What are four basic traits of the arthropods

1.they have exoskeleton(they are invertebrate their body does not have internal bones for support)
2. segmented bodies- Arthropods have bodies that are internally and externally segmented.
3. Circulatory System-(An arthropod has an open circulatory system. This means instead of a closed circulatory system of interconnected veins and capillaries, an arthropod’s blood is pumped through open spaces called sinuses in order to reach tissues

4. They're Bilateral symmetry( can be divided into two mirror images)

That is true! many fish species traveled to the u.s. because of it.