Cut out several gold fishes from a certain picture and insert each of them on a new layer:



Blur out the edges of the fishes' fins and the tails, using the Smudge Tool.



Then make many copies of the fishes' layer. Correct their sizes and placement, selecting the Free Transform option and Flip Horizontal selection. Then we should also change the distort level of several fishes, using the Distort option.



Merge down the layers with the fishes and correct the layer's brightness, making use of the next selection: Image ? Adjustments ? Curves (ctrl+m).



Create a kind of marking on a new layer, having the circle's shapes, using the Elliptical Marquee Tool and clicking on the shift button. Paint it in black, using the Paint Bucket Tool.



Select the next filter: Filter ? Render ? Lens Flare.



Using the Gradient Tool, it's possible to add more light on it: