GUDGEON, ETC. 



61 



barbules would lead anyone to infer, it is a bottom 

 feeder, and its colour and markings are such as readily 

 to hide it from observation when in its natural habitat. 



Fig. 19. 



The Loach (Cobitis barbatula}. 



Like the miller's thumb, it often hides under the 

 stones, or in the interstices of rockwork, but it is by 

 no means so voracious. In the aquarium it, as well 

 as most fishes, is very useful in devouring any odd 

 worm or dead insect or fragment that may have been 

 lying on the bottom of the tank, and that otherwise 



j would have decomposed and contaminated the water. 

 The gudgeon (Gobio'fluviatilis) is even a greater 



' favourite with some aquarium keepers than stickle- 



Fig. 20. 



The Gudgeon (Gobio fttiviatilis). 



backs. It grows to a larger size, often to 6 inches in 

 length, and is therefore a more attractive object. It 

 may readify be identified by the pair of barbules, or 



