Pseudotropheus saulosi and pseudotropheus demasoni are two different species, I suspect you have the latter.
Added: I noticed on another post you have a 10gal and a 20gal tank. Neither tank is suitable for mbuna (rock-dwelling cichlids of Lake Malawi), of which p.demasoni is a member. You can safely house them as a species only tank in a 40gal breeder tank, or, with other mbuna in a 55gal or larger. I suggest you read this for more information on mbuna keeping. http/www.fishforums.net/index.php?showtopic=27706