Male Keyhole Making A Nest?

[Katty]

My ~3ish year old male keyhole cichlid appears to be digging some sort of 'nest' in the gravel in the corner of the tank? On top of this, he chases the corydora tankmates out of that corner and his 'keyhole' pattern becomes very vibrant as he does so. Even weirder, his... anus? appears to be sticking out as a slightly pink nub.
 
He also did all of this last week for a couple days, which I fasted him for a day then fed him some pea for his apparent butt issue, which seemed to return his hind end back to normal, yet it also coincided with him ceasing to construct the 'nest', which he just recommenced building today, a week later. He will pick up gravel in his mouth and deposit at the edge of the small crater he has been constructing.

Does anyone have any idea what he is doing?

 

[Tongue_Flicker]

Yes, that is a nest. The bigger and 'cleaner' the nest, the more it is attractive to female keyholes. Try introducing a matured female for him to mate with and i would suggest separating the corys for the meanwhile.

 

[Katty]

Wow, weird, thanks! Unfortunately I don't have any ladies for him xD

Any idea if the thing going on with his rear end related to his nest building or is it a coincidence?

 

[Tongue_Flicker]

Is it short and rounded or pellet-like in appearance? The former is for a female, the latter's for males. It is their copulatory organs just waiting for a mate to fertilize