i have to say i have never had an agressive pleco (towards me). but i have been spiked a couple of times on my own fault. (the price of deciding not using nets to transfer plecs
our last big common cut me on numerous occassions. My L264 was very tame and gentle, but my wifes will try to gouge me. He has latched on and sucked very hard to the palm of my hand, to the point that it hurts.
could have become concentrated in the food, but i dont know how bad that would be for plecs. sorry for you loss though. did it look healthy otherwise, and have plenty of places to hide?