New York sunfish have a rearward projection on the gill cover called a gill flap. The difference between members of the sunfish and perch families is not as distinct. Sunfish basically are warmwater inhabitants, preferring, but not being restricted to, fertile lakes with moderate water temperatures and abundant aquatic plants near shore. Sunfish are spring spawners, with spawning for some species extending into early summer. Males build nests which are saucer-shaped depressions in the lake or stream bottom.
Males also guard the eggs and newly hatched young.
A few days after they hatch, the young rise out of the nest, at which time the guarding parent leaves them to care for themselves. All sunfish are carnivorous. Larger individuals feed heavily on fish and crayfish.