Will spiders die?
How long is the spider's silk, and if they keep pumping, will they be "squeezed dry" and eventually the spider will die?
In the movie, Spider-Man shoots spider silk from his wrist, but in reality, spiders do not shoot spider silk from their limbs. In addition, although we often call this behavior "spitting silk", in fact, spiders do not spit silk out of their mouths, to be precise, their spider silk is pulled out of their butts.
The reason why it can spit silk is because there is a magical silk sac in the abdomen of the spider, which is like a shower shower, with many small holes, which are the spitting device.
The root of the spitting device is connected to the silk gland, which stores a large amount of protein inside, and when they need to "spit silk", they will mobilize the silk gland to secrete protein mucus to spray out. The moist mucus dries up quickly when it encounters the air, and under the action of internal pressure, it is continuously pulled into spider silk.
Spider silk is the toughest protein fiber, with more than 2500 spider silk fibers in one spider silk, and its strength is second to none of all natural biological materials, and its tensile strength is three times that of bones.
However, such a high-quality material, when made by spiders, is very slender, and its diameter is usually less than 2 microns, only one-thirtieth of a human hair.
If someone can really spray pencil-thick spider silk like Spider-Man, it is not impossible to use it to pull tens of thousands of tons of cruise ships, or trains that are moving.
The main material of spider silk is a special protein fiber, how much spider silk can spit at a time, mainly determined by how much protein it has in its body. An ordinary round web spider can spit out up to 700 meters of spider silk at a time, and when the protein in the silk sac is exhausted, they will not spit silk again.
But they don't die because of this, but they will go around looking for and hunting protein-rich foods such as insects to supplement the silk sac with spitting material. When the protein is replenished, they can continue to spit silk again.
There is also a way to make them quickly replenish spider silk, that is, to eat the excess spider silk, the spider's digestive system is very sensitive to protein, it is easy to digest and absorb them completely, into the body's needs of amino acids. However, spiders can only recycle the spider silk they spit out, and cannot recycle other spiders. Therefore, hunting insects in large quantities is the main way they obtain protein.
Of course, under natural conditions, spiders know how to do what they can and properly preserve some proteins for their normal life activities. But if someone deliberately "squeezes" them, it will make the spiders very weak, and when they can't pull out the silk, they will be starved to death.
Spider Silk: For hunting, mating and traveling
There are currently 46,055 species of spiders worldwide, but not all spiders spit silk, and not all spiders rely on cobwebs to hunt.
Most of the spider webs we usually see in cartoons or TV series are this very regular round spider web, and the main representatives of round web spiders include large-bellied garden spiders, golden spiders, network brides and other species.
Circular webs are characterized by the fact that only a circle of weft filaments is sticky and can be used to catch prey, while the outer frame and the warp wires that extend from the center to the surroundings are not sticky.
Due to the frequent use of weft filaments for hunting, the mucus on it can easily dry up and fail, so the webs of round web spiders need to be replaced regularly and new webs re-woven. Theoretically, female garden spiders can weave a new spider web every day, but in the event of a storm, or before and after peeling and laying eggs, the spiders always have to give themselves a few days off.
But garden spiders sometimes follow the principle of saving and saving, weaving very perfunctory spider webs, such as the cobwebs of this big-bellied garden spider that looks like a ladder.
The rudimentary webs of the big belly garden spider
There are also curved-bellied spiders under the garden spider, and the spider webs they weave can really be described as "four walls of the family" and "four sides of the wind leakage", ah, such spider webs can really catch prey?
Webs endemic to curved-bellied spiders
For cunning spiders, there is no need to hunt with spider webs, they are good at hunting, and sometimes they can go down to the river to catch small fish, so they do not need to use spider webs to hunt. However, after laying eggs, female cunning spiders carry the egg sacs with them, and when they feel that the spider is about to hatch, they will climb to the top of the grass or bush to form a "parenting web", which looks very dense like cotton.
The "parenting web" of cunning spiders
The female spider is very relieved to put the eggs on it, so that the spider can accept the sunlight after hatching, and she will guard it herself, and will not leave until the spider molts once. Because the number of webs in a lifetime is equal to the number of times they lay eggs, they usually do not weave more than 5 times.
Speaking of the male spiders among the cunning spiders, they only make a web once in a lifetime and dedicate it to the greatest cause of life- reproduction. Male spiders usually do not tie nets, during the mating period, they will first jump to the female spider's web, pluck the spider silk and "dance" to attract the attention of the female, and even can be as enchanting as the peacock opening the screen.
After much effort, the female spider finally agreed to the request, then the male spider will make a net on the spot before mating, and then drain the semen into the spider web, and use the tentacles around the mouth to suck the semen and begin to reproduce.
In addition to these basic needs, spider silk inadvertently helps the entire spider population to complete the "territorial expansion".
For example, this Darwinian bark spider, in order to weave a huge hunting web above the wide river, came to the nearest tall tree on the bank of the river. After a long wait, a breeze blew through and it began to spray spider silk. Under the breeze, the spider silk continued to drift to the opposite bank, and finally landed on the other side of the river.
The spider began to follow the fixed "rope bridge" and perform unique skills such as "walking tightrope" and "hanging upside down gold hook" above the river. As it keeps shuttling.
A cobweb with a diameter of 2 meters was suspended above the river by a spider silk. Countless dragonflies and flying insects pass through it, and there are always some "daredevils" who will crash into the arms of the cobwebs and become darwin's spider's supper.
Such a rare "cross-sea bridge" has also become a bridge for countless spiders to migrate, and even some spiders only rely on a fluttering spider silk "flying in the wind" to cross their own inaccessible places. Because of this, spider populations have spread all over the world and evolved more than 46,000 species.
Why can't spider silk replace silk?
An interesting question is that the strength of spider silk is second to none in all kinds of materials, so why in ancient times, humans discovered that silk can be used to weave clothes, but did not choose to use spider silk to weave clothes?
Not to mention, in history, there have been people who have really tried to weave clothes with spider silk. Because considering that silkworms can only spit silk once in a lifetime, and many spiders can spit silk at any time, the famous French naturalist Reaumur in the 18th century did relevant research; In the early days of the founding of the People's Republic of China, the Shanghai State-owned Silk Spinning Factory and the Suzhou First Silk Factory also studied the possibility of using spider silk instead of silk as a garment raw material.
However, their conclusions are highly consistent - compared with silk, spider silk is too thin, only one-tenth of silk, and it is easy to break in the weaving process, resulting in the difficulty, high cost and cost-effectiveness of using spider silk to make clothes. Of course, we can screw multiple spider silk into one, or switch to a machine specially designed for textile spider silk to solve the problem that spider silk is too fine and easy to break, but this will inevitably make the manufacturing process more cumbersome, and the production cost will also be greatly increased.
In addition, it is also difficult to breed spiders. Spiders are different from silkworms, they are very active, when outdoors, as long as they follow a spider silk "flying in the wind", they can float around like dandelions. There are also problems in indoor breeding, because the habits of spiders are relatively isolated, it is difficult to squeeze in a pile like silkworms, so it is difficult to centralize management, and the area is also more.
The last difficulty is the feed problem, silkworms in the natural growth state, only need to use mulberry leaves to grow, the current feed although the addition of corn flour, soybean flour and vitamins, but the cost is not too high. However, spiders feed on insects, their nutritional conversion efficiency is not as high as that of vegetarian animals, and the price of these protein-containing bugs is also very expensive, and the cost will be greatly increased.