THE CARE OF HOME AQUARIA 41 



the tadpoles may have sufficient after the more active fishes have 

 taken their share. In this case any surplus not consumed should 

 be removed with the pipette after a few hours; (3) the tadpoles 

 may be removed to another receptacle occasionally and fed sep- 

 arately. However, a careful study of the conditions of the aqua- 

 rium should make this latter method unnecessary. 



Although tadpoles are vegetarian in their diet, the young 

 frogs and toads after their metamorphosis are strictly carnivor- 

 ous and are adapted to a flesh diet only. They may be fed on 

 insects, earthworms, mealworms, grubs, or pieces of fresh meat 

 cut to a suitable size. Just at the time of change when the horny 

 ^aws of the tadpoles are being shed to allow the development of 

 the teeth, they will take no food. This period of change extends 

 from a few days to several weeks, according to the species and 

 the temperature of the water. These remarks apply equally well 

 to newts and salamanders. 



For smaller animals, and especially for attached forms such 

 as the sea-anemone and coral, the use of the feeding-stick is 

 advisable. This is simply a sharp-pointed stick of sufficient 

 length to reach the bottom of the aquarium. The point of the 

 stick is dipped in ground meat or finely minced clam made into 

 a thick paste and carefully introduced into the water until the 

 animal to be fed is reached. With a little care this can be done 

 so as to avoid the loss of much food. 



Crayfishes and crabs are naturally scavengers and will eat 

 almost anything. They prefer a meat diet, however, and if 

 deprived of this they are very likely to turn cannibal and eat 

 each other. 



CLEANING THE AQUARIUM. 



It must be clearly borne in mind that cleanliness is abso- 

 lutely necessary to the welfare of the inhabitants of the aquari- 

 um. In an aquarium which is properly set up contamination can 

 arise only by bacterial decay of organic substances allowed to 

 remain in the water. There are three general sources of such 

 organic matter ; first, fecal matter from the animals, relatively 

 unimportant because the deposits are small in amount and regu- 

 lar in occurrence ; second, decaying vegetable matter from dead 

 portions of the plants, also relatively unimportant since in the 

 well balanced aquarium there is little tendency for the death of 

 the plant tissues, and third, decay of excess food matter, the 

 usual source of pollution. 



