Just quickly...
^ Looks like a random screen grab not appropriate for an art piece. Overall boring to look at, not much happening, boring pose, bad frontal lighting flattens forms, fish competing for attention. Boring symmetrical composition, looks more like cropped image than an actual composition.
^ more dynamic and interesting pose for camera, well balanced primary and secondary focal points that keep your eye moving around within the image. lighting is offset to bring out the forms.
If you want to make an artpiece then try stepping out a little from directly copying the reference.
Try combining multiple references or at least consider the background and lighting oppurtunities to form an interesting scene.
