Okay... these little Thor Amboinensis shrimps always make good and colorful subjects but they are soooo tiny.. 
I like the whole environment, which is rich in geometry and textures, it's also good that you tried to snoot the light on the main subject. I think I get the general idea of what made your time worth for this image.
But from my side, I also see some problems in your image :
- probably not close enough, the subject is a bit lost, too centered too, I would have put it more aside. The benefit of getting closer is that it would probably get rid of the remaining disturbances in the bottom foreground
- now for the angle, it looks difficult from the grounds around to shoot otherwise than from top, I would have liked you to aim this shot with a lower angle, coming from the right side. You say it was not possible, which I understand. Personally, I now skip photo opportunities with an environment that isn't convenient to shoot nor aesthetic enough. I used to feel guilty missing a potential shot but since I read it from Martin Edge's book, I am now comfortable with this option.
- third problem is the light. Again that was nice trying to focus the lighting only on the shrimp, but since the area is so small and it is so difficult to get the exact beam coverage, it also lighted up the coral in the top right corner, which attracts too much of the reading.
Anyway that was just my feelings. 