Re: NANFA-- My Flagfins are Spawning, BAP?

Mysteryman (
Sun, 04 May 2003 21:38:13 -0700

Well, let me see...
My situation matches in many respects, but not all.

I did have a temperature increase:
-- The fish were outside during that last cold snap. The temperature in
the aquarium has been slowly rising over the past two weeks, going from
the high 50's to 73.

I did extend the photoperiod:
-- I have a sleep disorder, so for awhile I wasn't turning the lights on
& off like I should. I bought a timer at Wal-Mart, and set it to run the
lights for ten hours, starting about one hour after sunrise, in order to
prevent abrupt lights-on. That gave them about 11 hours a day.

Massive water changes:
--Like I said before, I did these water changes to get the pH back down
after accidentally raising it. I suppose it has other beneficial
effects. pH dropped from ~7.5 to 7.0 in a week. Very soft water.
Distilled, in fact, mixed with creek water with a pH of 6.
Measurable traces of ammonia detected by test kit; new tank still

--I fed them frozen brine shrimp, live mosquito larvae, and TetraMin
brand flake food. I suspect they'd eat anything they could fit into
their mouths.

Substrate, decor, & plants:
--Pea gravel. I was going to switch to sand, but I never got around to
--Just a bunch of Anacharis, which fills about 1/3rd of the tank.
--One piece of driftwood, which leached tannins aplenty into the water.

--Undergravel Filter
--Aquaclear 200 external hanging filter
--Small Prime 10 Canister filter, 100 GPH
Zeolite, sponge, and activated carbon media.

Two males, five females.
As it turns out, my prior supposition was correct, in that the largest
specimens are males. I would almost dare to say here that any specimen
over 2 & 3/4 inches long shall be a male. I placed two of these
suspected males in the tank with five obviously gravid females.

Behavior: these fish tend to stay near the bottom of the tank, and
school tightly. At feeding time, however, all bets are off! After two
weeks in the aquarium, they have come to recognize me as the
foodbringer, and rapidly ascend to the surface when I approach.
The three fish which are currently involved in spawning activity hug the
bottom much more closely than the other fish.

The rival males display to each other in a way different from the way
they display to the female. Male to male display tends to be one of
fully extended finnage, stiffened bodies, quivering, and a head-to-tail
position. Displays toward the female tend to be an alternating
headstand/tailstand kind of thing, up & down, up & down, with the male
occasionally prodding the female in the side with his snout. That's when
they stop chasing her long enough to bother, of course.

I never noticed any of the tail-wrapping as described by Albanese, and
as I mentioned earlier, eggs were being dropped a few at a time instaed
of all at once. Could that be an abnormality brought on by inexperienced
breeders or poor health conditions? I know that some other
Pteronotropises are quick-batch spawners.
Egg-dropping, however, does indeed seem to be concentrated along the
edge of the tank, within an inch of the glass or less. I wonder why they
would do that? Does it have something to do with the water mantle around
submerged objects? Yeah, I bet that's a river current, relatively
still water affords the best opportunity for egg fertilization, so
laying eggs where the water is sluggish makes sense.

As for egg-eating: I'm not sure if I ever noticed any eggs being eaten.
Like I said before, the two males seemed to be in some sort of
competition to fertilize the eggs, and while I suspect that the loser in
each bout would have been happy to eat the winner's eggs, the pea gravel
allowed the eggs to sink beyond his reach in very short order. I'm not
sure if a sandy substrate would have made a difference, or whether the
fish would have spawned at a higher "altitude" if there were no other
fish in the tank, thusly giving them more opportunity to eat eggs. This
is my first time with this species, so I can only make wild guesses.

( Well, technically, this is my first time spawning them normally in an
aquarium. I've been able to produce fry via stripping in years past, but
that's cheating. LOL! )

So, in four days or more I might get some more spawns, eh? Excellent!
And I still have four other females to go! I hope these males are up to
the task.

Thanks, Mark!
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