Good job and nice finish for a first challenge entry. This is an advanced editing challenge too, which makes the good score even better. I believe that I would have cropped the top off, right down to the eyes, and left the crab peeking out of the image, and his reflection to show that it was a hermit crab. Try scrolling down so that it is cropped that far at the top of the screen, and you will see what I am talking about. It would fit the challenge description better that way.
Just my opinion.
Hope to see more of your work here in the future.
Really nice idea and I like the sharpness of the claws and the eyes of the hermit crab. From a personal perspective I do find the reflection to be a little distracting. Nice colours