Name: Trichogaster trichopterus
Origin: Thailand, Borneo
Gold Gouramies are very hardy and pretty fish which are often sold to and chosen by beginners because of their hardiness, but they do have two points against this choice: first, they grow rather large (~15 cm) and may overcrowd smaller tanks. Second, the males tend to be very territorial and with their large size will often bully all the smaller fish, forcing them to stay hidden in some corner of the tank. This can be very frustrating to beginners, especially kids. The solution is to keep them in large, well planted tanks, or to keep only females. Sexing them is easy, since the male has a long and pointed dorsal (upper) fin, while the female's is short and rounded (as in the picture above). I find it quite disappointing that few employees in fish shops actually know this difference.
I find that gold gouramis of any sex can be very mean and aggressive towards others, especially dwarf gouramis. The one I have had to be put into a smaller aquarium because he was picking on the other gourami. I find that gold gourami are best kept with mollies, swordtails and fish of that nature. In my opinion the gold gourami should be the largest fish in the aquarium.
I have 7 gouramis in my tank and the gold gouramis are my favorites. They have thrived in my tank (of all gouramis) and some of my fish have lived for 6 years now. I find that gouramis do very well together, in groups of 6 or above. Since this many have been in the tank, aggression has been much less. The gold gourami is a great hardy fish for beginners and intermediate aquarium owners.
I bought a pair of these about a year ago, and they have grown to just under 15 cm. I keep them with an 18 cm Moonlight Gourami, four Blue Acaras (Aequidens pulcher), three Swordtails, one very large Koi Angel Fish, Catfish, and a lonely Kuhli Loach (at the moment). They all get on really well, which I am amazed at. I have only seen the Golden Gourami chase each other, never anything else in the tank. They truly are a beautiful fish and I would recommend them to anyone. I feed them on TetraMin, and they like my Cichlid food as well (Chicken Liver, Cod, and spinach, blended and frozen in ice cube trays). They will eat almost anything else as well. One of them went black for about a month, it has changed back to gold again now.
I have a Gold Gourami, and I tried to introduce another Gourami to my 100 liter aquarium. After a few hours, the new Gourami's fins were so severely nipped, I was afraid he wouldn't make it through the night. I moved him to another tank and returned him to the store the next day. The two Gouramis were males, which is why I say, beware of housing 2 males in the same tank!
I recently received a gold gourami from a good friend of mine, he said that it was chewing and nibbling the fins off of his knife fish and so I agreed to the deal. Although within an hour of placing the fish in the tank, it had already started biting and nibbling at my female opaline gourami's fins. By the next morning, I found my $45 precious little angel fish floating with its tail and fins nipped off. Poor fish. Later on that day I returned the gold gourami to the pet store and it is fine now. it turns out that they might have been mating because my opaline gourami was a female and the gold gourami was a vicious male.