- Scientific name: Tetraodon Nigroviridis
- Common Name: Spotted Puffer Fish, Freshwater Puffer Fish, Puffer Fish
- Aquarium size: 150 liters
- Temperament: Aggressive
- Temperature: 24ºC to 28ºC
- pH: 7.5 to 8.5
- Diet: Carnivore
- Length: 17 centimeters
The freshwater puffer fish, Tetraodon nigroviridis, is a brackish water puffer fish, which can live in a community freshwater aquarium, provided the right conditions exist, because despite being a territorial fish and somewhat aggressive, there are species with which it can live.
It is common for Tetradon nigroviridis to be confused with Tetradon fluvialitis or Tetradon Schoutedeni. The only drawback that the bug may have is that the fluvialitis Tetradon, is that it lives in brackish waters, while the Tetradon nigroviridis, can be kept in a freshwater aquarium.
If you like this fish, you can keep it in your aquarium for a long time, because it has a life expectancy of about 18 years, although in an aquarium it could live perfectly for 10 years.
In the aquarium, they can measure up to 17 centimeters.
There is no apparent sexual dimorphism between the male and the female, although some information suggests that the male is larger than the female , and somewhat more slender, although this difference is only noticeable in adult specimens.
Morphological have characteristics common to the family of the pufferfish , with a strong head, pointed mouth (with four teeth so characteristic fused), and large eyes.
Its body is devoid of scales, ventral fins are not observed, and the pectorals are strong as a paddle.
When threatened, it absorbs large amounts of water to intimidate its attackers.
The color of the back of the fish is bright yellowish green, lined with many black spots in the shape of polka dots.
The reverse is completely white, although under certain emotional stress circumstances, it can change color and turn gray.
Distribution and habitat
The freshwater puffer fish is native to India, Sri Lanka, Thailand, Cambodia, Vietnam, Malaysia, Indonesia, and the Philippines.
In these places we can find it in coastal areas, deltas of freshwater rivers, mangroves, streams and areas flooded by rains.
A suitable size for freshwater puffer fish should be about 150 liters , in which the temperature should range between 24ºC and 28ºC, with a pH of 7.5 to 8.5 ( digital pH meter ). Although they are considered a kind of fresh water, some salt must be added to the water, to make it partially brackish.
The aquarium has to have a sandy bottom, and be well planted , with roots, trunks and spaces that serve as shelter.
They are quite active, so you must leave enough space, so they can swim freely.
They need the water to be kept in good condition, for which we must do partial water changes every week, as well asremove all food scraps that the fish has not finished.
In the wild, its preferred food is snails, which should be fed regularly, as well as shellfish, to keep its teeth sharp.
Other foods that we can provide are shrimp, prawns, insects, larvae, octopus or squid, in small pieces according to your mouth.
What they do not usually accept are prepared foods, such as scales or granules, but if they accept some vegetables or failing that, they will nibble on the plants in the aquarium.
You have to be careful not to overfeed them, as they are quite gluttonous.
Behavior and compatibility
In the aquarium, we should not have more than one freshwater puffer fish, because they are quite aggressive with others of the same species.
It is only advisable to have more than one (ideally several, to reduce tension), when the aquarium is of good size and there is enough space for everyone.
However, there is no problem in keeping it with other species , as long as you look for strong and active companions, weaker or slower fish will bite their tails.
Some tankmates can be some types of goby and brackish water species.
It is known that like other Tetrodontids (yellow puffer fish, for example), they recognize their owner and allow themselves to be fed from his hand, while rejecting those they do not know.
Reproduction is not easy, but it is not impossible either. Perhaps the greatest challenge is in obtaining a mate, because due to the absence of sexual dimorphism, several specimens must be kept in the aquarium until a pair is formed, with the «problems» of fighting that we know.
To be successful in the reproduction of freshwater puffer fish, we must increase the salinity of the water, until it becomes brackish water.
The aquarium must have flat rock surfaces, where the female will deposit the eggs, which will be protected by the male.
Once incubated, the eggs hatch in a period of about seven days. Once hatched, the fry are still protected by the male, who makes a hole in the substrate.