snails & balloon mollies

Question
Actually it's 2 questions:
1) the pet store worker told me that these 2 sumatra tiger barbs could eat snails that grow in my 15 gal fresh water tank. Is that true? or do you recommend another kind of fish that can do the job without being too aggressive with other fish I have in the tank(balloon mollies, guppies, zebrafish, albino corydoras)

2) how do you know when mollies are pregnant? I have 3 females, 1 of which spawned 11 babies. Since I don't have any males, I'm assuming the one that spawned was pregnant to begin with. How about the other 2? Could they get pregnant from other fish?

Oops, I guess that was more than 2 questions. Sorry and thanks in advance for any advice you can give.

Blessings.

Answer
HiYa!

Ok to start off, even though I have Mollies, I'm no expert on them, so unfortunately I can't answer your question about them. I do know that if they have a swollen belly, chances are they are pregnant, unless of course they are balloon Mollies, who naturally have a big belly. Sorry I can't be of more use!

As for your snail problem, the best fish to control it, is of course the Clown Loach!! They LOVE LOVE LOVE!!! snails and will happily munch away on all of them, unfortunately your tank is too small for them, as they grow quite large and you really need to keep them in groups of 3 or more!

You could try a Pakistani/YoYo Loach, they grow to 10cm and ideally need a 26gallon tank but you could possibly get away with putting one in yours, though it depends on how many other fish you have in it already.

Sorry I couldn't be more help!

Cheers! Rach