A bit of second guessing, but Metriaclima glaucos, that is Metriaclima sp.'aurora blue' as it was until this year and which I'm pretty certain is the fish that has been sold under the trade name Metriaclima hajomaylandi Cobwe in recent years, at least in the UK, also has a population at Kanjindo Rocks which variously goes under the name Pseudotropheus sp. "flameback Kanjindo", Metriaclima sp.'aurora blue' Kanjindo, Metriaclima sp.'aurora blue kanjindo' and variou s recombinationsthereof.
Apparently, the Cobwe and Kanjindo Rocks populations are readily distinguishable. As you are going to be will have seen loads of the Cobwe fish, but are wondering about this one, then perhaps this is the Kanjindo Rocks fish. Some photos of the Kanjindo fish I can find on the net look very much like the one you've posted, others much less so, but then photo labels of the auroras and hajomaylandi type fish on the web seem to be all over the place.
If so, I wonder if that makes it Metriaclima glaucos - Kanjindo Rocks, Metriaclima cf. glaucos - kanjindo rocks or if it is different enough to remain Metriaclima sp 'aurora blue Kanjindo'?
Only seen the abstract of this paper so would quite like to see the full text if anyone could their way to sending a copy to firstname.lastname@example.org