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That’s Not a Floating Alien Brain, It’s a Bryozoan Colony

St. Lawrence River Institute of Environmental Science

Don’t be alarmed, those hard, floating, “alien brains” with a goop-like appearance are actually a colony of bryozoans.

On a recent sturgeon fishing trip in a shipyard just off the Willamette River in Portland, Oregon, I observed some floating balls that looked like masses of amphibious eggs, or some kind of strange, basketball-sized algae that resembled alien brains.

That’s when I started to do some research on what exactly these things really are.

This particular specimen pictured was retrieved from Hoople Creek in Ontario, but it belongs to a phylum of aquatic invertebrates that are filter feeders. This class of 4,000 species sieves food like green algae through tentacles lined with cilia, and inhabit freshwater, brackish, and saltwater environments. Some bryozoan colonies like the one pictured here have a gelatinous appearance while others have mineralized exoskeletons that look like corals.

My mother and I with her first sturgeon caught at the Vigor Shipyard in Portland, Oregon. If you're ever there, please don't disturb the alien brains.
My mother and I with her first sturgeon caught at the Vigor Shipyard in Portland, Oregon. If you’re ever there, please don’t disturb the alien brains.

The colonies reproduce through asexual budding. While they tend to inhabit slow moving waters, they attach themselves to coarse substrates and other hard substances, and they have the ability to move, only very slowly. It’s a demanding and somewhat inefficient use of the organism’s energy.

They are among the first colonizers of new or recently cleaned structures, so they often attach themselves to docks, marinas, and other offshore structures. Freshwater species are occasional nuisances in water pipes, drinking water purification equipment, sewage treatment facilities, and the cooling pipes of power stations. However, who’s to say they aren’t doing naturally through the same processes we’re trying to engineer? Either way, they’re definitely not alien brains.

If you enjoyed this story, and would like to see more, check out Randall Bonner’s Outdoor Writer Page on Facebook or check his Rain or Shine Blog for updates on more online and print articles. You can also follow him on Twitter @RandallJBonner or Instagram @RandallJBonner

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That’s Not a Floating Alien Brain, It’s a Bryozoan Colony