I don't know about the diet part, but the fish Mike pictures belongs to the
'type' A. agassizii found mostly in the Rio Amazonas of Peru & Rio Solimões of
Brazil. His fish is very similar to the common blue bodied "Red-top Blue/White"
aggie imported from many locations in Peru. I must say, however, that the Rio
Tigre form's orange body makes it a spectacular looking fish; one well worth
keeping as a pure population.