Sean Haydon, who posted the video, managed to record the reptile hunting fish among the rocks in the city of Adelaide on Wednesday. The snake is seen moving in the water between the stones, appearing moments later with the fish in its mouth.
"I knew they [snakes] fed on fish, but I had never seen one searching for fish among the rocks, " he told Australian portal ABC.
Reptile expert and snake catcher, Roly Burrell said it is quite common to find the red-bellied black snake in the water.
"They can actually hold their breath underwater for about half an hour," he said.
Bites of red-bellied black snakes have never resulted in death, but it can make the victim lose their sense of smell.