A green spotted puffer may be one of several different species of fresh or brackish water pufferfish in the genus Tetraodon, including:
Distinguishing these species is difficult,[1] in part because each species is highly variable in colouration.[2] Scientists working on these pufferfish as genomic lab animals consider it impossible to identify these species 100% reliably using colouration alone,[3] and tropical fish retailers commonly confuse them.[3]
A GSP or green spotted puffer can grow to be 6" in length they are primarily carnivorous; and their diet consists of crustaceans, mollusks, and other fish. The teeth of a GSP are fused together to form one nasty set of razor-like teeth, which are used to break off pieces of coral and crush the shells of their primary foods. Just like a rodent a GSP teeth continue to grow its entire life and are only worn down by the shells or its prey. So in captivity care needs to be taken in feeding the right foods so their teeth don't need to be manually trimmed. They are ferocious hunters, ruthless tank mates, and known killers. GSP start life out in freshwater streams, as they get older they migrate into brackish water and eventually end up in the ocean as fully grown adults. When they reach sexual maturity they travel back upstream to mate and spawn a new generation, much like the North American Red Salmon. So GSP can tolerate fresh water as juveniles but need to kept in water with some salinity in order for this fish to thrive. They like hard, alkali, and salty to full marine water conditions, with a PH of 7.8 to 9. With the right fish keeper the GSP has been known to live well over 10 years!