850 



ZOOLOGICAL SOCIETY BULLETIN. 



•^»?y.. 





MUDFISH OR BOWFIN. 

 This is one of the hardiest of fresh-water fishes, but ad 

 too large for small aquaria. 



will clean up waste particles of food and de- 

 cayed vegetation and work over the fecal matter 

 of the fishes, and will also tend to prevent an 

 excessive develo])ment of the microscopic plants 

 which form ,1 green scum on the glass. If 

 larger portions of plants begin to deteriorate it 

 will be found best to cut them off and remove 

 them since if they are not in good condition they 

 will not serve for aeration and will become a 

 source of danger. 



If care is taken in feeding — and a little study 

 and experience in tliis matter is the onlj' safe 

 guide — no appreciable amount of food need be 

 left to decay. If for an_v reason not all of the 

 food is consumed or if there is any accumula- 

 tion of fecal or other matter, these may be read- 

 ily removed by means of a long pipette, or a 

 rubber tube used as a siphon. For the small 

 aquarium the pipette with an inside diameter of 

 one-quarter inch and fitted _ 



with a large rubber bulb, is 

 most convenient, or, the tube 

 may be used without the 

 bulb by placing the thumb 

 over the upper end while in- 

 troducing it and while with- 

 drawing it after it is filled. 



For larger aquaria t h e 

 pipette is rather tedious and 

 the sijjhon is recommended. 

 In either case the water 

 should be strained through 

 a cheesecloth net and al- 

 lowed to flow back into the 

 tank rather than to a d d 

 fresh water to replace it. As 

 has been stated elsewhere, the 

 less changing of the water 

 the better, for fear of intro- 



r^>?\iO*: 



ducing some new factor to 

 interfere with the adjust- 

 ment already established. It 

 will occasionally be neces- 

 sary to add water to replace 

 that which escapes by evap- 

 oration. This should be done 

 a little at a time and care 

 should be taken to have the 

 temperature the same as that 

 of tlie water in the tank. 



For the purpose of remov- 

 ing any deposits on the glass 

 of the aquarium, a swab can 

 be made out of a stick with 



specimens are ^ ^''' "^ checseclotll Wrapped 



about the end. The cloth 

 may be removed each time 

 it is used, which should not be more often 

 than is necessary to keep the glass reasonably 

 clean, or if it is used over it should be carefully 

 cleaned and sterilized each time in hot water. 

 The swab will serve not only to remove ordinary 

 dirt, but also the green scum of the minute plant 

 life which in strong light will soon cover the 

 glass. These minute plants do no harm — in 

 fact they are as beneficial in yielding oxygen as 

 are the larger ones — and they are a natural part 

 of the balanced life of the aquarium. However 

 one keeps an aquarium to enjo}' the view of its 

 miniature water world, and if the green scum 

 interferes with the view it may be removed with- 

 out detriment to the adjustment. The scum 

 grows thickest on the side nearest the light and 

 it may be allowed to develop on that side as it 

 will serve to screen the strong ligiit somewhat 

 from the animals. 



THE SIREN. 



