Puffer salinity?

[GarGuy]

My LFS has some Green-spotted Puffers for sale and they are being kept in FW. I've heard that Tetraodon nigroviridis should be kept in FW but T. fluviatilis shouldn't. How do you tell them apart? Thanks!

 

[Pufferpunk]

Both require the same care & feeding but T flutiavilis (Ceylon puffer) require a 40g minimum tank size, while a 30g is OK for a single GSP. They are extremely easy to tell apart. The fluviatilis looks like a biocellatus (Figure 8) on it's back, with black spots on the sides & belly.
See: GREEN SPOTTED PUFFER