The opercle of L. peltastes tends to be steeply angled and stout, while those on L. megalotis are straighter and longer in comparison.

[4] Unlike the other four subspecies, L. m. peltastes was elevated to species without formal justification decades after its description.

[6] Northern sunfish inhabit the northernmost portions of North America, such as the Saint Lawrence River and Great Lakes basins, as well as Hudson Bay, the upper Mississippi River, and portions of Ontario, Canada.

[2] The simplest way to determine whether a longear sunfish is L. peltastes or L. megalotis is by range, although there is substantial overlap and introgression between these two species.

[8] Northern sunfish are not considered a gamefish; however, population declines have occurred across much of its range over the last century.

[11][12] Populations appear stable in Michigan, Illinois, and Ohio but this sunfish is presumed extirpated in Iowa and Pennsylvania.