Actually, Pictus are of the Pimelodid family, a species of highly predatory catfish. Those nice long whiskers are for searching out prey. They are far from oppurtunistic feeders as once night falls they will prwol the tank looking for food.Pictus species are opurtunistic feeders. If they are hungry and the cories can fit in their mouth, the pictus may try to eat them.
Or they get stuck in the mouth of the predator and both fish die.I'd be surprised if it managed to eat a cory or another catfish, their pectoral ray deffense system usually means they are spat straight back out again by all but the largest predators..
How big is your pictus?
Ben