My english is not good but I will try to explain.
All of chitala lopis & RCK - The skin area at base of swimming fin (near it cheeks) must have black color, at this point CK haven't. Your compare with your RCK and CK.
At this trick, CK lover can seperated chitala lopis from spottless CK at LFS.
In fishijn web. When chitala lopis just caught, normally it have silver olor (pic 3). In aquarium most of chitala lopis adapted it color to black (pic 4,dark black or black with shiny green).
I keep 5 chitala lopis (25", 16", 10-12", all wild caught) and 1 spottless CK (breeding)
If u visit BKK I can give u one.