Hello,
New here and new to keeping livebearers. Well I have an empty 55 gallon tank that needs some attention. Currently in the research and planning stages but I was thinking it would be fun to stock it with wild type livebearers, maybe specifically from the Yucatan region? Three I had in mind were Montezuma Swordtail (Xiphophorus montezumae), wild type Sailfin Molly (Poecilia latipinna), and Porthole Livebearer (Poeciliopsis gracilis).

Questions:
1) Could groups of these three fish thrive together in a 55 gallon? (I currently have a 75 gallon African Cichlid tank, so my understanding of stocking livebearers is a little off.
2) Are all of these fish surface dwellers? Do I need to add some bottom dwellers? If so, which fish would work with my plan?
3) Where could I find these awesome fish? AquaBid?

Thanks!

That's a stunning selection of fish. I've had all of these species, albeit not in the same tank.

None of them are strictly surface dwellers, although Mollies will prefer to feed from the surface. It's good to have bottom dwellers as janitors though, and some will also help with algae. I've kept Bristlenose Pleco's (Ancistrus sp.) with all of the mentioned species and they do well together.

Gracilis are smaller and more docile than your other selections but they should do fine if lots of cover is provided. You'll want lots of cover anyway to reduce fry predation.

The optimum dietary requirements are different, but not different enough that it couldn't be managed with a varied, high quality diet.

The biggest problem I foresee is population control because they'll overstock a 55g in a few months flat if you let them.  Of course, you can always get another aquarium .

Several of our members breed all of these species. Membership comes with a periodic 'Trader' publication in which you'll find fish for sale or trade.

I'm looking forward to seeing the set-up, good luck!

Thanks for the response!

Yeah, that was my thinking, i'll need a janitor in there. Someone mentioned to me using shrimp or a dwarf crayfish (Cambarellus patzcuarensis), though I thought they were more omnivores than algae eaters and I don't want them eating my fish. I'll look into plecos, but they can get pretty big right?

I plan on making it a planted tank with plenty of cover so no worries.

I might sub Yucatan molly (Poecilia velifera)for P. latipinna and Northern Mountain Swordtail (Xiphophorus nezahualcoyotl)for X. montezumae, depending what i can find.

Looks like I might have to become a member to aid in my fish search!

So in regard to stocking, what should the numbers look like? 6 sailfins, 6 swords, 6 portholes?

Also, I didn't even think of fry when planning this project, but yes there could always be another aquarium.

Thanks again.

I would start with a trio of each.  The Mollies & Swordtails like a lot of room and six of each species would overstock a 55 gallon.  Mollies and Swordtails can also have very large drops and they do it every 4-6 weeks.  Then the offspring will be dropping in 3-5 months, so you can see how quickly your house will turn into a fish room...LOL.

There are 'dwarf' bristlenose plecos on the market that are around 4-6".  Look for common names like "White Tip Bristlenose" or "Dwarf Bristlenose". All of the fancy forms, such as long-finned, albino, and black-eyed yellow stay under 6" in my experience.  Most experts believe they're hybrids, but at best they're an unidentified Ancistrus sp., in case that matters to you.  I love them regardless. 

So starting the tank off with 3 Mollies, 3 Swords and 3 portholes? And start removing fish once the tank reaches 6 adult fish of each? I know these fish like to be in groups, so is 6 a good group size?

Thanks again for answering my questions.

You could start with a group of six Portholes as they do seem to be more comfortable in a group, but the other fish are fine without a group. The trios should be one male & two females. With your janitors that will pretty much stock your tank with some breathing space for the first round of fry, but it won't be big enough to grow them out.

ok!
Thanks for your help!