This is MAYBE a Lithochromis rubripinnis (Blue pseudonigricans)
The dominant coloration is very dark blue, almost black below
In a less dominant mood, the blue lightens and the stripes appear
Below are the many colors of the dominant male:
A holding female is shown below:
Below are some pictures of juvenile males:
I have some serious doubts about the identification of this fish and am researching the ID at the moment.