I can't comment on species because there are so many that look so much alike, and the difference may be few spots on a certain fin, or a mid blotch one side off center that separates one from the other.
That said Geophagine males usually have much steeper defined profiles.
Here is a couple examples.
Male
female, less steep more rounded below
another species
male lower in the shot female above more in background
At maturity males also seem to get more flowing fins, and sometimes more striking colors
Below male G altirons