75 Gallon Tank Recent Odd Pleco Behaviour

[cjde]

My 3-year-old common pleco‘s behaviour has become quite odd. Goes from frantic zipping up and down and across the 75-gallon tank, to aggressive head-butting on the heater, to floating vertically at the surface, unmoving. In the tank with a 3-year-old Oscar. No history of fighting. The water is well filtered and aerated, gets a 3/4 change once a week. Seems to be eating and there are no signs of disease on his body. Wondering if it’s mating behaviour. Suggestions? Thanks in advance.

 

[Gudgie]

Please fill out the emergency template. That should help to figure out if there could be a water quality issue or something else going on. Can't comment on the mating behavior, but glad he visibly looks fine!

 

[cjde]

I should have mentioned that he seems to have injured himself during his zipping about. This appeared overnight. Other injuries he’s has like fin tears etc. have healed very quickly. Attached a pic but it’s not very clear.

Pleco has been really agitated lately, frantically swimming all over the tank and bumping onto things. Shares 75 with a tiger Oscar. Get along just fine. This is recent behaviour. Water chem and temp good. Now I see a mark on his head. Not sure what I’m dealing with. Pic attached. Ideas?