Katherine Harmon Courage, author of the recent book Octopus! The Most Mysterious Creature in the Sea, summarizes here the results of a study on octopus dietary preferences. Previously, octopus diet preferences were inferred from the collection of shells and bones around an octopus's den (this habit of octopuses-- arranging shells, bones, and sometimes shiny pieces of glass or pottery in front of its den-- inspired the hit Beatles song "Octopus's Garden"). however, that only gives evidence of hard-bodied prey items, and with little to no time-of-meal information! In this study, researchers used a method including observation and digestive tract analysis.

They found that octopuses prefer eating crab before mating; just like humans, they have preferences that shift with circumstances. It is possible that energetic demands shape their food choices over time.

This study joins a growing body of fascinating research about octopus cognition and behaviour. Past studies have demonstrated that octopuses unscrew jars, escape from almost any state of captivity, pass basic cognitive tests, and even play; they are the cognitive equals of many vertebrates! This is particularly perplexing because conventional theory says that intelligence is seen in long-lived, social vertebrates (dolphins, primates, elephants, birds); octopuses, however, are short lived, spineless, asocial beings. Further still, each of their 8 arms has a "mind of its own," with neurons spread out throughout its body so that its arms are, in a sense, autonomous beings. It is possible that the octopus form of "thinking" is totally alien to what we are used to seeing in ourselves and our vertebrate relatives.

In short, we are only beginning to chip away at the complete mystery of the octopus mind. If you haven't already, I recommend setting up a google alert for "octopus cognition." It's definitely worth it,