Extensor Foot Tendons. In the foot diagram below, the main tendons on the top of the foot are labeled. The group of tendons are called the extensor tendons and are responsible for elevating the toes and flexing the ankle up (dorsiflexion).
Dwarf puffers are quite hardy and will tolerate varying water conditions but obviously will do best, as with any fish, in optimum water conditions. They do best at temperatures of 80/26 degrees with a ph of at least 7.
Spotted puffer fish are sold as freshwater puffers. And in parts of their range, they do sometimes live in freshwater. However, they really do their best in brackish water -- water with some salt in it, but less than full-strength seawater. Water with a specific gravity of 1.005 suits them.