Marine Aquarium 2.6 has now been ported to the iPhone/iPad by the Order N Development team. This Aquarium product runs in portrait or landscape mode on the iPhone, or in landscape mode on the iPad.
Marine Aquarium 2.6 runs at a resolution of 1024 x 768, which is the full resolution of the Apple iPad without any need for stretching, doubling, etc. The Aquarium can be zoomed in and out using pinch movements on the iPhone 3 Series (480 x 320) and iPhone 4 (960 x 480).
Fish may be selected using a Genius system to add stars to fish you like, and take away stars from fish you don't.
UPDATE: Marine Aquarium 2.6.1 for iPhone/iPad allows you to override the Sleep/Lock setting of your iPhone/iPad and run the Aquarium for a user-defined duration.
Marine Aquarium 2.6 for iPhone/iPad may be purchased on your device from the App Store. Details for Marine Aquarium for iPhone/iPad.