Guppy courtship? Or aggression between new tankmates?

[HannahJ]

So one of my dormmates called me up a few days ago, saying they were tired of the tank their (now ex-) girlfriend had gotten them, and would I (as the resident "fish person") take them before he flushed them and trashed the aquarium?

And so I came into possession of a 6 gallon bowfront desk aquarium, containing one male guppy, one platy, and one cory cat. The cory cat got tossed in my (now slightly overstocked) 10 gallon, which already has some corys and he is now much much happier. I felt bad for the lone guppy though, so I went and picked up three females this morning and tossed them in, since playing the guppy multiplication game is fun and I could use some controlled live food for my ghost knife.

However, the male seems to have spent all day chasing around one of the females non-stop. He goes up to her and nips at her tail (not the fin part, but the sides) and she half-heartedly swims away. Lather, rinse, repeat. For comparison, she doesn't try to escape him with nearly the speed she feeds with, and doesn't seem to be too bothered, but this has been continually going on all day.

The male has ignored the other two female guppies, he's only picking on this one. So, what's the consensus? Is he doing some sort of weird territorial aggression I should be concerned about, or is this some sort of courtship behavior? Should I consider adding one more male or female to change up the ratio? Or something else?

Thanks in advance for any help.

 

[HannahJ]

I should mention that the tank has a centerpiece decor full of hidey-holes and such and that she hasn't tried to hide or anything. But the option is there.

 

[Johnny Tuttle]

That's courtship, particularly if the male is shimmying around and not swimming straight ahead.

My male did the same thing. When she's pregnant (and that will be soon if not already), he might turn his attentions to the next female. I will warn you that I've had three adult females, and two have died not long after giving birth.

 

[HannahJ]

Yeah, it's looking more and more like courtship. He's quit the nipping and just wiggles by her all the time now, while she nibbles the rocks, completely oblivious to his attentions. It's actually turned very endearing. He's trying just so hard....

I hope the females don't die. It's been a while since I did the guppy thing (like 10 years, my tank growing up was a guppy tank) but I don't remember them dying off too bad, just multiplying. And I had a fishy funeral every time any of them died so I would remember it.... do you think I should add another female to the mix to prevent stressing? That might be crowding the tank a little bit, but I could pull out the platy if needed. It's an established 6 gallon bowfront with a 10 gallon HOB filter, 4 guppies, a platy, and a mystery snail.

To be honest, when the tadpoles in my 10 gallon all finally turn into toads, I'm probably going to move the guys from this tank into it, and make this tank the home of the betta that's in with the tadpoles, since he is completely unsuitable to community tanks. That would help with the potential overstocking and it will be great to have a good source of live fish for my ghost knife and the red eared sliders. Mmm....gupppy.

 

[Johnny Tuttle]

I'd probably wait for the move to add in another guppy, but please be forewarned: once the male picks his favorite target, he's going to stick with her. Mine just lost his favorite mate this week, and I don't know how he's going to react. My other female adult is humongous pregnant.