I have had one for almost 4 years now. H e was in my 37 gallon for about a year before he started to come out of his hiding hole. For the next two years he was an awesome aquarium addition. Then one day Mr. Wrasse had a big chunk missing in his back. I could not believe it but it healed. Then a few weeks later another big chunk was taken, This time I could see bone. What was happening is that the wrasse sleeps in the rock at night and the lobster is out feeding at night. The wrasse healded again but the lobster has lived in my refugium since then.