Perhaps the most familiar representatives of cephalopods are the sea octopus. These animals simply amaze with a variety of their sizes: from the smallest to truly gigantic!Giant Octopus (Octopus dofleini)
The body structure of an octopus
The basis of the body of the octopus is the mantle, with the help of which the mollusk makes movement (by a sharp discharge of water from the mantle cavity). The head of the mollusk has completely grown together with the torso; on it are quite complexly arranged vigilant eyes. The octopus's mouth is very small, with tentacles around it. The number of tentacles is eight. Some species of octopus have fins on the sides of the body.Fin octopuses because of the pterygoid fins, resembling ears, are called Dumbo octopuses in English
An octopus is an animal with a huge heart ... more precisely, with a huge number of hearts. The octopus has three! The mollusk’s blood is completely blue. Well, just not an animal, but unique! And of course, everyone knows that the octopus has an ink bag in which a special coloring matter is stored, released by the animal in case of fear or danger.An octopus siphon is visible just below the eye.
The color of these animals is yellow, reddish or brown. But the octopus, due to special cells, can change its color to any other. And he does it instantly! In general, octopuses are the largest intellectuals among all invertebrates. They have keen eyesight, and they “hear” them by trapping infrasounds, since they do not have normal hearing.The funnel-shaped octopus suction cups use the suction force of a vacuum
The average octopus is up to 1 meter in length, but there are both smaller (1 centimeter) and larger (3 meters). It should be said that males are smaller than females.Rectangular octopus pupils
Where does the octopus live?
His usual places for life are warm seas. In them, octopuses are located in shallow water or among reefs. The depth of their residence is up to 150 meters. But there are also more deep-sea representatives of octopuses.An "angry" blue reef octopus (Amphioctopus marginatus) of unusual color. In a calm state, these octopuses are brown with blue suction cups.
Octopus lifestyle and behavior
Octopuses are mollusks living alone. They lead a sedentary lifestyle. The greatest activity in these animals is manifested in the dark. They spend most of the day in their shelter and move very little. If the octopus settles down on soft ground, it will certainly burrow in the sand, so much so that only the eyes remain to observe what is happening on the surface.The same blue reef octopus in a calm state. These octopuses love to settle in the shells of bivalve mollusks.
What and how do octopuses eat?
Like many other cephalopods, octopuses belong to predatory animals. They grab their food with tentacles and kill it with poison, and only then they start to ingest it inside. If the victim was caught with a shell, then the octopus smashes it with its "beak" located near the mouth.The octopus in a shelter surrounded itself with building material - shell shells
The main components of the diet of an octopus are lobsters, crabs, fish, and also other mollusks.Imitation Octopus (Thaumoctopus mimicus) masquerading as a spiny lobster
Reproduction and offspring of octopuses
Octopuses produce their offspring only once in their life. Yes, and they live, however, not so long - an average of 1 to 2 years.And this is an imitation octopus, but pretending to be a ramp
Before the mating season in males, one of the tentacles turns into a reproductive organ called hectocotyl. With its help, the male transfers his sex cells to the mantle cavity of the female. For several months, the female continues normal life with male reproductive cells inside herself, and only then, after months, lays her eggs. There are a lot of them in the masonry: from 50 to 200 thousand pieces!Great Blue-Ringed Octopus (Hapalochlaena lunulata)
After the female makes the masonry, she becomes the most caring mother in the world! She literally blows dust off her future octopuses. And so, without departing from the eggs, she waits for the appearance of larvae, sometimes up to four months! An organism exhausted from hunger, often does not stand up, and the female dies. The males, after the transmission of male germ cells, die.A swimming giant octopus moves the back of the body forward, and its head back
Octopus larvae hatched from eggs are already completely independent. Apparently, nature did not foresee this in vain, because by the time of their birth, octopus babies are left without a single parent, and there is no one to protect them.A masonry of prickly octopus (Abdopus aculeatus) peers between the tentacles of a caring mother
Do octopuses have enemies and who are they?
These mollusks are the object of nutrition in large fish, sea lions, seabirds, fur seals, as well as in seals. In addition, a smaller octopus can get to the "dinner" and to its own relative - a larger octopus.A giant octopus demonstrates a membrane (umbrellas) between its spread tentacles
In addition to natural enemies, people hunt these mollusks.Common Octopus (Octopus vulgaris) Paul "draws lots" - opens the feeder
What is the use of octopus for people
Octopuses are eaten, their meat is very well appreciated by seafood lovers. In addition, octopuses are sometimes kept in aquariums, for the most part - not at home, but in public.