Spider and its type

The spider, also called a spider, a type of animal is an arthropod with two body segments,four pairs of legs, wingless and do not have a mouth chewers. All spiders are classified in the order Araneae, and along with scorpions, scorpion, mite-all-eight-legged arachnidsincorporated into the classroom. Field study of spiders is called arachnologi.

Spiders are predators (carnivores), sometimes even cannibals. Its main prey is insects.Almost all kinds of spiders, with the exception of about 150 species of the tribe Uloboridae andHolarchaeidae, and suborder Mesothelae, be able to inject through a pair of fangs to theenemy or prey. However, from tens of thousands of species, only about 200 species that bitescan be dangerous to humans.

Not all spiders make webs to catch prey, but all of them able to produce silk yarn - the strands of protein fibers are thin but strong - from the gland (called a spinneret) located at the back ofhis body. Silk fiber is very useful to assist the movement of the spider, swinging from oneplace to another, trapping prey, making egg sacs, protect the nest hole, and others.

Morphology (shape)

Unlike insects have three body parts, the spider has only two. Segment of the front is calledthe cephalothorax or prosoma, which actually is a combination of head and chest (thorax).While segments of the back called the abdomen (stomach) or opisthosoma. Betweencephalothorax and abdomen there is a thin connective-called pedicle or pedicellus.


In four pairs of legs attached to cephalothorax, and one to four pairs of eyes. In addition to a pair of large fanged jaws (called chelicera), there are also a pair or some similar hand tool of the mouth, called pedipalps. In some types of spiders, the pedipalps adult males grow andchange function as a tool in marriage.


Spiders do not have a mouth or teeth to chew. Instead, the mouth of the spider in the form ofa vacuum to suck up their prey's body fluids.

Predation

Most spiders are predators (predators) Ambush, waiting for prey to pass nearby while hiding behind a leaf, flower leaf layer, crack rocks, or holes in the ground covered with camouflage. Some types have color patterns That disguise herself on the ground, rocks or tree pepagan, so no need to hide.
Weaver spider (eg members of the tribe Araneidae) webs silk more or less round shape in the water, Among the leaves and branches, in the face of a rock fracture, in the corners of buildings, Among telephone wires, etc.


These nets are attached, to catch flying prey Insects That Become. Once trapped insect net, the spider promptly Walked over and stuck its fangs to prey to paralyze and simultaneously transmit the body's digestive enzymes into Their prey.


Slightly different, the spider hunters (Such as members of the tribe Lycosidae) are usually more active. The spider species of trees are used to explore, the sidelines of the grass, or the surface of the rocky walls to search for prey. The spider can catch up and jump to pounce on its prey.


Can be injected through fangs spider is usually well digested and Destroyed parts of the prey's body. Then SLOWLY crushed organs and body fluids were the resource persons are sucked in by the predators. For hours the spider sucks the liquid until it dries prey carcasses. That spiders have a jaw (chelicera) stronger, faster Could Spend Their food by damaging the body and crush prey with its jaws and fangs That. Live the rest of the little balls are crushed prey That Had Withered body.


Some weaver spiders have the ability to wrap the body of the prey with winding threads of silk. This capability is ESPECIALLY useful if the prey has dangerous self-defense tool, the which has a sting like a bee, or if the spiders want to save some time while waiting for prey Pls Their preferred to enjoy it later. 

Variability Types (Diversity Type)

Until now, about 40,000 species of spiders have been collected, and graded into 111 tribes.However, given that these animals are so diverse, many of whom have very small stature,often hidden in nature, and even many specimens in museums that have not terdeskripsi well, it is believed that the possibility of diverse types of spiders can all 200,000 species.


Order of the spider is further divided into three major categories at the level of suborders,namely:


-Mesothelae, which is a primitive spider not venomous, with sections of the body are clearly visible; show a closer kinship with the ancestral arthropod jointed.

-Mygalomorphae or Orthognatha, was to a group of spiders that make hiding burrows, andalso makes a hole in the ground trap. Many species are large, such as tarantulas and alsolancah Maung.

-Araneomorphae spiders are a group of 'modern'. Most spiders that we encountered included in this suborder, given that its members consist of 95 tribes and includes approximately 94%of the total species of spiders. Fangs of this group leads slightly tilted forward (rather thanupright as in the tarantula) and driven in opposite directions like claws biting prey.

source

http://id.wikipedia.org/wiki/Laba-laba