Which of the following is not the character of Ctenophora?

Options

A. Exclusively marine
B. Body bears eight external rows of ciliated comb plates
C. Digestion is only intracellular
D. Fertilization is external with indirect development

Answer

To determine which of the following is not a character of Ctenophora, we need to analyze the characteristics of this phylum based on the provided information.

### Step-by-Step Solution:

1. **Understanding Ctenophora**:
- Ctenophora, commonly known as sea walnuts or corn jellies, are a phylum under the kingdom Animalia.

2. **Identifying Key Characteristics**:
- **Marine Organisms**: Ctenophores are exclusively marine, meaning they live in oceanic environments.
- **Radial Symmetry**: They exhibit radial symmetry, which means their body can be divided into similar halves around a central axis.
- **Diploblastic Organization**: Ctenophores have a diploblastic body organization, consisting of two germ layers: ectoderm and endoderm.
- **Ciliated Plates**: They possess eight rows of ciliated plates (comb rows) that aid in locomotion.
- **Bioluminescence**: Some species exhibit bioluminescence, allowing them to emit light.
- **Digestive System**: The digestive system includes a mouth, pharynx, stomach, and anal pores, indicating that digestion is not solely intracellular but also extracellular in some cases.
- **Fertilization**: Fertilization is external, and development is indirect, involving a larval stage known as the cydippid larva.

3. **Evaluating the Options**:
- **Option 1**: They are exclusively marine. (Correct)
- **Option 2**: They have 8 external rows of ciliated plates. (Correct)
- **Option 3**: Digestion is only intracellular. (Incorrect)
- **Option 4**: Fertilization is external with indirect development. (Correct)

4. **Conclusion**:
- The characteristic that is **not true** for Ctenophora is **Option 3: Digestion is only intracellular**. This is incorrect because Ctenophores have both intracellular and extracellular digestion.

### Final Answer:
The characteristic that is not true for Ctenophora is **Option 3: Digestion is only intracellular**.

---