Name of the larva of Petromyzon is

Options

A. trochophore
B. tornaria
C. tadpole
D. ammocoete

Answer

To answer the question about the name of the larva of Petromyzon, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Organism**: Start by recognizing that Petromyzon refers to a genus of jawless fish commonly known as lampreys.

2. **Understand the Life Cycle**: Acknowledge that like many organisms, Petromyzon undergoes various stages in its life cycle, including a larval stage.

3. **Determine the Larval Stage**: In the case of Petromyzon, the larval stage is a crucial part of its development.

4. **Name the Larva**: The specific name for the larva of Petromyzon is "ammocete." This is a well-known term in biological studies related to the life cycle of lampreys.

5. **Consider Other Options**: The question provides several options: trochophore, toneria, tadpole, and ammocete. By process of elimination and knowledge of the life cycle, we can confirm that "ammocete" is the correct answer.

6. **Conclusion**: Therefore, the name of the larva of Petromyzon is **ammocete**.