Worms

The term worm is used to describe many different distantly-related animals which have a long cylindrical body and no legs. They are technically decomposers. Worms usually have a cylindrical, flattened, or leaf-like body shape and are often without any true limbs or appendages. Instead, they may have bristles or fins that help them move. A few have light-sensing organs. Worms may also be called helminths, particularly in medical terminology when referring to parasitic worms. Worm species differ in their abilities to move about on their own. Many species have bodies with no major muscles, and cannot move on their own. They must be moved by forces or other animals in their environment. They are a type of muscular hydrostat. In Helminthology, the study of worms, worms are classified in three phylums.

The first of these includes the flatworms. They have a flat, ribbon- or leaf-shaped body with a pair of eyes at the front. In this phylum divided in three groups or classes. Turbellaria, Trematoda, and Cestoda. Turbellaria lives in clear river. They have a pair of eyes to compare dark and light. They can differenciated colors and escape from light. Example for this class is Planaria. Trematoda is flatworms which lives which lives as parasities for animal and human. They have kutikula cover to protect them from wet-nurse enzyms. They have a mouth like sucker that is completed by hooks to attached its wet-nurse. For example of Trematoda are Fasciola hepatica which live in sheep’s liver. Clonorchis which live in human’s liver, and Schitosoma, bloodworm, which live in vena vessels, pigs, mammals, and cows. Cestoda have ribbon shaped body and segmented. They have 1500 spesies in this world. For example, Taenia saginata and Taenia solium. Some of Plathyhelminthes are parasities, for example, Fasciola, Clonorchis, Taenia saginata, and Taenia solium.

The second group contains the threadworms, roundworms, and hookworms. This phylum is called Nematoda. Threadworms may be microscopic, such as the vinegar eelworm, or more than 1 meter (3 feet) long. They are found in damp earth, moss, decaying substances, fresh water, or salt water. Some roundworms are also parasites. For example, Ascaris lumbricoides which live in small instentine of human, Ancylostoma duodenale, and Wuchereria bancrofti which cause elephantiasis.

The third group consists of the segmented worms, with bodies divided into segments, or rings. This phylum is called Annelida. Among these are the earthworms and the bristle worms of the sea. The most common worm is the earthworm, a member of phylum Annelida. Earthworms in general have been around for 120 million years. They enrich and aerate the soil. Some of Annelida can be eaten especially Polychaeta, Annelida that have many fur. They are Phylodoce maculataand Trypanosyllis zebra.

Worms are divided into three phylums that each phylums is definite with theur shapes. Some of worms are parasities but several of them can fertilize the soil and some of them can be eaten like Polychaeta. We must keep our clean because worms especially phylums Plathyhelminthes and Nematoda can make us sick. They lives in many places, freshwater, seawater, seashore, and soil.