(not from the net!)
Figure 8 Puffers are Brackish water puffers. I've had my F8 for over a year now...in *brackish* water. Yes, I do fluctuate the specific gravity at every water change, but it has never been freshwater. My current puffer was given to me by a co-worker who had a freshwater community tank and she actually bought 2 puffers. Well, several days later, her other fish turned up dead, with the victim's bellies eaten out as well as their heads and tails. So she gave her 2 F8 puffers to me. I didn't know they were brackish, so I kept them in a freshwater tank. Their health started deteriorating from there until one of them died...unfortunately. I did research, and then some more, and finally transferred the survivor to a larger tank, but this time, with brackish water. I used Marine Salt mix, not your plain ole' aquarium salt. Since then, my puffer has been livelier than ever before, and always hungry! I feed it live bloodworms, baby crickets, and of course, snails. A very curious fish, yet skittish at the same time! It follows my fingers across the tank as if trying to catch it. I'm in the process of looking for a larger tank for my puffer in the hopes of giving it a better environment. And yes, you guessed it, the new environment will be BRACKISH!
I have owned a figure 8 puffer for about 8 months now. I was just getting into the aquarium hobby and that was the first fish I bought. I got him from Wal-mart and he was being sold as a green spotted puffer. He was a lot different looking from the other fish and also his fins were in better shape, so I picked him. He has grown pretty well and his fins healed from all the interspecies nipping fairly quickly. He has a lot of personality and is a pretty voracious, although picky eater. I started him on freeze dried tubifex worms and the started putting freeze dried krill in for him. He won't touch the tubifex anymore. He will eat flake food though, and likes freeze dried bloodworms too. I have given him a few snails and he is excited about them at first, but quickly looses interest. His all time favorite food is live ghost shrimp. He will go crazy over one. I have him in a 20 L hex and kept him alone for a while, then bought a dragon fish (violet goby) and put it in there with him. If you are going to keep them in a community tank, you must keep them well fed. If they get hungry, they will nip at fins mercilessly. He took a big chunk out of the dragon fish's tail. I keep the water brackish with a thick layer of gravel and an aponogeton hybrid plant for cover and decor. I also have a bubble bar buried in the gravel to help move the water. One more note on feeding, he is pretty particular about freshness. He won't mess with a freeze dried krill after about 5 minutes in the water and sometimes won't eat something fresh unless you take out the old one first. I guess he just likes a clean tank. These are very durable barckish swamp fish that can take rapid temperature and chemistry changes pretty well. He acted funny after water changes at first. Now he just takes it in stride. He was hand feeding after about a week. watch the beak when they are bigger though, it could give a pretty serious bite!
Here's a little bit of clarification, for what it is worth. I work with tropical freshwater and brackish fish species and have conducted extensive research on many of the species I work with. I can say, without any doubt, that the figure 8 is a brackish species. However, it has been found and isolated in freshwater environments. Generally speaking, the figure 8 does prefer brackish environments and tends to do better with some salt added. It will thrive in environments where the salt varies from 5 ppt to 15 ppt. I would not keep these fish in a freshwater environment, but it is your investment.
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