What type of circulatory system is found in cockroach?

Options

A. Lacunar
B. Closed
C. Peritrophic
D. Fenestrated

Explanation

### Step-by-Step Solution:

1. **Understand the Types of Circulatory Systems**:
- There are primarily two types of circulatory systems: open and closed.
- In an open circulatory system, blood is not confined to blood vessels and flows freely within a body cavity.
- In a closed circulatory system, blood is contained within vessels and is pumped by the heart.

2. **Identify the Options**:
- The options given are: lacunar, closed, peritropic, and fenestrated.
- We need to determine which of these applies to the cockroach.

3. **Eliminate Incorrect Options**:
- **Peritropic**: This term refers to a membrane associated with the digestive system, not a type of circulatory system.
- **Fenestrated**: This refers to a type of blood vessel structure, not a circulatory system type.
- Therefore, we can eliminate both peritropic and fenestrated.

4. **Analyze the Cockroach's Circulatory System**:
- Cockroaches are invertebrates and possess an open type of circulatory system.
- In this system, blood (hemolymph) is pumped into a body cavity known as the hemocoel, where it bathes the organs directly.

5. **Conclude the Type of Circulatory System**:
- Since the cockroach has an open circulatory system, and given that "lacunar" refers to a similar concept of an open system where blood is not confined to vessels, we can conclude that the correct answer is "lacunar".

### Final Answer:
The type of circulatory system found in cockroach is **lacunar** (open type).

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