What Do Squid Eat? Inside the Hunting Tactics of Ocean Predators

Hunting is an art form for the squid. These deep-sea creatures evolved to thrive in the darkness and also survive its challenges. In an environment where other fish would be ill-equipped, the squid dominates the food chain. We spoke to an expert to learn precisely what squid eat and how they’re so adept at capturing prey.

A Natural Hunter of the Deep

Squids are some of the strangest-looking creatures in the world. Their appearance is deceptive, concealing several primary tools that cephalopods use to hunt. Dr. Jennifer Brandon, an Environmental Scientist and Sustainability Consultant, says there are four ways squid get the advantage over smaller fish. “Squids are visual hunters, with very large, well-developed eyes. Giant squids have some of the largest eyes in the animal kingdom,” she says. “Those huge eyes help squids that live in the deep sea hunt even in the dark, as they can pick up on tiny amounts of light and bioluminescence in their prey.” This extra-sensory ability gives squid the upper hand at depths of 1,000 to 2,000 feet. While the squid goes undetected, any prey with a light source is on the menu.

Dr. Brandon goes on to explain the anatomy of the squid, detailing the difference between it and other cephalopods. “Unlike an octopus, a squid has eight short arms and two very long tentacles that are used to grab prey and pull it to their sharp beak at the center of their circle of arms,” she explains. These two extra tentacles are called clubs, and are often lined with either suckers or hooks. “Their long tentacles are one of their unique features,” she says, adding, “The tentacles have suction cups at the ends to grab prey, and then the other eight arms can position and maneuver prey while they eat it with their beaks.” The squid’s tentacles are primarily used for hunting, as they have other body parts that facilitate movement. As the club tentacles pull in prey, the beak—or rostrum—functions as a mouth, chewing food so it can be digested.

Dr. Brandon adds that some squid have another potent trick up their tentacles. “Some squid species even inject poison into their bites,” she says. Some squid, like the striped pajama squid, are highly venomous. This unusual-looking squid excretes a toxin when threatened, and is considered venomous and poisonous. This, in addition to color-changing chromatophores and the ability to squirt ink, makes them powerful predators.

On the Offensive

While squids have a wide array of deadly weapons to use while hunting, Dr. Brandon notes that a squid’s defenses can also help offensively. ” Squids can also camouflage and swim very fast, allowing them to be both ambush predators and escape their own predators easily,” she says. The Humboldt squid is the fastest, clocking a whopping 15 MPH underwater. Outside the squid family, the octopus can cruise by at 25 MPH due to jet propulsion. Squids have the same means of a quick escape in the form of a siphon. The mantle of the squid allows it to take in water and excrete it quickly, producing a high-velocity disturbance that propels them forward.

This speedy swimming tool helps the squid evade predators, but also functions as a hunting tool. Squid move quickly, especially when their dinner is at stake. In the blink of an eye, they can ambush a fish before it realizes what’s happening. The squid’s powerful body is designed for hunting, enabling it to outrun predators such as sperm whales, larger fish, and other predatory squids.

What’s On the Menu

Squids are a carnivorous species. This is why their hunting techniques are so well-honed. Their diet consists primarily of creatures smaller than them, but it’s not uncommon for them to go after an animal of the same size. “Squid eat many types of small fish and can even eat other small squid,” says Dr. Brandon. Their powerful beaks also help them eat crustaceans by breaking through the outer shell, making the shellfish easier to consume.

Cannibalism within a species is not unheard of, particularly in species like the giant squid. This cephalopod lives in the Twilight Zone, where finding food can be a challenging task. The answer to this is to seek out other squid. Giant squid may consume other giant squid and even other, smaller squid species as a meal. In this case, beggars can’t be choosers, and in the animal kingdom, food is food.

A Change in Evolutionary Habits

While squids are still the kings of the deep, Dr. Brandon says this could all be changing. “In the last few years, there has been a heavy increase in squid fishing, particularly in areas where it is unregulated. This has led to some squid species being overfished,” she says. In a sad twist of fate, squid are being caught the same way they hunt for other fish: by being lured to the surface with a light, and caught for food or sport. This not only decreases the squid population but also causes confusion and light pollution to their native hunting grounds, according to Dr. Brandon.

Additionally, squid are now facing challenges in both their ability to hunt and their access to primary food sources. Squid are visual predators; increased water pollution impairs their ability to hunt. “They need clear water to hunt effectively,” says Dr. Brandon. “An increase in water pollution, turbidity, and algal blooms can hurt squid populations.” Experts are already noting changes in the hunting patterns of squids, some of which are brought on by climate change. Dr. Brandon explains that increasingly warmer waters are forcing squid out of their natural habitats, causing them to migrate to northern waters. She cites that squid previously native to Baja California are now being discovered as far north as Washington and Oregon. “We are seeing populations shift locations and often move north as waters warm. This can cause all kinds of new interactions with new prey and predators that they have never come into contact with before, and can cause ecosystem-wide effects,” she explains.