World’s longest animal discovered in Australian waters

The 46-metre-long siphonophore was found lurking 625 metres beneath the waves off the Western Australian coastline.

Published: June 9, 2020 at 1:07 pm

A deep-sea expedition led by the Schmidt Ocean Institute has discovered 30 potentially new species of marine creatures, including a siphonophore that’s thought to be the longest animal ever observed.

It has been estimated to be 46 metres long, nearly six times the length of a Routemaster double-decker bus.

Though they appear to be a single animal, each siphonophore is in fact a colony of organisms that clone themselves thousands of times and join together to form long chains. Like jellyfish, they have stingers that ensnare, paralyse and kill prey.

The discoveries were made using ROV SuBastian, a remotely operated robotic vehicle that’s capable of diving to depths of 4.5 kilometres.

The expedition in pictures

© Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
ROV SuBastian is lifted back on deck after a day of diving © Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
© Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
The 46m-long siphonopore is thought to be the longest animal ever discovered © Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
© Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
The expedition found several other species that may be new to science © Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
© Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
Chief scientist Dr Nerida Wilson takes samples of a hymenaster, a type of deep-sea starfish, for DNA profiling © Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
© Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
This zoarcid fish was collected from a trap mounted on the lander © Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
© Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
This rare deep-sea hydroid, a close relative of corals and anemones, was found 2.5km deep in Cape Range Canyon © Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
© Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team
This squat lobster species is distributed all over the globe, but this is the first time one has been found in Western Australia © Greg Rouse Scripps Oceanography/Nerida Wilson/FK200308 team

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