Odessa barbs are a vey peaceful fish, they will never bully a fish, unlike thier cousins the tiger barbs. the only reason for keeping odessa barbs in shoals is because when they are shoaling thier colors intensefies and that make them look realy pretty. Don't worry about keeping them swordtails, like I said Odessa barbs are not a fin nippers unless they are with a siamese fighting fish(Bettas) or angelfish. The odessa barbs make's a great addition to the well planted community tank, they would not harm you swordtails, if you ask me I will say that swordtails can bully them quit easily.GOOD LUCK WITH YOUR BARB. By the way you have a cute odessa barb, that's a good specimen.