Chinese alias: Networm, Flat Pearl, Round Pearl

Latin scientific name: Araneida；; araneae

English name: spider

Classification:

Boundary: animals in the animal kingdom

Phylum: Arthropod phylum

Class: Arachnida, Arachnida

Objective: Araneae, Kerek, 1757.

Sub-order:

Mesoderm, mesoderm suborder.

Protospider suborder

Araneae, a new suborder of Araneae

According to the literature, there are about 40,000 species of spiders in the world, and there are about 3,000 species recorded in China (as of June 2007165438+1October). They belong to 66 families and 39 families live in China.

The largest spider is 9 cm long, and the smallest is only 1 mm. The bird-catching spider we have here is nearly 10 cm long, and is known as the "king of poisonous spiders in the world".

In China ancient books, spiders have many different names. For example, networms, flat beads and round beads are recorded in Compendium of Materia Medica written by Li Shizhen: "Spiders are elegant and earthy, and there are nets in the soil".

Spiders have both advantages and disadvantages for human beings, but as far as their contribution is concerned, they are mainly beneficial insects. For example, in farmland, spiders prey on pests of crops. At the same time, spiders are recorded in many Chinese medicines, so it is of great significance to protect and utilize spiders. In particular, the protection of spiders in rice fields has three advantages: first, it can effectively stabilize the balance of biological populations; Secondly, reduce the residue of chemical pesticides in rice to ensure the safety of people and animals; Third, reducing production costs can increase production and income. Therefore, in the prevention and control of crop diseases and insect pests, it is advocated to use high-efficiency and low-toxicity pesticides to carry out biological control and protect natural enemies.

There are many kinds of spiders, which are widely distributed and adaptable. They can live on the soil surface, soil, trees, grasslands, rocks, caves, watersides, low-lying areas, bushes, mosses, houses or make webs, or inhabit fresh water (such as water spiders) and coastal lakes (such as lake spiders). In short, there are traces of spiders in water, land and air.

Spiders, in animal taxonomy, belong to Arthropoda, Arachnida and Arachnida. Arachnida is a small or medium-sized arthropod, with 14 orders and 5 orders extinct. 66 families of 7 orders of Araneae have been found in China.

Species classification

Araneae is divided into two suborders: ① There are more than 20 species of 1 family in China; ② Spinning suborder (about 107 family, nearly 40,000 species).

Among them, the post-spinning suborder is divided into A: Protospider suborder (about 14 family, 1500 species); B: New Araneae (about 93 families, more than 38,000 species).

Spiders are natural enemies of many agricultural and forestry pests and play an important role in biological control. Protecting and utilizing spiders has become an important part of biological control. Spiders can be used as medicine to treat diseases such as proctoptosis, sores and bromhidrosis. The venom of a few spiders, such as the black widow, is harmful to people and animals. Burrowing tarantulas of the Tarantula family are distributed in Europe and Asia, and are also common in Xinjiang, China, and their poison can kill people and animals. Some spider toxins contain hemolytic enzymes, which can cause local necrosis and ulceration of wound tissue and spread around.

There are many kinds of spiders. There are nearly 40,000 kinds of spiders in nature. These spiders can be roughly divided into three types: safari spiders, cobwebs spiders and cave spiders. The first kind will forage everywhere, and the second kind will wait for rabbits after weaving a net. Most people keep the third kind as pets: cave spiders. They like to hide in sand or holes and make a net at the hole. The net itself is not sticky, and it is purely used to sense the size of prey and hunt.

Appearance characteristics

Spiders vary in length from 0.05 mm to 60 mm. The body is divided into chest and abdomen. Some species have breastplates at the back of the head and chest (some don't), and there are usually 8 monocular eyes (6, 4, 2, 0) at the front of the head and chest, arranged in 2 ~ 4 rows. There is a big chest plate on the ventral surface, and a lower lip between the two frontal lobes in front of the chest plate. The abdomen is not segmented, and the abdominal stalk evolved from 1 abdominal segment (the seventh body segment). The abdomen is mostly round or oval, and some have various strange-shaped protrusions. The ventral rotator evolved from appendages, and there are 8 primitive species, which are located slightly in the front; Most species have six spinnerets, which are located in front of the anus at the back of the body; Some species have four spinnerets, and there are many spinning tubes on the spinneret, which are connected with various silk glands, and the silk is spun from the spinning tubes. Sensory organs include eyes, various sensory hairs, auditory hairs, lyre and tarsal bones.

Spiders are covered by chitin exoskeleton, and their bodies are obviously divided into three parts: head, chest and abdomen, which are often connected by a thin handle formed by the first abdominal segment, without tail segment or tail whip. Spiders don't have compound eyes, and they have six pairs of appendages on the head and chest. The first pair and the second pair belong to the cephalic appendage, in which the first pair is mostly 2 joints, the enlarged part at the base is a claw, the tapered part at the end is divided into claws, and the teeth are tubular. There are poisonous glands in the claws or head and chest, from which the venom is secreted. The second pair of appendages, called foot whiskers, are shaped like walking feet, but have only six joints. The base joint forms a jaw-shaped protrusion near the mouth, which can help feed, while the female spider's foot whiskers have little change, while the male spider's foot whiskers are specialized as reproductive auxiliary organs, which have the structure of storing and transmitting sperm, called limb-touching devices. The third to sixth pairs of appendages are walking feet, consisting of seven joints, with claws at the end and a cluster of bristles under the claws, which are suitable for crawling on smooth objects.

Most spiders have poisonous glands, with claws and claws. Most burrowing spiders move up and down, but they prey on the ground, and spiders that web in the air sweep around like pliers.

No tentacles, no wings, no compound eyes, only one eye, usually 8 eyes, but there are also 6, 4, 2 eyes, and some even have no eyes. As far as the color and function of eyes are concerned, they can be divided into day and night.

The mouthparts of spiders are composed of claw limbs, jaw leaves, upper lip and lower lip, which have the functions of poisoning, catching, crushing food and sucking juice.

Some spiders have clumps of sticky hairs under their tarsal claws, which have the ability to make spiders crawl on vertical and smooth objects. The spider that webs has several claw-like spines near the top of the hock joint, which are called secondary claws.

The abdomen of most spiders is unsegmented. Whether there are external female organs (called reproductive organs) is an important feature to identify female species. There is a special rotator in the middle or back of the abdomen. Three pairs of rotators are called front, middle and rear rotators according to their landing positions. The top of the spinning machine is provided with a film spinning tube which is surrounded by fur. Different spiders spin different kinds of silk with different spinning tubes. The spinner of the rotating tube is also a rotating organ. For example, there are 966 on the spinning machine of Lepidoptera. There are 8 kinds of silk glands extracted from the body through spinning tubes. With the growth and molting of spiders, the size and number of silk glands are increasing. Spider silk is a kind of bone protein, which is very sticky, tough and elastic, and will harden when exposed to air after spinning.

Androgyny, the male is smaller than the female, the male tarsal joints develop into acrobats, and the female has external reproductive organs after molting for the last time.

Living habits

According to the way of life and predation, it can be roughly divided into web spiders and wandering spiders.

The main feature of a web-forming spider is its web-forming behavior. Spiders secrete mucus through the protrusions at the top of their silk sacs, which can condense into very thin silk when exposed to air. The web made of silk is very sticky, which is the main predation means of spiders. For insects that stick to the web, spiders will first inject their prey with a special liquid jujube digestive enzyme. This digestive enzyme can make insects coma, twitch and even die, and liquefy their bodies. After liquefaction, spiders feed by sucking. Spiders are oviparous, and most male spiders will be swallowed up by female spiders after mating with them and become food for female spiders.

Wandering spiders don't weave webs, but wander around or pretend to hunt prey on the spot, such as tall-legged spiders, commonly known as "worms" in Taiwan Province Province.

Some spiders can make balloons out of nets and float to other places with the wind.

Spiders are not food on the human table. They don't even dare to stay away. Lu Xun said: "The first person to eat crabs is admirable. Who dares to eat if he is not a warrior? " Some people eat crabs, and some people must have eaten spiders. But if it is not delicious, future generations will not eat it "("The Second Feeling of Spring "). But recently, some areas, such as Sukhumi in Cambodia, have sold spiders as their dishes.

Spiders mainly prey on small insects. The tarantula beside the water can prey on small fish and shrimp, the bird spider can catch birds (it is said, but there is no exact literature record), and a 7.5 cm long spider in South America can even prey on small rattlesnakes. Web spiders prey on their webs.

(a) the corpse solution:

When spiders hunt, they first paralyze their prey with venom from fangs, secrete digestive juice and inject it into their prey to dissolve it, then suck it slowly and eat it completely.

(2) homemade fresh-keeping bag:

Spiders are afraid of light and often make webs where there is light and wind. Spider silk can be used not only to trap prey, but also as a fresh-keeping bag. The spider wrapped the leftover food in a net for the next time.

(3) Cleanliness:

Spiders clearly divide the places where they eat, sleep and pull things. Domestic spiders generally use cages as garbage stations, urinate in them and throw food scraps.

(4) Very subtle appetite:

Spiders have a strong sense of territory and should be kept separately. They only eat one or two meals a month and can fast for two months at most. The food is mainly insects, such as crickets and Cao Meng. As long as you put a wet sponge in the cage to replenish water, you can raise it to adulthood (about seven years) without changing the cage.

Not all spiders are poisonous (among them, arachnids are not poisonous)! And the toxicity is different. Usually, the toxicity of pet spiders in the market is relatively weak, and they will not take the initiative to attack people as long as they are not intentionally teased. Even if you are bitten, there is no danger to your life. Strong adaptability, no need for careful care. Spiders are the easiest pets to keep.

Spider silk is expected to be used to make high-strength materials, and experts from the Institute of Gene Biology of the Russian Academy of Sciences are actively studying the use of spider silk to make high-strength materials. There is a cluster of spinnerets behind the spider's abdomen, which passes through the silk glands in the body. Protein mucus secreted by this gland can condense into extremely strong spider silk in the air. According to the Moscow Communist Youth League newspaper, experts from the Institute of Gene Biology of the Russian Academy of Sciences found that the hardness of this material is 9 times higher than that of steel with the same thickness, and the elasticity is 2 times higher than that of other most elastic synthetic materials. Experts believe that after further processing, the above spider silk materials can be used to manufacture light body armor, parachutes, protective materials for weapons and equipment, wheel tires, plastic surgery appliances and high-strength fishing nets.