Might be vittatus, its hard to tell from just looking at pictures, especially at this size. Some tatf can have red on the tails too. Can you get a better lighted picture that shows his colors well?
I'm still strongly inclined to call that a tatf as well. There is a bit of individual variation in populations, and the very closely related to tanzaniae tigerfish, vittatus, displays confirmed sexual dimorphism. Its possible that tatf do this as well.