Nope, they should be in a single species tank.
Even then they sometimes gulp up eachother, or your hand during maintenance.
You need a group to make them feel at home.
Sweet fish, when you´re ready for them.
The price of those fish are incredible over here.
And i checked for you, 249us$ a piece, and you may want like 4 the least.
Very cool fish for handfeeding!
They eat bigger fish than themselves by letting the prayfish swim into his mouth.
The feeders reaction will be to try and turn, and gets folded up in the Gulpers belly!
I used the AqAdvisor to give you a clearer picture.
4 Gulper willl need a 180Gl and a huge canister as well
www.aqadvisor.com/AqAdvisor.php?AquTankN...;AqSearchMode=simple
btw you got a signature!lol