Short answers, pulled from the story.
The word octopus originates from the Ancient Greek term oktōpous, a compound of oktō meaning eight and pous meaning foot. Alexander of Tralles used this form around the year 525 to 605. English speakers first adopted the plural octopi in the early 19th century, assuming the word was Latin.
The giant Pacific octopus Enteroctopus dofleini reaches a live mass of 71 kg with an arm span of 4.8 meters. A smaller species Octopus wolfi measures just 2.5 cm and weighs less than 1 gram. The creature possesses three hearts: one systemic heart and two branchial hearts that pump blood through the gills.
Mating involves a specialized arm called the hectocotylus which transfers spermatophores into the female's mantle cavity. The male dies shortly after mating while the female dies after the eggs hatch. Senescence begins when the optic glands trigger cellular breakdown without repair.
Blood pressure can surpass 75 mmHg due to the copper-rich protein haemocyanin. This protein gives the blood a bluish color and transports oxygen more efficiently in cold conditions. The skin contains chromatophores that allow rapid color changes.
William Elford Leach first classified octopuses as the order Octopoda in 1818. The earliest octopus likely lived near the sea floor in shallow marine environments during the Jurassic period. Fossils are rare because soft-bodied cephalopods lack the external shells found in other molluscs.
Coins from the Minoan civilization dated to 1650 BCE depict octopus-like creatures. Mycenaean Greece pottery from 1200 to 1100 BCE also features these designs. Katsushika Hokusai created the 1814 woodblock print Tako to ama showing a woman intertwined with two octopuses.