The Inhabitants of the Aquarium 133 



serts the ovipositor into the opening just 

 long enough to drop one or two eggs. This 

 operation is repeated until the mussel has its 

 proper number of eggs, when a new victim 

 is looked for. After the eggs are deposited, 

 the male fish in turn hovers over the mussel 

 until it opens, when he ejects the impreg- 

 nating milk, which enters the mussel in the 

 same manner as the eggs. The latter hatch 

 in the gills of the mollusk and, after having 

 occupied for about two weeks this part of 

 the anatomy of their strange nurse or foster 

 mother, the young fish leave it to shift for 

 themselves in the open water. 



The Mosaic Minnow (Phoxinus loevis) is, 

 like the bitterling, an introduction from 

 Europe, where on account of its peculiar 

 markings it is called Mosaic or Zebra fish. 

 It is one of our liveliest aquarium fishes and, 

 with a sufficient amount of oxygen, will live 

 fairly well in captivity. To see the min- 

 nows at their best they should be kept in 

 numbers, when they hardly ever cease their 



