American Fisheries Society 427 



ture of about 20° centigrade (68° F.). It is to be 

 remarked, however, that carp do not all spawn at the same 

 time. Those six or seven years old spawn much later than 

 younger fishes — that is to say, not until July, or even August, 

 long" after the others are through. This explains how last 

 season fry were frequently found of two distinct sizes — a 

 fact that has led some breeders to believe that the carp may 

 spawn twice in succession the same season when meteoro- 

 logical conditions are favorable. This is an error of obser- 

 vation. Fry of good size in autumn come from the spawn- 

 ing of young fish which spawn about the end of May or 

 beginning of June, while very small fry, which are found 

 mixed with the others, come from eggs laid in August by 

 very old carp. 



Ten days are enough in warm weather to effect the 

 hatching of the eggs, and the fry develop pretty rapidly 

 when they find sufficient nourishing food. Nevertheless, 

 even those hatch very early, that is to say, in the first days 

 of June, and transported under favorable conditions, hardly 

 measure more than 3 or 4 centimeters (IVi to 1% in.) in 

 length at the utmost. At this age, and even much later in 

 the season, they are liable to be destroyed in large numbers 

 by ducks, which it is therefore important to keep out of the 

 waters occupied by fry. These palmipedes are also harmful 

 at the spawning of the fish. Indeed, having the habit of 

 dabbling along the shores, where the carp generally spawn, 

 of diving to the bottom and digging in the mud, they are a 

 continual detriment to the waters that they frequent; little 

 by little the muddy cloud settles on the submerged aquatic 

 plants, soon covering the carp eggs adhering to these herbs 

 with a layer of sediment impermeable to the air, and the 

 embryos are smothered and perish for want of oxygen. 



The pike is very often used in ponds to prevent too great 

 an abundance either of carp fry or of "white fishes " (bleak, 

 roach, etc.), the swarms of which may appropriate too great 

 a proportion of the fish-food, to the detriment of the market 



