What are the general characteristic of cestodes?

What are the general characteristic of cestodes?

Cestodes, commonly called tapeworms, are the taxonomic class of Cestoda, which are parasitic worms. They have a tape-like and segmented body. These animals are hermaphroditic, lack a digestive tract, and do not have a body cavity.

What is the structure of tapeworm?

Tapeworms are bilaterally symmetrical (i.e., the right and left sides are similar). Some consist of one long segment; others have a definite head, followed by a series of identical segments called proglottids. The head, or scolex, bears suckers and often hooks, which are used for attachment to the host.

What is cestodes in biology?

Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms.

What are the basic differences between the two order of cestodes?

When it comes to their shape, the cestodes have a tape-like, segmented body, whereas the trematodes have a leaf-like and unsegmented body. The cestodes have a head that has suckers and, in some cases, hooks. The trematodes have a head with suckers but no hooks.

What are the larval stages of cestodes?

Using these characters, six basic types of larval cestodes were identified: the procercoid, an alacunate form which cannot develop further until ingested by a second intermediate host; the plerocercus, an alacunate form with a retracted scolex; the plerocercoid, an alacunate form with an everted scolex; the merocercoid …

What is the life cycle of cestodes?

All cestodes cycle through 3 stages—eggs, larvae, and adults. Adults inhabit the intestines of definitive, or final, hosts, which are mammalian carnivores, including humans. Several of the adult tapeworms that infect humans are named after their main intermediate host (the fish, beef, and pork tapeworms).

What is the infective stage of Cestodes?

Within this crustacean intermediate host, the larval tapeworm (procercoid) develops. If the copepod is then ingested by a suitable fish, the larva migrates to the host’s body cavity and develops to the plerocercoid stage, which is infective to the definitive host (including humans).

What is the life cycle of Cestodes?

What is the infective stage of cestodes?

What are the common host of cestodes?

Echinococcus eggs from dog or fox fur cause human hydatid disease (humans are the intermediate host; canids are the definitive hosts). Reinfection with adult tapeworms is common; second infections with larvae are rare.

What are the other worms under cestodes group?

Tapeworms (Cestodes) The three common types of tapeworms are Taenia solium, found in pork; Taenia saginata, found in beef; and Diphyllobothrium latum, found in fish.

What structures make up the scolex of a tapeworm?

The head of tapeworms, scolex, contains structures, such as grooves, suckers or hooks, which enable the worm to attach to the gut wall. The major part of the tapeworm is called strobila and it consists of segments, proglottids. They each contain both male and female reproductive organs.

What are the parts of cestodes?

The body of cestodes (from the Greek cestos – belt, ribbon) is usually ribbon-like, oblate in the dorsoventral direction, consists of a head (scolex), neck and strobila, divided into segments (proglottids).

What is the life cycle of a cestode?

They have a head with suckers (sometimes hooks as well) and generally have a 2-host life-cycle. The life cycle of cestodes goes something like this. The raw or undercooked tissue of an intermediate host is eaten by the definitive host.

Why do Cestodes have suckers on their heads?

It’s because their bodies have a tape-like, segmented shape to it. Cestodes have a head, called a scolex, which has suckers. These suckers are used to attach to a person’s intestinal tract. Some cestodes also have hooks on their head as well. Although cestodes can be found in a person’s digestive tract, ironically they don’t have one themselves.

Which sense organs are not developed in cestodes?

The sense organs are not developed. The reproductive system in almost all cestodes is hermaphroditic. In most of them, the genitalia have a very complex structure. The hermaphroditic reproductive system is repeated in each proglottid. The first segments, budding from the cervix, do not yet have a reproductive apparatus.