Which type of blood vascular system is found in cockroach?

Explanation

### Step-by-Step Solution:

1. **Identify the Phylum**: The cockroach belongs to the phylum Arthropoda. This is the first step in understanding its circulatory system.

2. **Understand the Type of Circulatory System**: In arthropods, including cockroaches, the type of circulatory system present is known as an open circulatory system. This is a key characteristic of this group.

3. **Define Open Circulatory System**: An open circulatory system means that the blood is not confined to blood vessels as it is in vertebrates. Instead, it flows freely through cavities in the body.

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