Octopus, an invertebrate with eight tentacles. The name octopus is derived from the Greek words octō meaning “eight” and pous meaning “foot”. It is a cephalopod, like the squid.
The octopus is enveloped by its soft exterior and has no internal or external skeleton. It has a hard part, like a bird’s beak, for piercing the shell of its prey.
The octopus aids an amazing ability to camouflage itself, which is unique in the animal kingdom, by changing not only its colour but also the texture and pattern of its skin in response to its surroundings.
Octopuses prefer a solitary life and only interact with other species when mating. This is a different social behaviour to that of squids.
Among other members of the cephalopod family, which also includes squid and cuttlefish, the octopus has several distinguishing features.
Unlike squids, octopuses do not have a shell, called a ‘pen’, which provides structural support. Unlike the cuttlefish, it lacks bones, which are buoyancy aids.
And while squid swim in the water like fish and sea turtles in television footage, you’ve probably never seen this in octopuses. This is because octopuses generally have a benthic lifestyle. They prefer to crawl on the seabed rather than swim.
My personal opinion is that the difference between the long, slender squid with a pointed head and the octopus with a rounded shape is probably also due to these differences in lifestyle. The octopus lives a lifestyle that does not seem to require it to be streamlined and shaped to reduce drag.
The octopus’s preference for the seafloor allows it to play an ecological role in maintaining the replacement of habitats for so-called benthic organisms on the seafloor.
They also prefer burrows, as is typical of such a lifestyle. They tend to collect rocks and other debris around their burrows to create a ‘garden’. As such, they contribute to the physical structure of the seabed environment and influence various elements of the marine ecosystem.
Keeping octopuses in captivity is not an easy task. Not only do octopuses need specific water quality conditions, but they also require mental stimulation, as they are highly intelligent creatures. Without stimulation, octopuses have been known to escape from their enclosures with an alarming success rate.
They are relatively high problem solvers. They have even been known to get through incredibly small holes, open bottles from the inside and dismantle some of the most complex aquarium equipment.
They can even beat sharks in this way. Come to think of it, you’d have to be very smart to move all eight of your hands in this way.
Japan in Asia and Greece and Spain in the Mediterranean region of Europe are known for their tradition of eating octopus in a variety of dishes.
Lifespan varies widely between species. Smaller species such as the common octopus vulgaris (Octopus vulgaris) live for only one or two years, while the larger giant Pacific octopus (Giant Pacific Octopus) can live for about four years in the wild. Under suitable aquarium conditions, some are known to live up to five years.
Factors affecting octopus longevity include environmental conditions, predation and other conditions present in all animals, but also octopus-specific hemiparasitism (where the female dies after the eggs hatch).
They are commonly found in aquariums around the world, with the Monterey Bay Aquarium in the USA, the National Aquarium in Baltimore and the Okinawa Churaumi Aquarium in Japan seemingly world-renowned for their octopus displays.
However, octopuses are distinguished from their peers by their unique physical characteristics and behaviour. It has eight arms covered with suckers, a bulbous head and the ability to change the colour and texture of its skin, making it adept at both locomotion and camouflage.
There are about 300 known octopus species, each with unique characteristics. For example, the largest known species, the Giant Pacific Octopus, can reach a whopping 30 feet (1.5 m) in length, while the tiny Octopus wolffii is only 1 inch (2.5 cm) long. The Blanket Octopus is known for its long, blanket-like web, while the Dumbo Octopus, named after Disney’s flying elephant, has ear-like fins.
Factors that help distinguish between similar and subtle species are not only size and body colour, but also the presence or absence of fins, and the shape and size of the suckers and mantle.
Octopuses often appear in human folklore and mythology. From the kraken of Norse mythology to the Akkolokamui of Ainu folklore, depictions of octopuses range from fearsome sea monsters to gods. In Polynesian mythology, the octopus is such a revered animal that it is often associated with the creation of the world.
As far as reproduction is concerned, the male, like the anglerfish, suffers a rather tragic fate. After mating, male octopuses usually die within a few months. The female then lays thousands of eggs and works hard to protect and care for them until they hatch.
Coconuts and shells, how they use them. As I said in the beginning, they are smart animals anyway. Some species have been observed to use coconuts and shells as tools for protection and transport. They are rare examples of invertebrates using tools.
What colour is its blood? Octopus blood is blue. Incidentally, this is a feature shared with squid.
The blood is blue because of a copper-based protein called haemocyanin. In cold, low-temperature seas and in places with low oxygen levels, haemocyanin can transport oxygen more efficiently than haemoglobin, a substance found in red blood cells of common animals.
Furthermore, when swimming, the heart temporarily stops beating. This is why swimmers prefer to crawl.
Crawl because it has eight legs, blue blood and the heart stops beating. This may be too much information at this point, but a final word: their heart, which carries blue blood throughout the body, is three in number.
コメント