The towards are animal Invertébré S with the soft, cylindrical and lengthened body, generally of small size. Their name comes from Latin vermis (“Ver”), who also gave the vermiform word which corresponds to their characteristic form lengthened and cylindrical.

The term indicates

• the primitive form of organization of the Bilatérien S, which one finds in various animal groups (towards rounds, dishes, towards ringed).
• the larval shape of various insects.

Systematic

Place des towards in the animal world

See also: Bilatérien

Systematic traditional

Traditionally, the worms formed an immense very heterogeneous junction, gathering all the soft, with narrow and lengthened bodies, and deprived animal forms members.

Y were included the flat worms (Platyhelminthes), the ringed nematodes (Némathelmintes, and worms (Annélides), and moreover other isolated groups, the such Rotifère S, the chétognathe S, the bryozoaire S, etc

Systematic modern

The towards do not form a systematic group (they are not a group Monophylétique). Indeed, one indicates several animals by this name:

• the most current worms with “rings”, called Annélides;
• towards dishes (Plathelminthes);
• towards rounds (Nematodes);
• Moreover, the forms of some Insecte S (as their Larva S) are also called thus. These primitive forms illustrate the proverb " ontogenesis recapitulates the philogénèse": the insects are based on their capacity to take a vermiform type.

Annélides

See the detailed article: Annélides

The annélides are the worms most current in particular the Lombric (or Ver of ground) or the Sangsue. The Bonellie or marine worm, is a annélide with the remarkable sexual dimorphism.

Towards dishes

See the detailed article: Plathelminthes

The flat worms are either free like the Planaire (Turbellarié S), or parasites like the Tapeworm (or Ténia) or the Liver fluke.

Towards rounds

See the detailed article: Nematodes

Worms of palm

Worm of palm. Yellowish worm of color being mainly in the tropical countries. It is possible to eat these worm by removing the head of the worm (left black).

The shapes of insects

Some Larve S of insects have an appearance of worm, as the white Ver which is in fact the larva of a Coléoptère, or the Silkworm which is not other than the caterpillar Bombyx of the mulberry tree.

Certain adult forms Aptère S (without wings) are also called towards, the such female of the Lampyre, which one calls Ver shining because of his luminescence in the black.

Habitats

Some live under the marine water, worms, and others in the ground.

Parasitism

Many are the worms which can be, in an adult or larval state, parasites of the man or the animals.

In the group of the flat worms, one finds for example the Ténia, the Botriocéphale S, the ditch, the Bilharzie. In the round worms, Ascaride, Oxyure, Trichocéphale, Ankylostome, Strongle, Trichine, telegraphic,…

In general, the worms live the digestive bodies (Ténia), more rarely the muscles (Trichine S and Cysticerque S), the brain (Cénure S), the liver and the lung (échinooque S)

The worm of the heart is a mortal parasite at the Chien.

See too

Simple: WORM

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