Dont get caught up with MP size, unless you intend to print pictures above A4 5mp is more than adaquate. My origional Digital Camera is a Kodak DX4530 (I now use a Nikon D70 SLR) and still takes great pics. Heres some shots I took with it. Check Ebay and see what you can pick up there. TBH its all about practice, practice, practice when it comes to photographing fish.