In crustaceans, repiration take place by

Options

A. Gills
B. Book lungs
C. Ctenidia
D. Trachea

Answer

**Step-by-Step Solution:**

1. **Identify the Group**: Recognize that crustaceans belong to the phylum Arthropoda. This group is characterized by jointed appendages.

2. **Understand Respiration in Crustaceans**: Crustaceans are primarily aquatic organisms. Their respiratory system is adapted to their environment.

3. **Identify the Respiratory Structures**: Crustaceans utilize gills for respiration. Gills are specialized organs that allow for the exchange of gases (oxygen and carbon dioxide) in water.

4. **Differentiate from Other Structures**: While other respiratory structures like book gills, book lungs, and trachea exist in different groups of arthropods, crustaceans specifically use gills.

5. **Conclude the Answer**: Based on the above points, the correct answer to the question is that respiration in crustaceans takes place by gills.

**Final Answer**: Gills

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