Some ocean species inspire fear more than others and one creature that makes many fishers nervous is a deep-water animal known as the ‘red devil’, or Humboldt squid.
During a feeding frenzy, these huge scarlet squid can come together in their thousands, all communicating with each other by flashing like an underwater strobe light. But, despite working together to hunt, they don’t always have each other’s backs: Humboldt squid are known cannibals.
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What is a Humboldt squid?
Also sometimes known as the jumbo squid, these large, deep-sea cephalopods have a reputation for being bold predators that can hunt in packs, communicating with each other through the patterns displayed across their bodies. They can flash from red to white and back in an instant.
Some fishers call them ‘red devils’ because of their tendency to fight back when they’ve been hooked. Getting on the wrong side of the barbed hooks on their suckers or their powerful beak is not the best idea.
What do Humboldt squid look like?
The most iconic thing about Humboldt squid is their crimson colouration, which is the reason Mexican fishers gave them the name Diabolos rojos, meaning red devils. While hunting – or if an individual is distressed – they can flash between a vibrant red and bright white.
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How big are Humboldt squid?
They are also much larger than other squid, sometimes growing two metres long and weighing as much as 50kg – they are among the largest species of squid on the planet.
Where do Humboldt squid live?
Named for the Humboldt Current in waters off the coast of South America where they can be found, these animals typically live in the eastern Pacific Ocean between California and Chile in waters up to around 1,000 metres deep. At night, they emerge to shallower waters to feed.
What do they eat?
Adults eat lanternfish and other fishes, crustaceans, other species of squid and even other Humboldt squid (yes, they are sometimes cannibalistic!).
Like other squid species, they must consume larger prey in several bites to make sure they can fit down their oesophagus, which squeezes through the middle of their doughnut-shaped brain.
How do they hunt?
Like many other deep-sea animals, Humboldt squid migrate towards the surface of the ocean at night to feed under cover of darkness.
When they’re hunting, they often come together in huge groups – sometimes called a ‘squadron’ – which can, in some instances, have thousands of squid all going after prey.
It’s hectic but the squid communicate with each other and coordinate among themselves by flashing patterns across their skin. “For example, a half-light/half-dark pattern that Humboldt squid often exhibit when feeding might be a warning: “Look out—I’m going to grab that lanternfish!”,” writes Kim Fulton-Bennett on the MBARI website.
They use their long tentacles to grab their victim and bring it towards them so they can hold it still with their arms and take a bite with their razor sharp, parrot-like beat.
Their sharp beaks are among the hardest and stiffest organic materials on the planet but these becomes more flexible closer to their base, where they attach to tissue, to stop them slicing the squid to pieces while trying to feed.
Humboldt squid don’t typically compete with each other for prey but, if one of their own gets injured, things can turn dark quickly. If a squid is caught on a fishing line, rather than try to help their befallen comrade, the rest of the squad turn on it: attacking and eating it. Yikes.
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How do they reproduce?
Spying on Humboldt squid getting it on isn’t the easiest task but researchers believe they captured mating attempts on film when they attached cameras to these animals to learn more about their lives.
During mating, males pass a package of sperm – called a spermatophore – to the female who saves it for later. When ready to reproduce, she uses the sperm from the male’s ‘gift’ to fertilise her eggs, which she lays in huge jelly-like masses that float in the water. Marine biologists think that a female Humboldt squid can lay up to one million eggs in each egg mass and may spawn between 10 and 20 times during her lifetime.
Once mum has laid her eggs, that’s it: job done. Like many other cephalopods, there is no parental care and the little ones are left to fend for themselves.
The eggs probably hatch in just a week, which explains why they’re so hard to find and study, explains Stanford Doerr School of Sustainability’s Gilly Lab on its website. When scientists did stumble upon a Humboldt squid egg mass in 2006, it was totally by accident.
“About 16 meters (52 feet) below the surface, they swam into a gelatinous blob the size of a small car,” writes Gilly Lab. “They collected parts of it in jars and brought them back to the boat. The jars were full of squid eggs, which began to hatch that very night, and later genetic analysis confirmed they were baby Humboldt squid.”
Are they dangerous to humans?
They can be – Mexican fishers didn’t give these scarlet creatures the nickname Diablos rojos (‘red devils’) for nothing.
Humboldt squid are large, powerful animals with a sharp beak designed for slicing, the perfect weapon to severe their prey’s spinal cord. They hunt in packs that can number into the thousands – definitely not a feeding frenzy you want to get in the middle of!
Fishers say these cephalopods are aggressive towards humans and there are many stories of attacks. Some even say that if you fell overboard, these jumbo squid would tear you to pieces. Despite daunting legends of the harm they could do, there are no recorded human fatalities.
Divers who want to see thousands of these amazing creatures feeding together in the water sometimes wear chain mail to protect themselves or watch the spectacle from the safety of a metal cage.
Yet, when researcher Brad Seibel from the University of Rhode Island got into the water with these devils, he was surprised by how shy they were. They even seemed startled when he turned on his dive light. “Based on the stories I had heard, I was expecting them to be very aggressive, so I was surprised at how timid they were,” he is quoted saying on the university’s website. “As soon as we turned on the lights, they were gone.”
As with many other wild predators, it’s sensible to be cautious as these animals could potentially hurt you but the idea they go out of their way to track down and maul humans may be exaggerated!
Are they under threat?
It’s hard to say. The IUCN Red List of Threatened Species categorises Humboldt squid as ‘data deficient’. That means there isn’t enough data to make a call on their extinction risk.
However, these predatory squid are targeted by both artisanal and commercial fishers so they are at risk from overfishing.
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What nicknames does it have?
The Humboldt squid is also known as jumbo squid, flying jumbo squid, Red devil and Diablo rojo.
How long do they live?
Their average lifespan is one or two years
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Top image: Maximum Film / Alamy
