Octopuses are classic examples of wild animals that are stranger than fictional ones. They are highly intelligent and voracious marine predators capable of shape-shifting and camouflage. From tales of legendary sea monsters like the Kraken, to the more recent depiction of the octopus-headed Davy Jones from the Pirates of the Caribbean, octopuses have inspired and captivated the human imagination for centuries.
Octopuses are cephalopods (which references the way the head connects to the foot) like the squid, cuttlefish, and nautilus and have tentacle-like appendages around their head. Their head (technically called the mantle cavity) is a vault containing all of its vital organs including its heart, brain, gills and gonads. Octopuses have evolved from the same ancestors as gastropods (stomach footed creatures) like snails and slugs, making them cousins of sorts. While scientists are not entirely sure why the octopus evolved without a shell, one explanation could be that life outside the shell was one with more flexibility, access, and opportunities. This could also explain the evolution of heightened cognitive abilities in these softbodied molluscs; to help them outsmart and survive the cutthroat world of the ocean.
Octopuses function on three hearts, the equivalent of nine brains, and blue-coloured blood (copper-rich blood called haemocyanin). If this seems peculiar, how they procreate and the mysterious circumstances and events that surround their coupling are even more intriguing. Octopuses are “semelparous” in their life history. They breed only once in their lifetime, soon after which they die. While this phenomenon of hormone-programmed death soon after producing offspring seems unusual and heartbreaking to us humans, could this be an evolutionary strategy to protect young octopuses from their parents, who are known to have cannibalistic tendencies? Or is it a way to keep octopus populations in check? These are scientific mysteries that still need hard answers.
Over the past few years, India has seen a surge in the demand for octopus meat, especially in the export markets. As octopus fisheries prepares to scale up, covering larger areas, targeting juveniles or egg-bearing females and aiming for higher yields, incorporating what we understand of the ecology of these incredible animals will not only help protect these species but also our deep relationship with them.