#day octopus

A Day Octopus, scientifically known as Octopus cyanea. 

Today's fish of the day is the day octopus!

The day octopus, also known as the big blue octopus, and scientific name Octopus cyanea is a well known Indopacific cephalopod. Found in the Indian and Pacific ocean, this octopus can be found as far North as Hawaii to as far South as the Solomon islands, and found from the Hawaiian islands to as far East as the Red Sea and East coast of Africa. These octopi in particular are known for their color changing abilities. The name big blue comes from this color changing ability in fact, as sacs of pigments under the skin can be contracted at will to better match the surrounding environment for camouflage, and courting of mates. This color changing can also be used for communication between octopi, transmitting information of predators and prey nearby.

The diet of the octopus is made up of fish, crabs, and mollusks. This octopus in particular is diurnal, spending its time awake and active during the day, as opposed to the majority of other cephalopods of which are nocturnal. Small prey is eaten immediately when hunting, but larger prey ,such as adult crabs, must be taken back to the den of the octopi. The prey taken to this den are then killed, with crabs being killed with a  single venomous bite, and mollusks being killed by strategic drilling into their shells. These shells and hard carapaces are then discarded around the mouth of the den. These dens are regularly constructed and abandoned, with each octopus spending only around 35 days in each den before moving to find another. This is due to the fact that these octopi are heavily predated on by seals (especially monk seals!), whales, eels, and sharks. To protect from these predators, other than the creation and moving of dens, these octopi have the ability to squirt ink at hunters. Concealing the water so they can get away, along with rare cases of them attacking with their sharp beaks.

Breeding and reproduction can take place year round in the day octopus. Once they reach their sexual maturity, at a size of 8cm, with females larger than males, these octopi will search out another octopus. Males will mate with multiple females at a time, attempting to avoid the females cannibalistic tendencies as long as possible. After the mating however, the sucker on the male octopus begins expanding, continuing to do so as the octopi declines and eventually dies. The female however will survive a few months longer, remaining beside her eggs no matter what. She will slowly die for lack of food and exhaustion as she guards over her eggs until they hatch. These eggs hatch into planktonic larvae, which float in the current unable to swim for the first few weeks of their lives. After that they'll survive anywhere from 12-15 months, able to reach a maximum size of 22cm, and living through only one mating season.

OCTOPUSES PUNCHING FISH? A NEW LOOK AT INVERTEBRATE INTELLIGENCE

Collective behaviour, social interactions, and leadership in animal groups are often driven by individual differences. However, most studies focus on single-species groups, where individual variation is relatively low, with few studies focused on multispecies behaviours. A recent study has now revealed surprising social behaviour in the day octopus (Octopus cyanea). These octopuses are not solitary hunters—they collaborate with fish during hunts and, remarkably, have been observed punching their fish partners when they fall out of line.

Researchers observed these octopuses hunting cooperatively with various species of fish, including groupers and goatfish. Even more strikingly, the octopuses were seen physically punching fish that were not contributing effectively to the hunt, enforcing a form of social coordination previously undocumented in cephalopods.

This behaviour challenges traditional views of octopus sociality. Previously thought to prowl the ocean floor alone, using camouflage to ambush prey, the study indicates that the day octopus can form complex hunting partnerships with other species. The octopus does not lead these hunting groups but appears to enforce cooperation, suggesting a higher level of social interaction and intelligence than was previously understood.

These findings raise new questions about octopus cognition and social behaviour. The ability to interact in such a coordinated manner with other species indicates that octopus intelligence may share more in common with that of vertebrates than previously assumed. It also prompts further investigation into whether these behaviours are learned or innate, and how they might vary across different octopus species.

Gif: Octopus displacing fishes by punching them, by Eduardo Sampaio

octopi can:

-change color in a fraction of a second

-the day octopus can change the texture of its fucking skin, raising some parts to make it look more like coral

-the mimic octopus knows what other animals are afraid of and essentially shapeshifts into that animal

-it knows how others view it and so it doesnt need to be an exact likeness of a lionfish to scare off all the other animals, just needs to look like one to them

-the mimic octopus can also be such a good flounder that it fools even the real thing

-the coconut octopus hides itself in (you guessed it) coconuts and similar things. Itll hide itself in clam shells, making a little house for itself (this is a signifier of intelligence)

-it also displays creativity (another hallmark of intelligence) by using one of those shells as a fucking shield against one punch shrimp

- learn. the algae octopus, after losing a fight with another male over a female (said other male was already in the process of mating with), then goes for an unoccupied female.

-theyre SO curious - often, the desire to know what you are outweighs the potential danger.

-DREAM. you know when a dog is dreaming and you see its lil paws moving like its chasing a bunny? weve observed that with octopi - they change color and move their suckers in their sleep - a sign of REM (dreams)

literally all of this means INTELLIGENCE and that octopi are fucking amazing

theres so much more i havent covered

Day Octopus: While most species of octopus are nocturnal, the Day Octopus is diurnal, although it's mostly crepuscular, being active at dawn and dusk. It maintains a den to which it returns after foraging. They also exhibit significant levels of social repulsion, and individuals often chose a solitary den when given the option.