I'm guessing they're woodi, but not 100% sure (they're WC and the guy I got the group from got them as macrophthalamus, but there are two different species in my group of 16). Could also be esox, but there's so few photos out there of them that it's impossible to get a possitive ID. Not too much is known about them as they're hard to watch in the wild, and not too many people are keeping them in captivity (I've never seen them offered anywhere). I had a tank full of a bunch of different Rhampho's when I was at Stuart's in Malawi, and they were a favourite to watch feed feeders. Thinking these guys will get to about 12-16", with the R. macrophthalamus getting close to the same size. The coolest thing is that they spawn mid-water, no bower on the ground.
I actually think watching mine that they would do great in a community tank, as long as it was large enough (at least 6', I'm getting an 8' tank for them in a week or two). The only time they really get aggressive is feeding, and I could easily see smaller fish 'accidentally' getting tagged pretty hard when they're feeding (mine eat NLS pellets). There are some other smaller, much more peaceful fish in with them right now that are doing fine (three female Paracyprichromis nigripinnis that I've been unable to catch).
freeskierrocket - Where did you get yours from? Was it WC as well? and how could you sell it? They're awesome!