What is a stickleback in a food chain?

A stickleback is a small fish that typically occupies freshwater and coastal marine environments. In a food chain, it serves as both a predator and prey; it feeds on small invertebrates and zooplankton, while being a food source for larger fish, birds, and mammals. Its role helps to maintain the balance of aquatic ecosystems by transferring energy from primary producers to higher trophic levels.