two questions about pearl gouramis

The orange coloration is about the only physical aspect that separates the males from females. What you might consider doing is getting a group of 3-4 young pearls (2" or so in size) to grow out and see which are females. The remaining pearls can be returned, and this is more plausible if you get the fish from a privately owned dealer, not a chain store. Private dealers are more flexible and are more willing to take in fish, esp. if the fish were orig. purchased from them. Just tell the owner of the store you go to that you're wanting to get a small group of pearls in hopes of getting certain genders, and that you plan on returning the remaining individuals, and they may comply with this plan. An alternative is to try and find larger pearls (3" and up) whose gender is more obvious.
 
I kept a single pair in a 55g for years without so much as a squabble from either fish. They're generally very peaceful towards one another and other fishes, as well.
 
My pair of pearls never have problems... and I've seen them as little as 2" with very distinct gold on the guys. Another way to tell is that the top fin on the guys is longer.
 
Well...I have 4 Pearls, 3M/1F with no problems. For some reason, it's hard to find a female. If it's just a pair of Males, they will fight. A group wouldn't matter because it will spread out the aggression.
 
Pearls are one of my very favorite fish! I have 4 - a male and 3 females. They are peaceful and quite shy fish. I did have 5 - the 5th one was another male, but he died suddenly last year. I have no idea why.
I started out with 3 juveniles bought at a lfs. They turned out to be 2 males and a female. I couldn't sex them until they were older. I found 2 more females at another lfs in NJ. They were adults, so it was easy to tell that they were female.
Since they seem to stay near the top of the tank, or sequestered in the plants, I moved them into a heavily planted 29g. They seem VERY happy. Their tankmates are a very small school of Harlequin and Espei rasboras and a few cories. I just added a German Blue Ram that was given to me - a lfs surrender.

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Also, females (at least sexually mature, not sure about younger) will have a bit of a swollen appearance behind the gills. Not 100% sure why, at first I thought mine had a parasite, until I realized that every female pearl I saw had that.
 
I have two pearls in my 29 gallon - a male and a female. Tank mates are 8 cories, 1 clown plec, and 2 honey gouramis (a male and a female, as well). All get along great; the pearls are very serene. The cories are, of course, oblivious to all as they bumble along the substrate in search of food, but even the honey gouramis, which are only 1/4 the size of the pearls, aren't bothered by the pearls. I was afraid they might be because they so much smaller than the pearls, but it was their tank first, so they've always known where all the good hidey-holes are.
 
Also, females (at least sexually mature, not sure about younger) will have a bit of a swollen appearance behind the gills. Not 100% sure why, at first I thought mine had a parasite, until I realized that every female pearl I saw had that.

Eggs.
 
IMO you don't have to have that many cories, it might be too many for the ground surface area. Yes, peal gourami are very nice. Before they mature, you can tell the female from male because the male has a longer dorsal fin and the female's is shorter and rounder at the tip. When they mature, the male will go through cycles when he is looking to mate and will bother the female so 2 females will be ideal for a mature male.
 
I think the glo fish may be too hyper for the more staid pearls. And with the fish you list, 2-3 gouramis seem like overstocking to me. Personally I'd go with the pearls. Do you already have the listed fish besides the molly & fry? I'd start with only ~ 8 corys, not that 12 won't "fit" at the bottom but the tank may seem too busy with all those species.
 
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