In my very first post for this blog, I wrote about how the name “vampire squid” is pretty much false advertising. Vampire squid aren’t vampires and they aren’t really squid either.
That may be disappointing to you (it definitely is when I tell school kids that, though they’re more disappointed by them not being vampires, than not being squid). If you are disappointed with that knowledge, but still have a glimmer of hope in your heart that has you thinking, “They’ve got to at least suck blood, right? I mean what self-respecting, name-giving person would name something “vampire” if it doesn’t suck blood?”, prepare for more disappointment, because vampire squid don’t suck blood. What they do eat is horrifying, but not in the run screaming in the night way. It is horrifying more in the run screaming to the bathroom way, because vampire squid eat poop.
Just in case you think that was a typo, I’ll write it again.
Vampire squid eat poop.
Vampire squid live mainly in the Midnight Zone (aka the Bathypelagic Zone) of the ocean. This environment, thousands of feet below the sea surface, is a difficult place to live. The water pressure there is crushingly intense. For an animal 3,500 feet (1,066 meters) below sea level, the pressure is so intense that it is like having a cow sitting on each square inch of its body.
Not only that, but there is also very little oxygen in the Midnight Zone. There is so little oxygen that another name scientists have for this part of the ocean is the oxygen minimum zone. Since all animals need oxygen to survive and most living things aren’t built to survive having cows sitting all over them, not many animals can live in the Midnight Zone.
The lack of animals in the Midnight Zone makes it hard for the animals that do live there, because most ocean animals eat other ocean animals to get the food they need. Prey is scarce in the deep sea. To make matters worse, sunlight does not reach that deep. Predators that live there have to to find dinner in complete darkness.
Vampire squid have solved all the problems of the Midnight Zone. They can handle extreme pressure and they don’t need that much oxygen to survive. And, instead of trying to find and catch other animals to eat, they get their food from a source that is fairly abundant in the deep sea.
If you were able to hangout deep in the ocean, you would notice that there were white flakes of stuff falling all around you. Though these white flakes look like snow (and are actually called "marine snow"), they are not crystals of ice like the stuff that covered my yard just a month ago (I live in Rochester, NY). They’re more like the fish food flakes you may have shaken into your home aquarium, except these flakes are not coming from someone shaking a giant can over the ocean. Marine snow flakes come from the bodies of fish, squid, sea turtles, plankton, and other living things near the surface.
Like you, ocean animals poop. Some of them also die every day, like when they get eaten. When an animal gets bitten, sometimes parts of it don’t quite make it into the predator’s mouth and fall out as crumbs. These bits of poop and dead stuff get pulled by gravity towards the bottom of the ocean, creating a blizzard of gently falling flakes of disgustingness that scientists call marine snow. “Disgustingness” is a human’s opinion, though, because poop and dead stuff contain calories and nutrients, which are what all living things need from their food. For a vampire squid, marine snow is super-abundant and nutritious free food that a vampire squid can snack on anytime it is hungry. It is basically like manna from heaven, if manna was poop and dead stuff.
It wasn’t until 2012 that we figured out that vampire squid eat marine snow (which was a year after I finished writing A Day in the Deep). Vampire squid do not have feeding tentacles that true squid use to catch prey. Instead, vampire squid have these long stringy things that come out of their bodies, called filaments.
Scientists weren’t sure what these filaments were used for until they started watching videos of vampire squid taken by the Monterey Bay Aquarium’s Research Institute’s remotely operated vehicles (ROVs) (ROVs are basically small submarine robots).
The scientists observed that some of the vampire squid appeared to be using the filaments to collect marine snow. The scientists came up with a hypothesis that the vampire squid were catching marine snow to eat it (a hypothesis is a guess based on facts that explains a mystery). They tested this hypothesis by looking at what was in the stomachs of recently dead vampire squid (as well as doing a few other experiments; you can read the description of everything they did here). They discovered vampire squid had indeed been eating “the remains of gelatinous zooplankton, discarded larvacean houses, crustacean remains, diatoms and faecal pellets” (“faecal pellets” is a more polite and scientific way of saying “poop.” Also, “faecal” is the British spelling. The American spelling is “fecal” as in “feces”. “Remains” is a polite way to say “dead stuff.”) In other words, they were definitely eating marine snow.
So we now know vampire squid eat poop. Should we change their name to "poop squid"? From a marketing perspective, poop squid would probably get as much attention for them as vampire squid, so it’s a tough call. I say we compromise and call them “vampire poop squid.”
To learn more about vampire squid, read my book A Day in the Deep.
Also here's a video on vampire squid eating habits:
Online references and resources
California Academy of Sciences. "Vampire Squid Diet."
National Geographic. "Vampire Squid's Surprising Diet Revealed."
The New York Times. "When It Needs to Feast, Vampire Squid Is a Softy."
SciNews. "Eating Habits of Mysterious Vampire Squid Vampyroteuthis Infernalis Revealed."
Smithsonian. "Poop Eating Vampire Squids Aren’t Actually Squids at All."
Photos and Images
Click the photos and images used above to find their sources.