Changes in
fertility of rainbow trout eggs retained in coelom
T. Azuma, H. Ohta, S. Oda, K. Muto, T.
Yada, T. Unuma-2003
Fisheries Science, 69(1): 131
Abstract:
Effects of prolonged retention time of
ovulated eggs in the parental coelom on fertilization success were studied
in rainbow trout Oncorhynchus mykiss using cryopreserved sperm with a
uniform fertilizing ability. Proportions of successful fertilization, eyed
eggs and hatched alevins were examined at different time periods up to a
retention time of 14 days beyond the ordinary stripping time, and were
compared with eggs incubated in artificial coelomic fluids (ACF). Eggs that
were retained longer in the coelom showed gradual decreases in all the
proportions of successful fertilization, eyed eggs and hatched alevins. The
progress of cleavage after fertilization slowed with prolonged retention
times. Eggs incubated in ACF lost their fertilizing ability much sooner than
those retained in the coelom. The hatching rate of eggs retained for 2 weeks
in coelom was 36%, while it was 1% in those eggs incubated for 4 days in
ACF. Thus, eggs retained in the coelom showed higher fertilization success
than those incubated in ACF.
(Nikko Branch, National Research Institute of
Aquaculture, Nikko, Tochigi 321-1661, Japan, Tel: 81-288-55-0055. Fax: 81-288-55-0064. Email: azuma@fra.affrc.go.jp)