Is Keeping an F8 or GSP in Brackish Water Irresponsible?

[Mike Jones]

I find it amazing that all of you in this forum instantly pounce on anyone in here that keeps their Figure8(Tetraodon biocellatus/Tetraodon steindachneri) or GSP(Tetraodon nigroviridis) in freshwater instead of brackish. I have been lurking on here for a while because I am considering purchasing one of the above mentioned puffers and was planning on putting it in a brackish aquarium. Then was until, I went to a dinner party with my wife a couple weeks ago and noticed that the host couple kept a 190 gallon freshwater aquarium with a variety of fish including two figure8s and one 5 inch GSP. The owners explained to me that they have owned the puffers for over six and a half years and have never had and complications with them. I inspected them closely and noticed that they were vibrant and their colors clearly stood out. The fish were also very responsive and came to the glass when I approached it.

I then spoke to the LFS owner that I will purchase my puffers from and he explained that he has always kept both these species in fresh water. According to him, he has many happy customers who have done the same. I later met one of his customers who told me that she has kept her figure8 in freshwater for the last two years with no problems.

Just to double check that I have been studying the correct species I visited fishbase.org an excellent icthyology database. Fishbase claims that the figure8 is "not a brackish water species." As for the GSP it says "adults inhabit freshwater streams, rivers and floodplains." Further more, Dr. Neale Monks http://users.macunlimited.net/n.monks/brackfaq.html , who has written several articles for Tropical Fish Hobbyist and Practical Fish Keeping agrees with the previously mentioned findings.

My point in writing this is to show that as of yet there is no definitive evidence on what water conditions are best for figure8s or GSPs. The only way this question can be truly solved is for scientists to again go into these puffers native habitats and retrieve a multitude of adult species in order to document exactly what type of water they thrive in. Scientists can also conduct a controlled experiment where multiple fish of the same species are kept in brackish or freshwater conditions in order to observe their health and well being. I personally plan to keep my puffers in freshwater until somebody with evidence proves me otherwise.

[Phaedrus]

In the wild the fish are not limited to a specific salinity. They have the freedom to travel from freshwater stream out to the ocean as their life cycle dictates.

In the home aquarium however, we are limited in practical terms to a single salinity. The best we can do is increase it as they age to match the habitat they are most likely to be found in at that size.

You have some good anecdotal evidence to support freshwater only, as do we for brackish and marine conditions.

6 and a half years is a long time. But 190 gallons is also a very large tank, and obviously well maintained by the sounds of it. That probably has more to do with it than anything. For a fish who will ideally live for ~15 years, it's still a youngster. Premature death or other illnesses may still set in from a lack of marine conditions. I guess we'll have to check back with him in 10 years.

You can choose to stick to freshwater if you like, but to say that it is unproven that they live in brackish water is just wrong. What do you think river mouths and floodplains are? By definition, when freshwater and sea water meet, they create brackish water.

I also fixed that link for you: http://users.macunlimited.net/n.monks/brackfaq.html

Not to discredit the Dr or anything, but the links he has are woefully out of date if they work at all. He also calls a hydrometer a hygrometer. Hygrometers are used to measure the moisture content of a gas, i.e. relative humidity. Shouldn't an expert know that?

Even the good doctor may be pursuaded to change their mind upon further consideration or evidence. And to that end, I'd really love to see the kind of research you propose.

[Mike Jones]

All I was saying is that we still don't know exactly which type of water is the best. I personally think that these fish can live in brackish or freshwater and live normal lives. We don't know what the optimum is until further research is completed. The people or person who decided that keeping their puffer in freshwater is horrible may have had the wrong freshwater settings. For instance, the PH may not have been high enough or the water softness/hardness was off. One of these factors being wrong does not mean that puffers should be banned from all freshwater tanks. Thanks for fixing the link.

[Phaedrus]

Well ideally we wouldn't keep them in the same salinity, be it fresh, brackish, or marine, for any predetermined length of time at all. The fish itself would choose its own salinity (as it does in the wild) by simply moving to an area that has a different salinity.

Altering the salinity ourselves is impractical because we can't easily adjust the salinity on the fly without damaging the bacterial colony, not to mention the fact we have no idea what salinity the puffer might prefer at any given moment.

The best we can do is provide a stable, and toxin free environment. And in our experience, those who have kept GSPs and F8s in freshwater do tend to experience more problems than those who acclimate to brackish water. It is unclear how much of this is due to better keeping on the part of the owner who is concerned enough to seek out and follow proper care instructions. In fact, a GSP or F8 receiving great care in freshwater will almost certainly do better than ones receiving poor care in brackish water.

Also, there have been times when people thought they had perfectly healthy, vibrant puffers, until they increased salinity and discovered a whole new shade of healthy.

We may jump on people a little too quickly and harshly, but otherwise, sometimes they might not get the message. It's also sometimes tiring to hear the same problems and give the same solutions over and over again.

We do the best we can with what we know works.

I'm sure RTR will be along shortly to give a much more informative post.

[RTR]

"We", meaning me, certainly do correct folks who say that F-8s are FW fish, and I see no need to wait for "further research" to get more information, after I did more than 150 tank-years of work on F-8s alone and showed that in light BW they lived to the mid to upper teens in BW routinely while in FW none, repeat none, made to ten years unless extensive water mods had been done although excluding sodium chloride.

My GSP work was much less, but enough to convince myseld that they held their color, appetite, health and activity best in high BW to full SW. High BW may well be their optimum for captivity, but the difference between that and full SW appears trivial, and full SW offers so much easier and better upkeep that the choice to me is obvious.

Any individual is allowed their own choices. I will never again keep F-8s or GSPs or Ceylons in FW (nor DPs and other FW puffers in other than FW), and will continue, in your words, to "jump on" anyone who suggests the contrary. But in the end it is their, or your, own choice. Your tank, your fish, your option. But until you have proof to the contrary, do not expect me or anyone else here with significant puffer experience to allow equal time and to permit equal value to be given to opinions contrary to fact - which has been shown by more personal experience (backed by a scientist's training and equipment) than most hobbyists manage in a lifetime.

[Mike Jones]

The reason I want to keep my future GSP in freshwater is because I want to do what is best for the fish. I own marine salt and a hydrometer so I am not causing problems here because I am lazy. Maybe the best the thing for the GSP would be to keep it in very light brackish water like 1.005-1.008. Can someone here give me specific reasons why they have come to the conclusion the GSP needs strong brackish water. For instance, did one of you have bad experience with a GSP in fresh water. Has there been a study done to prove this conclusion that you can point me in the direction of. If you are coming from personal experience can you please be specific about your observations and why came to a particular conclusion. I would love to be proved wrong here as that would result in my knowing that my fish are in the best care.

[Rocker]

To me that is answered in RTR's post.

[TheSmJ]

Mike, I can't understand why you won't take 'our' word for it. There's a huge difference in reading a bunch of books and websites about a subject, and actually experiencing it first hand for many years.

The people on this board who happen to have very good luck with these puffers also happen to be the ones calling them FW, BW, and SW respectively. Many people who come here find their fish's health problems are solved after changing their fish over to what 'we' claim to be what they are likely to desire.

If you really want us to consider otherwise, perhaps your friend should join this board and post his/her experiences with the fish, what their fed, what their tank mates are, and even a few clear photographs of their fish in their current state.

[Jager]

mike a few things to show you why we hold what we do.

RTR has done this for 50 or so years probably more with puffers.

gsps are routinely seen in the ocean near rivers, and also seen moving up and down estuaries that are more FW near the river, and more BW/SW near the ocean.

GSps live 18 years on average. so a 1/3 of its life in FW maybe, but keeping them long term (past ten) has proven that they go BW/SW enough of the time to warrant them living in that in home aquaria. I have 11 years experience with puffers, and its not always the major signs of trouble that you see but a slow deteriorating life and stunted growth even in that 190, due to lack of salinity.

[slammer3166]

Mike,
Ive had my gsp in fresh water,they seemed fine but not very active- I went to bw it seemed like they perked up a bit and there colors looked better,now there in a sw setup and to me they seem happier lol and are very active-I guess to each his own how you want to house your fish but these peeps out here are very astute on these puffers.

[tekknoschtev]

As mentioned above, people (myself in this case) note that their fish is happy, healthy, and active in freshwater. After I did some reading I began slowly acclimating my puffer to Brackish water, and she was a completely different fish. I'll admit the reasoning for pushing her to full marine conditions was my own, but because of maintenence, and aestetics (brackish is very limited in the lines of natural decor in my opinion, not saying that it cant be done however). I kept GSPs in freshwater, and they didnt make it to even 6 months, though that may have been due to my own mistakes, I have noticed that she seems more... stable (for lack of a better word) in the brackish/marine conditions we have her in.

I dont have nearly the experience of people on this board, but what you have listed is really just the dual of what we've experienced. Anecdotal evidence. But its reading many many actual experiences from people like RTR that help me make my decision on thigs like this. Studies cant beat real world experience, especially when conducted for the length of time some people on this board have been working on these kind of things.

Thats my personal opinion though - as said above, its your fish, do what you please, but I havent heard/experienced/read any amount of information that would suggest FW for the entirety of their lifespan is best to make me change my current practices.

[Pufferpunk]

Within 3 years, My GSPs grew from 2-7", in BW (& eventually SW).

As far as Fishbase (quoted from RTR):
Fishbase always cites their references. For the F8 and the GSP, the
ecological info is from Rainboth, W.J. 1996. But I have not looked up the
original citation. Fishbase is a compilation of data from any or all
available data in the scientific literature, but that serves both for
assurance and as a warning. A fish having been found in a survey of this or
that habitat in the massive Tonle Sap has little or nothing to say about
that site being the population center for that particular fish, or a stray
from other habitats, or a fringe population with marginal survival
prospects. The distribution and ecology of these fish has not been studied
widely as they have no economic importance. Reports include them mostly as
found here and there, but they are rarely key species in studies.

Those indigenous groups using tropical fish collection as an income
supplement are not literate populations. Collections tend to be seasonal
(water and weather conditions permitting) and time-available from other
activities. The collected specimens are pooled and later transported to a
"wholesaler" or agent who arranges transport and handling to a population
center or abroad. The paper trail, if any, is not detailed or particularly
accurate. By the time the creature passes through an importer in the States
or elsewhere, the a regional wholesale distributor, then the LFS, it is
highly unlikely to have traceability back to even the country of origin,
much less finer-grained data.

Without some non-trivial economic importance, fieldwork is too expensive to
be supported. What little information we have that is really useful tends
to come from talented individuals, such as Dr. Ebert on puffers, who happens
to have a personal affinity for a group or family of fish, and has made
enough side notes and generated enough personal experience to compile some
publication for hobbyists after years of field work on other topics.
Several individuals have done similar works on Rift Lake fish, Rainbowfish,
etc. Those reports are our only real and valuable ecological source data.

Substantiation you will have to do yourself.

My personal experience with these fish is that they do best in light
brackish water (~1.005) over aragonite substrates (to support the high pH),
with no exposure to unoxidized metabolites, and minimal exposure to nitrate
(<20ppm). Under such conditions I expect them to live 15-20 years. In FW
conditions I have never had one survive more than a few years, and they have
been subject to chronic or repeated cornea and skin problems. YMMV, but I
would never put one of these fish under my care into FW.

When Dr. Ebert's book came out, one of the things that delighted me most
about it was that this fish, along with the GSP, were both noted as doing
far better in brackish conditions. Both of those observations matched my
own.

I have no way of knowing whether or not the fish we see in the trade are
collected from the inland areas reported on fishbase, or from coastal,
estuarine, or mangrove areas and potentially represent different
populations. My personal experience does not at all agree with the fishbase
report. But then they list the fish as being an algae and plant eater as
well (from stomach contents). Obviously they have missed the experience of
seeing these fish feed in captivity - algae or plant material is ingested
routinely, along with the mollusk or small crustacean feeding on it. So
there they are not incorrect as much as they misunderstand and misinterpret,
or simply have never observed either in the wild or captivity, the dynamics
of feeding for the fish.

[Mike Jones]

OK, I will keep the GSP in Brackish water. You guys win, I am convinced. I went to another aquarium store place in my area and they had there GSP and Figure8 in a salinity of 1.010- 1.012 and the fish did look slightly better and more active. I also read some of Dr. Ebert's writings and he obviously knows what he is talking about. My aquarium's salinity is at .996 and I will be raising it to 1.010 using Instant Ocean through out the next seven days as not to kill the good bacteria. Thanks for the replies.

[kass]

If you dont want to kill of the bacteria you should raise the salinity slower. Its recommended not go increase it more than 0.002 per week.

[Boxermom]

You guys win, I am convinced.

Its actually the fish that win, not the people here.