Do you know that squids produce ink as a defence mechanism?
What is that one animal that has eight arms, a pair of tentacles and a mantle? No, it is not an octopus. Then what? Well, it is a kind of carnivorous marine mollusc belonging to the group of cephalopods. Yes, now you guessed it right. We are talking of a squid. In fact, if you visit a sea food joint, you might even find squids on the menu. The defence mechanism of these sea creatures is quite interesting.
Inking: The defence mechanism
Since the time they hatch, squids have a sac full of ink located near their head. At the base of this sac is an ink gland where the ink is produced from the very early stages. Besides, there is a funnel-shaped organ nearby that produces mucus. In fact, scientists believe squids first create the ink followed by the mucus and combine them together to make a cloudy foam-like thing. Now, when they are safe, the ink remains inside the sac. However, as soon as they feel a hint of danger, the body (its tube-like organ called siphon) pulls from the sac which is then expelled into the surrounding water, creates a smoke screen sort of a thing, that they use to quickly disappear. Not only that, when they come face to face with big predators, squids even produce the ink and give it a shape to look exactly like themselves, thus creating an illusion. How fascinating is that!
Experts believe that the ink of squids is quite toxic (it is made up of the pigment melanin that gives colour to hair, eyes, and skin in humans) and enough to distract a potential predator by blocking its sense of smell or irritating its eyes. Oh, also, the ink is usually black in colour. But it can also be brown, red, or even blue depending on the circumstances. Interestingly, squid’s ink is used to make pen ink, paints and even make-up! The Chinese even use it to make their herbal medicines for treating hypertension.
Camouflage champions
Whenever we think of camouflage, we consider chameleons to be the best in the deed. However, if you look at squids carefully, you will know that they too are one of nature’s camouflage champions. They can change their skin colours using leucophores, a reflector that produces different hues inside a squid’s body, as a response to threat. Simply put, these are pigmented, light-reflecting cells that enable squids to control the brightness and colour of their skin. Usually, squids change their colours to match with their surrounding environment.
Can move in many different ways
Squids are not only buoyant but can move around in many different ways and speeds. Usually, they move slowly and forward. However, while preying or escaping harm in their way, they prefer jetting. What happens here is that their siphons (tube-like cells located near the mantle) contract, in turn closing their muscular walls. This propels them forward as if fuelled by a jet. To do so, squids quickly absorb a large amount of water and juts them out equally fast. The process usually looks like a real-world jet propulsion. How cool is that!
Squids first emerged in the Jurassic Age
Yes, you read that right! Squids first arrived alongside dinosaurs millions of years back during the Jurassic Age. In fact, the earliest known fossils of prehistoric squids can be traced back to 100 million years ago and is known as Belemnotheutis Antiques. Mostly found in the waters near England, this ancient squid species is also used to learn more about the Jurassic period and also about the evolution of squids in general as well as with respect to the process of inking. Unfortunately, the first-ever squids may have gone extinct due to poisoning from algal blooms.