How to Identify Squid and Octopus: A Quick Guide

If you're planning a Krabi diving adventure, knowing how to identify marine animals like squids and octopuses can make your experience even more rewarding. At first glance, a squid and octopus may seem pretty much the same. After all, they’re both cephalopods with tentacles and live in the ocean. But looking deeper, you will find plenty of differences between these fascinating creatures. From where they live to how they defend themselves, squids and octopuses are more different than expected. This post will break down the difference between a squid and an octopus and where to find them in Krabi.

While squids and octopuses share similarities, their appearances make it easy to tell them apart. Octopuses have round heads with eight arms branching out like the spokes of a wheel. Conversely, squids have a triangular-shaped head, a long body, eight arms, and two extra-long tentacles. Squids also have a small, bony plate inside their body called a pen, which is what’s left of their ancestors' shells.

Another difference is squids have two fins on their heads, while octopuses don’t. There are a few exceptions, like the Dumbo octopus, a deep-water species with ear-like fins that look like Disney’s Dumbo, the elephant.

Both creatures have suckers on their arms, but squids take it up a notch with hooks and sucker rings with sharp teeth on their extra tentacles. Their eye placement also sets them apart. Octopus eyes stick out from the top of their head, while squid eyes are tucked between their head and mantle.

Most squids range from 60 cm (about 2 feet) to nearly 20 meters (over 65 feet), though the tiniest squid, the sepiolid, is less than an inch long. On the other hand, Octopuses vary from as small as 1 cm to around 9 meters (about 30 feet) in length.

Squids spend most of their time in the open ocean, swimming alone, or gathering in schools with other squids. They rely on the fins at the top of their bodies to move slowly, but they use jet propulsion when they need to speed up.

On the other hand, Octopuses are solitary creatures that prefer living near the seabed. They hide in rocky areas, caves, or discarded objects like cans or pots. They can crawl along the sea floor using their arms and are known to venture onto rocks above the waterline to catch prey.

Though both creatures move using jet propulsion, their behavior during hunting and mating is quite different. Squids are social hunters, working in groups to catch prey in open water. They use their tentacles to grab fish, crustaceans, or even other squids, breaking their food into pieces as they eat. Squids mate in large groups and attach their eggs to solid surfaces like rocks or coral.

Octopuses, however, hunt alone, often pouncing on prey from hiding spots. They use their arms to pull prey toward their beak, where they inject poison to paralyze the target before eating it. Octopuses feed on clams, crabs, small fish, and even other octopuses. During mating, males use a modified arm to deliver sperm to the female, who lays eggs in her den.

Cephalopods have impressive ways to protect themselves from predators, and squids and octopuses take different approaches. Squids rely on speed and distraction. When threatened, they release a cloud of dark ink to confuse predators and make their escape.

Like squids, octopuses can also release ink as a defense. But since they’re one of the smartest sea creatures, they have other tricks too. They can mimic other animals, change their color and texture to blend in with their surroundings, use objects like coconut shells for protection, and even flash bright colors to warn predators about their venom.

Another key difference lies in how long these animals live. Squids typically live between 9 months and 5 years, depending on the species. Octopuses, however, have shorter lifespans, usually surviving for only 1 to 3 years, even the larger ones.

The Phi Phi Islands lie between Phuket and Krabi in the Andaman Sea. Koh Bida Nok and Maya Bay are the most popular dive sites. These islands feature limestone cliffs and sheltered bays, ideal for spotting marine life. Octopuses often hide in crevices along coral reefs, while squids swim in shallow waters at night. The waters around Phi Phi offer opportunities for both recreational and technical dives.

Located about 40 km west of Koh Lanta, Koh Haa is a group of five small islands offering clear waters and diverse marine life. This spot offers shallow lagoons and deeper walls, providing diverse habitats for squids and octopuses. It’s also a great site for night diving, where these creatures are more active.

Located near Ao Nang, these sites are famous for marine life and soft corals. Shark Point, in particular, offers a good chance to see squids during the day and octopuses hiding among rocks.

These dive sites are located near the southern tip of Koh Lanta in the Andaman Sea, part of the protected Mu Koh Lanta National Park. They are deep-water sites with vibrant coral walls and abundant marine life. Octopuses are often found in rocky crevices, while squids are seen swimming in the open waters at night.

Diving in Krabi offers an unforgettable opportunity to encounter amazing marine life, including squid and octopuses. Take your time underwater and enjoy the beauty of these creatures. When you're ready for your next adventure, book your trip with Giant Stride for a safe and exciting diving experience.