Define the Redia Larva?
Redia is the third larval stage in the life cycle of F. heputicn. Redia develops from the germ cell Is of the sporocyst and comes out of the sporocyst by rupturing tlie sporocyst wall. Redia then migrates to the liver of the snail.
1. Each redia measures about 1.3-1.6 mm in length.
2. Body of redia is elongated, cylindrical and sac-like.
3. Body-wall is composed of tegument, epithelial layer and delicate mesenchyme.
4. Anterior end consists of mouth which leads into a muscular pharynx with pharyngeal glands and sac like intestine.
5. Just behind the pharynx is a muscular ring-like swelling called collar which helps the redia in locomotion.
6. Just posterior to the collar is a permanent aperture called birth pore through Which another generation of redia called second generation of redia or the next larval stage, the cercaria exits to the outside.
7. Posterior region has two stumpy processes called lappets which help the redia
in anchoring to the tissues of the snail and are also helpful in locomotion.
8. The space between the body wall and intestine contains n few germ cells.
9. Germ cells often give rise to second generation of daughter rediae.
10. The germ cells of redia as well as germ cells of daughter redia give rise to the next larval stage called cercaria.