Yellow watchman goby

[Freenow54]

My new watchman goby is in quarantine feeding it well with fish oil covered flakes mysis shrimp and pellets soaked in fish oil. Problem is it likes to hide in my provided structure. How can you tell if it's eating? I have to move the structure to get it to display itself so I know it's alive I don't like doing that. Is there a better way?

 

[Mr. Mojo Rising]

Its a very timid fish, it will hide every time you get close. Drop the food and take a few steps back and observe from far