Re: NANFA-- Fertilization of Eggs

Jay DeLong (
Mon, 04 Jun 2001 21:13:30 -0700

At 11:13 PM 6/3/01 -0400, you wrote:
>then after a few days the idea came to me to try to artificially fertilize
>the eggs.

> so today i took a small dish of water and took the eggs from 2 females
> and the white organs from 2 males and squished them all up between my
> fingers in the water in the bowl and stirred up the bowl.

That ruined your chances for fertilization right there, George. Eggs go
through a process known as water-hardening, after which fertilization is
impossible. Upon exposure to water, the micropile (the hole where the
sperm penetrates the the egg's membrane) closes and the egg then becomes
rigid and swollen. Unlike with internal fertilization in mammals and birds
and such where the first lucky sperm causes the micropile to close,
processes in fish eggs are triggered by exposure to water, which in nature
is the time when fertilization occurs (the male fertilizes the egg
immediately upon release by the female).

Therefore, don't allow the eggs to contact water prior to fertilization or
there won't be any fertilization. If you have viable eggs, keep them in
their own ovarian fluid and add milt to them, mix them gently, then add
them to water. Really, though, you're going about this the hard
way. There's no way to know that the eggs are mature enough or that the
sperm is viable. Your chances would be increased greatly if you took the
fish off their spawning bed while in the act of spawning (the fish, that
is, not you!).

Jay DeLong
Olympia, WA

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