How does the number of spines in the central disk compare to the number of spines in the arm?

In many species of sea stars, the central disk typically has fewer spines compared to the arms. The arms are often equipped with a greater number of spines, which serve various functions such as protection and locomotion. This distribution allows for a more effective defense mechanism while maintaining flexibility and mobility in the arms. Ultimately, the specific ratio can vary depending on the species and its ecological adaptations.