King David said:
“How great are Thy deeds, O Lord! You created all of them in wisdom. "
(Tehilim, 104: 24)
We can see the infinite wisdom of the Creator in everything that surrounds us. In this article, I will give just a few facts about spiders and their webs, in which we can see a wonderful manifestation of Divine wisdom.
Why don't spiders stick to their own webs?
Why don't spiders stick to their own webs? Spiders have tiny claws at the ends of their legs. Both legs and claws are covered with small bristly hairs. When the spider moves, it can adjust the angle of its claws. It minimizes the amount of contact with sticky webs. Paw hairs also help spiders not stick to their own webs.
Cobweb threads are one of the thinnest materials in the world.
Cobweb threads are one of the thinnest materials in the world. The diameter of each strand is 20 ppm. For comparison: the diameter of a human hair is 1 tenth of a millimeter (that is, it is twenty million times thicker than a spider's thread).
Where do spiders get their webs from?
Where do spiders get their webs from? There are numerous spider glands in the abdominal cavity of spiders. The spider glands produce a liquid viscous secretion made of protein. This secret has the ability to instantly harden in air. Therefore, when the protein secretion of the spider's glands is released through the spinning tubes, it solidifies in the form of thin filaments.
Internal structure.
Spiders feed on liquid tissues sucked from their prey, mainly insects. The digestive system of spiders consists of a specialized sucking stomach, another stomach with blind outgrowths, and an intestine surrounded by a digestive gland ("liver") and opening at the end of the body by the anus.
The circulatory system is not closed. It consists of the heart, arteries, veins and spaces (sinuses) between organs, washed by colorless blood (hemolymph). The heart is a pulsating tube with holes (ostia) that runs along the dorsal side of the body cavity. Unlike insects, it is not divided into several chambers.
Spiders, as already mentioned, breathe air. Their respiratory organs are the trachea and lungs, called pulmonary books. Each such book consists of a pouch, one of the walls of which is folded in the form of numerous leaf-like folds, resembling pages. They exchange oxygen and carbon dioxide between blood and air. Outwardly, the lungs open with spiracles. The most primitive spiders have two pairs of pulmonary books; in the more advanced, one or both of them are replaced by tracheas penetrating the body.
The excretory system consists of a pair of coxal glands in the cephalothorax and the so-called. malpighian vessels in the abdomen that open into the intestines.
The nervous system is similar to that of insects. It consists of an abdominal trunk with branches and ganglia extending to different organs, collected in the cephalothorax into a large subpharyngeal node, above which there is the supraesophageal - "brain". There are sensory hairs on the pedipalps and walking legs.
The genitals are represented by the ovaries in females and the testes in males. Their holes are located below at the base of the abdomen.
Spiders use the fibers of the web for additional purposes
Spiders use the fibers of the web not only for weaving, but also for additional purposes.For example, spiders use them to wrap their prey and to protect eggs, as well as to build nests or line burrows. Some spiders weave fibers that emerge from their burrows or nests. These fibers act as signal lines that are triggered when an insect passes through them.
Main functions
The web's functions are not limited to catching food. It is of key importance in the life of the arachnid, since it is indispensable in certain cases.
Prey hunt
Building webs for catching prey is one of the reasons why spiders need to make webs. The structure of the web depends on its ability to immobilize the victim. Some species of predators are so small that they themselves become prey to large insects. The poison injected by the spider into the victim's body does not work immediately. To prevent the prey from escaping, the predator takes it and wraps it in fiber, after which it waits for the entrails of the prey to turn into a liquid state.
If we compare a spider's web and human hair, the former will turn out to be finer. It is comparable in strength to steel wire.
Attracting males
Some species of arachnid females secrete a spider's secret with pheromones during the breeding season. This "mark" attracts the male. Signal fibers are formed by most species, but in some, the initiative comes from the male.
In search of a female for reproduction, males weave a sperm mesh, onto which a drop of seminal fluid is preliminarily allocated. To attract a female, males attach their threads to the female's web and set it in motion. So they inform her about the purpose of their stay. For mating, the female goes to the male's web space.
Distracting the attention of predators
Orb-webs create distracting dummies from nets, gluing leaves and twigs with cobwebs. They place "snag" on their web, thus trying to mislead the predator. The animal hides not far from the dummy and pulls the strings, making deceptive movements with them.
For the first time, a spider capable of making its counterpart was discovered in the forests of the Amazon by biologist Phil Torres. He came across a web with a strange, in his opinion, spider. At first, the biologist thought he was dead, but when he got closer, he discovered that it was a skillfully made copy of the leaves. The bait maker was waiting for prey elsewhere.
Spider web cocoon
From the secret of the spider's glands, predators weave cocoons for offspring. The number reaches 100, depending on the fertility of the female. Cocoons with female eggs are suspended in a safe place. The shell of the cocoon is formed from 2-3 layers and is impregnated with a special secret that glues all its parts.
If necessary, females transfer the cocoon with eggs to another place. It attaches to the spinneret on the abdomen. When viewed close up, the cocoon resembles a golf ball. Eggs bulge out under a dense layer of fiber and form tubercles. Cocoon for offspring is used even by those species of predators that hunt and never weave a web.
Defense mechanism at the entrance to the burrow
Burrowing species of predators dig shelters in the ground and braid its walls with cobwebs. They use it to strengthen the soil, which helps to protect the burrow from adverse weather conditions and natural enemies.
The functions of the web do not end there, the arthropod animal uses it as:
- Movement means. An agile predator uses it as a vehicle. With its help, he can quickly move between trees, bushes, leaves and even buildings. Thanks to the use of cobweb threads, spiders move several kilometers from the point of departure. They climb a hill, release the instantly solidifying fiber and are carried away by the air stream.
- Insurance. Jumping spiders weave an openwork fabric to insure themselves while hunting for a prey.They are attached with a thread to the base of the object and jump onto the prey. Some species of spiders, in order not to lose their burrow, stretch fiber from it when leaving and return back along it.
- Underwater shelters. They are created only by species living in water. It is known why the web is necessary for them when building underwater holes - it will provide air for breathing.
- Stability on slippery surfaces. This feature is used by all types of tarantulas - the sticky material on their paws helps them stay on slippery surfaces.
Some species do without weaving spider webs, they only hunt. But for many, she is an assistant in the process of survival.
Spiders digest food outside their body
Spiders are the only living things that digest food outside of their body. After capturing prey, the spider covers it with digestive juices. The juices turn the victim's body into liquid matter, which the spider sucks in. Spiders repeat this process many times and end up digesting most of their prey.
Human use
Mankind has copied a lot of constructive natural finds, but weaving a web is a very complex natural process, and it has not been possible to reproduce it qualitatively at the moment. Scientists are currently trying to recreate a natural process using biotechnology, based on the selection of genes that are responsible for the reproduction of proteins that make up the web. Such genes are introduced into the cellular composition of bacteria or yeast, but modeling of the spinning process itself is currently impossible.
