Most of the Lepomis genus spawns in colonies along
shallow water that is a specific temperature (Gerald 1971). The
species gulosus, however, do not spawn in
colonies. Males of the warmouth nest around the months of May
to June (Ohio DNR). The average temperature male warmouths
begin to spawn is approximately 21.1° C (EOL). Before a female is
ready, the temperature needs to be around 24.5° C (Fish
Channel).
Nests are primarily built close to rocks or vegetation (Ohio DNR).
The gulosus can mate with different species of the
Lepomis genus (Avise 1977).
Courtship
Most fish in the Lepomis genus have a unique frequency
pitch and characters for mating calls when circling females for
courtship (Gerald 1971).
Physical Traits during Spawning
Male gulosus undergoes several different physical
characteristics while spawning. Before a nest has been built, the
male will develop bright coloring (Fish
Channel). The eyes also change
color to red. 
After egg fertilization the male defends the
nest and becomes very aggressive (EOL). This aggressive
behavior is much like other species of the Lepomis genus.
The male gulosus opens its mouth and flares its gills to
appear bigger as a way to intimidate other fish. The male defends
any intruders, including other females (Ohio DNR).
Hatching and Maturation
The eggs hatch after approximately 5 day and the males guard the
nest until this time (Fish Channel). Before the young leave, they hide in
sediment to avoid being prey. Gluosus are considered
sexually mature either after a time span of one year or by their
size (EOL).