Thanks for the comments! I used a 105mm macro lens and a tripod for all the pictures (some top down, some through the side). I actually used a very large DOF for all which was achieved using a small aperture and a long exposure. The backgrounds where fairly dark to begin with but I removed them completely with photoshop, contrast and sharpness where adjusted but I did not alter the color or lighting. For #3 I took advantage of the shadows present and made sure to meter the lighting correctly to include them. I added a radial zoom blur to the edges of #4. The blur effect in #6 was actually from the fish breathing during the long exposure, I just cleaned it up a little.
Thanks again.