Small hermit crab disappeared, including the shell

[animuldoc]

Hi, I have a very young tank, three weeks. My LFS who set up my 120 gallon tank for me said I can get in Bert’s after about five days so I did. I got e7 trochus, 10 blue legged, hermit, crabs, two cleaner shrimp, and one sand sifting star. I had watched the BRS 60 videos for beginner before I got all this, but I’m also trusting my LFS, who have been in marine aquarium business for 27 years. Anyway, so I know there’s a lot of controversy on if I should have anything alive in my tank right now. (besides, bacteria and algae .). I can discuss that later but my question is I’m seeing fewer and fewer crabs. I thought it was because they’re kind of hidden in my rocks for the most part. but I did see one empty shell the other day. I do have extra shells that are slightly bigger scattered throughout the aquarium. But that empty shell is gone also now. how does that happen ?

 

[blaxsun]

One of the other crabs may have upgraded (or downgraded); this is a fairly common occurrence. A lot of times they are hidden very well in the rocks, so keeping an accurate count can be challenging under the best of circumstances!