One of the things I'm finding interesting, is how restricted some species can be.
In rivers of east central Panama, the Pacora, Utrive, Cabre Bre (all )south of the spine of the Cordillera Central mountains, I find only 2 cichlid species, Isthmoheros tuyrense, and Andinoacara coerleopunctous (at least so far).
It is not until the Rio Mamoni system, a few miles furtther east, does Darienheros calobrensis appear.
I suppose this may not be significant to many aquarists, but shows how a distance of only a few miles and the connection (or not of is rivers,) restrct species distribution, and may effect (in my case) a biotope tank.
Both the Isthmoheros, and Andinioacara, are found throughout the entire east/central region.
But not until the edge of the Darien, does Darienheros appear.
It may also be, that the velocity of flow, and topographical conditions in some rivers may support different species requirements.
Above the more Central Cabre bre river
Below the Mamoni