Animal showing thigmotaxis is
(a) Ascaris
(b) Taenia
(c) Fungi
(d) Hydra

Options

A. Ascauis
B. Taenia
C. Fungia
D. Hydra.

Answer

To solve the question "Animal showing thigmotaxis is," we will analyze the options provided and understand the concept of thigmotaxis.

### Step-by-Step Solution:

1. **Understand the term "thigmotaxis":**
- Thigmotaxis refers to the movement or response of an organism in reaction to touch or physical contact stimuli. It is a type of taxis, which is a directional movement toward or away from a stimulus.

2. **Analyze the options:**
- **(a) Ascaris:** Ascaris is a type of parasitic roundworm. It does not exhibit thigmotaxis as it primarily moves through the host's body and does not respond to touch in the same way as other organisms.
- **(b) Taenia:** Taenia is a genus of tapeworms, which are also parasitic. Similar to Ascaris, Taenia does not show thigmotaxis.
- **(c) Fungi:** Fungi are not animals; they belong to a separate kingdom. They do not exhibit thigmotaxis as they do not have the capability for movement in response to touch.
- **(d) Hydra:** Hydra is a simple aquatic organism that belongs to the phylum Cnidaria. It has a nerve net that allows it to respond to stimuli, including touch. Hydra exhibits thigmotaxis by moving or reacting when it comes into contact with objects or food.

3. **Conclusion:**
- Based on the analysis, the organism that shows thigmotaxis is **(d) Hydra**.

### Final Answer:
The correct answer is **(d) Hydra**.

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