very nice male Jin Kang.. a golden flowerhorn.. some might call it a golden trimacus.. or tri thong.. well what ever you might wanna call depending where that fish was bred from.. i see yours very nice.. .. well another way to test it .. is testing that badboy with some females that is a lil smaller than him.. so he'll be more dominant..in case they start attacking each other..
but i would go with a male.. since it shows his hump and plus the body is pretty proportionated, and stocky than a female.. that would be more oblonged..
well it is pretty hard also that we cant see the venting.. specially in person..