I received the book today - which is very quickly when considered it was sent on the 3rd of August from Japan - and it turns out to be the second edition of 2004. I wonder if there are changes between both editions except for the cover.
Perhaps the easiest way is to count pages. This one has 224. Jools or HH, how about your books?
I'll post a picture of the cover later on (must charge batteries first).
I think I have read somewhere that the older copy has some photos in black & white and that the newer edition may have a few extra fish and / or photos.
I also purchased a copy of this book from the same seller, I'll let you know when it turns up. Thanks for the link btw, I've been looking for it for some time. I did see it on Amazon Japan and another Asian book seller a while ago, but at the time neither indicated which edition the were offering. There is also a site in America that has it listed, among other interesting fish books.