Your parasite looks to be the beginning of Hexamita. This is commonly referred to as Hole in the Head, though it often occurs on the body. Hexamita is common in cichlids and if left untreated, will create craters all over the body before eventually killing the fish. Many believe it is feeder fish that bring this into our tanks. Equally as many will show you a fish with the same problem that has never had feeders. Regardless, metronidozole is the way to go. I would recommend mixing it in the food. Jungle Anti-Parasite food contains it, but many fish hate the way this food tastes. API General Cure is a mix of metro and praziquantenel (sp?) and will also do the trick. Treat it ASAP before it gets worse.