The fish is Hericthys carpinte. One of the best ways you can tell is by the size of the spots and the way they are situated on the body. Cyanagutattus "pearling" is much smaller and evenly sized. They also more or less are evenly lined along the body. Carpinte have unevenly sized pearling and less evenly distributed.
Here's a H. cyanaguttatus:
This is H. carpinte "Rio Salto"
Regarding sex...the female species of this family will generally have a noticeable black blotch in the dorsal fin. It's difficult to sex the fish at the size in the photo.
Here's a H. cyanaguttatus:
This is H. carpinte "Rio Salto"
Regarding sex...the female species of this family will generally have a noticeable black blotch in the dorsal fin. It's difficult to sex the fish at the size in the photo.