AGE AND GROWTH OF THE CISCO 215 
Table 2. — Year of collection and number of specimens in the collections used in the study of age and 
growth of the cisco 
Lake 
Year of collection 
Total 
number 
1928 
1930 
1931 
1932 
Trout 
182 
608 
610 
1,300 
Muskellunge _ 
281 
245 
016 
188 
1,330 
135 
118 
378 
631 
249 
191 
440 
47 
66 
113 
68 
68 
Total 
718 
937 
1, 853 
379 
3, 882 
The relatively limited data from the small collections from Allequash and 
Tomahawk Lakes are not considered in the general discussions of this paper, but are 
treated in a special section (appendix A). 
METHODS 
GEAR USED IN COLLECTING 
With the exception of a small number of 0-group individuals picked up on the 
beaches of Trout Lake all samples used in this investigation were collected by means 
of gill nets. The 1928 collections were made in nets of the following sizes of mesh: 3 
1%, lji, 1%, 2, 2%, and 3 inches, and in Trout Lake a 1% by 8-inch trammel. The 
trammel used in the capture of Trout Lake ciscoes would operate as a 1%-inch gill 
net. In this year no net records were kept for individual specimens. It is unlikely, 
however, that in any of the three populations (Trout Lake, Muskellunge Lake, Silver 
Lake) ciscoes were taken either in the 2%-inch- or 3-inch-mesh nets. 
The nets used in 1930 had also been used in 1928. However, the discarding of 
worn-out nets at the close of the 1928 season was so extensive that the only sizes of 
mesh available in 1930 for the capture of ciscoes in the three lakes named in the 
preceding paragraph were l}{ and 2 inches. These same nets were used in the early 
part of the 1931 collecting season. The depth of these nets varied from 3 to 4 % 
feet. 
The gill nets used in 1930 and in the early part of the 1931 season were in a sorry 
state of repair. Not only were many of the meshes broken, but holes of considerable 
size were of frequent occurrence. The making of repairs was not feasible as the thread 
had deteriorated to the extent that even ordinary handling and use of the nets fre- 
quently produced new tears in the webbing. 
The gear was completely replaced on July 22, 1931, after which date the following 
sizes of mesh were used: 1%, 1 }{, 1%, 2, 2]{, 2%, and 3 inches. Each net was 50 
yards long and approximately 6 feet deep; 5-inch leads were used as a precaution 
against tangling of leads in the webbing. All Clear Lake samples (1931 and 1932) 
were taken in the new gear, but only a few lifts of the new gear were made in the 
other lakes. 
The question of gill net selectivity, particularly with reference to the use of gill net 
samples for the study of age and growth, is considered in a special section (pp. 294-306). 
METHODS OF FISHING 
The new nets purchased in 1931 were fished in gangs containing 1 net of each 
of the 7 mesh sizes. In sets of the old nets the larger mesh sizes, known to be 
ineffective on the cisco populations that were being sampled, were occasionally 
: Throughout this paper, sizes of mesh, unless otherwise indicated, are presented as stretched measure. 
