WHOLESALE BREEDING 221 



while reeds and cattails protect fish from birds of prey, they also harbor 

 their most active enemies— frogs, turtles and snakes. 



Another method of holding back the vegetation is with boards held 

 by stakes — as in figure 207. At this farm the boards are placed only 

 on the breeding ponds, and for an entirely different reason from those 

 already described. We will come to it in a moment. 



Breeding Methods. At no point is the difference more marked 

 between the small and the wholesale breeder than in methods of propaga- 

 tion. What is Best for an individual would, when multiplied by the 

 needs of the wholesaler, become a time-consuming burden. We refer 

 principally to the preparation of the spawning bed. The standard method 

 now in use by most establishments is pictured in figure 207a. It is a 

 frame 24 x 30 inches, 5 inches deep, with a 12-inch strip of poultry 

 netting attached the long way in the centre of the lower edge. This 

 allows a 6-inch opening on either side at the bottom. To this netting 

 is attached with string either thick sod with the earth washed out, or, 

 more recently, Spanish Moss which has had the outside covering re- 

 moved, and which is used mainly for cheap furniture or mattress stuffing. 

 Boards of trade in New Orleans, La., or Jacksonville, Fla., will give 

 names of dealers to those interested. The material is quite cheap and 

 is good for more than one season's use. 



These frames are floated in the breeding ponds the evening before 

 spawning is expected. The fish swim up through the lower openings and 

 spawn on the material, which is from 2 to 3 inches thick. As the frames 

 become well filled with eggs, they are removed to the hatching tanks. 

 Single nail heads projecting from the centres of all four sides of the 

 frames prevent the surfaces from bumping together and destroying fry 

 which might be clinging there. After the fish are free-swimming, the 

 frames are of course removed from the hatching tanks and, after ex- 

 posure to the sun, used again or stored. 



The object of the boarded edges in figure 207 is to keep the grass, 

 as well as rootlets, out of the water, so that the fish will spawn only in 

 the frames, and not on the grass, which would be their natural tendency. 

 Obviously, concrete edges also will serve the same end. In ponds where 

 fish are allowed to breed without supervision, grass edges are a help 

 unless there are present plenty of aquatic plants with finely divided 

 leaves. 



In Japan and usually in Japanese hatcheries in America, willow 

 roots are used to catch spawn. It is thrown into the breeding ponds 

 in bunches and after being filled with eggs is placed in hatchery ponds 

 (the large ones in figure 208c) and held down about a foot from the 

 bottom by an arching piece of wire netting. Otherwise it is likely to 



