No doubt there is a very great similarity between an octopus and a squid, such that many conclude that these two sea creatures, octopus and squid, are the same.
Though they may look alike, they do have their biological, physical disparities, even their mode of hunting and habitat.
So, what are those differences that exist between the octopus and a squid? The answer is found below.
Biological Classification
Octopus and squids belong to the cephalopoda class meaning “head-footed”, due to the fact that they have no feet, as such their most unique feature is their head.
The cephalopoda not only include octopus and squids but also include snails, and nautilus. They are invertebrates. The giant squid is the largest cephalopod while pygmy squid is the smallest.
They have symmetrical bodies, multiple arms or tentacles which emanates from their bodies.
Octopuses and squids developed to have bodies which does not require a hard shell for protection, unlike the nautilus and snails, this is due to other adaption like enhanced intelligence, camouflage, flexible and strong arms, which they you to capture prey.
There are over 309 species of octopus and squids in the ocean so what is they clear difference between the two of them?
Habitat
Octopus make the seafloor their home mostly in the dark crannies while squids live generally in open ocean.
They both live in in Salt water from the tropics to more temperate zones.
Type of Food
For one thing, octopuses are vulnerable because of their soft body, as such they choose to stay at the bottom of the ocean or sea floor where they mostly feed on crustaceans that dwell also at the bottom of the ocean or sea floor, they do this by grabbing their prey, pierce and paralyze them by injecting them with poison after which they use their saliva to dissolve and loosen the prey’s meat before devouring them using their mouth and beak.
Squids on the other hand feed on shrimps and other small fishes by using their two extra tentacles with sucker rings which helps them capture shrimps and smaller fish and eat in chunks.
Appearance
Octopus have a rectangular pupil in their two eyes, and a rounded head, a mantle, eight arms with variety of colors whereas squids on the other hand have a triangular head, two fins on their mantle and a circular pupil on their eyes.
They have a pen (a rigid backbone-like structure) with arms and tentacles combine together, which have suckers and hooks for catching prey.
For some specie of octopus like the Dumbo octopus which are found in deep water, they have fins just like squids.
The eight arms of octopus are more flexible than those of squids which allows them to manipulate their movements and also handle objects.
Body Size
It is a common belief that octopuses are larger in size than squids but that is far from it. Octopuses only grow between 1cm-9cm while squids grow between 60cm-20m in length, though the sepiolid specie which is the smallest specie of squids is below 1inch long.
Defenses
Octopuses defend themselves from danger and threats by simply changing their color or squeezing themselves into the most cramped crannies to hide while squids quickly dispatch clouds of ink into the water body for swift escape as soon as they sense danger or feel threatened.
Mode of Reproduction
Male octopuses use a special arm (called the hectocotylus) to transfer sperm to a female, who then lays clusters of eggs in strings that might look like decorative fairy lights in their den.
Females guard the eggs until they hatch, which can be between 30 days and a year later, depending on the species. Mating in squids on the other hand is carried out in large groups and attach their eggs to solid structures such as stones or corals.
Squid parents do not invest in their young, they just allow them to hatch and try to make it into the world.
- Lifespan: Octopuses generally do not live for a long time. They have a lifespan of 1-3 years, while squids can live from 9 months to 5 years. Male octopuses and squids usually die shortly after mating.
- Social structures: Octopuses are reclusive animals (except for mating periods) while squids can in schools or independently.
