Answer: Prey fish
Step-by-step explanation:
Lionfish and Nassau grouper compete for prey fish as a biotic factor. As lionfish populations increase, they may prey more heavily on the shared prey, causing a decrease in the population of prey fish. This decrease in prey fish could lead to a decrease in the population of Nassau grouper, which may struggle to find enough food to survive and reproduce. This can result in a decline in the Nassau grouper population, which may have negative impacts on the ecosystem as a whole.