Originally Posted by
Longfin Lover
So....ummm is this what I think you said? Each scale expands out (wider) and grows back towards the tail with the root closer to the head. The root or base gets thicker and the colour denser in the middle sort of like a fingernail? As each scale gets thicker with age, the whole area if it it is good would be a denser colour?
Actually, each scale expends it's total circumference. The root doesn't really get "closer" to the head. As the entire scale increases in size, the color pigment within each scale "stretches" causing the outer area of the scale to become lighter than the center of the scale. This is referred to as "Hoshi" in Japanese. Yes, in very high quality fish, this "stretching of the color" can be observed in some cases up tp 5-6 yrs of age. The longer it creates hoshi, the better the quality of the fish as it reaches maturity and beyond. Once the color becomes homogenous, due to adding layer upon layer of color each year, the color will appear deeper, just like spray painting a car with 10 or more coats of clear lacquer to allow a sense of "depth" to be observed.
So there are no new scales just expanding ones. Do fish replace lost scales with new ones from an injury?
Yes and no! Young fish, usually under 3 years old, can replace lost scales more easily than more mature fish. Fish at 3 yrs and older have a very difficult time replacing scales. This is why, as a fish gets very large it is assumed that it's age is relative and if there are no scales missing or deformed, this is also considered a factor in judging. It's not easy to maintain a fish throughout it's life, to say, age 10, without losing a scale or two along the way.
But some scales loose colour and then some get it back too?
Again, yes and no. If a scale loses it's beni, or red coloration, it is usually gone for good. There are a couple of circumstances where it could return, but they are not the norm. As to sumi/black, if a fish is young, say 4 yrs or younger, sumi can be rather unstable in it's appearance. It can rise and fall based on growth, water temperature and certainly water conditions. Learning how to look at sumi on a young fish to judge it's inherent "quality" is a lesson for another day/time. But, if you can learn to discern the difference, you can end up with some very nice quality fish.
Thanks for any info...just trying to understand.