Scientists Study Sea Creature Which Makes a Home of Body Fluid（在线收听）

Some very small, deep sea creatures are known as the master builders of the sea. They can build complex homes that provide protection and capture food. These structures are made from a fluid that comes out of their heads.

When the structures get used up, the creatures — called giant larvaceans — build a new one. Usually this takes place every day.

Some people call these homes "snot palaces" because they are like big houses made of mucus, a fluid produced by living tissue for protection.

Some people think studying larvaceans' homes could help the building industry if scientists can understand how they make them. One of those people is Kakani Katija, a bioengineer at Monterey Bay Aquarium Research Institute in California.

Her team released its findings on the so-called "snot houses" in Nature magazine recently.

The creatures inside these houses are small — the biggest ones are around 10 centimeters, but they are important to the environment. They live in oceans around the world. Katija and other scientists said they are the closest relatives to human beings without a backbone.

"They are like an alien life form, made almost entirely out of water, yet crafted with complexity and purpose," noted marine biologist Boris Worm of Dalhousie University. He was not part of the study.

Worm said the creatures help the ocean environment also. When their homes are used up, the creatures drop millions of tons of carbon to the seafloor. It stays there preventing global warming, he said.

Larvaceans take microplastics out of the water and put it on the sea floor. In addition, the waste in their homes is eaten by creatures living at the bottom of the ocean.

What they build interests and remains a mystery to scientists. Because the mucus houses are so fine and easily broken, researchers are unable to take them to a laboratory for study. So, Katija and her team used a robot submarine, cameras, and lasers to watch the creatures in waters 200 to 400 meters deep near California's Monterey Bay.

These mucus structures are not simple. They include two heart-like areas that capture food. The mucus houses often are nearly clear and completely cover the larvaceans.

And the houses are 10 times bigger than the creatures themselves — reaching more than one meter in size. It would be the same as a person making a five-story house, Katija noted.

Water can flow through the structure so that, when it comes through the water, the larvacean stays hidden from fish that might eat it.

Katija said NASA engineers looking to build structures on the moon would probably like to learn about the larvaceans.

Katija's team used a laser to study the structure of the inside of the mucus houses.

Then, the researchers recreated it with computer software to model the inner workings of the structure. But she said the scientists are still far from understanding everything going on.

Biologist Jack Carroll of Providence College in Rode Island was not part of the study, but had good things to say about it. He said Katija's team did useful work.

"We have a lot to learn," Carroll said. "I'm in awe of these animals."

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Words in This Story

master – adj. having or showing great skill

snot – n. fluid that comes from the nose and other tissue

alien – adj. foreign

crafted – adj. something made with care, requiring a special skill

global – adj. related to the whole world

NASA – n. short for the National Aeronautics and Space Administration; the U.S. space agency

awe – n. a strong feeling of wonder