Oiifidii I.iikc J-ishts 445 



From two to five or six males would gather alxiut a single female near the Ixjtlom, 

 and then the whole group would rise to near the surface, all making vigorous bodily 

 movements and agitating the surface. They then would descend as if exhausted. 

 It is i)r(>lial)le that eggs and sperms were emitted duritig this ascent <»f the compact 

 company hut nothing was seen. Surface di>turl(ances similar to those made by 

 the fish observed were fre<|uent further dcjwn stream from the weir, and it is 

 likely that these too indicated spawning acts. The observations were made on 

 April 22. IIJ20, alxiut 2 V. M.. with bright sunlight on the stream. 



Twenty or more I'ike I'erch could be seen in the stream from the weir, and it 

 was evident that many more were in the water below ; and some were entering the 

 weir. The spawning behavior is similar to that <lescribed by Hean ('13, p. 267). 

 He says that the female can readily lie distinguished in the water by her larger 

 size and by the fact that she is attended by several males. In sjwwning. the female 

 rushes up toward the surface but does not come rnit of the water. The males 

 <lart alMiut her with fluttering motions, discharging the milt while the female dis- 

 charges the eggs. He notes that aftir tbi< act the female dro])s back to the bottom, 

 followed by the males. 



Some eggs that were fibtained at the Hatchery measured 1 u of an inch in 

 diameter. They average al)out iso.txx) jier (|uart. The feniales may contain from 

 200,000 to 300,000 eggs each ( Hean, '02, p. 3</j). Careful records have l)een 

 made of the output of Oneida I^ke Pike Perch at the Oneida Hatchen*' and the 

 average number of eggs jier fish has been detennined to Ik* iR'tween 50.000 and 

 60,000. I.each considers the numln-r of eggs to lie alKuit 45,000 to each jniund of 

 weight of the fish. The eggs are adhesive and often cling together in masses in 

 hatchery ojierations. Hatching takes ]ilace in seven days at a mean temperature 

 of 57° F, or 28 days at a temperature tif 40° F. The fry when hatched are 3 16 

 of an inch in length (Leach. '2/, p. 13). The fry are active from the time of 

 hatching and soon engage in camiibalism ( lUick, 'i i. p. 2S<i). 



riie adult fish are commonly aUiut tw«i |Miunds in weight, in I-ike Frie. accord- 

 ing to Jordan an<l F.vermann ('(13, p. 362), but they may breed when less than a 

 |Kiund in weight (r,(KMle. 03, p. i(i|. The Yellow Perch is thought to reach 

 a maximum weight of aliout 50 |Miunds, but Nichols and Heilner ( "20, p. i ) record 

 40 jviunds for the largest one taken. 



.\d.imstonc i'22. p. H^^) marie a study of the growth rate in the Yellow and 

 the Blue I'ike Perch, using siH-cimens fn.in I .iki- I- rir lli^ r,-.„\f^ .li, ,«,,,,. r.i.. 

 fion iK'lween size and age are here given 



Tarlk No. 12. Siiowixr. K \ I'ikk r»R, m is- I ski Imi 



WHeht Aer 



