THE BITTERLING 



C J. HEEDE 



Rhod 



eus amarus 



The Bitterling or Bluefish, Rhodeus 

 amarus, is a native of Central and West- 

 ern Europe and some parts of Asia. 

 This carp-like fish is a very interesting 

 inmate of the aquarium, and, though but 

 little known in the United States, is much 

 admired by European fanciers. It is 

 bright silvery in color, with a bluish- 

 green stripe running from the head to 

 the tail. The fins are pinkish. During 

 the breeding season, which occurs from 

 April to July a great change occurs in the 

 coloration of the male. He is now 

 adorned with beautiful markings of steel- 

 blue, violet, green and yellow — the colors 

 of the rainbow. The dorsal and anal fins 

 become bright red with black linings ; 

 tubercles develop on the pectoral fins and 

 gill covers. The female retains her usual 

 color and protrudes the long, worm-like 



Photo by Dr. E. Bade 



ovipositor. A mature fish will measure 

 from two to two and one-half inches in 

 length. 



The aquarium in which it is proposed 

 to breed the Bitterling should be pro- 

 vided with a sand or gravel bottom. One 

 or two freshwater mussels must be intro- 

 duced, either the pond mussel, Anadonta 

 mutabilis, or the river mussel, Unio pic- 

 torum. Rather small ones will be best as 

 large mussels might be able to eject the 

 spawn. By means of her long tube or 

 ovipositor the female inserts the eggs, 

 two at a time, in the gill opening or aper- 

 ture of the mussel. The milt of the male 

 discharged immediately, just above the 

 mussel, finds its w T ay to the eggs and fer- 

 tilizes them. The fry leave the foster 

 mother, the mussel, within a period of 

 ten to fifteen days after the spawn has 



