Xenotilapia sp. 'forked tail' female? - Photo by Bruno Dickmann
Xenotilapia sp. 'forked tail' was discovered by the German Bruno Dickmann during a journey to Lake Tanganyika in 1999, organized by the German exporter C.J. Aquarium. The locality where it was found was a small bay between Nkamba Bay and Kasaba Bay in Zambia, which is well-known for another reason; it’s the same locality where Tropheus moorii Ilangi is caught.
Xenotilapia sp. 'forked tail' male? - Photo by Bruno Dickmann
In fact it was the selfsame Tropheus who led to the discovery. After Dickmann had caught some T. moorii Ilangi, which was the purpose for visiting this locality, he went out to see if he could find Xenotilapia nasus or Xenotilapia sp. 'fluorescent green'. He dived deep, 55 meters (approximately 180 feet), and reached a sand-floor with big rocks scattered and covered with sediment, he then discovered a sand-dwelling cichlid he couldn’t identify. He managed to catch several of them and they were put to decompression for three days, slowly moving the fishes to the surface 10 meters at a time. Unfortunately they died nearly as soon as they were taken out of the water on the third day.
The cichlid caught by Dickmann clearly is a Xenotilapia spp., with some resembling with X. bathyphila, but the latter don’t have the strongly forked caudal fin. X. sp. 'forked tail' has a higher build body and a longer snout, with a protruding nose. Whether this sand-dwelling cichlid is in fact a new species or a local variant of X. bathyphila is not known.
Addendum: When the above was written, not much was known of the geographical variation present in Xenotilapia bathyphila, which had only been sporadically imported in the past. Today our knowledge of X. bathyphila is much better, and the fish depicted in Dickmann undoubtedly correspond to this species. Please also note that X. nasus and X. sp. "fluorescent green" are today considered to be the same species - more information here.