Seafaring, Space, Symbiosis, and Squid

Imagine you are a seasoned astronaut floating through the mystical blue abyss that is space, documenting the thousands of bright white stars that buzz relentlessly above your head. Suddenly, a shape you don’t recognize appears close by. Is it a rock? An alien spacecraft? A piece of debris? Wrong. It’s a squid!

While I admit that seeing a squid floating aimlessly in space is highly improbable, Hawaiian bobtail squid have frequented the International Space Station. In June 2021, Professor Jamie Foster from the University of Florida worked with NASA to send Hawaiian bobtail squid from the University of Hawai’i Kewalo Marine Laboratory into orbit as part of a program to study the effects of space travel on the immune system.

Hawaiian bobtail squid are small, ocean-dwelling mollusks. These animals are also bioluminescent, meaning they have a special relationship with a certain type of bacteria, called Vibrio fischeri, that allows the squid to glow in the dark.

While these baby squids are born without Vibrio fischeri, the bacteria quickly enter through pores in the squid’s body, which is also known as the mantle. Inside the mantle are the squid’s ink sac and light organ. Vibrio fischeri bacteria multiply inside the light organ and communicate through chemical signals that cause the light organ to glow. A thick, reflective tissue also surrounds the squid’s ink sac and light organ. This tissue works in conjunction with the squid’s eye to match the light emitted by the squid to the moon’s silvery reflection on the ocean’s surface.

In an act called counter-illumination, the squid’s ink sac absorbs any light that its bioluminescent bacteria may be emitting toward the seafloor so that the squid’s body blends in seamlessly with the bottom of the ocean. This unique interaction between the squid and the bacteria it houses is called symbiosis, which is an arrangement that’s mutually beneficial to both organisms. The squid is able to camouflage itself from potential predators and the bacteria get to eat and breed in a relatively safe environment.

So how does this apply to humans and space travel?

“Gravity gives all animals on the planet directional queues,” explains Professor Foster.

If people react to the stresses of spaceflight, then so do squids. Professor Foster also explains that squids and humans share what’s called an innate immune system, which is how our bodies interact with good and bad microbes.

“We do not function properly if we do not have our microbes present and the squid are the same way,” said Professor Foster “They will not glow in the dark, they will not be able to hide from predators if they don’t have that beneficial microbe.”

In order to understand how the squids’ immune system reacts to space travel, the squids were frozen and preserved in space.

“They were frozen at a certain time point so we could capture… the genes that are actively being used at any moment in time,” said Professor Foster

While the squids did not survive their return to Earth, they provided tremendous insight into the practice of sending animals to space and the future of space travel. Due to the distance between the moon and Earth, sending animals to the moon is not currently a viable option. We can however, continue to send smaller organisms like worms and flies beyond low Earth orbit.

There is always room for development in space travel and Professor Foster explains how sometimes, the easy fixes are the ones that make all the difference.

“When we were first starting… the squid were getting their little tentacles stuck on the tube, so we had to prevent them from getting stuck,” said Professor Foster. “We cut tiny, tiny pieces of aquarium floss, stuck them in the tubes, and the squid all of a sudden didn’t start swimming into the tubes… You’ve got this million-dollar rocket project and it was 25 cents worth of aquarium floss that saved the day.”

As we adapt, so will our perspectives on space travel. Professor Foster predicts that space travel will become standardized.

“Whether you’re a tourist, or a scientist, or working in a different field… I think that there’s going to be a whole new economy of low earth orbit that is happening right now,” said Professor Foster. “There’s going to be a lot of great science that can be done to help people on Earth.”

It’s important to acknowledge the emerging opportunities in the field of space exploration, but it is also extremely important to not lose sight of the present and future of the planet we already have.

“There’s one constant that has been on Earth since day one, and that is gravity,” explained Professor Foster. “The climate has changed, the day length has changed, sunlight changes, everything changes… but gravity has not changed.”

It’s invaluable to note all of the scientific work being done in space keeps these constants in mind in an effort to help people on Earth. So, the next time that you look up into the night sky, thank your lucky squids for all of the milestones they have allowed us to achieve whilst building a future in which we wholeheartedly believe.