Arend_van_den_Nienwenhuizen Photo of a Blue F. gardneri from the 1950s

What about Blue gardneri?

In the early days of the killi hobby there were only two types of gardneri were known in the hobby While there had been photos of 'gardneri' published previously they were usually F. filamentosus or F. walkeri. But, fro Scheel and Clausen's collections inthe 1960s, F. gardneri clauseni from Akure, Nigeria was introduced into the hobby. These fish occur in teo color forms, yellow and ble, which refers to the outer submarginal band in the unpared fins. The yellow was known incorrectly as Aphyosemion calliurum ahli while the blue was referred to Aphyosemion calliurum calliurum. This was a mistake as A. Calliurum is a small brown fish more closely related to the Lyretail (Apysemion australe) than to any Fundulopanchax blue or otherwise. A. gardneri was first recognized as a superspecies by 1970 by Scheel. Four nominal subspecies exist and a fifth, spoorenbregi is shrouded in mystery, there is a non-zero chance it's F. gardneri obuduense. In 1981 Parenti moved them to Fundulopanchaxwhere they remain today. Prt of the mystery was resolved when Michel Popoola found them in the wild thus ending the mystery of where the fish that showed up one time in a commercial shipment with no location data was actually from

There are blue populations of F.gardneri and they can show up in yellow strains for a reasons, explained herein.