Xenotilapia sp. 'red princess' was discovered in 2001 in Chituta Bay, Zambia by the Duthchman Evert van Ammelrooy (van Ammelrooy pers. com.). It was exported to the US the same year and to Germany in 2003 (Kohler 2003; Loose 2004). Until now it has only been found at Chituta Bay and Cape Chaitika, where it occupies the intermediate zone between the rocks and the mud-floor on a depth of 40-50 meter - app. 130-165 feet (Ammelrooy, personal communication). Recently a geographical variant of X. sp. "red princess" has been imported to Germany under the name of X. sp. "fireline - the exact locality where this variant has been found is not known.
Heinz H. Büscher has examined a specimen and in a comment on Loose´s paper, he states that Xenotilapia sp. 'red princess' may in fact be a geographical variant of X. nigrolabiata (Loose 2004).
Whether Xenotilapia sp. 'red princess' is in fact a geographical variant of X. nigrolabiata or a new yet undescribed species has to be resolved, and until then it’s safest to regard the 'Red Princess' as a potentially undescribed species.
Addendum: after an examination of the types of Xenotilapia nigrolabiata present at the Africa Museum, Tervuren [Belgium], it was clear the "Red Princess" indeed corresponded to said species (Andersen 2007)