The smallest nematocysts in hydra are

Options

A. volvents
B. penetrants
C. glutinants
D. all of same size

Answer

### Step-by-Step Solution:

1. **Understanding Nematocysts**: Nematocysts are specialized cells found in members of the phylum Cnidaria, such as hydra. They contain a coiled thread-like structure that can be ejected to deliver venom, primarily used for defense and capturing prey.

2. **Identifying Types of Nematocysts**: In hydra, there are different types of nematocysts, including:
- **Volvents (Desmonem)**: These are the smallest nematocysts, measuring about 9 microns in size.
- **Penitrens**: These are the largest nematocysts, measuring about 16 microns.
- **Glutinens**: These are intermediate in size, measuring around 14 microns.

3. **Determining the Smallest Nematocyst**: Among the types mentioned, Volvents are identified as the smallest nematocysts in hydra, with a size of 9 microns.

4. **Conclusion**: The smallest nematocysts in hydra are Volvents.

### Final Answer:
The smallest nematocysts in hydra are Volvents.

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