So I recently had the opportunity to purchase a West African Lungfish (Protopterus annectens). These are ancient sarcopterygians that grow very large and are pretty unique animals. They possess many traits that early tetrapods had and many odd characteristics for fish such as a four chambered heart and primitive lung structures. These are traits more commonly found in amphibians (some of the first tetrapods) rather than most fish.
After talking it over with my SO, whom obviously has a say in whether or not we could house this fish as an adult, we came to the conclusion that we can make the space for him if he ends up growing 3ft+. With lungfish living 20 years, and quite often more in captivity, they are definitely a long term commitment. In fact there is a Queensland lungfish at the Shedd Aquarium in Chicago that has been in their collection since 1933. (That’s 81 years!) Visually lungfish look so reminiscent of a salamander or axolotl, it’s hard to believe they’re a fish at all. There are only six extant species of lungfish with the largest species reaching over 6ft in length.
Almost all lungfish species are wild caught so I want to give this little guy a nice environment that allows him to behave as he would naturally. Right now I have him set up in a 20gal with some sand and plants while he adjusts. He is already roughly 6-7in in length so he’ll need to go into a 29 gal or 40b as soon as he settles in and I’m certain he’s healthy. He was a rather unexpected purchase and so I have to hunt down a stand for the bigger tank since I used to keep them on a large dresser which I no longer own.
Behaviorally hes a pretty sedentary critter except for when food is around or when he goes up for air. The rest of the time is spent napping among the plants, under the driftwood, or sifting through sand for food he may have missed. I also didn’t have a net large enough to for him but I was pleasantly surprised to find he doesn’t mind being handled gently. Right now he’s being fed NLS large fish formula 3mm sinking pellets and frozen bloodworms. Once I’ve had him for a while I’ll likely write a caresheet on P. annectens. I’m open to name suggestions as well!