Swimming Decorator crab

I have a yellow wrasse that doesn't look too well. I don't remember how old it is but I don't have it that long, maybe a year or two. I got it full grown.
For the last few months he is having trouble swimming. Wrasses don't swim well anyway but this one seems to have a tail that is semi paralized.
He looks good, eats and gets around but fish, like people also develop other diseases and maladies that we can't see on their skin. We usually see spots, discolorations, fungus, fin rot ...

I kind of like bristleworms but now I just have too many of them. Whenever I move a rock I notice it is loaded with the little slimers. I recently had a small clam up on the rocks and it fell onto the gravel. The worms sucked it out in no time so now it is war. Over the years I have made dozens of bristleworm traps and just about any design works. You can even put a piece of clam or fish into a piece of stocking and they will be stuck all over it.
This design I made in about 5 minutes ...

This month my tank is 41 years old. I don't remember when I was 41 years old.