Congratulations - that's one of my favourite species. I wouldn't say Pseudochromis aldabraensis is particularly rare in the wild. I have collected them in the Persian Gulf, where they are fairly common in a range of habitats. They are often associated with Diadema sea urchins, so collecting them is not always easy. The species ranges from southern Oman and the Persian Gulf east to Sri Lanka. It seems likely that the locality information for the original (holotype) specimen (supposedly from Aldabra, which is off the coast of east Africa) is erroneuous - but that does not alter the validity of the name!There is a very similar species in east Africa (P. dutoiti), and until my studies published in the early 90s, the two species were confused. (Current data on FishBase still confuses the two.) The Red Sea species P. springeri is also closely related, as is an undescribed species from the island of Socotra. (The latter looks like P. springeri but grows much larger.)
It's great to see that this species (and several other dottybacks) are being captive bred.