Final answer:
The alligator hunting small mammals for food represents a predation interaction in the wetlands ecosystem. Predation involves a predator consuming its prey, which is vital for ecosystem balance.
Step-by-step explanation:
In the scenario described where an alligator hunts down small mammals for food in a wetlands ecosystem, the species interaction is an example of predation. Predation is a biological interaction where one organism, the predator, hunts and consumes another organism, the prey. The alligator, acting as the predator, lowers the fitness of the small mammals, which are the prey, by killing them and eating them. This interaction is crucial for maintaining the balance of organisms within the ecosystem.