What is the larval form of trematodes?
Cercaria (plural: cercariae) The larval form of the parasite develops within the germinal cells of the sporocyst or redia. A cercaria has a tapering head with large penetration glands.
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 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.
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 does a cercaria do?
A cercaria develops inside a snail, which is its first intermediate host, then it emerges and has a short free swimming life in the water. To prepare for morphological study, place snails in small dishes containing clean water in one (Fig.
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.
What is sporocyst larva?
A larval form of digenetic trematode (fluke) that develops in the body of its molluscan intermediate host, usually a snail; the sporocyst forms a simple saclike structure with germinal cells that bud off internally and develop into other larval types that continue this process of larval multiplication (considered to be …
What is Sporocyst larva?
Which is the first stage of larva of Fasciola?
Miracidium larva
[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.