What does the mollusk octopus (octopus) grow up on? How long is the life span? How many feet do you have? What's the difference between squid and squid? (with culture skills)

Octopus, also known as octopus, Shiju, dead cattle, stone suction, tide, is a common mollusk in the ocean, is a carnivore, often feed on crustaceans (shrimp, crabs, etc.), how long is the life span of the octopus? How many feet do you have? What's the difference between squid and squid?

How long is the life span?

The average life span of an octopus is only about 3 years. If the living conditions are very ideal and do not get caught, the octopus can live to about 4 years old at most. The lifespan of the deep-sea giant octopus is different. Some scientists say that the deep-sea giant octopus can live for up to 100 years, and its hatching time is as long as four and a half years. So far, the largest octopus tentacles have been found to be about 10 meters long. Biological experts say there may be octopuses of more than 15 meters (tentacle length) in the depths of the ocean.

How many feet do you have?

The octopus has eight feet. Octopus body is short oval, saccular, finless, head and body boundary is not obvious, there are large compound eyes on the head and 8 retractable wrists, each wrist has two rows of fleshy suckers, and the wrist is connected by membranes of different lengths, and there are two rows of sessile suckers on the wrist, so it is called "octopus" and does not belong to fish.

The difference from squid:

Family and genus difference

1. Squid: squid belongs to animal kingdom, molluscs phylum, cephalopod, sheath subclass, squid order, squid family, squid molluscs.

2. Octopus: octopus belongs to the molluscs of the genus octopus, octopus.

Difference between wrist and foot

1. Squid: squid has a slender, cone-shaped body with more than a dozen tentacles, two of which are longer. There is a sucker at the front of the tentacle, and there is a horny tooth ring in the sucker. When preying on food, wrap it around with the tentacle and swallow it. Like to gather in groups, especially in the spring and summer mating and spawning period.

2. Octopus: the octopus body is short oval, saccular, fin-free, the boundary between head and body is not obvious, there are large compound eyes and 8 retractable wrists on the head, each wrist has two rows of fleshy suckers, usually crawl with wrists, sometimes swim through the telescopic membrane of the wrist, can hold other objects forcefully, and spray water from the funnel under the head for rapid retreating.

Food habit difference

1. Squid: squid is a fierce carnivore. Most of its food is small pelagic species such as small males, sardines, scads and shrimps. It also preys on a large number of its kind. It is also an important prey for tuna, turtle, belt fish and seabirds.

2. Octopus: octopus feeds on branchial and crustaceans (shrimp, crab, etc.), and some species feed on plankton. The octopus sucks water into the outer membrane and expels it through a short funnel-shaped body tube after breathing. most of it crawls along the seafloor with a sucker, but when frightened, it ejects water from the body tube, which has a strong hydraulic force, which quickly moves in the opposite direction. ink-like substances are emitted when in danger, as smoke screens, some kinds of substances can paralyze the attackers' sensory organs.

Difference of origin

1. Squid: squid is distributed in tropical and temperate waters between latitude 40 °S and N. The main squid fishing grounds in the world are in the northern part of the South China Sea, the Gulf of Siam, Kyushu of Japan, the central Philippines, Western Europe and the eastern and western seas of the United States. Most of the fishing grounds are located around the islands and reefs, with slow water flow, high salinity, rough bottom, submarine grooves, coastal water system and warm current water system.

2. Octopus: octopus is widely distributed in tropical and temperate waters all over the world, and it is distributed along the north and south coasts of China. It lives underwater and adapts to a water temperature of no less than 7 ℃ and a specific gravity of 1.021 sea water. It will die in a low salinity environment. The sediment of the sea area had better be a gravel zone.

Cage culture technology:

1, cage setting: can use cage culture (3.94m × 1.82m × 0.9m), the mesh is smaller than the fish species, need to add a net cover to prevent octopus escape, mostly in the harbor with quiet waves, the suitable water temperature is 15: 23 ℃, in general, it is more in spring and summer (June, July) and autumn (10 ~ December).

2. Seedling stocking: octopus fry caught in cages are the most suitable, and those caught from the bottom dragging net can also be used. the amount of seedlings varies according to water temperature and running water conditions, using large cages to release seedlings 36 kilograms per cubic meter, and small cages for stocking seedlings 25 kilograms per cubic meter. In order to prevent seedlings from killing each other, the same batch of seedlings should be put into the cage after satiety.

3. Bait feeding: small mixed fish and shellfish with low price can be put, and frozen small mixed fish can also be put in, but they must be fresh. It is better to reduce or stop feeding for 1 ~ 2 days when the residual bait is long. It will cause water pollution. If you stop feeding for more than 3 days, you will kill each other. The feeding behavior was irregular when the water temperature was about 13 ℃, and the octopus did not eat when the water temperature was below 7 ℃.

4. Aquaculture management: cage culture is suitable for large-scale aquaculture. The survival rate of seedlings caught in cage is 70% 80% after 2 months, and the survival rate of seedlings caught by fishing is about 50%. When the seedlings were released in cages, the mortality rate reached 2030% on the 15th, and then the death rate decreased gradually. After 15 days of culture, the octopus was divided into large, medium and small sizes and cultured in different cages. Clean the cage once in 15 days in spring and autumn and once in 30 days in winter.