This is a striking case, a nagyi-male without any colours in the caudal. I have not heared or seen anything similar before. I shall ask some of our specialists of this species whether this has been observed before. Normally the colouration of the caudal in the males of the known varieties of nagyi (Kuantan, Cherating, Pekan Nenasi and even the somewhat strange fish from Kota Tinggi) are clear and obvious.
Stefanie: Did you observe this with relatives of that individual, too? Or is it a singular phenomenon?