I believe your loach has some kind of disease that causes the fish to lose pigmentation.... I recall reading up on it a number of years back... will try to find the link
Interesting! I learned something new today! (Thanks Vince for the link)
Years ago, I got a gold fish that completely in jet black and after 2 years it's become albino and my family asked me what's happened to the fish but I have zero clue to answer their question LOL.
"One major cause for the glandular imbalance is osmotic shock. This happens when the water chemistry is altered too quickly for the fish to acclimate. Water chemistry changes can upset the melanin producing gland.
If I had to guess, probably when you moved, the water chemistry changed, and triggered this condition. Some clown loaches are more sensitive than others to water chemistry changes. "
you're actually kidding me...i've seen one or two of these before in the lfs in years past...if i'd known the value i'd definitely have bought and resold them