Big Blue Octopus

The Big Blue Octopus, or Octopus cyanea, often referred to as the Day Octopus or Reef Octopus, is part of the Octopodidae family. It inhabits the Pacific and 🌊 Indian Oceans, stretching from Hawaii (🇺🇸 United States) to the eastern coast of Africa. Found primarily in coral reefs, this species thrives at depths ranging from 1 to 150 meters. The Big Blue Octopus can grow to a mantle length of up to 22 centimeters (approximately 9 inches), with arms that can extend to about 80 centimeters (about 31.5 inches). It can weigh up to 6 kilograms (around 13 pounds).

First identified by British zoologist John Edward Gray in 1849, the initial specimen resides at the Natural History Museum in London. Notably diurnal unlike most octopuses, Octopus cyanea is mostly active during dawn and dusk, often establishing a den as a personal refuge. This den can be found in rock crevices, under overhangs, among coral heads, or in spaces the octopus creates in rubble or sand.

Octopus cyanea employs remarkable camouflage abilities to survive and hunt. It can change its color, patterns, and skin texture rapidly to blend with its environment. This ability is so refined that it has been observed to alter its appearance up to 1,000 times in seven hours. A fascinating behavior called "passing clouds" is often displayed, where it creates the illusion of shadows moving across its body to startle or trick prey like crabs.

In terms of diet, the Big Blue Octopus is a predator with a diverse menu, including fish, crabs, shrimp, and molluscs. Small prey is consumed immediately, while larger items are taken back to the den. Crabs fall victim to a toxic bite, while molluscs are drilled open and predigested. Interesting cooperation has been noted in some instances of it hunting alongside the roving coral grouper.

The lifespan of Octopus cyanea is about 12-15 months. As with other cephalopods, after mating, males die shortly after, and females die after the brooding period. Males attract females through displays before mating by inserting a specialized arm into the female’s mantle cavity for fertilization. The life cycle progresses from hatching as planktonic larvae to a benthic, or bottom-dwelling, adult existence.

They exhibit unique physiological traits, such as having three hearts and copper-based blood. Two of these hearts pump blood to the gills, and the third circulates it to the rest of the body. The copper-based hemocyanin imparts a bluish color and is essential for oxygen transport in their blood. Their nervous system is advanced, with most neurons found in the arms, allowing for high dexterity and independent arm movements. Their problem-solving skills and ability to learn and remember experiences make them one of the most intelligent invertebrates.

Through understanding these complex traits, we gain insight into the Big Blue Octopus’s extraordinary adaptation and survival mechanisms in its marine environment.