3505091” Of gameîes, egga, embryos
155
Belova
(1981) reported one case of good survival of carp sperm cells stored for
7 days. This author also indicated that the survival of silver carp, grass carp
and bighead carp sperm cells declined after 12—hour storage at 6—8°C.
Belova
(1983)
showed
that
storing the
excised
testis
of
silver
or
common
carp
gave
poorer
results
than
storing the ejaculates.
During 24—hour storage at 4—6°C,
Nedovesova
(1983) observed a significant decrease in sperm RNA content but not
in DNA content°
Cryopreservation°
The
cryopreservation
of
cyprinid
spermatozoa has
had
limited success.
However,
Withler
(1982) studying the Indian carp, Labeo rohi—
ta, showed that frozen spermatozoa were after thawing as effective as the fresh
control;
all
works
on
other
species
have
given
limited
results
(Moczarski,
1977;
Stein, 1978; Durbin et al., 1982; Billard, 1980; Chao and Billard, 1984,
unpublished data). The best percentage of fertilization ever recorded has never
exceeded
50%
the controls, although many more cryopreserved spermatozoa were
used.
B.
Ovum survival
Ovum
survival
as
determined
by
the
percentage
of
fertilization
or
of
hatching,
is
usually short after ovulation (Horvath,
1978a).
In ovario,
the
percentage of fertilization declines within 50—80 min (Woynarowich and Horvath,
1981) or 3—4h (Suzuki,
1980;
Jahnichen, 1978), and ova may still be fertilized
at 6h
(fig.
2)° In species such black carp and silver carp, in ovario ova sur—
vival
after
ovulation
is
even
shorter
because
of
the
higher
temperature used
during spawning: after 30—40 min. 50% of the ova were already overmature and no
longer fertilizable (Horwath, 1978a).
Ova
stripped
after
ovulation
and
stored
in
vitro
in
an
undiluted
state
progressively lose their fertilizability. Survival sometines exceeds 6h in carp
(fig.
2) but more generally the hatching percentage drops to 0 in less than 4h
(Sjafei, 1985; Renard and Saad, unpublished. In the range of 15—20°C, ovum sur—
vival both in ovario and in vitro decreases as the temperature increases within
the range of 15—20°C
(Suzuki,
1980;
Horvath,
1980; Sjafei, 1985). However in
vitro storage at less than 10°C is also unfavorable (Sjafei,
1985).
Thai
carp
ovum
fertilizability
is
not
extended
by'
chilling storage
iJ1
a
refrigerator
(Withler, 1980).
After
dilution
ovum
fertilizability
is
very
short
in
fresh
water
or
va—
rious saline
solutions,
even
at isoosmotic
strengh.
This
phenomenon,
due
to
autoactivation without any sperm contribution, was mentioned by Yamamoto (1961)
in the goldfish and is reported for other cyprinids.
The fertilization rate or
carp ova begins to decline immediately after dilution either in fresh water or
in saline
solution,
and
becomes nil
within a
few minutes
(Sjafei,
1985).
In
silver carp,
the
ova
lose
their capacity for fertilization after 30—40 sec in
water and
more
than
50
sec
in
saline
(Mikodina and Makeyeva,
1980).
Various
attempts to inhibit autoaotivation have not been very successful;
autoactiva—
tion was only delayed in goldfish by adding an esterase inhibitor to the saline
mution
(Hamano,
1957),
by adding sodium oxalate
to
medaka
ova
(Yamamoto,
1954),
or
by adding ficoll to zebra fish ova (Harvey, 1982). After dilution in
&
pooled ovarian fluid,
autoactivation is
delayed by a few hours
(Christen,
1985, personal communication), suggesting that this medium includes a factor(s)
Mch prevents this activation.
155
Belova
(1981) reported one case of good survival of carp sperm cells stored for
7 days. This author also indicated that the survival of silver carp, grass carp
and bighead carp sperm cells declined after 12—hour storage at 6—8°C.
Belova
(1983)
showed
that
storing the
excised
testis
of
silver
or
common
carp
gave
poorer
results
than
storing the ejaculates.
During 24—hour storage at 4—6°C,
Nedovesova
(1983) observed a significant decrease in sperm RNA content but not
in DNA content°
Cryopreservation°
The
cryopreservation
of
cyprinid
spermatozoa has
had
limited success.
However,
Withler
(1982) studying the Indian carp, Labeo rohi—
ta, showed that frozen spermatozoa were after thawing as effective as the fresh
control;
all
works
on
other
species
have
given
limited
results
(Moczarski,
1977;
Stein, 1978; Durbin et al., 1982; Billard, 1980; Chao and Billard, 1984,
unpublished data). The best percentage of fertilization ever recorded has never
exceeded
50%
the controls, although many more cryopreserved spermatozoa were
used.
B.
Ovum survival
Ovum
survival
as
determined
by
the
percentage
of
fertilization
or
of
hatching,
is
usually short after ovulation (Horvath,
1978a).
In ovario,
the
percentage of fertilization declines within 50—80 min (Woynarowich and Horvath,
1981) or 3—4h (Suzuki,
1980;
Jahnichen, 1978), and ova may still be fertilized
at 6h
(fig.
2)° In species such black carp and silver carp, in ovario ova sur—
vival
after
ovulation
is
even
shorter
because
of
the
higher
temperature used
during spawning: after 30—40 min. 50% of the ova were already overmature and no
longer fertilizable (Horwath, 1978a).
Ova
stripped
after
ovulation
and
stored
in
vitro
in
an
undiluted
state
progressively lose their fertilizability. Survival sometines exceeds 6h in carp
(fig.
2) but more generally the hatching percentage drops to 0 in less than 4h
(Sjafei, 1985; Renard and Saad, unpublished. In the range of 15—20°C, ovum sur—
vival both in ovario and in vitro decreases as the temperature increases within
the range of 15—20°C
(Suzuki,
1980;
Horvath,
1980; Sjafei, 1985). However in
vitro storage at less than 10°C is also unfavorable (Sjafei,
1985).
Thai
carp
ovum
fertilizability
is
not
extended
by'
chilling storage
iJ1
a
refrigerator
(Withler, 1980).
After
dilution
ovum
fertilizability
is
very
short
in
fresh
water
or
va—
rious saline
solutions,
even
at isoosmotic
strengh.
This
phenomenon,
due
to
autoactivation without any sperm contribution, was mentioned by Yamamoto (1961)
in the goldfish and is reported for other cyprinids.
The fertilization rate or
carp ova begins to decline immediately after dilution either in fresh water or
in saline
solution,
and
becomes nil
within a
few minutes
(Sjafei,
1985).
In
silver carp,
the
ova
lose
their capacity for fertilization after 30—40 sec in
water and
more
than
50
sec
in
saline
(Mikodina and Makeyeva,
1980).
Various
attempts to inhibit autoaotivation have not been very successful;
autoactiva—
tion was only delayed in goldfish by adding an esterase inhibitor to the saline
mution
(Hamano,
1957),
by adding sodium oxalate
to
medaka
ova
(Yamamoto,
1954),
or
by adding ficoll to zebra fish ova (Harvey, 1982). After dilution in
&
pooled ovarian fluid,
autoactivation is
delayed by a few hours
(Christen,
1985, personal communication), suggesting that this medium includes a factor(s)
Mch prevents this activation.