KENSINGTON, Maryland (AP) – builders build the equivalent of a complex five-story house that protects them from predators and funnels and filters food for them – all from snot that comes from their heads.
And when these sensitive mucus houses are clogged, the tadpole-looking animals – called giant larvae – build a new one. Usually every day or so.
These so-called “snot palaces” could potentially help build humans if scientists succeed in cracking the slime’s architectural code, said Kakani Katija, bioengineer at the Monterey Bay Aquarium Research Institute.
Her team took a step to solve the riddle of the snot houses and maybe even replicate them one day, according to a study in the Wednesday magazine Nature.
The creatures in these houses may be small – the largest are about 10 cm tall – but they are intelligent and crucial to the environment of the earth. They can be found worldwide and are the closest relatives of people without a backbone, said Katija and other scientists.
Together with their homes, “they are like an extraterrestrial life form that is almost entirely made up of water and yet are made with complexity and convenience,” said Dalhousie University marine biologist Boris Worm, who was not part of the study. “They remind me of a cross between a living veil and a high-tech filter pump.”
When they leave their clogged houses about every day, the creatures collectively drop millions of tons of carbon onto the ocean floor, where it stays to prevent further global warming, Worm said. They also take microplastics out of the water column and drop them on the ocean floor. And if that’s not enough, the other garbage in their abandoned houses will be eaten by the ocean’s basic inhabitants.
But it is what they build that fascinates and mystifies scientists. Because the snot houses are so sensitive, researchers could not often take them to the laboratory to examine them. So Katija and her team used a distant submarine, cameras and lasers to observe these creatures in the water about 200 to 400 meters deep in front of Monterey Bay in Northern California.
These slime structures are not easy. This includes two heart-like chambers that serve as a labyrinth for the food that drifts into it, except that there is only one way: into the mouth of the larva. The snot houses are often almost transparent and flow around the creature, which looks like a tadpole but is not.
“It could be the most complex structure an animal makes,” said Katija. “It’s pretty amazing that a single animal can do this.”
And the houses are comparatively large – about ten times larger than the animals themselves – and are more than one meter wide. It would be the equivalent of a person building a five-story house, Katija said.
“They create these small versions of houses by secreting mucus from cells on their heads and then expanding them like a balloon into the structures that we see,” said Katija. All in about an hour.
Water can flow through the structure, so when it moves through the water there is not much movement that predatory fish can perceive. That, Katija said, essentially masks the house from what the larvae want to eat.
NASA engineers who want to build structures on the moon would probably like to learn from the larvae, she said.
None of this could be done in the laboratory. The Katija team used 3D laser scanning technology to virtually fly through the inner chambers of the snot palaces and then re-created them with software to model the interior of the structure. But she said the scientists are still far from understanding everything that is going on there.
Providence College biologist Jack Costello, who was not part of the study, said Katija’s team “was doing a really cool job … detailing the complex houses.” In the best of circumstances, this is not easy and they made it deep in the oceans. “
“We still have a lot to learn,” said Costello. “I am in awe of these animals.”
Follow Seth Borenstein on Twitter: @ Borenbears
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