What did Garza and Robles observe about sea stars after heavy rains?

• A. They stayed at lower levels at night after heavy rains.
• B. They moved to higher levels at night after heavy rains.
• C. They showed no change in vertical position after heavy rains.
• D. Sea stars were attracted to the surface during the day after heavy rains.

Answer: (A)

When organisms respond to changing environmental conditions, their behavior often includes shifting where they position themselves in the water column. Garza and Robles’ observation shows sea stars move to deeper, lower levels at night after heavy rains. This downward shift suggests they’re seeking more stable conditions: deeper water is less influenced by surface runoff, turbidity, and salinity changes caused by the rain, and the cooler, darker environment at night can also be less stressful for them. In short, the sea stars adjust their vertical position to maintain favorable habitat conditions after rain, rather than staying near the surface or moving upward.