Guppies harassing Swordtail

[wxruss8]

I've had these two male fancy guppies for a little over a month, where they've lived peacefully with two zebra danios. This weekend I added two glass catfish and a velvet swordtail. The guppies (one more than the other) is constantly harassing the swordtail (who is bigger) by kind of picking at him and swimming extremely close to him. What should I do? It doesn't really seem to be hurting the swordtail, but I don't want him to get too stressed.

 

[Luananeko]

Male guppies pretty much have one thing on their minds at all times: breeding They don't care what gender or species, they'll keep trying to flirt with anything that remotely looks like a guppy female (even if it's another male livebearer) if there are no females of their own species around. They likely only ignored the danios because the danios are too fast for the guppies to keep up.

If it seems to bother the sword and interfere with him getting enough food, etc, then you'll want to separate them, but otherwise it should be harmless.

 

[wxruss8]

Cool, thank you! Yep, that's exactly what it looks like, flirting. The sword just kind of ignores them mostly. During feeding time, they all go after the food and focus on eating, so it's not interfering with his food intake. I'll keep an eye on it.