NANFA-- Free-swimming fry

Mysteryman (bestfish_at_alaweb.com)
Mon, 05 May 2003 15:36:35 -0700

I can count about 20 free swimming fry in the tank.
Since prior reports indicate that the eggs take 3 days to hatch, I can
only assume that spawning has been going on for longer than I thought!
There are also a few dead fry on the bottom, which the adults haven't
eaten for some reason.
The fry are colored a dark grey, are translucent, and some of them have
some lighter bands on them. Their heads are a somewhat golden color, and
they are easy to see under the aquarium lights. They are about 1/4 inch
long, and very slender. I'd say they are about 2/3 the size of baby
guppies.

These fry are also very alert, very agile & very speedy for something so
young. I gave up trying to catch them, and instead just poured a quart
of green water over them. I also ground some flake food into flour, and
it looked like a couple of the fry were pecking at it already! Maybe
they'll have it figured out by the time the next batch hatches, and can
teach those newbies.

Most of the fry are congregated into a little school near the surface of
the water, hiding inside a clump of Anacharis plants. Coincidentally,
that is where the spillway for the filter is, so I'm not sure if they
like the spot for the current, or the plants, or the combination of the
two.
A few stragglers are hanging out in the rear corners of the tank at the
surface.
The adults stay near the bottom, so for now it seems the fry are safe
from them. Even at feeding time the adults seem to concentrate on the
offered food while ignoring the fry, but I'll have to watch more closely
to be sure.

I was worried that the canister & hanging box filters would be
deathtraps for the fry, but after disassembling them I found no fry. The
fry stay close enough to the surface to avoid the intakes, and since
they are such strong swimmers, I think that they may be able to avoid
them anyway. If I were to do it all over again, though, I would use
simple sponge filters to minimize the risk. I'd also probably lose the
undergravel filter, since I suspect that a number of fry are probably
trapped under it even now.

I still have a pool outside with some 25 more adults, and a thick amount
of Anacharis plants. The temperature & photoperiod are very similar to
those in the aquarium, but the pH is much higher, since it's filled with
ordinary tap water. I searched and searched with a flashlight, but I
couldn't find any fry. I suppose that pH is probably a very important
factor in breeding this species.

Well, I guess that's about it. This whole experiment was conducted to
see if I could get them to spawn normally in aquaria, and the answer is
yes. I had used the stripping method to produce fry before with success,
but I wanted to do it "right" this time. After reading the other
spawning accounts from those who came before me, I'm starting to see the
correct "recipie" take shape. I'll go ahead and add my data to the BAP
database for the cause. Maybe someday soon the Flagfin Shiner can take
it's very well-deserved place as a mainstream aquarium fish, produced by
the thousands on commercial farms.
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