I bought a yellow canary wrasse about a month and a half ago. When I released him into the tank, he stayed out for a few minutes then disappeared into the sand. I did not see him for 2.5 weeks and marked him as dead. Then one morning I was passing by the tank and saw him swimming around. By that evening, when the lights went off, he was gone. It took him another week to start swimming around when the lights came on at 5pm. Now he is all over the tank. You have to be patient, he will come out when he is ready.