What are the characteristics of trematoda?

What are the characteristics of trematoda?

Trematodes are flattened oval or worm-like animals, usually no more than a few centimetres in length, although species as small as 1 millimetre (0.039 in) are known. Their most distinctive external feature is the presence of two suckers, one close to the mouth, and the other on the underside of the animal.

What are the characteristics of flukes?

Flukes are leaf-shaped, ranging in length from a few millimeters to 7 to 8 cm. The tegument is morphologically and physiologically complex. Flukes possess an oral sucker around the mouth and a ventral sucker or acetabulum that can be used to adhere to host tissues. A body cavity is lacking.

What is the habitat of trematoda?

Geographic range: Human blood flukes live in the warm regions of the world, especially South America, Africa, the Caribbean, and the Middle East. Habitat: The larvae of human blood flukes live in freshwater snails. The adults live in veins in the abdomens of mammals such as rodents, dogs, cattle, baboons, and humans.

How many species of trematoda are there?

All trematodes are parasitic, and most adult trematodes parasitize vertebrates. Around 9000 species have been described.

What are the characteristics of Cestodes?

They have a tape-like and segmented body. These animals are hermaphroditic, lack a digestive tract, and do not have a body cavity. 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.

What is trematode life cycle?

There are three distinct larval stages involved in all digenetic trematode life cycles: the miracidium, sporocyst, and cercaria. Some taxa also produce rediae and/or encysted metacercariae. All of these life stages except for the miracidium can be found in first intermediate hosts.

What are the symptoms of liver flukes?

Untreated, infections may persist for up to 25–30 years, the lifespan of the parasite. Typical symptoms include indigestion, abdominal pain, diarrhea, or constipation. In severe cases, abdominal pain, nausea, and diarrhea can occur.

What are the characteristics of liver fluke?

The body of liver flukes is leaf-like and flattened. The body is covered with a tegument. They are hermaphrodites having complete sets of both male and female reproductive systems. They have simple digestive systems and primarily feed on blood.

What is the function of trematodes?

Trematodes expel undigested material through their mouth because they do not have an anus. Nitrogenous waste excretion and other osmoregulatory functions are preformed by the protonephridium, which consists of flame cells and tubule networks, all of which act as a primitive kidney. Most trematodes reproduce sexually.

How do trematodes affect humans?

Foodborne trematodes cause infection in humans via the consumption of contaminated food (raw fish, crustaceans or vegetables). Infection can result in severe liver and lung disease and together these diseases are estimated to cause 2 million life years lost to disability and death worldwide every year.

Why do trematodes have so many eggs?

Because of the small chance of transmission of parasite stages from host to host, internal parasites put much energy into reproduction, producing many, many eggs and/or larvae because so few ever reach the next host in the life cycle.

What are the 3 main classes of parasites?

A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites.

How many species of trematodes are there in the world?

With over 20,000 species in the class Trematoda, trematodes can be found in various habitats across the globe. Depending on the species, trematodes may depend on one or several hosts to complete their life cycle. Some examples of trematodes include: S. japonicum. S. haematobium.

How are trematodes similar to Other platyhelminths?

While different trematode species may possess features that are absent in others, they share a number of morphological features. For instance, like most platyhelminths, trematodes are defined by dorsoventrally flattened (unsegmented) bodies that are bilaterally symmetrical.

How is the life cycle of a trematode completed?

The trematode life cycle is completed when eggs shed by adult worms are excreted in host feces and hatch to release ciliated miracidia, which then infect a suitable intermediate host.

What kind of fossil is a trematode made of?

For example, a trace fossil from a trematode might be a slight indentation on a fossil snail shell. Despite the poor fossil record, scientists believe that Aspidogastrea is an ancient group, because many of its species, including those in the families Multicalycidae, Rugogastridae, and Stichocotylidae, use cartilaginous fishes as hosts.