What is the first intermediate host of Digenea?
snails
trematode flukes of the subclass Digenea, mollusks (mostly snails) serve as the intermediate host. Fertilized eggs usually hatch in water. 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.
What is the diagnostic stage of trematodes?
Diagnosis of trematode infection is commonly accomplished by identification of eggs in feces or urine. The eggs of most species are structurally distinct and the diagnosis can be made by standard light microscopy. With the exception of fascioliasis, the drug of choice for trematode infections is praziquantel.
What is the life cycle of flatworms?
They start life as eggs that are passed out in the faeces of birds such as oystercatchers. If eaten by a mudflat snail, or whelk, the eggs hatch and the larvae multiply by budding. The tiny fluke larvae leave their whelk hosts and invade another shellfish, cockles.
What are the differences between Digeneans and Monogeneans with respect to infecting the host?
Digeneans have asexual reproduc- tion in a molluscan host followed by transmission to a vertebrate definitive host in which sexual reproduction occurs. In contrast, an intermediate host and asexual repro- duction are absent in the Monogenea (except perhaps in the Gyrodactylidae).
What is Digenetic life cycle explain it with reference to the life cycle of Fasciola hepatica?
Its life cycle is digenetic, i.e., completed in two hosts (a primary vertebrate host, the sheep and a secondary or intermediate invertebrate host, the gastropod mollusc). The adult parasite is found in the primary host, while a part of its life cycle as larval stages are found in the invertebrate host.
What are the features of Digenea?
Key features Characteristic features of the Digenea include a syncytial tegument; that is, a tegument where the junctions between cells are broken down and a single continuous cytoplasm surrounds the entire animal.
What are the intermediate host of trematodes?
Most trematodes have a complex life cycle with at least two hosts. The primary host, where the flukes sexually reproduce, is a vertebrate. The intermediate host, in which asexual reproduction occurs, is usually a snail.
What is the intermediate host of blood trematodes?
Freshwater snails of the genus Biomphalaria are an important intermediate host for this trematode.
What is definite and intermediate host?
The definitive host is the one which harbors the adult parasite and where the parasite reproduces sexually. The intermediate host is the host which harbors the larval stage or the asexual forms of the parasite. Few parasites require two different intermediate hosts in addition to a definitive host.