New footage has revealed a trailing ribbon of conjoined tentacled clones sweeping the ocean off the coast of Australia. Known in some regions as the "long stringy stingy thingy", siphonophores blur the line between organ and organism. They somehow manage to be both at once.

"The whole thing looks like one animal, but it's many thousands of individuals which form an entity on a higher level," marine biologist Stefan Siebert of Brown University told Wired.

The Ningaloo Canyons Expedition, a team of international researchers from institutes including Western Australia Museum, Schmidt Ocean Institute and Scripps Institution of Oceanography, recently came across one of these spectacular deep sea aliens.

They were exploring a little-studied but biologically rich part of the ocean off the coast of Western Australia, using ROVs and sonar. The creature was spied on the way back up:

"Everyone was blown away when it came into view," biologists Nerida Wilson and Lisa Kirkendale from the Western Australian Museum told ScienceAlert. "There was a lot of excitement. People came pouring into the control room from all over the ship. Siphonophores are commonly seen but this one was both large and unusual-looking.

"Although the ROV pilots made an estimate of its length, it has yet to be formally measured. However, it does appear to be longer than any other animal on the planet," they added.

The outer ring was estimated to be around 47 metres long (154 feet). The whole giant thing is composed of tiny individuals called zooids. They clone themselves thousands of times into one of several flavours - some with stinging tentacles and even red lures to attract food, others specialised for reproduction or movement. Each individual acts like an organ in the larger siphonophore body.

Biologist Rebecca Helm from the University of North Carolina Asheville describes the feeding clones on Twitter:

The siphonophore in the video "appears to have assumed a planar feeding posture, which makes it look a bit like a spiral UFO," Wilson and Kirkendale explain.

In a colony this massive, there would have to be at least millions of these conjoined organ-individuals working together, to sift the pelagial depths for food. They share their spoils with each other by passing nutrients along a stem they're all connected to - a vertical branch which also serves as a passageway for nerve signals.

Helm believes there are many millions of these siphonophores floating out there in the ocean, along with other strange creatures they interact with - such as this sea slug (Cephalopyge trematoides) that finds them tasty:

Another memeber of the entourage is this bizarre barreleye fish (Macropinna microstoma). It has a fluid-filled head shield thought to allow them to sneak into stinging tentacled zooids and steal their food.

It's a soothing glimpse of the strange ocean depths that siphonophores call home. And you can check out even more amazing weirdos from the Ningaloo Canyons in the video below.

With so much incredible life hidden away in our planet's oceans, who even needs aliens?