The redear sunfish (Lepomis Microlophus, also known as the shell-cracker) is a freshwater fish in the Centrarchidae family and is native to the southeastern United States. Since it is a popular sport fish, it has been introduced to bodies of water all over North America. It is known for its diet of mollusks and snails.

Redears are the solution to many problems in and out of the water. Redears have thick pharyngeal teeth (hard, movable plates in its throat) which allow it to crush exoskeletons. It is even capable of opening small clams. The specialization of this species for the deep-water, mollusk-feeding niche allows it to be introduced to lakes without the risk of competition with fish that prefer shallower water or surface-feeding. In recent years, the stocking of redear has found new allies due to the fish's ability to eat quagga mussels, a prominent invasive species.
Redear sunfish are stocked in many small ponds and fish hatcheries to control the spread of certain aquatic parasites. Redear prey upon aquatic snails, which are an important link in the life cycles of certain aquatic parasites.