: a larval form of a digenetic trematode

What is Radia in zoology?

ˈri diˌi/. Zoology. a cylindrical larval stage of some trematodes, produced by a sporocyst and giving rise to daughter rediae or to cercariae.

What is Metacercaria larva?

Definition of metacercaria : a tailless encysted late larva of a digenetic trematode that is usually the form which is infective for the definitive host.

How does the miracidium move?

As their name implies, the ambulatory buds facilitate movement of the larva through the tissues of the molluskan host. This movement is abetted by contractions of the redial body. Unlike the sporocyst, the redia possesses a digestive tract with an anterior mouth, a muscular pharynx, and an unbranched cecum.

What is miracidium larva?

The miracidium is a ciliated, nonfeeding larva (Fig. 9.18). Under favorable conditions, it escapes from the eggshell, usually through the operculum, into the environment. The miracidium is elongated and covered with flattened, ciliated epidermal plates.

What is the infective stage of liver fluke?

The cercariae migrate onto wet herbage, encysting as metacercariae, the highly resilient infective stage of the liver fluke. Following ingestion, the young flukes migrate to the liver, through which they tunnel, causing considerable tissue damage.

What is Redia larva?

Definition of redia : a larval form of a digenetic trematode (such as a liver fluke) that is produced within a sporocyst, has a mouth, pharynx, and gut, and contains cells which give rise to other rediae or to cercariae — see also redial entry 3.

Is Fasciola hepatica a trematode?

The trematodes Fasciola hepatica (also known as the common liver fluke or the sheep liver fluke) and Fasciola gigantica are large liver flukes (F. hepatica: up to 30 mm by 15 mm; F.

What type of organism is clonorchis sinensis?

Clonorchis sinensis, the Chinese liver fluke, is a liver fluke belonging to the class Trematoda, phylum Platyhelminthes. It infects fish-eating mammals, including humans. In humans, it infects the common bile duct and gall bladder, feeding on bile.

Where is miracidium larva found?

platyhelminthes. The first larval stage, the miracidium, generally is free-swimming and penetrates a freshwater or marine snail, unless it has already been ingested by one. Within this intermediate host, the parasite passes through a series of further stages known as sporocysts, rediae, and cercariae.

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What is a scolex?

Definition of scolex : the head of a tapeworm either in the larva or adult stage.

What is the difference between cercariae and Metacercariae?

At this stage, the cercaria is released from the snail and seeks out a second intermediate host to infect. Metacercaria: … It is in this stage that the parasite infects the definitive human host via ingestion of the snail or other second intermediate host.

What is cercaria in zoology?

A cercaria (plural cercariae) is the larval form of the trematode class of parasites. It develops within the germinal cells of the sporocyst or redia. … The motile cercaria finds and settles in a host where it will become either an adult, or a mesocercaria, or a metacercaria, according to species.

What is Rhabditiform larva?

Rhabditiform larva is characteristic to nematodes (roundworm). Ascaris is a roundworm. Tapeworm larval stage is called as coenuri; Hydra (cnidarian) lack any larval stage while parenchymula is the free-swimming flagellated larval stage of Leucosolenia (Porifera).

What is a Sporocyst?

1 : a case or cyst secreted by some sporozoans preliminary to sporogony also : a sporozoan encysted in such a case. 2 : a saccular body that is the first asexual reproductive form of a digenetic trematode, develops from a miracidium, and buds off cells from its inner surface which develop into rediae.

What is a Coracidium?

Medical Definition of coracidium : the oncosphere of a tapeworm at about the time of hatching while still surrounded by the embryophore.

What type of parasite is Fasciola hepatica?

Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic trematode (fluke or flatworm, a type of helminth) of the class Trematoda, phylum Platyhelminthes. It infects the livers of various mammals, including humans, and is transmitted by sheep and cattle to humans the world over.

Which larva of liver fluke has birth pore?

Usually, near the mouth of the redia there is a birth pore leading from the brood chamber. Within the brood chamber of the redia, germ balls differentiate into either secondary (daughter) rediae or the next larval stage, the cercaria.

What is Glochidium larva?

The glochidium (plural glochidia) is a microscopic larval stage of some freshwater mussels, aquatic bivalve mollusks in the families Unionidae and Margaritiferidae, the river mussels and European freshwater pearl mussels.

Can you poop out liver flukes?

Diagnosis of Fluke Liver Infections Doctors diagnose Clonorchis, Opisthorchis, or Fasciola infections when they see fluke eggs in a person’s stool (feces) or in the contents of the person’s intestines. However, finding eggs in stool may be difficult.

How does liver fluke affect humans?

Liver flukes infect the liver, gallbladder, and bile duct in humans. While most infected persons do not show any symptoms, infections that last a long time can result in severe symptoms and serious illness. Untreated, infections may persist for up to 25–30 years, the lifespan of the parasite.

Can liver flukes cause weight gain?

Once inside cattle, metacercariae migrate through the gut wall, cross the peritoneum and penetrate the liver capsule and bile ducts. Symptoms associated with liver flukes include reduced weight gain, reduced milk yields, reduced fertility, anemia, and diarrhea.

How common is Clonorchis sinensis?

Clonorchiasis, caused by Clonorchis sinensis (C. sinensis), is an important food-borne parasitic disease and one of the most common zoonoses. Currently, it is estimated that more than 200 million people are at risk of C. sinensis infection, and over 15 million are infected worldwide.

What means do Clonorchis sinensis obtain its nutrients?

Clonorchis sinensis is considered a parasite as an adult fluke. It is found in the biliary systems of its hosts, which range from reptiles to humans, absorbing bile as its source of nutrients. ( Buchsbaum, et al., 1987) eats body fluids.

What does Clonorchis sinensis cause?

Clonorchiasis is an infectious disease caused by the Chinese liver fluke (Clonorchis sinensis) and two related species. Clonorchiasis is a known risk factor for the development of cholangiocarcinoma, a neoplasm of the biliary system.

Is clonorchis hermaphroditic?

C. Clonorchis sinensis adults are flattened, lance shaped, and measure approximately 10 to 25 mm long by 3 to 5 mm wide. The oral and ventral suckers (acetabulum) are relatively small. Like other flukes, they are hermaphroditic.

Which of the following is a trematode?

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.

What is the intermediate host of Clonorchis sinensis?

sinensis is a fish-borne trematode. There are three hosts in the life cycle of C. sinensis including freshwater snails (the first intermediate hosts), freshwater fish and occasionally shrimps (the second intermediate hosts), and human or carnivorous mammals (the definitive hosts).

How do you say Miracidium?

noun, plural mi·ra·cid·i·a [mahy-ruh-sid-ee-uh].

How many plates cover Miracidium larva?

Echinostoma paraensei miracidia have 18 plates along the outside of their body.

Which is the first stage of larva of Fasciola?

[Miracidium larva comes out from the egg shell of the fertilized egg by eroding tlie operculum wit11 the help of proteolytic enzyme. It is the first larval stage in the life cycle of F. hepatica. It is a free swimming stage in fresh water.