 90,000 

 young carp had come into life contrary to regulations and owed their 

 existence to a mere accident. It had by no means been the intention 

 that the 570 large carp should spawn in this pond, but they were 

 intended to grow up into large food-carp. For the simple reason that 

 they were not yet supposed to be ready for spawning, no pike had been 

 placed in the pond with them, and about a dozen of the carp which 

 were fully prepared for spawning had made good use of this circum- 

 stance, and had done their utmost to stock the pond with young fish. 

 If the pond had been intended for a spawning pond, twelve spawuers 

 and six milters would have been sufficient for a pond of two hectares. 

 This number had been placed in the large '' Daehsberger" pond, which, 

 on the second day of our visit, was subjected to the same process of 

 fishing as the Maxa-pond. We were now destined to witness the injuri- 

 ous influence of other enemies of the carp than the pike. The young 

 cai]> in this pond were on an average six times as heavy as those cap- 

 tured on the previous day, and the total yield was twice as large as 

 that of the Maxa-pond. The increase in the size of the eighteen carp 

 originally placed in the pond was also much greater than that of the 

 carp placed in the Maxa-pond ; but the total number of fish captured 

 fell below the expectation. Even during the first haul we were struck 

 with the unusually large number of sticklebacks which were brought 

 up with the carp. Large numbers of these dangerous fellows were boldly 

 pushing their way in the tubs among the pretty golden -yellow young 

 carps, in some cases, it is true also struggling for life, as they cannot 

 live without fresh air as long as the carp. "What damage was done by 

 these fish of prey, which, by persistent attacks, even succeed in killing 

 large fish, during one summer, to the young carp of the Daehsberger 

 pond, m;iy be gathered from the circumstance that we only captured 

 L'.">, COO young carp, whilst in other years as many as 100,000 to 150,000 

 had been caught every autumn. In stocking the Stettiner Half such 

 circumstances should be taken into consideration, the recurrence of 

 which may in this case be avoided by simply laying the pond dry and 

 pouring in a solution of lime and water. The average production of a 

 hectare of water may therefore be calculated at 45,000 young car]) per 

 annum. In order, therefore, to produce the required number of 

 22,000,000 of carp in four years, all that would be necessary would be 



