Aquatic amphibians are ammonotelic in

Options

A. adult stage
B. larval stage
C. immature stage
D. both A and B

Answer

**Step-by-Step Solution:**

1. **Understanding the Life Stages of Amphibians:**
- Amphibians undergo two distinct life stages: the larval stage and the adult stage.
- The larval stage is typically aquatic and resembles a tadpole, similar to fish, while the adult stage is usually terrestrial and has limbs for movement and lungs for respiration.

2. **Waste Excretion in Amphibians:**
- Amphibians have a specialized organ called the kidney that plays a crucial role in waste removal.
- The waste products excreted by amphibians can vary depending on their life stage.

3. **Ammonotelism in Larval Stage:**
- In the larval stage (tadpole), amphibians are ammonotelic, meaning they excrete waste primarily in the form of ammonia. This is efficient in aquatic environments where ammonia can be easily diluted in water.

4. **Ureotelism in Adult Stage:**
- In contrast, the adult stage is more terrestrial, and amphibians excrete waste mainly in the form of urea, a process known as ureotelism. This is more suitable for land-dwelling organisms as urea is less toxic and conserves water.

5. **Conclusion:**
- Since aquatic amphibians (in their larval stage) excrete ammonia, and both larval and immature stages are aquatic, the correct answer to the question is "both A and B" (larval stage and immature stage).

**Final Answer:**
Aquatic amphibians are ammonotelic in both the larval stage and immature stage.

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