A Pleco...lol... I don't know, I just want to compliment you on how good he looks!
-FHM
Stressed... How can you tell?its a stressed bristle nose, looks like a female but that depends on big/old it is
plecs come out in light patch's like above when they are stressed. If its just been introduced then its bound to be stressed. Just make sure water is perfect and plenty of hiding spots
To young to tell how old then, photo makes it look bigger