i was gonna ask about that topic here myself. I found EVERY fish with EVERY fin, all 441 versions and even made a great completed spread sheet. And the highest paying fish is $179.00, the Canary Fire Arrow. Nope, nothing comes close to 300 bucks. And i tried "warping" my extreme fish to see if there is a "hidden" fish. Spent 20 grand on the mutating fluids, again and again. No "unknown" change from the Twin-fin Shark and Spotanus. No change from the Silky fin fish of same breeds. Nothing. So what is this hidden fish? Anyone find out?