Like octopuses squid are also cephalopods, i.e, their feet originate from their head. We have discussed octopus earlier. today we will discuss squid. If you want to know interesting facts about octopuses, click here.
Till date more than 300 species of squid have been discovered. The size of the normal squids hover in around 50-60 cm. while the giant squid can reach up to 13 meters.
They can swim faster than any other invertebrate.
They have the largest eye in the animal kingdom. The giant squid have the eyeballs of the size of a basketball.
Squid show sexual dimorphism. A mature female is larger than the mature male squid.
They have a very large brain and are considered to be very intelligent.
They possess fins, but unlike any other marine animal, fins are not their primary source of locomotion. They swim backwards i.e, they swim tail first rather than head first.
Unlike other molluscs squid don't have any outer shell covering their body. The hardest part of their body is the beak. The beak is made up of chitin and it is used to kill prey.
They are carnivorous i.e, they eat crusteceans, fish and smaller squids.
Due to their visual similarities, squid are some times mistaken for the octopus. Unlike Octopuses the squid have 10 arms(8 arms and 2 tentacles). Like the octopus they squirt dark ink to distract predators and escape.
Their skin is covered with chromatophores. Due to this they can change their color to match their surroundings. Like fishes they also possess gills.
The giant squid is the largest invertebrate animal in the world. The Humboldt squid is very aggressive and it some times even attacks sharks.
Some squid have bio-luminescent organs in their body due to which they are able to glow in the dark.
The giant squid can grow up to 60 ft and weights up to 1000 lbs. They have a large beak which is very sharp and resists bending. The beak is made up of chitin and it is used to kill its prey.
Squid have three hearts. Their blood contains hemocyanin(a copper rich protein)in place of hemoglobin like ours.
Many species of squid are considered food in many countries.
The life span for a common squid is around 1 to 2 years.