What is characteristic feature of trematode?
Trematodes are flatworms classified in the phylum Platyhelminthes, class Trematoda, subclass Digenea. In general, trematodes are dorso-ventrally flattened and leaflike in shape. Their bodies are covered with tegument, which is usually armed with scalelike spines. They have two suckers: one oral and one ventral.
Which are 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 are trematodes also known as?
Trematodes, also called flukes, cause various clinical infections in humans. The parasites are so named because of their conspicuous suckers, the organs of attachment (trematos means “pierced with holes”). All the flukes that cause infections in humans belong to the group of digenetic trematodes.
What is the function of trematodes?
Using the powerful muscular pharynx that makes up the mouth part, trematodes (both the larvae and adult stages) are able to suck food from the host as they remain attached using both the posterior and ventral suckers.
What is the structure of trematode?
Structurally, trematodes are flat and elongated worms whose outer surface (tegument) contains microvilli that both protect the worm and act as a nutrient absorptive surface. Adult worms possess anterior and ventral suckers, which are useful in maintaining attachment to host tissue.
What is the difference between cestodes and trematodes?
Cestodes are tape-like and segmented in shape, have a head with suckers and possibly hooks, and lack a digestive tract. Trematodes are leaf-like and unsegmented, lack hooks entirely, and have an incomplete digestive tract. Generally, cestodes require two hosts and trematodes need three to complete their life cycles.
What are the stages of trematodes?
Not all trematodes follow the typical sequence of eggs, miracidia, sporocysts, rediae, cercariae, and adults. In some species, the redial stage is omitted, and sporocysts produce cercariae. In other species, the cercaria develops into an adult within the same host.
What is the diversity of trematodes?
Trematodes, dominated by the digeneans, comprise a group of abundant and ubiquitous parasitic metazoans with high diversity and more than 18,000 nominal species [1]. These metazoans utilize multi-host systems to complete their complex life cycles, often with a mollusc as the first intermediate host [2,3,4].
What is one morphological characteristic of nematodes that differentiate trematodes?
Nematodes have a simple body form, often referred to as a “tube within a tube,” with a simple digestive system that extends from the mouth at one end to the anus at the other. Trematodes have flat, unsegmented bodies usually shaped like a leaf or an oval. Nematodes have two sexes and reproduce sexually.
Are trematodes multicellular?
The trematodes or flukes are multicellular flatworms. Different species range in length from less than 1 mm to several centimeters. The flukes of medical importance are all digenetic, reproducing sexually in a definitive vertebrate host and asexually in a snail intermediate host.
What is difference between trematodes and nematodes?
Trematodes are hermaphroditic and utilize oral suckers, ventral suckers or acetabulum for attachment organs. Nematodes are characterized by a cylindrical body shape and do indeed have a body cavity. Its body covering is a cuticle and the digestive tube ends in the anus.
How do trematodes move?
Adult flukes are typically flat, oval-shaped worms that have a layer of muscles just below the tegument, or skin, that allow the worm to expand and contract its shape and, thus, move its body.
Where are trematodes found?
Human infections are most common in Asia, Africa and Latin America. However, trematodes can be found anywhere where untreated human waste is used as fertilizer. Humans can be infected by trematodes either by consuming undercooked contaminated fish or plants, or by ingesting contaminated water.
What is a trematode in biology?
Trematoda is a class within the phylum Platyhelminthes. It includes two groups of parasitic flatworms, known as flukes . They are internal parasites of molluscs and vertebrates. Most trematodes have a complex life cycle with at least two hosts. The primary host, where the flukes sexually reproduce, is a vertebrate.
What are the characteristics of algae?
General Characteristics of Algae. Algae are eukaryotic organisms that have no roots, stems, or leaves but do have chlorophyll and other pigments for carrying out photosynthesis. Algae can be multicellular or unicellular.
What are the life cycle adaptations of trematodes?
Life cycle adaptations. Trematodes have a large variation of forms throughout their life cycles. Individual trematode parasites life cycles may vary from this list. Trematodes are released from the definitive host as eggs, which have evolved to withstand the harsh environment. Released from the egg is the miracidium.
Are trematodes parasites of fish?
The smaller Aspidogastrea, comprising about 100 species, are obligate parasites of mollusks and may also infect turtles and fish, including cartilaginous fish. The Digenea, the majority of trematodes, are obligate parasites of both mollusks and vertebrates, but rarely occur in cartilaginous fish.