• A marine biologist shared a video of a rare blanket octopus sighting
  • The video shows the females' signature colorful "cape"
  • Male and female blanket octopuses are said to be among the "undersea world's oddest couples"

A marine biologist had a rather special encounter with a female blanket octopus in the Great Barrier Reef. Sightings of these creatures are quite rare, and sightings of males are even rarer.

Marine biologist, videographer and photographer Jacinta Shackleton was snorkeling in the Great Barrier Reef near Lady Elliot Island when she spotted the female blanket octopus, reported. The sighting was so exciting that she had quite a difficult time capturing the encounter, the outlet noted.

In an Instagram post, Shackleton shared a stunning video of the sighting and noted that these creatures are "rarely encountered" since they often spend their lives in the open ocean. Indeed, this was a special sighting of the female blanket octopus as only a few people have seen them, noted. In the video, one can see the "rarely seen" female's signature "fleshy cape" where the species gets its name from.

However, as rare as the sighting of a female blanket octopus in the wild is, sightings of its male counterpart may even be rarer. This is because blanket octopuses are among the "undersea world's oddest couples," with the females being significantly larger than the males, National Geographic noted.

"The first live male was only sighted in 2002!" Shackleton said in her post.

In fact, the females can grow up to six feet long while the males are just about the size of a walnut and also don't have the females' signature colorful cape. This means that the species has among the largest gender size discrepancy in the animal kingdom.

Although the reason for the massive size discrepancy isn't exactly unclear, it is believed that it's because the males spend their energy on looking for females instead of growing, National Geographic noted.

Another thing that makes blanket octopuses so interesting is the fact that they are actually immune to the sting of the Portuguese man-o-war, which is said to be "highly dangerous" to humans. They even use the tentacles ripped off from jellyfish as a weapon against predators as well as to hunt for prey.

According to the Great Barrier Reef Foundation, blanket octopuses are quite intelligent just like their other relatives. Not only can they recall, learn and mimic the behavior of other octopuses, they have also displayed different temperaments and preferences.

There are so far no major threats to blanket octopuses. To date, they are listed as "least concern" on the International Union for Conservation of Nature's Red List of Threatened Species, although their current population is "unknown."

Great barrier reef (2)
A diver takes photographs during an inspection of the Great Barrier Reef's condition in an area called the 'Coral Gardens,' located at Lady Elliot Island, Australia, June 11, 2015. Reuters/David Gray