yes, he is a julidochromis marlieri. these is a dwarf variant from gombe and its usualy mislabel as juli transcriptus.
if you can pair him up wil be great.
this is a little nasty cichlid and its from lake tanganyika.
i don't think there will be much trouble with mbunas but if you can get him a little protein food that will be great cause difrent from mbunas he is omnivour.
it reaches the size of 3'' and for its size its very aggresive
great find..!