similarities and differences between octopus and squid taken from internet

About	Octopus is a cephalopod with eight arms. It is a head-footed animal	Squid is a cephalopod with eight arms and two tentacles arranged in pairs. It is a head-footed animal
Anatomy	An Octopus has a mantle, a head, 8 arms endowed with 1 or 2 rows of suckers but no hooks or sucker rings	A standard Squid has 2 fins, a mantle, a head, 8 arms and 2 tentacles each endowed with hooks and/or suckers or sucker rings
Fins	Most octopi do not have fins, though some deep water octopuses may be the exceptions.	Squid have 2 fins on their heads
Shell	Octopi do not have any shell or stiff bone in their body	Squid possess a stiff structure known as a pen, which acts like a flexible backbone
Live in	Octopi live in dens on the sea floor	Squid live in the open oceans
Diet	Octopi eat bottom dwelling Crustaceans.	Squid eat fish and shrimp.
Blood	Blue	Blue
Class	Cephalopoda	Cephalopoda
Phylum	Mollusca	Mollusca
Order	Octopoda	Teuthida
Superorder	Octopodiformes	Decapodiformes
Kingdom	Animalia	Animalia
Sub Class	Coleoidea	Coleoidea
Species	300	298
Size	Octopuses range in size from 1cm to more than 5m	Average Squid no more than 60cm Giant one up to 13m, some reported even 20m (66ft.)
Nature	Octopi are solitary in nature and always live alone	Squid maybe solitary or may live in schools
Catching and Eating Their Prey	Octopi grab their prey and pierce through its shell and inject paralyzing venom into it. Dissolves and loosens meat with saliva	Squid catch food with their two long tentacles and eat it in chunks.
Lifespan	1 to 3 years	9 months to 5 years
Geographical Distribution	In salty water of the tropics to the temperate zones.	In salty water of the tropics to the temperate zones.
Plural	Octopodes/Octopi/Octopuses	Squid (when referring to a collective); Squids (when referring to 2 or more species of squid)