I've noticed the bristles are later to start to appear on the L144's than some other more common bristlenose plecos. You are right brad, around 8 months. You can't always go by how they interact with each other because the young females will puff themselves up and try to scare other females away from food more often than young males toward other young males. If you have more than one you can begin to watch the shape of the mouths when they are against the glass....males have a slightly pointier mouth where females are more rounded in the snoot. And as they get older, you can also see there's a difference in the shape of their bellies when they are against the glass. With the brown bristlenose, when I would catch them and place them in a clear plastic container when I was shipping them, when I held it up to bright light, tiny bristles were there at an earlier age than the L144's. With males you will begin to see tiny bristle stubs around the mouth, but don't confuse them with those side bristly things......for the life of me I cannot remember what they are called,(begins with odo.....??), anyway these odo thingys are on either side of both males and females mouths and are sharp. Maybe someone will come along and put the name of those little thingsy here for my brain!
