Off-Season Spawning of
Eurasian Perch Perca Fluviatilis
H. Migaud, J.-N. Gardeur, P. Kestemont, P.
Fontaine-2004
Aquaculture International, 12(1):
87-102
Abstract:
This study was designed to determine the effects of
the selection for body weight and of two final warming durations during an
out-of-season reproductive cycle on gonad recrudescence, plasma steroid
levels and spawning in Eurasian perch Perca fluviatilis males and
females. Two different bodyweight classes (200–250
and 350–400 g) and two different warming
periods (1 or 2 months) were studied.
At the end of the chilling period, a significant
effect of the selection for body weight was observed on gonad development
whereas fish were the same age. According to higher levels in testosterone
(12 ng mL-1), a better development was recorded for smaller
breeders (P < 0.05). A short water warming period up to 14°C
(1 month v.s. 2 months) allowed higher rates of females with completed
gonadogenesis (33–38% v.s. 7–8%)
and spawning (31–33% v.s. 0%) (P
< 0.05). Spontaneous out-of-season spawning (17 ribbons) and larvae were
obtained. Relative fecundity was about 100 eggs g-1 of female
body weight. Five ribbons were partly fertilized with a rate ranging from 5
to 90%. These studies have shown that delayed spawning in Eurasian perch can
be obtained by a temperature manipulation, but results are not sufficient
because of low stimulation rate of females, low spawning rates and high
heteroge-neity of fertilization rates. The effects of other environmental
factors like photoperiod should be tested in further experiment to improve
the protocol inducing out-of-season spawning production.
(Laboratoire de Sciences Animales,
INRA – INPL –
UHP Nancy 1, MAN, 34 rue Sainte Catherine, 54000 Nancy, France, e-mail of P.
Fontaine: pascal.fontaine@lsa-man.u-nancy.fr)