In Crustacea, respiration occurs through

Options

A. Tracheae
B. Gills
C. Book lungs
D. Book gills

Answer

**Step-by-Step Solution:**

1. **Identify the Organism Group**: Crustacea is a class within the phylum Arthropoda that includes crabs, lobsters, shrimp, and other similar aquatic organisms.

2. **Understand the Respiration Process**: In Crustacea, respiration is primarily concerned with how these organisms exchange gases with their environment.

3. **Evaluate the Options**:
- **Option 1: Trachea** - This is a respiratory system found in insects, not in Crustacea.
- **Option 2: Gills** - This is a common respiratory structure in aquatic organisms, including many crustaceans.
- **Option 3: Book lungs** - These are found in arachnids (like spiders) and are not present in Crustacea.
- **Option 4: Book gills** - This is a structure found in some primitive crustaceans, but it is less common than gills.

4. **Conclusion**: The primary mode of respiration in Crustacea is through gills, which are adapted for extracting oxygen from water.

5. **Final Answer**: In Crustacea, respiration occurs through **gills**.

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