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By: Efraim Harari

The squid is a marine cephalopod that is often mistaken for an octopus. While the squid and octopus are similar in some ways, they are two different types of sea creatures. There are around 300 different species of squids found in the oceans worldwide. The squid is one of the few creatures that can inhabit the freezing waters of the Antarctic. Squid habitats are most commonly found in the deepest zones of the oceans. Because of this, most marine biologists believe that there are many more species of squids that have yet to be discovered.

The squid has eight arms and two feeding tentacles, which are longer than the arms. Some species of squids are known to have ten arms! The squid is an invertebrate (animal without a backbone) that has an extremely soft body. Most squids have a long, tube-shaped body, with a large head, a sharp beak, two large eyes, and two lateral fins on their sides. The size of a squid varies from area to area. Some species are as small as one inch, while others can exceed forty feet in length!

All squids are carnivorous; however, their diets vary according to their size. Smaller species of squids eat krill, plankton, crustaceans, and small fish. Larger species will eat large fish and smaller species of squids, while the giant squid will even eat young sharks and whales! When hunting for prey, the squid usually waits in hiding until its victim is in striking range. Once its prey is in reach, the squid quickly grabs it with its two long feeding tentacles. Then it uses its arms to transfer the prey from its tentacles to its mouth. The squid uses its parrot-like beak to tear off small pieces of its prey so that it can swallow them.

Due to the squid’s very soft body texture, it is easy to be consumed and is therefore a common food source for many sea creatures. The smaller species of squids are the ones that are often eaten by small and medium-sized predators. Predators include fish, seals, penguins, sharks, whales, and other squids.

Generally, squids in the wild will only reach up to three years of age before being eaten. Some of the larger species of squids, have been known to reach the age of fifteen.


The colossal squid is not only the largest species of the squid, it is also the largest invertebrate in the world (the giant squid is the second largest). It is quite massive, growing to a length of over forty feet and often weighing over 1,000 pounds.

The colossal squid inhabits the cold waters of Antarctica, New Zealand, and even some areas of Africa. It lives in the deeper regions of the sea, making it difficult for scientists to observe and learn more about them. Adult colossal squids descend to depths greater than 7,000 feet. Most of what we know about these humongous creatures comes from the exploration of their dead bodies that sometimes wash up on beaches.

Besides for being so large, the colossal squid is quite powerful as well. Its size, weight, power, and arsenal of “weapons” make it easy for it to capture large fish to eat. These “weapons” are part of the colossal squid’s body, and they are lethal to the squid’s prey. Like most squids, the colossal squid has eight arms and two tentacles. What makes the colossal squid unique is that its tentacles possess two rows of sharp, rotating hooks that swivel, as well as two rows of suckers. The arms have moreand much larger suckers, and hooks that do not rotate. The colossal squid also has a very large beak, the largest of any squid. Between its sharp beak, suckers, and hooks, the colossal squid has all it needs to grab, hold, and eat large prey.

Safety Features

The squid has many predators to be concerned about, and so it needs to rely on its traits of speed, quickness, and flexibility, along with its complex system of camouflage, in order to protect itself.

When in danger, the squid will release a cloud of dark ink, called sepia, to momentarily confuse its predator and thereby give itself time to make a quick getaway. The squid also has the ability to blend in with its surrounding environment by changing its skin coloring. Squids have thousands of pigment cells, called chromatophores, which expand or contract to change the color or pattern of the squids’ skin in order to match their backgrounds, making them practically invisible.

Is it a Squid or an Octopus?

Many people mistakenly think that the squid and the octopus are the same creatures. Although they are both multi-armed mollusks, they have many differences and are easy to tell apart.

Below are some of their differences:

Most squids have at least ten limbs - eight arms and two tentacles. The octopus, onthe other hand, has eight limbs – eight arms, and they don’t have tentacles.

The squid has two fins, whereas the octopus has none.

The squid’s body is cigar-shaped, while the octopus has a bell-shaped body.

Squids use their two feeding tentacles to grab and capture prey, whereas octopuses inject venom into their prey, which paralyzes the prey.

Mollusks, Start Your Engines…

The squid is the fastest swimming invertebrate in the sea. When necessary (such as when chasing prey or escaping from predators), and for short periods of time, it is able to swim with powerful bursts of speed. In order to accelerate its speed, the squid squirts water rapidly from its mantle cavity (the mantle looks as if it is a hat that protects the main part of the squid’s body). The squid moves by jet propulsion: as the mantle opens, water is taken in, and as the mantle closes, water is released throughthe siphon, a nozzle-like structure located below the eyes. The siphon acts as a jet engine, enabling the squid to “fly” through the waters. The squid shoots backward, tail first and can propel itself as much as twenty-five body lengths in a second! Some squids even leap above the water and glide over the surface, like flying fish, when being pursued by predators.