My common pleco named Twizzle has killed one of my male bristlenose plecos.
I fonud him in his favorite pot with his back end sucked clean. He was not ill prior to this and generally kept out of Twizzles way as did his companion.I know that plecos fight over territory but do they kill each other over it ?
If they don't normally do this my pleco must be some kind of serial killer as this is his 5th victim ( 4 large fantail goldfish + my pleco ).
I have since then moved my other bristlenose to one of my fry tanks to keep him safe.

Plecos do fight but it's rarely deadly. Could the bristlenose have died and then Twizzle sucked on him? Plecos like to suck on dead fish. Plecos also suck on goldfish because they're easy targets. They can kill goldfish from sucking. I guess he could have killed the bristlenose the same way. I'm sorry. I guess Twizzle should only be kept with fish too small to suck on.

I think as with people & other animals, fish are all different & in amongst the peaceful breeds you'll get a killer or a fighter & in amongst the fish known to be agressive you'll get the odd one thats not...

My bristlenose was fine up to that point and was still just alive I found him ,I put him out of his pain.
If could see Twizzle when he is in one of his 'moods' you can tell he is doing it for the hell of it. I dont want to put him with any of my baby fish in case he hurts them too.
I feel that he is just a grumpy pleco, as my gibbicepts pleco is very docile is the total opposite of Twizzle.