Yes, there is something fishy on this picture.. But I dont believe it's the fish, but the reflection in the upper right corner of your picture. I also had this problem last time I went to an aquarium and solved it by using a lenshood and by moving close up against the glass. The second problem I see you've run into is of course the blur. Typical, but hard to deal with since the light is poor and the fish is.. lets say: not standing still? I got this amazing picture of a shark swimming against me totally destroyed because my lens couldn't handle the poor light.

But here, the more I look at your picture, it kinda feels all right! You can see the movement very good actually. Wonder what they are thinking; ''what are we doing here? What are we doing here?''

-Niklas