the grading lies more on asian arowanas, particularly the red.
they can be divided into 1st grade red and 2nd grade red. 1st grade red can have different intensity of color ranging from yellow to orange to red to blood-red and chilli-red. the higher intensity red is more desirable and often demand very high price. tt is often difficult to diffferentiate 1st grade red from 2nd grade red when the fish is young. young 1st grade red's tail and anac fin have intense red color and their scales are shiny gold in color with some green at the base. young 2nd grade red has orange fins and the scales color are no obvious and often whitish silver. when the fish grows, in 1st grade red, the color of the fins remains red, their scales and the gill cover will develop its color. the type of color it will developed into depends on which type of 1st grade red you have. nn the other hand, the adult 2nd grade red will only have pinkish or orange colored fins, thier scales and gill color will only developed pink or orange color.
for other arowanas, silver, pearl etc. it mostly depends on the colour of the scales and abodomen. in terms of scale, it can also divided into thin or thick frame. thin frames with colour tints are most demanded. the colouration of the dorsal(back) fin and the anac is also important. good grade arowanas have fins which colour flows with the fish.
