1933, April 21 to May 8; peak, April 26 to 30. 



1935, April 21 to May 8. psak, April 30 to May 2 . 



1936, April 19 to May 10;peak, April 30 to May 5. 



1937, April 28 to May ll;peak. May 3 to 9. 



1938, April 12 to 27; peak, April 16 to 26. 



The principal spawning grounds are in 

 Tamarack River and Shotley Brook which flow 

 into the eastern end of Upper Red Laxe and 

 Black Duck River which enters the southeastern 

 corner of Lower Red Lake . There are other 

 spawning streams of minor importance. EXiring 

 periods of low water, as in 1935 and 1936, the 

 walleye may spawn in the lake near shore if 

 prevented from entering upstream spawning 

 localities . 



THE YELLOW PERCH OF LOWER RED 

 LAKE 



The yellow perch, Perca flavescens 

 (Mitchill) ranks second to the walleye. The 

 total production averaged 145,702 pounds annual- 

 ly from 1927 to 1938. In the period 1927-1938, 

 yellow perch made up an average of 16.5 per- 

 cent of the yearly catch . Because of the 

 importance of yellow perch to the Red Lakes 

 fisheries, those facts concerning the life history 

 of the species obtained during the investigation 

 are presented here. 



Scale samples and data on length, weight, 

 sex, and maturity were collected from 311 yel- 

 low perch, the total unassorted catch from 18 

 nets (5,400 linear feet). On the same day, 

 August 24, scale samples and data were obtained 

 from 196 "culls" sorted from the catch of all the 

 remaining fishermen. Scale samples and data 

 were also collected from 88 perch which were 

 selected from catches made on August 25 to 

 provide a more extensive range of sizes and age 

 groups for study. Lengths only were recorded 

 of 896 yellow perch, which, in addition to the 88 

 selected fish mentioned above, constituted the 

 entire catches of yellow perch from 34 nets 

 lifted on August 25. 



Length -frequency distributions 



With the yellow perch as with the walleye 

 it is valid to base tabulations of the length -fre- 

 quency distributions of the age groups (table 17) 



on the combined selected and unselected samples . 

 Since inclusion of the selected fish distorted the 

 data on the numerical representation of the age 

 groups, a record of the age composition of the 

 unselected sample of 311 fish has been included 

 at the bottom of the table. The frequency dis- 

 tribution based on all unselected samples of the 

 commercial catch (right of table) did not include 

 the "culls ' measured on August 24. This cir- 

 cumstance accounts for the fact that at certain 

 lengths the totals for the age groups exceed the 

 number of fish measured in all commercial 

 samples. One of the 595 scale samples collected 

 could not be used for age determination. 



There was considerable overlap of the 

 length -frequency distributions of the age groups, 

 especially among the older and larger fish. 

 Every length interval from 180 to 259 millimeters, 

 standard length, was represented by at least 3 

 age groups, and some by 4, 5, or 6 age groups . 

 In the unassorted samples of the commercial 

 catch (rig^t of table) the perch were concen- 

 trated between the lengths of 200 and 249 milli- 

 meters, standard length (9.0-11 .2 inches, fork 

 length; 9.4-11.8 inches, total length; 7.5-13.0 

 ounces), 90.0 percent of the total falling within 

 that interval. This length interval of greatest 

 abundance in the commercial catch corresponds 

 with the lengths of greatest abundance of age- 

 groups VI and VII. That these age groups were 

 the best represented in the commercial catch is 

 indicated also by the fact that age-group VI made 

 up 60 percent and age -group VII 26 percent of 

 the unassorted sample of 311 fish. The irregular 

 nature of the frequency distribution of the small- 

 er perch suggests that commercial gill nets may 

 make a number of "accidental" captures (fish 

 tangled in the webbing by their fins or mouth 

 parts). The fact that the IV-group fish were 

 poorly represented in both the selected and un- 

 selected samples may indicate poor survival in 

 1934. 



Rate of growth 



Examination revealed that inclusion of 

 selected material with unselected did not alter 

 average lengths and weights and calculated 

 lengths of the age groups as determined from 

 unselected samples alone. For purposes of a 

 study of growth the data of both the selected and 



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