GSP (Green Spotted Puffer) Care – Brackish

Scientific Name : Tetraodon nigroviridis

Common Names : Green Spotted Puffer, GSP

Care Level : Moderate

Size : 6″ (15 cm)

pH : 7.5 – 8.2

Temperature : 78 – 82 °F (25 – 28 °C)

Specific Gravity : adaptable, from low-end brackish (1.005) up to low-end saltwater (1.20)

Lifespan : to 10 years, sometimes as much as 15

Origin / Habitat : brackish rivers and estuaries of Borneo and Sumatra

Temperament / Behavior : aggressive fin-nippers

Breeding : practically non-existent in captivity

Aquarium Size : Minimum of 30 gallons (113.5 L)

Tank Mates : Must be chosen with caution. Most will just be eaten. Some possible companions are: mollies, scats, monos, archerfish, bumblebee gobies, and other GSPs.

Fish Disease : Freshwater Fish Disease – Diagnose, Symptoms and Treatment – Be sure to quarantine, as they are wild caught and often come in with parasites.

Fish Food : When young their diet consists of snails, brine shrimp, plankton, Krill, crickets, cockles, prawns, whitebait, worms, ghost shrimp. When larger (about 4″ or so): all the above, and also clams, mussels, squid, scallops, shrimp, crab legs, oysters, lobster, and crayfish.

Tank Region : Middle. Very active swimmers.

Gender : Even for experts, it is nearly impossible to sex them. Usually the only way is by dissection, or if they happen to lay eggs (an unlikely occurrence).

Puffers are messy eaters and high waste producers. Extra filtration is necessary for these dirty fish. Immaculate aquarium upkeep is a must. Algae growth also needs to be removed by the fish keeper. There are no brackish water algae eaters that can live with a Green Spotted Puffer. (Sorry, you’ll have to do your own maid service!)  Because of their aggressiveness towards tank mates and the high amount of salt they prefer, there are not many fish that can live with them as companions in general, or for clean up. Only after my puffers were raised to saltwater, was I able to  “trick” them into letting me keep hermit crabs with them by scattering many empty shells around the substrate. They just can’t tell the hermit crabs are there. Perfect water parameters are necessary for Puffers. This means 0 ammonia, 0 nitrIte and nitrAtes below 20. I do 50% weekly water changes on all my tanks, vacuuming under décor and getting into plants to remove all uneaten food as I go. Puffers are scaleless fish and are without gill covers. Therefore, these fish are very sensitive to most meds and this is why keeping perfect water conditions are so important for them. The best way to keep them healthy is not to let them get sick. Water changes, water changes, water changes!

When choosing your long-lived pet (10+ years), try to find one with a round belly that comes to greet you at the glass. You can start a young one out in a 10-15g tank, but once it is >2” they need a 20-30g tank/fish. Keep in mind that in tanks this small, puffers will not be tolerant of tank mates. Puffers are wild-caught fish and many come in with internal parasites. If your Puffer eats, but still looks thin, or has stringy-looking feces, it could be carrying internal parasites. I prefer the product Discomed, by Aquatronics, for the treatment of internal parasites. You must soak their food in it and treat for 7 days. Puffers get pretty beat up during shipping and over crowding. Most have nipped fins when received; some are even missing fins. Getting them into brackish water as soon as possible is one way to help with that. I also like to add Melafix to the water to help with re-growth. I quarantine all new fish so I don’t have to treat the whole tank and to prevent spreading possible diseases.

One of the most difficult aspects of keeping these special fish is their diet. All puffers are predatory fish and need hard-shelled, meaty foods to keep their teeth trimmed. Like rabbits, their teeth grow constantly and can overgrow enough to cause starvation in the fish. Puffers eat crustaceans in the wild. Foods for smaller puffers are frozen/freeze-dried krill/plankton, gut-loaded ghost shrimp, glass worms, crickets, worms and small snails (the size of their eye). Snails are an essential food to a Puffer’s diet, especially when small. Many serious puffer keepers breed their own snails. As your puffer gets larger, there are many more crunchy foods for them to eat. Larger Green Spotted Puffers will eat cut-up pieces of scallops, shrimp, crab legs, whole mussels, clams, oysters, squid, lobster and crayfish. Mine love to chase live crayfish, fiddler crabs and gut-loaded ghost shrimp. I gut-load (pre-feed) my live food with algae wafers, so my puffers get their veggies. I buy most of these foods at the fish department of my grocery store, freeze and later thaw in warm vitamin water as needed. Smaller Puffers (under 2”) need to eat every day, skipping one feeding/week. Feed them until their bellies are slightly rounded. Medium sized Puffers (2-4”) should be fed every other day. Larger puffers (4-6) should be fed every 3-4 days. You may find this schedule difficult, as Puffers are very adept at begging for food!  Feeding puffers every time they beg will cause fat, lazy fish and eventually you will be killing them with kindness.

These little alien-looking creatures are highly intelligent (for a fish), personable and entertaining. I have had luck with them tolerating some tough, fast-moving tank mates, only to find them missing after several months or even years. Younger Puffers may seem more docile, but all will nip the fins of slower-moving or long-finned fish. I have been very successful keeping my Green Spotted Puffers with their own kind and also with the Ceylon Puffer (T. fluviatilis), as long as they are all the same size. I wouldn’t suggest any other Puffers with them. Some folks have mentioned some success in keeping Green Spotted Puffers with Figure Eight Puffers (T. biocellatus), but I believe it is only because the Green Spotted Puffers are still young. Figure Eight Puffers are only mildly aggressive and grow to half the size of a Green Spotted Puffers. Adult Green Spotted Puffers are extremely aggressive predators and the majority of them have a nasty disposition. They are vicious fin-nippers and known killers. Therefore, choose their tank mates carefully or be prepared to loose a favored fish.

Green Spotted Puffers need a heavily decorated tank with plenty of swimming room, lots of hiding places and various broken lines of sight. If your puffer is constantly swimming up and down the glass, he is bored and needs more décor to swim around and investigate. Some folks occasionally move décor around for added interest to this clever little fish’s life. Always have a secure lid on your Puffer tank and check often that it is closed. They are known jumpers!

Do not try to make your Puffer puff!  Puffing is a defense mechanism brought on by fear and stress. It is not good for your Puffer to inflate itself. Never take your Puffer out of the water!  It can puff with air and may never recover. I have had some success in “burping” a Puffer by holding it vertically (head up) under water and gently shaking it by its tail until the air is released. A puffer with air inside cannot right itself and will die. If you ever need to catch your Puffer (even when getting it from your LFS), scoop it up with a container.