Breeding the Pearl Gourami

From Microcosm Aquarium Explorer

Pearl Gourami pair: magnificent fish that breed readily. Aaron Norman

Pearl Gouramis for sale in a European aquarium shop. JJPhoto.dk

By Mary E. Sweeney

It happened by accident. I had no intention of breeding any of my fishes. I had tried my hand at that, enjoyed the arrivals of plenty of fry, and just wasn’t interested in all the care and feeding required at the time.

I had been keeping two pairs of adult Pearl Gouramis, Trichogaster leerii, and several assorted Corydoras catfishes in a 30-gallon tank when a wonderful friend presented me with a much-coveted albino Oscar, Astronotus ocellatus, for my birthday.

Yes, the gouramis had been happy in the 30-gallon for two years or more, even if they did look a little lost in all that water. They didn’t spawn because of the depth of the water and the turbulence created by the outside power filter, but indeed they were hale, hearty and exceptionally beautiful. But really, they didn’t need that tank. In fact, it did seem like a real waste of tank space — and I did have that spare 15-gallon tank stored up under the eave.

Evicted & Resettled

So it came to pass that later that day, Felix, the new Oscar, was installed in the gouramis’ former home. The 15-gallon tank was scrubbed with salt and very well rinsed. The outside of the glass was cleaned with vinegar and water until it shone, and a suitable stand was stolen from the telephone answering machine. I may have overdone it a bit out of guilt. After all, they had been so happy in the 30-gallon tank.

I took a couple of inches worth of nice, natural-colored, medium-sized pebbles from their original tank along with all the plants---a couple of Amazon swords, Echinodorus sp., a nice bit of Vallisneria, and some “frogbits,” Elodea sp. — and planted them carefully (that guilt again) in the new tank. There was even a bit of stray Java Moss that I had learned to hate for its propensity for clogging the impeller on the power filter.

I piled some bits of old flowerpot and gravel around the roots to make sure they wouldn’t be disturbed in any way, although with gouramis and corys, the plants are seldom bothered. The plants had been doing just so-so in the bigger tank under fluorescent lighting, and, frankly, I been a little disappointed with their performance.

Then I filled the tank halfway with water from their original tank and I topped it off with new water. I threw in a few drops of chlorine/chloramine remover for good measure and turned the submersible heater (with thermostat) to 82º F (28º C). Gouramis like their water nice and warm and the corys don’t mind either.

The tank was placed in a corner near a window that provides indirect light. There was no filtration or aeration. A hood with incandescent lighting was placed on top of the tank. The hood covered the entire tank. The only other equipment was a cone feeder for the Tubifex worms I planned to give them as a consolation prize for being summarily evicted from “their” tank. There wasn’t even a background covering for this jury-rigged tank. It was a pretty bare-bones setup as far as equipment and the niceties went.

Surprises

Then, after ensuring that the water was of equal temperature in each tank, I captured the gouramis and corys and popped them into the new tank. It looked pretty darn good.

As expected, after a few days, the water and sides of the tank were taking on a greenish hue, so I turned the light off on the tank during the day and just kept it on in the evening. In no time the water reverted to its original crystal clarity.

Then I noticed that the Frogbits were at least twice as long as I had remembered, the Val was getting new shoots, and so were the Amazon Swords! The Java Moss was well-anchored to a few pebbles of gravel in a corner and was a beautiful healthy green. Something nice was going on in this tank. The plants were thriving as they never had before in any of my tanks (and I had gotten compliments on my green thumb from time to time.) Apparently I had achieved a perfect balance of indirect natural light, incandescent light, and unfiltered fish poop!

It did my heart good to see the gouramis pecking gently at the leaves of the plants. I knew they were enjoying tasty algae and perhaps some nutritious rotifers. On my next foray to the pet shop I picked up some Tubifex for them and some small feeder guppies for the Oscar. Between the corys and the gouramis, the Tubifex disappeared in no time. Their regular diet consisted of good quality (or at least costly) flake, freeze-dried Tubifex, Daphnia, and some frozen brine shrimp.

After a few days of the rich Tubifex and frozen foods, the gouramis really perked up. They had been lovely before, but now they were really spectacular. The two females had nicely rounded bellies and were colored up like non-breeding males, and the males were out of this world with bright red throats, truly pearly sides, and interesting silvery filaments on their anal fins.

Setting the Scene

Since all the signs pointed to romance, I did a good 25% water change (because when the fry arrived, it would be risky to start changing water) and lowered the water level a bit, down to about 7 inches.

Condensation formed nicely on the underside of the hood and dripped back into the tank. Condensation is evidence of the high humidity that is beneficial to labyrinth fish fry. When their labyrinth organ is developing they are very susceptible to chilling and a tightly covered, warm tank with airspace above mimics their humid natural environment.

Each male chose a corner and made a lovely big bubblenest. The nests stayed well put thanks to the tops of the plants floating at the surface and the males seemed truly delighted with the arrangement, vigorously blowing bubbles between passes at the ladies. While I never actually saw them embrace, within a few days tiny specks in the bubblenests and depleted females proved that they had indeed spawned. The males remained busy tending their nests and the females stayed well out of the nursery area.

It was truly fascinating to watch the fry develop in the bubblenests. At first they manifested as small dark spots. Then, within days, I could see slivers of tails hanging from the underside of the nest — hundreds of them in each nest — that would bounce out of the nest and then float back up into the mass.

The males busily tended the nests, catching displaced fry and blowing them back into the bubbles all the while. This is the reason I lowered the water to 7 inches. In the wild, pearl gouramis live in very shallow water thick with vegetation. When the fry fall out of the nest it’s a short trip for the father to scoop them up and return them to safety. The thick vegetation anchors the bubblenest and keeps the family together.

In nature, the mother is free to go about her own business after spawning, but in the aquarium she doesn’t have that option, so you must take care that the male doesn’t savage her after she has released her eggs. My fellows didn’t, possibly because they had been tankmates so long or perhaps because of the thick planting where the females laid low.

Feeding the Fry

When the fry became free-swimming the question arose as to what to feed them. I knew those tiny, tiny glasslike slivers could be fed on a suspension of crushed egg yolk or infusoria, but because the egg yolk could cause problems with water quality and because infusoria can be tricky, I chose a commercial liquid fry food for convenience.

There were hundreds of little slivers darting around in the tank. Within a short while, their numbers had diminished and I was left with perhaps 20 young gouramis, which was fine with me.

I avoided doing any water changing for the first month because they are delicate and I didn’t want to disturb the balance of the tank. After they had a little growth, I covered the end of the siphon hose with a piece of foam rubber to avoid siphoning the fry, and changed 10% of the water per week.

It wouldn’t have hurt anything to have used a sponge filter in the tank after the fry had hatched, but it was never necessary.

Now, with all these gouramis, I think it’s time to think about moving them back to their old tank. The oscar could do with a bit more room...

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See:

• The Microscopic Gourami