AGE AND GROWTH OF THE CISCO 
233 
Table 19. — Comparison of growth in length, expressed in millimeters, of 11 cisco populations 
[The data for the 6 lakes at the right were adapted from various authors as indicated in the text] 
Age 
Trout ‘ 
Muskel- 
lunge 1 
Silver 1 
Clear 1 
Huron 3 
Ontario 3 
Erie 3 
Indian 
Village 3 
Ocono- 
mowoc 4 
Pine 4 
Hudson 
Bay 3 
Male 
Fe- 
male 
XII 
225 
XI 
219 
376 
X . 
213 
369 
345 
386 
345 
IX 
197 
354 
361 
358 
374 
338 
VIII 
189 
345 
351 
292 
303 
285 
362 
330 
336 
VII 
179 
196 
335 
340 
274 
297 
275 
374 
336 
314 
324 
VI 
1C8 
189 
323 
326 
258 
270 
255 
336 
315 
283 
308 
V 
158 
181 
308 
312 
244 
253 
235 
342 
282 
246 
290 
IV 
148 
174 
169 
287 
291 
235 
233 
215 
316 
223 
195 
284 
Ill 
137 
161 
155 
255 
260 
218 
226 
190 
301 
174 
162 
214 
II 
117 
143 
129 
196 
199 
185 
196 
160 
260 
135 
125 
184 
I 
81 
90 
80 
110 
109 
127 
129 
125 
1 Calculated lengths at the end of the year of life indicated. 
1 A combination of calculated lengths and actual lengths measured in November. 
3 Actual measured lengths at time of capture during the growing season. The ages of the fish are really greater than indicated 
here. 
* Actual measured lengths in midwinter after the completion of the growing season. 
Table 20. — Comparison of growth in weight, expressed in grams, of 10 cisco populations 
[The data for the 6 lakes at the right were adapted from various authors as indicated in the text] 
Age 
Trout 
Muskel- 
lunge 
Silver 
Clear 
Huron 
Ontario 
Erie 
Indian 
Village 
Ocono- 
mowoc 
Pine 
Male 
Fe- 
male 
Male 
Fe- 
male 
XII 
172 
XI 
119 
1, 190 
X 
1,062 
668 
696 
436 
IX 
880 
1,085 
751 
623 
406 
VIII 
111 
796 
950 
454 
354 
611 
343 
VII 
729 
917 
488 
269 
810 
527 
262 
VI 
50 
106 
673 
841 
221 
303 
213 
782 
445 
190 
V 
47 
96 
95 
647 
770 
175 
216 
156 
648 
366 
120 
IV. 
41 
60 
86 
84 
578 
705 
159 
181 
128 
523 
257 
85 
III 
37 
51 
82 
73 
418 
530 
143 
159 
85 
462 
166 
60 
II - 
31 
46 
66 
61 
267 
306 
100 
105 
278 
105 
45 
I 
71 
80 
31 
It should be mentioned that the length data of table 19 are not in all cases strictly 
comparable from one population to another. The data for Trout, Muskellunge, Silver 
and Clear Lakes are all calculated lengths; the data for Lake Huron are a combination 
of calculated lengths and actual lengths measured in November; the data for Lake 
Ontario, Lake Erie, the Indian Village Lakes, and Hudson Bay represent actual 
measurements of fish caught during the growing season; and the data of Oconomowoc 
Lake and Pine Lake are actual average measurements of fish taken in the winter 
after the close of the growing season. These small differences in the manner of presen- 
tation should not affect the value of the data for purposes of comparison. 
Though growth in length of the cisco varies widely in different localities, certain 
consistent likenesses as to the manner of growth are apparent. The greatest growth 
in length occurs in the first year of life. The growth of the second year is large but 
less than that of the first. Growth decreases markedly in the third year of life. 
Throughout the later years the annual increment of growth in length tends to remain 
fairly constant. Growth in weight is too greatly complicated by the questions of 
differences in form and of change of form to permit a general description of the style 
of growth with respect to this character. 
