Question

Identify the larval stages in the development of liver fluke:

• A. Veliger, Trochophore, Sporocyst, Planula
• B. Sporocyst, Planula, Trochophore, Redia
• C. Miracidium, Sporocyst, Redia, Cercaria
• D. Planula, Sporocyst, Muller, Trochophore

Hint:

Remember the liver fluke larval sequence: Miracidium → Sporocyst → Redia → Cercaria.

Answer 1

The Correct Option is C

The liver fluke (\textit{Fasciola hepatica}) is a digenetic parasite with a complex life cycle that includes multiple larval stages: % Option (A) Miracidium – free-swimming larva that infects a snail (intermediate host) % Option (B) Sporocyst – sac-like structure inside the snail % Option (C) Redia – larval form developing inside sporocyst % Option (D) Cercaria – leaves the snail and encysts as metacercaria on vegetation Stages like Planula, Veliger, or Trochophore are associated with other invertebrates like cnidarians or mollusks, not flatworms.

Answer 2

The larval stages in the development of the liver fluke are Miracidium, Sporocyst, Redia, and Cercaria.

Liver fluke, a parasitic flatworm, undergoes a complex life cycle involving multiple larval stages to complete its development.

1. Miracidium: This is the first free-swimming larval stage that hatches from the egg. It actively seeks out and penetrates the intermediate host, usually a freshwater snail.

2. Sporocyst: Inside the snail, the miracidium transforms into a sporocyst. The sporocyst is a sac-like structure that reproduces asexually to produce multiple rediae.

3. Redia: The redia stage develops within the sporocyst. Rediae continue asexual reproduction, producing many cercariae.

4. Cercaria: These are free-swimming larvae that emerge from the snail into water. Cercariae then find a suitable substrate, such as aquatic vegetation, where they encyst and form metacercariae, the infective stage for the definitive host.

This multi-stage larval development ensures the liver fluke can successfully infect both intermediate and definitive hosts, completing its life cycle.