The colossal squid and the giant squid are two of the most mysterious creatures in the ocean. Both have been known to man for centuries through legend or myth, but little even to this day is actually known about them.
For a long time they were believed to be one and the same. Today, we know that there are distinct differences between the two.
Let’s take a closer look at these enigmatic creatures, and what sets them apart from each other.
Colossal Squid Vs Giant Squid Appearance
The colossal squid and the giant squid are both cephalopods, meaning they have a head and tentacles. They are also from the same order of species – Oegopsida, and both exhibit deep-sea gigantism, meaning they are extremely large for their surroundings.
Both the Colossal Squid and Giant Squid are known for having the largest eyes (larger than 10 inches) in the animal kingdom. Living at such depths, these eyes come in handy for capturing any light and movement in the deep, dark oceans.
Despite the many common features that these squid share, there are significant differences.
To begin, these squid belong to different families. The giant squid belongs to the family Architeuthidae and the genus Architeuthis. Like all squid, the giant has a mantle (torso), eight arms, and two longer tentacles (the longest known tentacles of any cephalopod).
The arms and tentacles account for much of the squid’s great length. The two tentacles have many suckers on the tips, called clubs. They also have eight arms with suckers in two longitudinal rows. At the end of the arms they have a parrot-like beaks at the base.
Giant squid have small fins at the rear of their mantles used for locomotion. Like other cephalopods, they are propelled by jet.
The colossal squid on the other hand is a member of the family Cranchiidae and is the only known member of the genus Mesonychoteuthis.
The colossal squid is known only from a small number of specimens, and so little is actually known about this squid species. This is due to the fact they live deep in the ocean in freezing waters. We do know, however, that they have a similar appearance to other members of the Cranchiidae family, with hooks on their arms and tentacles.
They have eight arms and a pair of long tentacles just like other squid species, but 25 rotating hooks that are aligned in two rows at the ends of their tentacles, which is unique to this species in the family Cranchiidae.
Their body is conical in shape and they have two broad fins that help them navigate through deep waters.
Colossal Squid Vs Giant Squid Size
The giant squid reaches an average length of around 33ft (10m) for males and between 39ft and 43ft (12m) for females. There are of course exceptions to this rule, and the largest giant squid to be discovered was around 59 feet and weighed around a ton!
These animals are sexually dimorphic, with females being larger and heavier than males. Females may weigh up to 275 kg (606 lb) and males may weigh 150 kg (330 lb).
The colossal squid is more massive than the giant squid, and is the heaviest living invertebrate species, reaching weights up to 495 kg (1,091 lb). They may reach up to 46 feet (14 m) in length with a mantle length of 2 to 4 m. On average though, the colossal squid is slightly shorter than the giant squid, but its stocky frame is heavier.
The colossal squid also has the largest eyes documented in the animal kingdom, with an estimated diameter of 30 to 40 cm (12 to 16 in).
This size difference between these two species may be due to the different habitats that they prefer. The colossal squid prefers deeper, colder waters. Though both species have deep-sea gigantism.
Where Do Colossal Squid and Giant Squid live?
The habitats of the colossal squid and the giant squid overlap to some extent. Both creatures are found in deep waters, particularly in areas with high marine traffic like the Antarctic Ocean. The giant squid however, has a much larger range.
You can find the giant squid in all of the world’s oceans. They have been recorded in the North Atlantic and North Pacific, around Newfoundland, the North Sea and at the other end of the world around New Zealand. They have also been found in deep areas around the Azores and Madeira.
The giant squid is typically found in depths of around 2,000 to 3,000 feet (up to 1000 meters). Whereas the colossal squid is thought to prefer colder, deeper waters than the giant squid. It is believed to inhabit waters in the Southern Ocean from Antarctica to the southern tips of Africa, South America, and New Zealand.
The colossal squid is thought to inhabit waters around 7,200 feet (2200 meters) to as deep as 23,000 feet (7000 meters). Juveniles however live above 3000 feet and only move into deeper waters as they mature.
What Do Colossal Squid and Giant Squid Eat?
The diets of the colossal squid and the giant squid are similar, as they both feed on fish, crustaceans, and other smaller squid. However, the colossal squid is thought to live a pretty slow paced life and don’t have many food requirements. The giant squid on the other hand is a more active hunter, and is even believed to hunt and eat small whales.
We know that the colossal squid eat Patagonian toothfish because the example on display at Te Papa in New Zealand was still attached to the toothfish it was eating when it was hauled up on a long line.
It is believed that one 5 kg toothfish may provide enough energy for a 500 kg squid to survive for up to 200 days. So it’s food needs really are low, allowing it to remain at lower and quieter depths avoiding predators.
Both species are ambush predators, but while the colossal squid relies on its hooks to catch prey, the giant squid uses its two tentacles, gripping it with the serrated sucker rings on the ends. Giant squid need to shred their food before they eat it, which they do with their radula.
Lifespan of a Colossal Squid Vs Giant Squid
The lifespan of a colossal squid is unknown, as no one has ever been able to study one in captivity. Current estimates however, suggest an average lifespan of 2 years.
Colossal squid are considered to be gonochoric, meaning that they die shortly after breeding and mating.
The giant squid, on the other hand, is believed to live for between one to five years in the wild and reproduce only once in that time. Recent observations in 2020 of a female giant, suggest that they may also be monogamous.
The colossal squid has few natural enemies because of the depths that they live in. Few creatures can survive that deep, and predators are few and far between.
Sperm whales are thought to be the primary predator of the colossal squid. They can dive to great depths in search of their prey, and they have been known to attack and eat both colossal and giant squid.
When a sperm whale eats a colossal squid, remnants of the squid’s beaks remain in the stomach of these whales. From observations, it is estimated that colossal squid could make up to 70% of a sperm whale’s diet. This suggests that these massive squid may not be as rare as once thought.
Other predators that can dive to great depths, such as the southern elephant seal also hunt juvenile colossal squid. But only sperm whales are known to hunt adults.
The giant squid is known to be preyed on by sperm whales, pilot whales, southern sleeper sharks and killer whales. Though similarly to the colossal squid, only sperm whales are known to prey on adults. Juveniles make better prey for the remaining predators, as they are smaller in size and don’t travel as deep.
Evidence of scarring from examined sperm whale skin shows that the squid don’t go down without a fight!
Cephalophoda (the class encompassing the 2 orders of squid as well as extant and extinct octopus, cuttlefish and nautilus) can be traced back to the Late Cambrian period (497 – 485.4 million years ago). They became dominant during the Ordovician period (485.4 – 443.8 million years ago).
Cephalopod are a class of Mollusca in which the most intelligent and also the largest molluscs belong. Namely, octopi and squid. Around 800 species of cephalopod exist today.
In human history, while little is actually known about both the colossal squid and the giant squid, both species are thought to have been known about to some degree for centuries.
The first recorded sighting of a colossal squid was in 1861, and the first recorded sighting of a giant squid was in 1639. But observations of giant squid have been recorded as far back as the 4th Century BC with a documented account from Aristotle, of a giant squid he called ‘Teuthus‘.
Roman author Pliny the Elder also wrote about a massive squid in the first century AD. But possibly the most prominent impact of giant squid in history, is the Scandinavian mythology around the Kraken. This tentacled sea monster was said to, lurk around the waters of Norway, and to be able to sink any ship. C
ould it be that these stories, though steeped in myth, came from early accounts of giant or colossal squid? Or could it have been an account of another giant cephalopod like an unknown giant cuttlefish or octopus?