THE PUBLIC AQUAEIUM 



319 



spoonful of salt to each gallon of water will be necessary. If other 

 fishes are obtainable, it is just as well to destroy diseased speci- 

 mens, as the fungus roots penterate into the flesh and can not be 

 destroyed if the growth is far advanced. External parasites on 

 jBshes should be picked off after the fish has been lifted carefully in 

 the dip net. 



One of the first in- 

 dications of trouble 

 in the aquarium is 

 the presence of the 

 fishes at the surface 

 with their mouths 

 out of the water, 

 showing that they 

 are suffering for lack 

 of air. The water 

 may be dipped up 

 and allowed to fall 

 back slowly, but the 

 relief afforded will 

 be merely temporary. 

 The temperature of 

 the aquarium should 

 be observed and some 

 of the fishes removed. 

 It may be necessary to 

 increase the quantity 

 of plant life or stim- 

 ulate its growth by 

 admitting more light. 

 If the weather is not 

 cold and the window 

 can be opened, air 

 blowing across the 

 surface of the water 

 will be helpful, as it 

 may only be neces- 

 sary to aerate the 

 water and lower the 

 temperature some- 

 what. There may be 

 refuse at the bottom, 

 which should be re- 

 moved, of course. 



In taking care of 

 the aquarium a few ' 



simple implements, such as' a half-inch rubber tube for siphoning out 

 the water, a glass " dip tube " for removing small particles of dirt 

 from the bottom, a shallow dip net of cheesecloth for lifting fishes, 

 and a cloth-covered pad or rubber scraper with a long handle for 

 cleaning the glass, will be necessary. The dip tube is operated by 

 closing the top opening with the finger to admit or exclude the water 

 as desired. A pair of long wooden forceps and a slim stick are also 



L 



® 



® ® ® Q) 



Fig. 47. — Aquarium implements. 1, net ; 2, forceps ; 3, 

 stick for feeding ; 4, swab for cleaning glass ; 5, tube for 

 taking up refuse 



