Arthropods

Arthropods are the largest phylum in the animal world and includes insects, spiders, shrimp, centipedes and other similar animals. Arthropods are animals berbuku another name-book. Arthropods commonly found in marine, freshwater, land and air environments, including various symbiotic and parasitic forms.
Characteristics that distinguish the phylum arthropods were: body segmented, the segments usually unite into two or three clear areas, segmented limbs in pairs (Originally naming Arthropoda), bilateral symmetry, berkitin exoskeleton. Flow periodically and updated as the growth of animals, such as pipes alimentari canal with mouth and anus, open circulatory system, blood vessels are normally only tangible dorsal structures such as a pipe to channel alimentar with lateral openings in the abdomen, the body cavity; a blood cavity or hemosol and coelomic reduced.

The nervous system consists of an anterior ganglion or brain located above the canal alimentari, a pair of connecting the channel from the brain to the rope around the canal and the nerve ganglion alimentari located below the alimentary canal, Malpighian tubule excretion usually by. Empty tubes that enter the canal alimentari and excretion of the material passing out through the anus, respiration with gills or trachea and spiracles, no cilia or nefridia.
Anthropoda nervous system such as the annellida, there is the ventral part of the body is shaped like a rope ladder.

Arthropods have four classes, among which are:

1.Class Myriapoda.
2.Class Crustacea.
3.Class Arachnid.
4.Class Insecta.

Arthropod phylum in the animal world is the largest in the world. Four of the five parts of the animal species are arthropods, with over a million modern species are found and the record of early Cambrian fossils that achieve. Number of species is about 900,000 with a wide variety of species. This amount is approximately 80% of animal species known today. Arthropods can live in freshwater, marine, land, and practically all of the Earth's surface is filled by this species. Arthropods are considered closely related to annelids, for example, is Peripetus in South Africa.

Arthropods may be the only one who can live in Antarctica and burrows in the steep rocks of high mountains. All members of this phylum have jointed bodies and outer skeleton composed of chitin. The main body cavity called a hemocoel. Hemocoel consists of a small room that is pumped by the heart. The heart lies on the dorsal side of the body.