There is no capillary system in case of most of the invertebrates except

Options

A. Crustaceans
B. Cephalopods
C. Insects
D. Gastropods

Answer

To solve the question "There is no capillary system in case of most of the invertebrates except," we will analyze the options provided and understand the circulatory systems of the mentioned invertebrates.

### Step-by-Step Solution:

1. **Understanding Capillary System**:
- A capillary system refers to a network of tiny blood vessels (capillaries) that connect arteries and veins. In organisms with a closed circulatory system, blood is contained within vessels, allowing for efficient transport of nutrients and gases.

2. **Identifying the Options**:
- The options provided are:
- Crustaceans
- Cephalopods
- Insects
- Gastropods

3. **Analyzing Crustaceans**:
- Crustaceans (e.g., crabs, lobsters) possess an open circulatory system. In this system, blood (hemolymph) is not confined to vessels but flows freely in cavities called sinuses. Therefore, crustaceans do not have a capillary system.

4. **Analyzing Cephalopods**:
- Cephalopods (e.g., octopuses, squids) have a closed circulatory system. They possess a heart that pumps blood through vessels, including capillaries, allowing for efficient oxygen transport. Thus, cephalopods do have a capillary system.

5. **Analyzing Insects**:
- Insects also have an open circulatory system where hemolymph flows through sinuses and bathes the tissues directly. They do not have a capillary system.

6. **Analyzing Gastropods**:
- Gastropods (e.g., snails, slugs) similarly have an open circulatory system. Their blood (hemolymph) flows through sinuses, and they do not possess a capillary system.

7. **Conclusion**:
- Based on the analysis, the only group among the options that possesses a capillary system is cephalopods. Therefore, the correct answer to the question is **cephalopods**.

### Final Answer:
**Cephalopods**