Pyrosomes: Can You See Them?

This month's Creature Feature is “spotlighting” a critter from our famous Pelagic Magic® Dive – a Pyrosome!

Now, most people have never heard of a Pyrosome before, so lets break down the word a little so it makes sense: “Pyro” is an old Greek word, meaning fire, and “Some” from the ancient Greek word, Soma, meaning body. These “fire bodies” can sound like a painful interaction, but they are not – these animals are instead bioluminescent!

 

 

This is the nerdy part

But what, exactly, are pyrosomes? Well, buckle up, it's about to get real nerdy. Pyrosomes are the pelagic brethren of tunicates, and you have to be a real nerd to be looking for tunicates on your average dive. Most tunicates are small, sessile (adhered to a substrate) invertebrates that live a lifestyle similar to sponges – they pump water in, filter it for food, and pump it out. They don't really move much, they can't swim, and they are fairly good about being nearly invisible, making these critters something that just goes unnoticed.

 

Just a bunch of drifters

Next reef dive, I challenge all divers to find a tunicate: look for small, probably clear tubes sitting upright on a ledge, between corals, or in a cave! If you're fortunate enough to have gone on a Pelagic Magic dive, you probably saw enough Salps (pelagic tunicates) to fill a bucket, but divers much more rarely catch glimpses of pyrosomes. As open ocean critters – they drift through the open deep blue, with no intention of ever inhabiting a reef. Each Pyrosome is a living colony of zooid tunicates that work together to funnel water for food and travel. A larger colony might look a bit like a pinecone, or strawberry, and a small one more like a sea raspberry, as they are sometimes nicknamed.

 

Protector of Critters

Pyrosomes can often become protection for juvenile fish to hide inside, or a magic carpet for a shrimp to hitch a ride. Part of the fun of a Pelagic Magic dive is experiencing new animals we may have not even know existed – if you haven't tried a Pelagic Magic dive, check it out! We run them Tuesdays and Thursdays, but can add on Pelagic Magics on other nights if we have interest! Mahalo for reading and learning with us and the staff at Jack's Diving Locker!