ARTIFICIAL SPAWNING OF EURASIAN PERCH, PERCA FLUVIATILIS L. USING OVOPEL

Abstract

Spermiation and ovulation in the Eurasian perch Perca fluviatilis L. were induced with Ovopel, pellets containing GnRH, and then compared with hCG and CPE. Males from the control group produced a significantly smaller volume of milt (average about 17 ml kg BW -1 ) than those from the hormonally-treated groups (over 24 ml kg BW -1 ). Spermatozoa motility was similar in both the treated and untreated males, but the fertilization ability varied significantly between individual males. Over 90% of the treated females ovulated. Ovulation in the control group was noted in a limited number of females. Mean embryo survival to the eyed-egg-stage was over 50% in the treated groups, in contrast to 7.5% in the control group. The poor quality of perch gametes might result from high water temperature oscillations before the natural spawning season. The quality of eggs, expressed as survival to the eyed-egg-stage, decreased with latency time.