REPRINT FROM CALIFORNIA FISH and GAME "CONSERVATION OF WILDLIFE THROUGH EDUCATION' VOLUME 42 JULY, 1956 NUMBER 7 THE YELLOW PERCH, PERCA FLAVESCENS (MITCHILL), IN THE KLAMATH RIVER' MILLARD COOTS Inland Fisheries Branch California Department of Fish and Game INTRODUCTION The primary purpose of this study, undertaken in 1951, was to deter- mine the relationship between yellow perch (Perca flavescens) and young salmonids in the Klamath River. Yellow perch are indigenous to the eastern part of the United States and Canada. Their native range includes the Hudson Bay drainage, south to Ohio, and Nova Scotia to the Dakotas. Through fish-cultural activities their distribution outside this range has been widespread. Curtis (1949) reports that yellow perch were first introduced into California in 1891. Several subsequent importations were made. He further notes that by 1918 they were widely distributed in the Sacra- mento-San Joaquin River drainage, although not numerous, and then appear to have vanished from this area. However, specimens are still occasionally taken in the drainage, with an apparent concentration in Snodgrass Slough, Sacramento County. Yellow perch were first collected in the Klamath River in California on May 4, 1946, when anglers brought four specimens from Copco Lake to the Fall Creek State Fish Hatchery for identification (Figure 1). Copco Lake is a storage reservoir of the California Oregon Power Company on the Klamath River near the California-Oregon state line. Although but little is known of their spread downstream, a 6-inch perch was collected just above the U. S. Highway 101 bridge at the town of Klamath, near the mouth of the river, on June 14, 1951. Yellow perch now are abundant in Copco Lake and are fairly common in the nu- merous dredge-pond backwaters along the upper Klamath River. How they entered the Klamath River is not definitely known, but probably they either descended the river from Oregon or were "unofficially" planted in Copco Lake. Yellow perch are also present in Lost River near Tulelake, Siskiyou County, and in the various irrigation canals just east of Tulelake in Modoc County. METHODS The majority of the perch were collected with riffle-type fyke nets of one-half-inch stretched mesh, which were usually set overnight in riffles just below the quieter stretches of the river, or in connecting channels between dredge ponds and the river. Others were taken by gill net, chemical treatment of backwater dredge ponds, hook and line, I Submitted for publication July, 1955. ( 219 ) 220 CALIFORNIA FISH AND GAME O R E G O N C A L I F O R N A • 0 Cow KLAMATHON Lake • HAPPY °CRESCENT CAMP CITY KLAN 4TH 0 • 0 oRicK a. a 0. 5 ip 20 3,0 miles Seale FIGURE 1. Map of the Klamath River in California. Black triangles indicate collecting localities for yellow perch. and by means of a mechanical fish trap installed in the Klamath River at the Klamathon Egg Collecting Station, 16.5 miles below Copco Dam. Fyke and gill netting were not satisfactory methods of collecting perch for stomach examinations. After a prolonged period in the nets, many of the fish had either digested or regurgitated their food. The following fishes are associated with the yellow perch in the Klamath River : Pacific lamprey, Entosphenus tridentatus King salmon, Oncorhynchus tshawytscha Silver salmon, Oncorhynchus kisutch Steelhead rainbow trout, Salmo gairdneri gairdneri Klamath small-scaled sucker, Catostomus rimiculus Klamath tui chub, Siphateles bicolor bicolor Klamath speckled dace, Rhinichthys nubilus klamathensis Brown bullhead, Ameiurus nebulosus Largemouth bass, Micro pterus salmoides Green sunfish, Lepomis cyanellus Pumpkinseed, Lepomis gibbosus Sculpin, Cottus sp. AGE AND GROWTH Scales from 140 perch were mounted and "read". Measurements were made from the focus to the extreme anterior edge of the scale along an interradial space, using an Ames dial gauge attached to a compound microscope. The growth (Table 1) was calculated on the assumption that at the time of annulus formation a direct proportion existed between scale length and fork length. Annulus formation of YELLOW PERCH IN KLAMATH RIVER 221 TABLE 1 Calculated Growth Rates of Klamath River Yellow Perch in Each Age Group Fork length in inches at end of year of life Age class Number examined II IV V 39 3.50 II 61 3.31 5.67 IH 33 3.34 5.54 7.26 IV 4 3.54 5.92 7.49 8.48 3 3.34 5.90 7.40 8.83 10.10 Total 140 Average calculated fork length _ 3.38 5.64 7.30 8.63 10.10 Average calculated increment___ 3.38 2.26 1.66 1.33 1.47 Range - - - - - - - - - - - - - - - - - - - 2.53-4.47 4.34-6.70 6.16-7.82 8.10-9.30 9.60-10.30 Average calculated standard length - - - - - - - - - - - - - - - - - - 3.00 5.01 6.46 7.66 8.97 Average calculated standard length (mm.) 76 127 164 195 228 Average calculated total length_ 3.55 5.92 7.67 9.06 10.61 perch collected from the Klamath River appears to be completed some- time during the period March through May. The season's growth is completed during October and November. The growth of yellow perch young-of-the-year may be traced in Figure 2. A comparison of the average calculated total lengths at each annulus with data compiled by Carlander (1950, 1953) indicates that the perch NUMBER OF SPECIMENS 20 9 30 II a 1 4 10 214 79 33 5.0 (r)ai 9 1. 0 MAY JUNE JULY AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MAR. FIGURE 2. Range and mean length of yellow perch young-of-the-year collected from the Klamath River, May, 1951, through March, 1952. 222 CALIFORNIA FISH AND GAME collected from the Klamath River displayed a growth rate comparable to that in other waters (Table 2). TABLE 2 Comparison of the Calculated Total Lengths at Each Annulus of Klamath River Yellow Perch With Those From Various Waters Num- Total length in inches at end of year of life ber Location of Authority* fish II III IV V VI VII VIII New Hampshire, Shawtown Lake _ _ _ 2.8 3.9 4.6 5.1 6.0 6.7 Stroud (1942) Montana ponds 32 2.6 5.3 6.6 7.0 Brown and Thorenson (1951) Virginia, Claytor Lake 59 3.1 5.5 8.5 9.9 Roseberry (1951) Lake Erie 2,644 3.7 6.7 8.5 9.5 10.4 11.0 Jobes (1952) Lake Michigan 2.8 4.5 6.0 7.1 8.5 9.7 Van Oosten (1948) Minnesota 2.4 4.5 6.3 7.7 9.2 9.6 10.4 10.9 Smith and Moe (1944) Iowa, Red Haw Lake_ 87 3.7 7.2 10.3 Lewis (1950) Iowa, East Lake 88 3.4 5.7 7.1 7.6 8.2 9.3 Lewis (1950) Connecticut 224 3.7 6.0 7.7 9.0 9.9 10.6 11.2 11.6 Thompson (1942) California, Klamath River 140 3.5 5.9 7.7 9.0 10.6 * Taken from Callender (1953). LENGTH-WEIGHT RELATIONSHIP AND CONDITION A total of 848 yellow perch was measured during the course of this study (Table 3). Fork length measurements and weights were taken from 276 fish (Table 4). Thirty-three of the specimens, ranging from TABLE 3 Fork Lengths of 848 Yellow Perch From the Klamath River March, 1951, Through March, 1952 Midpoint length in Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. inches 1.0 1.5 6 2 2.0 2.5 3.0 8 3 __ __ 21 3 3 __ __ 14 4 -- 3.5 11 6 3 __ __ 9 6 5 8 7 92 41 14 4.0 6 1 15 __ 1 __ 6 2 87 33 17 4.5 2 4 _ 2 24 1 -- -- -- 1 21 3 2 5.0 2 3 i 3 15 8 2 -- -- -- 2 __ 5.5 11 4 7 11 19 3 1 1 6.0 9 10 1 9 32 4 2 1 1 4 4 2 1 6.5 4 5 2 8 20 4 1 3 __ 2 5 4 1 7.0 1 __ __ 4 6 __ 1 __ __ 3 10 1 1 7.5 4 6 __ 1 __ 2 4 10 1 1 8.0 8.5 __ __ .... 1 1 9.0 -- -- -- -- -- -- -- -- -- -- 2 -- 9.5 1 10.0 10.5 Totals 56 35 32 64 143 53 20 13 17 24 265 89 37 YELLOW PERCH IN KLAMATH RIVER 223 TABLE 4 Length-weight Relationship and Coefficient of Condition of Klamath River Yellow Perch RmIclength Calculated Coefficient midpoint weights of condition Number of Taal Standard fish length* length* (inches) Orm10 c K (ounces) (inches) (nun.) (grams) (English) (metric) 2 - - - - - - - - - - - - - - - - 1.8 45 0.04 1.1 1.9 40 36 1.66 1 - - - - - - - - - - - - - - - - 2.2 55 0.06 2.0 2.3 49 36 1.66 1 - - - - - - - - - - - - - - - - 2.6 65 0.1 3.2 2.7 58 36 1.65 1 - - - - - - - - - - - - - - - - 3.0 75 0.2 5.0 3.1 67 36 1.66 6 - - - - - - - - - - - - - - - - 3.4 85 0.3 7.3 3.5 75 38 1.73 22 - - - - - - - - - - - - - - - - 3.7 95 0.4 10.2 3.9 84 38 1.72 31 - - - - - - - - - - - - - - - - 4.1 105 0.5 13.9 4.3 93 38 1.72 37 - - - - - - - - - - - - - - - - 4.5 115 0.7 18.3 4.8 102 38 1.72 19 - - - - - - - - - - - - - - - - 4.9 125 0.8 23.5 5.2 111 38 1.72 14 - - - - - - - - - - - - - - - - 5.3 135 1.0 29.7 5.6 120 38 1.72 14 - - - - - - - - - - - - - - - - 5.7 145 1.3 36.8 6.0 129 37 1.71 25 - - - - - - - - - - - - - - - - 6.1 155 1.6 45.2 6.4 138 38 1.72 18 - - - - - - - - - - - - - - - - 6.5 165 1.9 54.6 6.8 146 38 1.75 17 - - - - - - - - - - - - - - - - 6.9 175 2.3 63.4 7.2 155 38 1.75 17 - - - - - - - - - - - - - - - - 7.3 185 2.7 77.4 7.6 164 39 1.78 22 - - - - - - - - - - - - - - - - 7.7 195 3.2 90.6 8.1 173 38 1.75 15 - - - - - - - - - - - - - - - - 8.1 205 3.7 105.5 8.5 182 38 1.75 8 - - - - - - - - - - - - - - - - 8.5 215 4.3 121.9 8.9 191 38 1.75 2 - - - - - - - - - - - - - - - - 8.9 225 4.9 139.9 9.3 200 38 1.75 2 - - - - - - - - - - - - - - - - 9.3 235 5.6 159.6 9.7 209 38 1.76 2 - - - - - - - - - - - - - - - - 9.7 245 6.4 181.1 10.1 218 38 1.75 Total 276 Mean - - - - - - - - - - - 38 1.73 • The following length-conver ion factors were determined: total length equals 1.050 fork length; fork length equals 1.126 standard length; standard length equals 0.888 fork length; total length equals 1.182 standard length.