Earlier quoted context omitted.
According to seafood watch, market squid are at the very least sustainable [0]. Squid and octopus are different I believe, but calamari is squid if I'm not mistaken. As for Octopus, it appears a bit more iffy [1]. As for intelligence, that's secondary to sustainability for my eating habits at this point. [0] - http://www.neaq.org/conservation_and_research/projects/fishe... [1] - http://seafood.edf.org/octopus#bmb=1
there's good reason to suspect that a lot of calamari is pig asshole: http://www.dallasobserver.com/restaurants/npr-claims-pig-rec...
In fact, there isn't even anecdotal evidence listed.