OUR HERITAGE OF THE FRESH WATERS 
107 
A PACK-TRAIN OF HORSES LADEN WITH CANS OF YOUNG TROUT FOR PLANTING 
IN A COLORADO LAKE 
several hatcheries along the Great Lakes devoted 
to its increase. It is doubtless the favorite food- 
fish derived from inland waters. Planked White- 
fish is considered as great a delicacy in the Lake 
regions as planked Shad around the shores of the 
Chesapeake. 
The largest part of the catch is made in Lake 
Michigan and the least part in Lake Ontario. 
The gill net is the principal apparatus used in 
capture, but many are taken in pound nets and 
seines. The Whitefish is seldom taken with the 
hook, and then only with worm or insect bait. 
It inhabits chiefly the deeper parts of the Lakes, 
moving into shallower waters early in summer, in 
midsummer seeking again the cooler depths. In 
the fall months Whitefish again come inshore to 
spawn, some of them entering streams for that 
purpose, but the migratory movements vary some¬ 
what in the different Lakes. 
Recent investigations have shown that the Com¬ 
mon Whitefish is late in maturing, probably not 
spawning until after fiv’e years of age. It deposits 
on the average about 35,000 eggs, which hatch in 
about five months. 
The food of the Whitefish consists of small 
crustaceans, small mollusks, and insect larvae, but 
chiefly of various kinds of Entomostraca. White- 
fish hatched in the Aquarium were carried through 
the critical period of infancy on a diet consisting 
of the larvae of mosquitoes. 
These fishes, now ten years old, have lived and 
grown on a diet of chopped fresh meat. Had it 
been possible to supply them with their natural 
live foods, their size would doubtless have been 
greater. These specimens are apparently the only 
Whitefishes ever brought to maturity in captivity. 
Whitefish eggs and young Whitefish are de¬ 
voured in great numbers by predatory fishes. 
The largest Whitefishes seldom reach a weight 
of 20 pounds, and such are rare, the average as 
brought to market being only three or four pounds. 
Females are larger than males. 
The Whitefishes as a group are considered the 
most important fresh-water fishes in the world, 
and there can be no doubt of the fact that they 
are undergoing progressive depletion. 
FRESH-WATER DRUM (Aplodinotus 
grunniens) 
{For illustration see Color Plate, page I2j) 
The Fresh-water Drum is a large fish belonging 
chiefly to the Great Lakes and the Mississippi 
Valley. It reaches a length of three or four feet 
and a weight of 40 or 50 pounds. It is a food-fish, 
wherever taken, and more popular in the South 
than in the North. 
In 1899 the catch of Drum in the Mississippi 
and its tributaries exceeded 3,000,000 pounds; in 
the Great Lakes in 1917 the catch amounted to 
nearly as much. 
The Drum is a bottom fish, living mostly in 
muddy waters, feeding on Snails, Mussels, and 
Crayfish, for which its heavy paved teeth are well 
