82 FISH FARMING I 



Having established the aquatic plants, you may 'with safety 

 introduce any quantity of the various species of mcllusca, and 

 take care they are always present in sufficient quantities to 

 satisfy your stock of fish, but not in such bulk in sporting 

 waters, at any rate as to satiate the trout so that they da 

 not seek other preferably surface food. Mcst of the crusta- 

 ceans are also safe, but some of them are parasites of an objec- 

 tionable nature, and, careful as you may bs, they at times 

 attack your stock of fish, with unfortunate results. The 

 remedy for this evil is simple a strong bath of rock-salt in 

 solution but the bother and trouble of catching the fish and 

 bathing them is most annoying. In the fry-ponds and the 

 stream that feeds them, establish an ample supply of daph- 

 niae, cyclers, and cypris all commonly classed as " water 

 fleas " : they form invaluable food for the fry. They can be 

 obtained from Mr. W. Baily, of the Malvern Wells Fishery. 



In this connection a. matter of importance occurs : Wherever 

 a- strong flow of well aerated water passes over the fish, these 

 parasites seldom trouble them. Another matter, and one which 

 I cannot explain, but can vouch for, is that wherever fresh 

 water shrimps (Gammarus pulex) are introduced in large 

 quantities, these parasites give considerably less trouble. 



The larvae of nearly all the water flies can bs obtained now, 

 and these certainly should be introduced where possible. Mr. 

 E. Valentine Corrie, of Winchester, sends out large quantities 

 of these larvae, and the Sol way Fishery Co., Dumfries, and Mr. 

 C W. Wilson, of Rigmaden Fishery, can supply you with all 

 the most suitable aquatic plants 



