Vampire squid

Classification

Scientists named this animal Vampyroteuthis infernalis, which means “vampire squid from hell.” But the vampire squid is no squid at all—they’re the only living member of the family Vampyroteuthidae in the phylum Mollusca.

This misleadingly-named cephalopod has a storied history of misclassification. When this species was first discovered in 1903,they were classified as a type of cirrate octopus like the flapjack octopus due to the webbing between the arms and pair of fins on the mantle. In the 1940s and 1950s, however, scientists determined that it was neither an octopus nor squid, but part of a different group based on its unique features.

Appearance

What big eyes you have!

One of the vampire squid’s most striking characteristics is their large eyes—the biggest eyes of any living animal in proportion to their body size. Their eyes are about one inch in diameter, while their bodies can grow up to 12 inches in total length. If a human had the same proportions, our eyes would be about 9 inches in diameter!

If you watch a video of a vampire squid in the deep sea, you’d think their eyes glow bright blue. But that’s actually a trick of the light. When the clear eyes of a vampire squid are illuminated by the lights of a remotely operated vehicle, they reflect the surrounding water and appear blue in the footage captured by scientists.

Bright blue bits

A light-producing organ produces bright blue bioluminescence at each tip of a vampire squid’s arms. 

Tentacles and filaments

The vampire squid has two fine tentacles, or filaments, that can extend up to eight times the length of their body. Each filament has tiny hairs and sensory nerves that help them sense their surroundings and possibly detect food.

Cloak

A vampire squid inverts their webbed arms when startled, producing a “cloak” that covers the mantle. This motion exposes spikey-looking appendages called cirri on the undersides of their webbed arms. The cirri are usually iridescent, reflecting the light of remotely operated vehicles as they move.

Colors

Vampire squids are a reddish rust color. Many cephalopods have special muscles that control their pigment sacs called chromatophores that allow them to change their color. Vampire squid lack these muscles, so you won’t see a vampire squid shifting color.

How does the vampire squid survive in the deep sea?

Though the cold, dark, low-oxygen waters of the deep sea make survival difficult for most animals, the vampire squid is most often found in the oxygen-minimum zone. The vampire squid has evolved to survive in the extreme conditions of this harsh deep-sea environment.

Energy efficiency. The waters of the deep sea have low oxygen and unpredictable food, so a vampire squid must conserve energy. They have the slowest metabolism of any cephalopod so energy from food lasts longer. They’re also neutrally buoyant—that squishy, gelatinous body is only slightly denser than the seawater surrounding them so they can remain suspended in the water column without expending much energy.

Waste not, want not. The vampire squid uses their large surface gill area to makes the most of the little oxygen available in their environment. They have a respiratory pigment called hemocyanin in their blood that carries oxygen. They have the highest affinity for oxygen of any known cephalopod species!

A see-food diet. The vampire squid’s keen sight likely allows them to spot the largest particles of marine snow to snack on.

Diet

The vampire squid don’t share the same diet of their batty namesake. They’re detritivores, meaning they dine on dead organic material, and they're the only living cephalopod species that doesn't primarily consume live prey. Some studies find that older, larger vampire squids may occasionally consume fish, crustaceans, and jellies. But for the most part, vampire squids are gentle drifters who prefer a drifting, decaying buffet.

So what’s on the menu? Mostly marine snow—particles of dead animals, rotting materials, poop, and snot. Yum! Marine snow gently drifts down to the deep sea from above and looks like an underwater snowfall. 

To feed, the vampire squid extends its two thin filaments covered in adhesive mucus. The animal traps the marine snow in its filaments, then pulls them through its arms, scraping off trapped food particles along the way. Suckers on its arm secrete mucus that envelops the food particles, creating a sort of marine snow mucus dumpling. The mucus dumpling is slowly moved to its mouth underneath its mantle, where it’s then eaten. 

Diet

The vampire squid is no bloodsucker—it’s a detritivore, meaning it eats dead organic material. It’s the only living cephalopod species that doesn’t eat live prey.

What’s on the menu? Mostly marine snow: particles of dead animals, rotting materials, poop, and snot. Yum! Marine snow gets its name because it gently drifts down to the deep sea from above and looks like an underwater snowfall when illuminated by a submarine’s headlights.

Mucus dumplings

To feed, the vampire squid extends its two thin filaments covered in adhesive mucus. The animal traps the marine snow in its filaments, then pulls them through its arms, scraping off trapped food particles along the way. Suckers on its arm secrete mucus that envelops the food particles, creating a sort of marine snow mucus dumpling. The mucus dumpling is slowly moved to its mouth underneath its mantle, where it’s then eaten.

Bolas de moco

Para alimentarse, el calamar vampiro extiende sus dos filamentos delgados cubiertos de moco adhesivo. El animal atrapa la nieve marina en sus filamentos y luego los pasa por sus brazos, raspando las partículas de alimento atrapadas en el camino. Las ventosas en su brazo secretan moco que envuelve las partículas de alimento, creando una especie de bola de moco de nieve marina. La bola de moco se mueve lentamente hacia su boca debajo de su manto, donde luego es ingerida.

Defense strategies

The vampire squid doesn't produce ink. They've evolved other strategies to stay safe from predators.

The pineapple pose

The vampire squid wards off predators by pulling their arms up and over their body and shrouding themself in a cloak-like web. This motion hides the mantle and exposes spikey-looking fleshy appendages on the back of its webbed arms called cirri. Scientists nicknamed this unique defense strategy the “pineapple pose”!

Mucus cloud

The vampire squid may eject a luminous mucus cloud to distract predators. 

Re-growing limbs

A vampire squid can regenerate the top of an arm that’s broken or bitten off by a predator—a small price to pay for a quick escape!

Mating

While most cephalopods mate only once, the vampire squid reproduces multiple times in their lifetime. 

A male vampire squid transfers his sperm to the female with his funnel, a cylindrical muscular structure cephalopods use for respiration and movement. The female uses the sperm to fertilize her eggs then releases them into the water column. She releases only a few eggs at a time and uses relatively little energy when spawning.

Lifecycle

After the vampire squid egg is fertilized, it develops into a larva with a large head and eight short arms. 

A juvenile vampire squid has four fins on the mantle. Two of these fins get reabsorbed into the animal's body as they mature, a trait unique among all living cephalopods. Confused by this mysterious species’ distinct appearance in each stage of development, scientists once thought there were 10 different species of vampire squid!

Predators

The vampire squid’s ability to thrive in the oxygen-minimum zone keeps them relatively safe from danger. They’re sometimes found and preyed upon by predators including fishes, cephalopods, sea lions, sharks, and whales.

Conservation

Though the dark and mysterious underwater world of the vampire squid may feel far away, climate change is already affecting deep-sea animals. As the ocean warms, studies show an increased number of low-oxygen “dead zones,” and the deep oxygen-minimum layer where the vampire squid lives is also expanding. To help us better understand our changing ocean, scientists study species like vampire squid that can survive in the oxygen-minimum layer then compare them to species that live outside these harsh conditions.

Cool facts

• The vampire squid is the only living cephalopod species known to be a scavenger.
• A vampire squid’s eyes are the largest in the animal kingdom by proportion.

Lifecycle

After the vampire squid egg is fertilized, it develops into a larva with a large head and eight short arms.

As a juvenile, the vampire squid has four fins on its mantle. Two of these fins get reabsorbed into the animal's body as it matures. This is unique among all living cephalopods, and confused scientists for many years—they thought the adult vampire squid was a separate species from the juvenile.

Because the vampire squid has a distinct appearance in each of its stages of development, scientists at one point thought there were as many as 10 different species of vampire squid!

Ciclo de Vida

Después de que el huevo del calamar vampiro es fertilizado, se desarrolla en una larva con una cabeza grande y ocho brazos cortos.

Como juvenil, el calamar vampiro tiene cuatro aletas en su manto. Dos de estas aletas son reabsorbidas en el cuerpo del animal a medida que madura. Esto es único entre todos los cefalópodos vivos y confundió a los científicos durante muchos años—pensaban que el calamar vampiro adulto era una especie separada del juvenil.

Debido a que el calamar vampiro tiene una apariencia distinta en cada una de sus etapas de desarrollo, en un momento los científicos pensaron que había hasta 10 especies diferentes de calamar vampiro.

Predators

The part of the deep sea the vampire squid calls home is low in oxygen, and therefore also free of many predators. But predators exist nonetheless and include fishes, cephalopods, sea lions, sharks, and whales.

Depredadores

La parte del mar profundo que el calamar vampiro llama hogar es baja en oxígeno, y por lo tanto, también está libre de muchos depredadores. Sin embargo, los depredadores existen y entre ellos se incluyen peces, cefalópodos, lobos marinos, tiburones y ballenas.