Pleco Being Aggressive

[nanasloop]

Our tank had a common pleco and a bunch of swordtails and platys. The tank was recently upgraded size to 37 gallons. Seeing that our pleco did not do a ton of eating the algea off the bottom we got another pleco. This second one is smaller and a darker color. Earlier today everything was going okay then i noticed that the new pleco was on top of the older one. We are not sure on the variety of either pleco due to the fact that every pleco where we bought was different but said to be a common pleco. The older one is more leopard spot-ish looking and about 1-1.5 years old. The new one is a darker color that seems to be more stripped with dots also. Could the new one be aggressive in nature? Could this be them trying to mate? Any recommendation for what to do.

Thanks for your help in this matter.

 

[nanasloop]

As far as we know the older one is a Sailfin Plec. We still can't figure out the other one. But he looks like a Rhino without the horns (as far as we know). We're not sure... Will get pics as soon as we can. Please Help!!!! They both are small right now. The older one really hasn't grown much in the 1-1.5 years that I've had him... Any help will be appreciated!!

 

[Anguilla82]

they are probably just sorting out the pecking order.
its unlikely they will come to any harm. once the order is sorted peace will be resumed.
i notice the size of you tank is a bit small for a sailfin. they'll get to 18" plus relatively quickly given enough food.
if the other is a common plec then he'll get to the same sort of size as well.
just to bear in mind

 

[lilfishie]

i would suggest rehomeing both as they are future 1 foot plus in size, a BN would be more suited to your tank.