A few websites (like Seriouslyfish) recommend freshwater. We all "know" freshwater is a common misconception, at least for captive F8s, yet, Fishbase.org and IUCN redlist say F8s are freshwater fish.
Even more obscure is the claim of some that full marine works well, and that it is "debated" whether or not they live in full marine as adults. Recent statement, no documentation.
Several "random" websites with fish profiles recommend SG 1.005-1.008. No documentation.
On here, there seems to be more or less agreed that low end brackish is best, like 1.003-1.005, which is supported by RTR's long term experiment, unfortunately not published. I can't find on here which other salinity levels he tested.
On the Dutch (?) puffer forum, and also by "expert(s)" on a different group, it is recently claimed that adult F8s need a salinity of SG 1.010-1.015. No documentation.
Yet another more relaxed advice is that any low to middling salinity is just fine. Recent statement by, among others, someone whom I believe is a marine biologist.
The scientific literature says little about this, at least in the the narrow selection of publications I have had access to. The only paper I can think of that mention an SG for F8, is the paper by Doi et al. (2015), and they kept adult F8s in an SG of 1.015 for several years before the spawning experiment. Spawning was induced by lowering the salinity to 1.007. Eggs were hatched and fry reared in SG 1.005-1.007. Would the fact that they actually managed to spawn them indicate that they had been kept under optimal conditions? Or maybe it was optimal for breeding, but not necessarily for long term captive life? What made those Japanese scientist keep them at that salinity in the first place? The paper does not say.
Can someone please go out and attach GPS's to those mysterious fishies and measure the salinity along their trail, during their whole life span?? I'm kind'a obsessed, sorry...
