BMG, as you'll no doubt find out if you look around a little more on internet, nomenclature is a *huge* issue when it comes to dwarf puffers. I have seen them labelled as "fresh water puffers" (and they are FW
), "dwarf puffers," "dwarf malabar puffers," "Indian dwarf puffers," "green pea puffers," and "spotted puffers." These names all generally refer to the species Tetraodon (or Carinotetraodon) travancorius.
"Ahah," you say... "settled it is!" Not so fast... Becuase there are 2 more confounding issues at hand.
Firstly, there is another, more popular, type of puffer called the "Green Spotted Puffer," Tetraodon nigroviridis or fluviatilis (this may well have been the second species you saw, as the babies look relatively similar to the adult dwarf puffers and are about the same size). This grows considerably larger than the dwarf--to about 6 inches--and prefers brackish water to fresh. http://www.thetropicaltank.co.uk/Fishindx/puf-nigr.htm
Secondly, no convention has been reached on the two different color/marking morphs of the dwarf puffer. Some distinguish genus "Carinotetraodon" and "Tetraodon" but leave the species name "travancorius" the same. But... others call one "Tetraodon imitator" and "real." Here's a page which shows the two color morphs: http://www.rr.iij4u.or.jp/~kohda/en/en-dwarfpuffer.htm
I have been singularly frustrated by this taxonomic impasse, so when I bought my puffers (see my gallery, if you're interested) after much, much research, I just called them "Dwarf puffers" with the bnomial species name "Tetraodon travancorius."
My opinion is that you prob. first saw real dwarf puffers, and then saw the yellower morph *or* green spotted puffers a little later. Both species are extremely aggressive, and I'd recommend the dwarf puffers for a 29, as the GSPs will get very aggressive toward each other when older, esp. when in a relatively small tank. Also, brackish water (for the GSPs) is difficult, and precludes the usage of all algae-eating fish commonly on the market... IMO
, you should go with the dwarf puffers! They are adorable and hardy.
and isn't too rambling/specific!