I scored you high because I felt it was really well done and I know how difficulst it is to do a fish shot! I only wish the snail was easier to see. Great focus and the translucence is daring. I agree with all the other comments. I guess it didn't strike enough 'cutsie fancies'.
Great composition but I think that although the colour of the Discus could be better with the use of different light the eye is too dark but perhaps you wanted the dark background to emphasize the fish. Just a shame the vivid colours seen around the edges were not more prominent all over :0) Good shot