Seeing it Heiko's Way; The Pellegrin altum

[raglan]

OK, we've been 'round and 'round the Mulberry bush on this already.

We can extract three viable arguments which might be considered , in support of Heiko's assertions.
1/ Pellegrin described fish caught in the Atabapo area. So by definition, that is Pterophyllum altum. Other angelfish have to be compared to that.
2/ Reproductive isolation of the population, from incoming genes that exist outside of the specified area. This could be a physical boundary that prohibits other fish from entering the area.
3/ Differing traits as determined by visual inspection, or differing quantity or qualities, of some universal traits ( such as behaviours, scales or fin rays or colours or size).

Now it so happened that I got baby altums this year, and noticed their splendid profile, different but the same as others.

How different but the same ?

More altum-like.
Dime-size fish with predorsal notch that is more than some adults have developed.
Another person who shared the box of fish commented on the strong profile.
Of course, many adults we see that were thought "not" true altum, have more notch than some of these babies...it's a consistency that these babies have, of good notch. Not extreme, at this age, of course, but I haven't seen that on the other batches, some have pretty straight profiles at this small size. Even this week someone who is not that much into altums commented on the old baby pics as maybe not altum because they were not showing strongly notched predorsal profiles as babies.

So I enquired of my dealer...
Q/ Do you know where are these babies are from ?

A/ Puerto Inirida.

So , I wonder...is this perhaps canalisation of a characteristic, in this geographical area ?

Thanks, Heiko,
Sincerely,
Dave...recharging camera to try for a decent photo at least