We went to Alameda a few months back and got this from some enterprising fellow. He had found a cool book of old "Audubon-style" prints of birds and fish and was selling the pages for $3 a pop. We don't condone desecrating a good book, but if it's filled with pictures rather than text, why not showcase some that you really like?
We bought this one and took it down to our local frame shop, where they have a selection of frames made out of remnant moulding sticks. This one fit perfectly, and though we wouldn't necessarily have thought to pick it out had we been doing a custom job, we think the citron-tinted wood looks great with the pinks and yellows of the fish. Total cost - about $20.