Saltwater fish who eats and moves rocks

Question
Hi,
My husband has a 500 gallon saltwater aquarium and he just got a new fish that we don't know the name of but would like to know so that we can research it more.  I am (hopefully) attaching a picture.  This guy (or girl) seems to clean the little rocks by sucking them up and then moving them (or the dust) through his gills.  He also spent his whole first night in the tank making a little hiding spot by moving the tiny rock from where it originally was into a BIG pile around the live rock so that he now has a little cave.  Very cool fish - do you know what he is?
Thanks so much!  Oops, sorry.he's hiding in his cave now so now picture.  He is Yellow/tan ish with faint tiny spots and at the store he was almost standing upright instead of swimming normally.....strange.

Answer
Hi Christa,
 I strongly suspect that you have a yellowheaded jawfish.  (P.S. There was no picture attached)
They come from the Caribbean.  They typically make deep "burrows" down into the gravel and are very busy fish constantly working on maintaining and upgrading the burrow.  Very cool fish.

-- Ron
  rcoleman@cichlidresearch.com
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