Name: Tetraodon nigroviridis
Origin: Southeast Asia
Green Puffers are not a good fish for beginners. They need a good amount of room, I suggest a 200+ liter tank. Though these fish are aggressive, they can have tankmates. Usually larger, and I stress "LARGER", non-aggressive fish make great tank mates. Green Puffers are always hungry, and they will eat themselves to death. These fish are beautiful and playful specimens. Their swimming patterns can keep anyone staring aimlessly for hours.
Puffers are very entertaining fish. And can grow large and live a full life, if you take care of them properly. Green Pufferfish are brackish, so they need salt, such as Instant Ocean, not aquarium salt. Their diets should consist of bloodworms, ghost shrimp, and pond snails. The snails are to help keep their teeth from growing too large. Also, Puffers are fin nippers, and only should be kept with other Puffers, African Cichlids, and sometimes Molly's.
I wanted to stress that these fish are brackish meaning they need salt. Not only do they need salt they need to have a tank all of their own. I placed mine in a tank made up of different types of unusual fish such as a columbian shark catfish, cory catfish, albino shark, dragon fish or Goby. After a day and half I removed it from my 200 L tank to my 40 L tank until I cycle a 110 L just for it. Reason being this little guy may be small (mine is less then 5 cm), but he still has the aggressiveness to act bigger than my 18 cm columbian shark catfish, since he did take a good nip out of its dorsal fin. So keep them in a tank by themselves, and aquarium salt is required. It prefers hiding places such as a small cave and grass. It will eat some plants. My java plant has been chewed on by it. They are really cool looking and have a great potential with the right fish keeper. I do recommend you have a lid on the tank...since mine was placed in a smaller tank he has been doing a lot of jumping.
I would like to stress that these fish are NOT strictly brackish OR completely aggresive. I have had one in a 200 liter freshwater tank with 4 parrots of varying sizes, a geophagus and two neon cats. Besides the cats, he is the most docile in the tank. He is well fed and seems truly happy in this evironment. His length currently is about 6 cm. He does seem to be most intelligent, especially likes to play and seek. However, dot not put this fish in with other nippers, as I did have it in with some barbs who nipped at him, the result being two barbs that seemed paralysed on one side. This condition lasted about three days with twitching and lack of swim coordination. Happy to say both have survived and live with the others in a separate tank.
There has been much confusion on this species and Tetraodon fluvatilis. Most of this is disinformation, unfortunately being perpetuated on the internet. If you look on Fishbase.org, which is where ichthyologists post info, and in a recent edition of Aquarium Fish Magazine, it's easy to tell these two species apart. Fluvatilis is a highly aggressive and poisonious species from brackish waters, that looks totally different from Nigroviridis. Nigroviridis is a totally harmless species of fish that only requires one or two tablespoons of salt per 40 liters of water. It is totally freshwater.
If puffers are not offered hard food such as snails and clams, their teeth will grow to the point where they cannot eat anymore. If this happens you have to trim their teeth. To do this, fill two containers with 1 litre of aquarium water each. Add 1 - 2 drops of clove oil to one of the containers. Clove oil can usually be found at drug stores. Capture your puffer and place it in the container with clove oil. After a couple minutes the puffer will slow down and eventually stop moving. When this happens trim the teeth with a very sharp pair of cuticle scissors, or some other small sharp scissor. Supposedly, cutting the teeth is like cutting fingernails, but I found the teeth of my puffer to be much more brittle. When the operation is complete, simply put the puffer into the other container. When it wakes up it can be returned to the tank. I have heard that some pet stores will do this operation for you. Of course it is best to avoid this situation altogether by meeting the proper nutritional needs of your fish.