Those things on his cheeks are something that every pleco has but they tend to be hidden inside of the cheek. They use em for self defense and ya only see em when the pleco thinks it's threatened. Most loaches have something similar as well.
I've dealt almost exclusively with common pleco and if they had these structures, they never stuck them out when getting caught and handled?
I have handled plecostomus and pterygoplichthys species, and these don't have them occular spines
From what I've noticed atleast is that they need to be under extreme stress. My bristlenose and clown plecos all use to do it but generally only when either infighting or if I grabbed em by hand, not a fan of netting em. Granted theirs didn't come out as far as the one in the pic does but they do definitely become visible/harmful. Lol had it once when I was moving a bristlenose around, he managed to pin my thumb in-between his cheek bristles and pectoral spine and refused to let go lol. Chewed my thumb up a bit when he tried to struggle free. Lol I was just glad it was only a bristlenose and not a common. Only got to see em on the common once and that was only because the larger one crushed the smaller one to death and forced em out. He was a mean pleco tho, he killed atleast a handful of fish before getting rehomed.
They are very well hidden for the most part. Only specie/s I can think of that show em 24/7 is the royals. This here is a pic of a BN pleco with hers visible, not mine just taken from Google. But yeah they pretty much just slot in inside of the cheeks.
Yes most panaques have these spines out, and ancistrus and hypancistrus do flare them when caught or when they fight.
Love those streamers on his tail. Lol wish I had a tank big enough for one, they had a lil 2in baby for sale up here that I wanted so badly but I decided against it. Had a lovely stark white spotted pattern, not sure if they keep em or not when they grow up tho.
They have those spots only till they reach 4-5"
Lol reminds me of my old common I had a couple years back. He killed a 14in giant gourami, 2 madtom catfish, and a 6in common pleco. Tried to spine the Oscar at one point and got himself beaten to the point that he looked like this for a month. Least to say he calmed down quiet a bit after that, never thought I'd see one fish suplex another tho lol.
