That is correct. Your turn.
Had a few large males in the past. It use to go by the common name of Tiger cichlid (after it's juvie pattern) but I think I'd be among the few that still call it that. Not a fish you see too much of now days.
'Water Fluid Organism Fin Underwater'!
Well, that what the caption says when you hover over the picture with your mouse cursor at least....
Is this Guapote' displaying the 'other' silver/green coloration of Petenia splendida, (Red Bay Snook)?
Time to give some hints. South American cichlid that belongs to a genus with 18 described species. A distinctive marking common to members of this genus is it's horizontal stripe that starts above the eye on the forehead and ends below the back part of the dorsal fin. Though this particular species often does not express this stripe fully.
Nope. Not an Aequidens species. Only 15 described species in that genus and it lacks the distinctive horizontal stripe from top of the eye to the back of the dorsal fin.
Another hint: Mystery fish is a delayed mouth brooder, as are the other members of the genus.
The fish comes from the Aguas Calientes river basin on the Parana river basin in Bolivia.
The fish is known to lay eggs on a leaf and drag the leaf to a safe location. Once the eggs hatch into wrigglers the female takes them up into her mouth and mouth broods them into the fry stage. The fish is thought to be a specialized molluscivore based on the shape of it's mouth and jaw, as well as finding crushed snail shells in the guts of dissected fish.
I was hoping to get more people into this game so I have refrained from guessing. The fish is instant recognition to me and I think it should be very easy for anyone some what familiar with CA cichlids. I'll give it another day for someone else to get it before posting.