Final answer:
Carnivorous sea stars (C), also known as starfish, are common in the middle tide zone along rocky shores and can withstand the harsh, fluctuating conditions of the intertidal zone.
Step-by-step explanation:
The student asked which organisms are common in the middle tide zone along rocky shores. The middle tide zone, also known as the intertidal zone, is characterized by organisms that can withstand periodic exposure to air and sunlight at low tide and submersion at high tide.
The environment in this zone is harsh due to the fluctuating water levels, waves, and potential for desiccation.
Examining the options given:
- sea anemones (A)
- hermit crabs (B)
- carnivorous sea stars (C)
- corals (D)
- goose-necked barnacles (E)
- giant brown bladder kelp - Macrocystis (F)
Sea anemones (Anthozoa) firmly attach themselves to rocks and can handle the changing tides. Hermit crabs are mobile scavengers often seen in mid to lower tidal zones. Carnivorous sea stars, or starfish, are frequently found in the intertidal zone, where they prey on mussels and other invertebrates.
Corals typically reside in warm, shallow, and more stable water conditions and are uncommon in the intertidal zone. Goose-necked barnacles are filter-feeding crustaceans that attach to the rocks in the intertidal zone. Giant brown bladder kelp, though found in coastal areas, generally prefers the subtidal zone where it remains submerged.
In Kachemak Bay, Alaska, for example, sea stars, sea urchins, and mussel shells are commonly found, indicating that the area has organisms adapted to the intertidal conditions. Therefore, the correct answer to the student's question is carnivorous sea stars (C), which are commonly found in the middle tide zone along rocky shores.