TROUT IX S.A. WATERS 265 



^'fry" are the prey of herons, cormorants, hamraerkops, 

 the larger kingfishers, otters, muis honds, large trout, 

 etc. If suitable spawning beds are not provided in the 

 upper waters, or if impediments to the migration of 

 spawning lish are not removed, the fish must spawn on 

 the most comfortable material they can find in the lower 

 waters; and if in water near the pools,, the fry are more 

 or less promptly devoured, especially in rivers running 

 low when food is scarce, becoming the prey of the larger 

 and hungry fish. 



The fry in our rivers seem to drop down to the deeper 

 w^aters from their nurseries after the first rains between 

 March and May of the year following their birth, so, as 

 the spawning season for Brown Trout is generally from 

 ^la}' to June and for Rainbows from June to July, they 

 remain in their upstream home from 10 to 12 months. 

 The author has found Trout in spawn and milt more 

 or less developed as follows:— 



BroAvn Trout in Upper Berg and Wemmer's Hoek, 

 October and November. 



Eainbows in Berg and Dwaars Rivers, October. 



Rainbows in Eerste River, October, November and 

 December. 



Rainbows in Lowrens River, April and October. 



Rainbows in Hex River, November. 



When natural spawning beds do not exist, they can be 

 easily made by cutting channels from 4 to G feet wide, 

 parallel with the course of the stream, and covering 

 their bottom to a depth of 12 to 18 inches with pea-sized 

 gravel. The stream can then be diverted over these beds 

 and can by simple sluices at each end be controlled so as 

 to afford protection to the alevins from floods. Of course 

 the water in these channels must be allowed to return 

 to the stream lower down. By opening the sluices before 

 the spawning season a full flow of water can be turned 

 over the "redds", and the fish can be'safely left to find 

 their way to them in due course. Such an arrangement 



