Which Centrals?
Cincelichthys pearsei, and bocourti, are primarily vegetarians.
Some Vieja are at least 50%-75% vegetarian, in nature eating fallen fruit, leaf litter and algae.
Vieja maculacauda make regular forays into brackish areas and straight sea water to eat marine algae.
Most Central Americans are omnivores (not carnivores) so get plenty of vegetation in their diet.
The only true primarily Central American Carnivorous piscivores are Parachromis, Petenia, and Caquetaia, and even they end up getting plenty of vegetation in their diet when they eat entire insects, crustaceans, and fish (guts and all)