FISHES. 133 



what oxygen it can, sinking again quickly to the bottom. 

 Sometimes, in order to remain as near to the surface of the 

 water as possible, it will rest upon the top of the rockwork 

 or upon the broad buoyant leaves of some aquatic plant. 

 Such conduct as this shows that the poor fish is uncomfort- 

 able, that his suiToundings are not suited to his requirements, 

 and that sooner or latter, unless it be removed, it will die. 

 As long as the Loach remains contentedly on the bottom of 

 the tank, the aquarium-keeper may be sure that the water 

 contains all the oxygen necessary for the welfare of his fish. 

 In this way the Loach is useful as a ganger of the condition 

 of the tank. Few deep aquaria, however, are so well balanced 

 that Stone Loach within it will remain in perfect health. As 

 these fish are generally found in shallow running water, it 

 is reasonable to suppose that tanks of the least depth and 

 the greatest area are the most suitable for them; and in 

 an aquarium about 4in. deep, 18in. long, and 12in. wide, I 

 have found them to live in perfect health, and apparently 

 quite happily. I have never seen them come to the surface 

 of the water in a tank so constructed. Such an aquarium 

 as this can be made with hardly any expense in less than 

 two hours, and filled with water as soon as completed; while 

 short directions for making it have already been given in 

 Chapter II. A few rather large and flat stones should be 

 placed upon the bottom of the aquaria in which Loach are 

 kept, for on and under these the fish wiU frequently lie. 



Loach are easy to catch. A short hunt among the stones 

 of the stream in which these fish are found will soon drive a 

 few from their lairs. When disturbed they swim only a short 

 distance, then sink to the bottom and remain motionless 

 there. After a fish has been "marked down," it may be 

 snaa-ed with a horsehair tied to the end of a short stick, or 

 filliped with the fingers, or driven by a splash, into a hand-net 

 held just in front of it. The net shoiild touch the bed of 

 the stream, or the fish will very likely escape by getting 

 under it. The natural food of the Loach is larvae of insects, 

 water-worms, and the like. In captivity it should be fed 

 upon water-worms, small garden-worms, and tiny pieces of 



