There are a few new Tank Mates available in Happy Aquarium. You can find them under the Special tab, or under the reserved Tank Mates section of the game’s store. The trio of items come in the form of a Baby Angel, Baby Red Devil and Batfish.
The Baby Angel and the Baby Red Devil cost the same – at either 58 Pearls or 48 Facebook Credits (or around $5 US). Meanwhile, the Batfish costs more, at 69 Pearls or 58 Facebook Credits.
There are around 4,000 units of all three Tank Mates available, but as Limited Edition items, you never know when they might sell out for good. That being the case, head over to the game’s page to purchase any that interest you.