From Tap Fish's facebook page:
"We have great news everyone! To continue playing Tap Fish with all the latest updates (including the mystery breeding lab) and the ability to purchase fish bucks, you can now download "Tap Fish 2" from the App Store. Once you install "Tap Fish 2" you will be asked if you wish to restore your previous game from "Tap Fish", "Tap Fish Exotic" or "Tap Fish+". Select your old game and continue playing using "Tap Fish 2"."