Pyrosomes are one of the ocean’s weirdest creatures

By Australian Geographic | May 27, 2019

Trust us, you haven’t seen anything like a pyrosome before.

In March, a group of CSIRO scientists aboard the RV Investigator came across an unusual problem: while exploring the ocean floor, a bloom of pyrosomes interfered with their data collection system.

Pyrosomes are extremely bizarre creatures that most people haven’t heard of. And that’s because they’re rarely seen, leading scientists to regularly refer to them as the “unicorns of the sea.”

The CSIRO scientists described the pyrosomes as “firm, cucumber-like creatures” that are made up of thousands of individuals that reproduce asexually by cloning themselves and forming colonies, mostly in the shape of hollow tubes.

These hollow tubes can be many metres long, while some could fit nicely in your hand.

They’re also bioluminescent. “They descended around our ship the night of 28 March and there were so many around that it was literally glowing in the dark due to their bioluminescence,” the CSIRO wrote on Instagram.

There haven’t been many opportunities to study pyrosomes up close, and so their run-in with the CSIRO research vessel was fortunate.

“Not much is actually known about pyrosomes so this voyage provided a great opportunity to collect samples and study more about their cell structure, their size distribution and their decomposition rate.” they wrote.

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Ahoy from #RVInvestigator! Here’s a quick highlight from our voyage in March. A bloom of pyrosomes (pictured here) interfered with the scientists’ data collection on board. 👀🚢 ⠀ ⠀ Here are some facts about pyrosomes:⠀ • The firm, cucumber-like creatures are actually made up of thousands of individuals that can reproduce asexually by cloning themselves and forming colonies in the shape of hollow tubes. ⠀ • They also have the ability to reproduce sexually and form entirely new organisms, meaning they have two methods of rapid reproduction. ⠀ • They glow with bioluminescence. ⠀ ⠀ Interestingly, they descended around our ship the night of 28 March and there were so many around that it was literally glowing in the dark due to their bioluminescence! 🌟⠀ ⠀ There were SO MANY blooming pyrosomes that they inhibited the data collection from equipment being deployed from the ship.⠀ ⠀ Luckily for us, they were collected on in-situ pump equipment used to sample seawater.⠀ ⠀ Not much is actually known about pyrosomes so this voyage provided a great opportunity to collect samples and *study more* about their cell structure, their size distribution and their decomposition rate. ⠀ If this isn’t a huge (ahem) metaphor for dating in the social media age, I don’t know what else to tell you. Because honestly, this feels familiar… 🍆⠀ ⠀ To all our Aussie STEM teachers out there, if you’re interested in telling the story of the science on board our #RVInvestigator, the closing date for applications for our Educator on Board program has been extended until the 3rd June! ⠀ Check out the link in our bio to find out more. ⠀ ⠀ 📸: Svenja Halfter ⠀ ⠀ #oceanresearch #tinderorscience #whoknows #plentyoffish #nah #plentyofpyrosomes #weLOVEscience #csiro

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The pyrosome isn’t the only suggestive animal of the ocean recently encountered by the CSIRO.

Here you can, see the deep sea ‘peanut worm’ that’s making everyone uncomfortable:

peanut worm

(Image credit: Rob Zugaro)