Your coco is really good looking! I had one that was about 8in long, he was healthy and happy too untill....I bought my Barnacle Blenny. The blenny made my coco jump ship so that he could live in his tube! :scared:
The coco was eaten by my little lobster before he could make a new home.
Anyway, yours looks great!
Here is a really bad picture of my Barnacle Blenny in my Coco worm's tube!