Date: Tue, 15 Apr 1997 21:10:08 -0700 (PDT)
From: esarchy@wsunix.wsu.edu
To: gilholm <gilholm@enternet.com.au>
Subject: Re: trigger for breeding Ancistrus Dolichopterus, Sturisoma Barbatum, Rineloricaria Fallax, Sturisoma panamense

On Tue, 15 Apr 1997, gilholm wrote:

> Shane I breed all of the above catfish but despite many hours of observation and experimenting with temperature, P.H. etc I have not found a reliable trigger to start the breeding cycle.

Any ideas?
Regards
Norm Gilholm

Norm,
I have a fairly reliable spawning trigger, but the answer is a little complex so bear with me :) I have been working with various triggers for quite a while now. Mainly because I am trying to spawn some fishes that have not been spawned before. We know that most tropical fishes spawn at the beginning of the rainy season. I started doing some research into how waters are affected by the rainy season. I came up with the following list:

1) The water's O2 level raises considerably. This is from a combination of rain disturbing the surface, run off of fresh (high in O2)
water from the land, and the currents created by the addition of the rain water.

2) The water temperature drops as the fresh rain is added. It also drops because of 1 (i.e. the increased aeration/ circulation cools waters that have been standing for a long time). The clouds that come with the rain also act to block out the tropical sun for, atleast, part of the day and this cools the water.

3) The water becomes even softer. The fresh rain has no measurable hardness and its presence dilutes the effect that any salts in the water have on its hardness.

4) The rain lowers the pH. I have tested rain water that had a pH of 5. The rain dilutes the water and lowers the pH. Also remember that rain has no buffering capacity. This is also caused by all the dead leaf litter that is washed into the waters. The leaf litters also bring various tannins and other plant extracts.

5) The rains bring lots of food! Not only are little critters washed into the water, but flood waters open up whole new areas to exploit for food.

I am sure that you have heard of using one of these five things to spawn fish. Corydoras seem to be set of by #2. Everyone knows that most Corydoras will spawn after a large water change that drops the tank's temp. Other fishes will spawn from #5. Just keep giving them lots of high quality foods and they will spawn. Some fish need a combination of #1- 5. Asian glass cats (Kryptopterus) have been spawned using a combination of #1 and #3. Doug Underwood and I have put some time into coming up with ways to cause conditions #1- 5 to happen all at once. Doug has spawned Panaque nigrolineatus (Royal Pleco) (see the new TFH Lee's column) by providing all five conditions at once. Now he can work backwards by removing a condition (#1- 5) until he finds out which condition, or combination, triggers the fish to spawn. Now to the fishes you mentioned. For nearly all of the loricariids
#5 seems important (good diet). Number 1 is important for those loricariids that come from the rapids. Numbers 3 and 4 also seem to be fairly important as I have never had much luck spawning any of the spp. you mentioned in hard water with a high pH.
Not only #1- 5 must taken into account. No fish (except Convicts) will spawn without a suitable site. Rineloricaria need some sort of tube.

You can mess with #1- 5 for a lifetime and never spawn Rineloricaria if they do not have a suitable spawning site. I hope that I have not been too long-winded. The next time that you get a spawn go over your records. When was the last water change? Did a new piece of driftwood add tannins or soften the water? Did the power go out and drop the tank's temp? Look all of these things over and then ask yourself what set off the spawning? Let me know what you find out. I would be interested to hear.

-Shane