CUR HERITAGE OF THE FRESH WATERS 
87 
Photograph by Ih R. Sanborn, New York Zoological Society 
YOUNG SMALL-MOUTH BLACK BASS WINTERING IN AN AQUARIUM 
The fish remain poised in mid-tank, crowded closely together. As long as plants can be kept growing 
in the cold water the fish will pack themselves tightly among them. While the temperature of the water 
remains low, the fish seldom take food. 
to the fins, during the early period of their 
lives. It is now practically certain that 
all Mussel spawn which fail to find a suit¬ 
able fish host sink to the bottom and die. 
The young Mussels are temporarily pro¬ 
vided with minute hooks for attachment 
and are soon enveloped in the epithelium 
of the fish, where they remain encysted 
until the shell begins to form and they can 
safely drop off. 
All fishes are not equally susceptible to 
these temporary mollusk parasites; some 
receive very few, others shed them too 
soon, while still others die as a result of 
carrying too many. Practical work is in 
progress, and large numbers of fishes 
“infected,” as it is called, with young 
Mussels are liberated to stock the public 
waters, as their “parasites” develop and 
fall off. 
TURTLES, FROGS, AND CRAYFISH 
The “planting” of the Mussels is, there¬ 
fore, left to the fishes. It is even possible 
to send Mussel-bearing fishes to waters 
outside the Mississippi system and thus 
introduce the more valuable Mussels else¬ 
where. 
There are several species of large Tur¬ 
tles of the kinds known as “sliders” in 
