I have a race of sentient amphibian humanoids that live on a very hot and humid planet that has massive amounts of large lakes, ponds, and rivers. They are carnivorous and for simplicity they have a similar caloric intake to humans, and for domestic fish species imagine fish like what we have on Earth. So fish like salmon, trout, tuna, etc. They posses the knowledge and ability to farm so that they can feed the fish.
Would it be plausible that a society of these amphibious humanoids could subsist of fish farming?