Scientists aim to recreate tiny sea critters’ giant ‘snot palaces’
KENSINGTON, Maryland — Master builders of the sea construct the equivalent of a complex fivestorey house that protects them from predators and funnels and filters food for them — all from snot coming out of their heads.
And when these delicate mucus homes get clogged, the tadpolelooking critters — called giant larvaceans — build a new one. Usually, every day or so.
These so-called “snot palaces” could possibly help human construction if scientists manage to crack the mucus architectural code, said Kakani Katija, a bioengineer at Monterey Bay Aquarium Research Institute.
Her team took a step toward solving the mystery of the snot houses and maybe someday even replicating them, according to a study in Wednesday’s journal Nature.
The creatures inside these houses might be small — the biggest are about 10 centimetres — but they are smart and crucial to Earth’s environment. Found globally, they are the closest relatives to humans without a backbone, Katija and other scientists said.
Together with their houses “they are like an alien life form, made almost entirely out of water, yet crafted with complexity and purpose,” said Dalhousie University marine biologist Boris Worm, who wasn’t part of the study. “They remind me of a cross between a living veil and a high-tech filter pump.”
Also, when they abandon their clogged homes nearly every day, the creatures collectively drop millions of tonnes of carbon to the seafloor, where it stays, preventing further global warming, Worm said. They also take microplastics out of the water column and dump it on the sea floor. And if that’s not enough, the other waste in their abandoned houses is eaten by the ocean’s bottom dwellers.
But it’s what they build that fascinates and mystifies scientists. Because the snot houses are so delicate, researchers haven’t often been able to take them to the lab to study them. So Katija and team used a remote submarine, cameras and lasers to watch these creatures in water about 200 to 400 metres deep off northern California.
These mucus structures aren’t simple. They include two heartlike chambers that act as a maze for the food that drifts in, except there’s only one way for it to go: into the larvacean’s mouth. The snot houses often are nearly transparent and flow all around the critter.
And the houses are comparatively big — about 10 times bigger than the critters themselves — reaching more than one metre wide.
“They create these small versions of houses by secreting mucus from cells on their heads and then expand those much like a balloon,” Katija said. All in about an hour.
NASA engineers looking to build structures on the moon would probably like to learn from the larvaceans, she said.