Looks good, nice fish too, depends what you were trying to achieve though with your photo as to feedback. If you were after just a documentary of your fish then the exposure looks alright and its well focussed which is always good. If you were after something more 'arty' then the compositions a bit static where the subject is centralised, try moving the subject around in the frame. Golden Ratio and all that maybe worth a look at (if you hadn't already)-although golden ratio makes for good 'guides' you'll work out what looks good to you and what doesn't.
Hope any of thats helpful,
Neil