230 ILtinois NATuRAL History SURVEY BULLETIN 
Vol. 26, Art. 2 
Fig. 7—Ridge Lake fisherman with his catch arranged for the rapid taking and recording 
of pertinent data. 
As anglers brought in their catches, the length, weight, and fin-clip mark of 
each fish were recorded by an employee of the Illinois Natural History Survey. 
A sample of 
scales from each fish was taken for age determination, and a record was made of time spent in 
fishing and kinds of bait on which the fish were caught. 
fig. 7, where the time of day was recorded 
on his lake fishing permit card. The fish- 
erman was questioned about the baits and 
tackle he used, and the information ob- 
tained was recorded on the permit card. 
If the fisherman had brought in fish, these 
were weighed and measured, and a few 
scales from each were taken for later use 
in studies of age and growth rates. The 
scales from each fish were placed in a 
small envelope, and the length and weight 
of the fish were recorded in appropriate 
