Which organism would live in the intertidal zone as it can survive both in water and outside of the ocean?

• A. Estuary
• B. Shark
• C. Starfish
• D. Angler Fish

Answer: (C)

The intertidal zone blends aquatic and terrestrial challenges, so the best-fit organism is one that can endure being submerged and then exposed to air. A starfish on rocky shores exemplifies this, because many sea stars inhabit this zone and have adaptations to stay moist and respire while out of the water during low tide. Their water vascular system and tube feet let them cling and feed when submerged, while dermal tissues and moist surfaces allow gas exchange during brief exposure to air. In contrast, an estuary is a habitat, not an organism; sharks and anglerfish are adapted to living in water and would not tolerate the dry conditions of the shoreline for significant periods.