Crab and Octopus Square up to One Another in Seabed Showdown

A diver has captured a dramatic video of a crab squaring up to an octopus on the seabed in Australia.

The video sees the blue-ringed octopus crawling along the seabed before encountering the crab, poised with its claws in the air. Undeterred, the octopus quickly punches the crab in its underside, causing the crab to recoil. Luckily for the crab, the octopus then crawls away.

Jules Casey, a diver who shares photos and videos of her adventures with her 90,000 Instagram followers under @onebreathdiver shared the video in April.

Casey said in the caption: "How awesome are blue-ringed octopuses?! In the very first frame, you see this BRO come towards my camera with two outstretched arms, what you don't see is those two arms exploring my camera. She was curious but once she realized it wasn't food she continued to hunt.

A diver filmed a dramatic showdown between a crab and an octopus.

"She then touches a crab and his quick reflexes and defensive position are almost hilarious...she continues and again touches a pair of mating crabs this time but she's not interested and moves on."

The crabs in the video were lucky to escape. The blue-ringed octopus' venom is 1,000 times more powerful than cyanide, according to Ocean Conservancy, which says that it has enough venom to kill 26 humans within minutes.

What's more, the blue-ringed octopus is known for using its venom when hunting crabs, condemning them to a horrifying death. Ocean Conservancy says that the octopus captures crabs by pecking through their exoskeleton with its beak before inserting the venom. While the crab is paralyzed, the octopus picks off its meat.

Crabs are not the only animals hunted by the octopus. The octopus also hunts shrimp and small fish and can release a cloud of venom, which enters potential prey through the gills.

Knowing that the octopus is deadly, viewers may be concerned about the diver and her safety. However, despite being incredibly venomous, blue-ringed octopuses are not aggressive and are only likely to bite humans if they are cornered or handled.

In another Instagram post, Casey said: "Yes they are highly venomous but they don't randomly attack. They are often quite shy and will look for a safe place to hide from you."

There have been no reported deaths from the octopus' bite since the 1960s, according to Ocean Conservancy, and Healthline reports that there have only been three deaths attributed to the species.

Despite it being a rare occurrence, if a blue-ringed octopus were to bite a human, the victim would first experience muscle numbness, followed by nausea, vision loss or blindness, loss of senses and loss of motor skills. The venom would ultimately cause muscle paralysis and would lead to respiratory failure.