how do these fish interact together in aquaria? so long as I provide a large enough tank and plenty of food, do you think these species at full size would be functional/good tankmates?
bad idea man. At the store we tried to put them together in one of the tanks. The pikes killed all of the oscars.
I don't think the larger Lugubris-type pikes would have any problem putting an oscar its place. As mentioned by aclockworkorange, there are tons of species of pike, and their size and temperament vary greatly. Mixing pike species may be something you want to avoid until you're familiar with pike aggression. I started out with a single pike species per tank. You also need to make sure you have an adequately sized tank/filter, as large pikes can be messy and sensitive to water quality, and the same can be said for oscars.