Glochidium larva is that of

Options

A. Bivalvia
B. Scyphistoma
C. Gastropoda
D. Veliger and Trochophore

Answer

### Step-by-Step Solution:

1. **Identify the Larva**: The question asks about the Glochidium larva. It is essential to understand what type of larva it is and in which group of animals it is found.

2. **Research the Phylum**: Glochidium larva is primarily associated with the Phylum Mollusca. This phylum includes various classes of mollusks, such as Bivalvia, Gastropoda, and Cephalopoda.

3. **Determine the Class**: Within the Phylum Mollusca, Glochidium larva is specifically found in the class Bivalvia. Bivalves are characterized by having two shells (valves).

4. **Understand the Characteristics of Glochidium**: Glochidium larvae are unique because they are parasitic and typically attach to the gills or fins of fish. This is a critical feature that distinguishes them from other types of larvae.

5. **Eliminate Other Options**: The other options provided in the question include various types of larvae from different classes:
- **Scyphozoa (Jellyfish)**: The larvae here are typically in the polyp stage and are not related to Glochidium.
- **Gastropoda**: The larvae in this class are called Veliger, which is different from Glochidium.
- **Annelida**: The larvae here can be Trochophore or other types, which do not include Glochidium.

6. **Conclusion**: Based on the information gathered, the Glochidium larva is specifically found in the class Bivalvia of the Phylum Mollusca.

### Final Answer:
Glochidium larva is that of Bivalvia (a class within the Phylum Mollusca).