I'll start us off, by listing the aquatic non-rare pets, since the two first stones I got were aquatic. Feel free to correct it, or even contribute with your very own family list that others can correct. I'll try to update this first post as more and more lists are posted, to keep it all neat and tidy.
Aquatic non-rare non-wild pets
- Sea Pony
- Fishy #22/ Tiny Goldfish #21
- Mr. Chilly(same as Tundra Penguin #9)
- Shore Crawler(same as Emperor Crab #4 and Shore Crab #3 + #7)
- Tree Frog(same as Frog #12)
- Wood Frog(same as Mojo)
As you can see, 4 of the 8 pets in this list has rare replacements elsewhere. Speedy and Jubling has replacements, but not with the same breed id. Sea Pony and Fishy(or Tiny Goldfish) are therefore perhaps the best options. I'll opt for Fishy first, just because he has a few health points more.