Which of the following pairs of species are most likely to occupy the same ecological niche as the lionfish (Pterois) in a coral reef ecosystem?

• A. Holothuria (sea cucumber) and Diadema (sea urchin)
• B. Acanthurus (surgeonfish) and Amphiprion (clownfish)
• C. Chelonia mydas (green sea turtle) and Hippocampus (seahorse)
• D. Scorpaena (scorpionfish) and Epinephelus (grouper)

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the concept of an ecological niche. An ecological niche refers to the role and position a species has in its environment, including its interactions with other organisms, its diet, and its habitat. Species occupying the same niche often have similar feeding habits, behaviors, and environmental requirements.
2. Step 2: Analyze the ecological niche of the lionfish (Pterois). Lionfish are predatory fish that inhabit coral reef ecosystems. They primarily feed on smaller fish and invertebrates, and they are known for their ambush hunting strategy.
3. Step 3: Compare the ecological niches of the given species pairs to the lionfish. For example, Holothuria (sea cucumber) and Diadema (sea urchin) are detritivores and grazers, which do not align with the predatory niche of the lionfish. Similarly, Acanthurus (surgeonfish) and Amphiprion (clownfish) are herbivores and omnivores, respectively, and do not share the lionfish's predatory behavior.
4. Step 4: Focus on Scorpaena (scorpionfish) and Epinephelus (grouper). Both of these species are predatory fish that inhabit coral reef ecosystems. Scorpionfish, like lionfish, use ambush hunting strategies, and groupers are also predators that feed on smaller fish and invertebrates. Their ecological niches closely align with that of the lionfish.
5. Step 5: Conclude that Scorpaena (scorpionfish) and Epinephelus (grouper) are the most likely to occupy the same ecological niche as the lionfish, based on their similar predatory behaviors and habitat preferences.