Adult Tetraodon nigroviridis are found in freshwater streams, rivers, and flood plains; young are found in brackish water. It is also found in mangrove forests.
This is however disputed and the exact habitat of this fish is not yet fully known. Diet consists primarily of snails, but includes small invertebrates such as mollusks, crustaceans, and some plant material.
This Pufferfish, known as "Midori Fugu" in Japanese is a popular aquarium pet. Typically younger fish are sold with a length of 2–3 cm. These fish can be kept with others of the same type, or other fish, but they are a rather aggressive species, so they will often nip the fins or scales of other slow moving fish. Some pet shops in Japan sell them with other fish they are known to co-habitate well with. These include Corydoras. Although they may reach 15 cm in nature, they rarely exceed 10 cm in captivity. These fish are omnivores, and tend to feed mainly on small invertebrates and plant matter (such as seaweed) in nature. In captivity, they can be fed live bait or frozen bloodworms, but they can eat manufactured fish food if they are raised on it from a young age. One issue in feeding them manufactured food is that their teeth continuously grow, and in nature eating hard invertebrates helps grind their teeth down. Without hard food, their teeth will continue to grow until it causes health problems. These problems can be solved by using fine coral sand in the tank, which the fish will chew. Also, occaisional feeding of snails or ghost shrimp will wear down their teeth naturally.
In nature, this species will often travel to the limits of where salt water becomes fresh water, so they can be kept in fresh water for brief periods of time. For long-term care, however, they should be kept in salt water. A salt concentration equal to 1/4th of ocean levels is suitable for younger fish, however adult fish spend most of their time in the ocean, so it is recommended to raise the salt level to 1/2 of ocean levels.
Click on any of the images below to view our Puffer Fish gallery.