Longest ‘sea worm’ found off Australia


Longest ‘sea worm’ found off Australia

Picture: Schmidt Ocean Institute.

Scuba divers have become accustomed to tales of “monster sea worms” that turn out to be colonies of organisms identified variously as salps, pyrosomes or siphonophores. But an example discovered recently off Ningaloo in Western Australia seems to have reset the scale for such sightings, with an estimated length greater than for any other known animal at around 45m.

The gelatinous siphonophore Apolemia, essentially a string of free-swimming hydrozoans each with the ability to clone itself, was discovered during a month-long expedition to explore the deep-lying Cape Range and Cloates Canyons using an ROV. 

The scientific team aboard the Schmidt Ocean Institute research vessel Falkor were excited by the discovery along with that of as many as 30 species previously unknown in the area.

Their ROV SuBastian completed 20 dives as deep as 4.5km, recording finds that included glass sponges, the bioluminescent Taning’s octopus squid, a long-tailed sea cucumber and a number of other molluscs, barnacles and squat lobsters. 

“We suspected that these deep-sea areas would be diverse but we have been blown away by the significance of what we have seen,” said chief scientist Dr Nerida Wilson of the Western Australian Museum. Other researchers on the trip represented Curtin University, Geoscience Australia and Scripps Institution of Oceanography. 

19 April 2020

The California-based Schmidt Ocean Institute is carrying out a year-long series of expeditions in Australia and the Pacific using Falkor and SuBastian, enabling scientists to explore a number of deep-sea canyons and coral reefs for the first time. 

It says the video footage and samples collected “will have important implications for the sustainability and protection of these underwater ecosystems – and for similar habitats worldwide that are in peril because of rising ocean temperatures and other environmental threats”.

Falkor, said to be the world’s “only year-round seagoing philanthropic research vessel”, and SuBastian are made available at no cost to international scientists who agree to make their discoveries public.

The dives were livestreamed and highlights can be seen here.



Get a weekly roundup of all Divernet news and articles 🤿

We don’t spam! Read our privacy policy for more info.

Notify of
Inline Feedbacks
View all comments

Related Divernet Posts

Diver Magazine Relaunch

Diver magazine needs YOU!

Are you still lamenting the demise of Diver magazine? Well now you can help resurrect an icon as we seek to bring back the magazine


Went for a dive and saw one fish

Editor-in-Chief of the Underwater Photography Guide NIRUPAM NIGAM went for a dive in the Gulf of Maine, a body of water historically known as “the

The Alex Van Opstal

WRECK TOUR 152 – The Alex Van Opstal

An old Weymouth favourite, the 5965-ton Belgian motor ship Alex Van Opstal, an early casualty of World War Two. It was sunk by a mine on 15 September, 1939, just 15 days after the German invasion of Poland.

Buford Springs Cave topside view

2 divers die at Florida cave site

Two men have died while scuba diving at western Florida cave-diving location Buford Springs Cave.  Three teenage swimmers found 63-year-old Stephen Roderick Gambrell unresponsive at

Sponges fragments

Sponges: Glue of the reef

A variety of environmental threats hang over scuba attraction the Florida Keys, but a team of dedicated divers are doing their bit to shift the

nets and diver

Spanish divers battle illegal nets

Scuba divers from Spanish marine conservation group Equilibrio Marino have removed a 600m fishing net from the Mediterranean Sea off Malaga city beach. In the

Follow Divernet on Social Media

Would love your thoughts, please comment.x