Bryozoans by Lovell and Libby Langstroth © California Academy of Sciences

I’ve always been disappointed by aliens in the movies. When you picture them, what comes to mind? The human-robot from The Day the Earth Stood Still? ET’s toddler-like extra-terrestrial, with its long fingers, big eyes, and short legs? How about the toothy, bug-humanoid creature with wrestler’s arms that Sigourney Weaver hunts down in Alien?

To me, these aliens all have the same problem: they look like people. Sure, they’re stretched and smooshed, or have funny colors, or superhuman powers. But are they superior or more scary because of it? No way. And none of them can compete with what’s below the surface of our oceans right here on Earth.

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Coralline algae by Sherry Ballard © California Academy of Sciences.

I’ve been fascinated with sea creatures since I was about six years old. Although I collected rubber monsters and was always up for capturing snakes, frogs, and salamanders, I knew from an early age that sea creatures were different; definitely more like aliens to my dry world. They didn’t have arms and legs like we did, and you couldn’t always tell which was the business end, either. When I visited salt water, I’d often try to try to capture them, occasionally getting bit, stung, or poked in the process—which only proved that these creatures were forces to be reckoned with.

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Tube worm by Lovell and Libby Langstroth © California Academy of Sciences

As I got older and explored the sea with flippers and air tanks, I encountered their world fully. Initially the fish and giant kelps of the west coast caught my eye, but with time, it was the little things that rose to the top of my must-see list: the strange organisms that adhered to the bottom or drifted in the currents.

At first, I recognized only shapes and patterns, odd objects like encrusting algae the bright pink color of Milk of Magnesia, mysterious and flat. Were they animals, minerals, or something else? The vase-like tunicates never moved but didn’t seem like plants. Their odd openings and soft, gelatinous textures were fixed to the sea floor, but I wondered what they really were. (Now I know that they are invertebrate animals, more closely related to people than most other boneless creatures). Unlike the backyard worms I was familiar with, tube worms, in their shell-like homes concreted to a rock, reached out with feathery arms and showed no signs of eyes.

Tunicates by Eugene Weber © California Academy of Sciences

Nowadays, I’m more confident in my knowledge of sea creatures; they’re way cooler and scarier than anything in the movies. When the aliens finally arrive on Earth, if they’re not here already, there’s a good chance we won’t recognize them as life forms at all, just as most people don’t view ocean invertebrates as our relatives. And to me, that’s the scariest thought of all.

Editor’s notes:
I chose to use real photos because they expressed the strangeness of sea creatures much better than I could have with drawings. They are all borrowed from the kind people at UC Berkley’s scientific photo sharing site: CalPhotos.

I did a lot of searching for first contact/alien movies (excluding horror) to see what kinds of extra terrestrials are out there. Contact took place underwater, but even there the aliens look like humans made of liquid ice or cast glass. The only alien movie that breaks this trend is Arrival with its non-Frisbee space ships and octopus-like aliens that we barely see. Can you think of any notable exceptions that I missed?