REPORT ON MOSQUITOES. 107- 



small, which rarely make their way in any stage of their Hves 

 into the places where mosquito larvje breed, and therefore exert 

 no beneficial influence in this direction. Among- them are the 

 common gold fish, the European or food cai-p, the chubsucker, 

 silverdace, etc." 



Concerning the carp, it may be said here that its presence in 

 a pond is a disadvantage rather than otherwise to- the smaller 

 species. It eats their spawn and stirs up the bottom mud so that 

 the eggs are covered and choked. Being a bottom feeder, like 

 the catfish, the species is of no value as a mosquito control. The 

 gold fish stands on a somewhat different footing. 



CARASSIUS AURATUS. 



The Common Gold Fish. 



"It is a well known fact that gold fish in aquaria will eat mos- 

 quitO' larvae ^^■ith avidity. The amateur breeders of fine gold fish 

 about Philadelphia often breed mosquito^ larvse as food for their 

 stock. But the conclusion should not be hastily accepted that 

 the gold fish will prove a wholly satisfactory destroyer of mos- 

 quito larvae. In fact, while it is no doubt of some value in this 

 respect, it is of lethargic habit as well as largely herbivorous and 

 not as useful as many other species." 



Nevertheless the gold fish has its field of usefulness in foun- 

 tain basins and in small artificial ponds not too much overgrown. 

 In such places where it can reach the very edge of the water it 

 serves very well. Even in cisterns it thrives, and in such a 

 place nothing in the way of a wriggler can escape it. 



The gold fish is an introduced species which has escaped from 

 captivity and spread into ponds and streams in many places. 

 Under such conditions it loses its red or "golden" color and 

 becomes a silver fish. Dr. Bean quotes as follows : "In many of 

 our streams and ponds the gold fish has run wild, and hundreds 

 of the olivaceous type will be secured to one of a red color. In 

 the fauna of the moraine ponds and in quarry holes, the gold fish 

 stands first. It will breed in foul water where only cat-fish and 

 dog-fish (Umbra) can be found." 



