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What is the difference between flatworms and mollusks?

What is the difference between flatworms and mollusks?

Flatworms are thin, flat, acoelomate animals that can be free-living or parasitic. Roundworms and rotifers have a more highly evolved gut than flatworms. Mollusks are coelomates with a muscular foot, a mantle, and a digestive tract with two openings.

What is a flatworm classified as?

Flatworm, also called platyhelminth, any of the phylum Platyhelminthes, a group of soft-bodied, usually much flattened invertebrates. The phylum consists of four classes: Trematoda (flukes), Cestoda (tapeworms), Turbellaria (planarians), and Monogenea. …

What type of animal is a flatworm?

invertebrate animals
Flatworms (Platyhelminthes) are a group of bilaterally symmetrical, acoelomate, soft-bodied invertebrate animals found in marine, freshwater as well as moist terrestrial environments. Flatworm species include: Turbellaria. Tapeworms.

Is a worm classified as a mollusk?

Mollusks are invertebrates such as the common snail. Most mollusks have shells. Annelids are worms such as the familiar earthworm. Annelids look like roundworms on the outside, but on the inside they are more like mollusks.

Do flatworms have a complete digestive system?

Physiological Processes of Flatworms Most flatworms have an incomplete digestive system with an opening, the “mouth,” that is also used to expel digestive system wastes. Some species also have an anal opening.

Does Mollusca have body cavity?

Both flatworms and molluscs are triploblastic, bilaterally symmetric, and cephalized. But molluscs have developed a true coelom, an internal body cavity enclosed by mesodermal membranes. The coelom in molluscs, however, is strangely reduced to a small space around the heart, sometimes called a hemocoel.

What diseases can flatworms cause in humans?

Paragonimiasis is caused by infection with a flatworm. That’s a parasitic worm also called a fluke or lung fluke because it commonly infects the lungs. Usually, infection comes after eating undercooked crab or crayfish that carry immature flukes. Once swallowed by a person, the worms mature and grow inside the body.

Can flatworms live in humans?

There are a variety of parasitic worms that can take up residence in humans. Among them are flatworms, thorny-headed worms, and roundworms. The risk of parasitic infection is higher in rural or developing regions. The risk is great in places where food and drinking water may be contaminated and sanitation is poor.

What eats a mollusk?

Vertebrate predators of snails and slugs include shrews, mice, squirrels, and other small mammals; salamanders, toads and turtles, including the uncommon Blandings Turtle Emydoidea blandingii; and birds, especially ground-foragers such as thrushes, grouse, blackbirds, and wild turkey.

Do mollusks have brains?

Molluscs, with the exception of the most highly developed cephalopods, have no brain in the strict sense of the word. Instead, the cell bodies (pericarya) of nerve cells are concentrated in nerve knots (ganglia) in important parts of the body. In gastropods, the ganglia originally have been dispersed over the body.

What is the difference between a human and a flatworms digestive system?

They both have two openings (mouth and anus); and they also have an esophagus, pharynx. Mechanical digestion begins in the mouth of a human and occurs in the gizzard of a worm. Worms have only one intestine and humans have two (Large and small intestine).

Which flatworms have no digestive system?

Cestodes have no digestive tract; they absorb nutrients from the host across the body wall. Most other flatworms, however, have conspicuous digestive systems.

What kind of body does a flatworm have?

Phylum Platyhelminthes, also known as flatworms include both predatory and parasitic species, including important parasites of humans. Flatworms have three tissue layers. The flatworms are acoelomates, so their bodies are solid between the outer surface and the cavity of the digestive system.

How are annelids and flatworms related to each other?

Flatworms (Phylum Platyhelminthes), annelids (Phylum Annelida) and mollusks (Phylum Mollusca), while extraordinarily diverse, share a number of characteristics, which suggests they are more closely related to each other than other invertebrate phyla. Unlike poriferans and cnidarians, all three of these phyla are bilateral and have 3 tissue layers.

What makes a Turbellaria different from other flatworms?

As such, Turbellaria species lack a coelom (a body cavity located between the body wall and intestinal canal in most animals). They have sub-epidermal rhabdites in their ciliated epidermis that distinguish this class from other flatworms. They lack an anal opening.

How are flatworms different from trematodes and cestodes?

However, they can be easily differentiated from trematodes and cestodes by the fact that they possess a posterior organ known as a haptor. Monogeneans vary in size and shape. For instance, whereas larger species may appear flattened and shaped like a leaf (leaf-shaped) the smaller ones are more cylindrical.