If we drop the cetaceans and the pelagic species, it leaves us with a still reasonably respectable roster.
Either way, I'm of the personal opinion that, if aquatic animals are added in PZ2, it'll be similar to with JWE2 - They'll be there, but just not a focus immediately. Same goes for flying species if they're added. I wouldn't be surprised if the main focus was still on the "main" animals.
- Green Moray Eel
- Green Sea Turtle
- Scalloped Hammerhead Shark (my personal pick of the two)
- Manta Ray (or at the very least a similar species)
- Giant Pacific Octopus
- West Indian Manatee
- Great Barracuda
- Common Sawfish
- Blacktip Reef Shark
Either way, I'm of the personal opinion that, if aquatic animals are added in PZ2, it'll be similar to with JWE2 - They'll be there, but just not a focus immediately. Same goes for flying species if they're added. I wouldn't be surprised if the main focus was still on the "main" animals.