Form and Function

Fishes in the Class Actinopterygii have gills that covered with bony operculum and (Hickerman, 2011).  As the common name for Actinopterygii “Ray-Finned” suggests, these fish contains rays, flexible support for the fins (Wisconsin Fish).

The Lepomis gulosus also contains a swim bladder. The swim bladder is a sac with gas and air. It aids with buoyancy and respiration. Species of Lepomis also have small sensory pores that are anterior to the nostril (Wisconsin Fish).
A study by Timothy E. Higham found evidence to support the hypothesis that there is selection pressure on fish, such as the Warmouth Sunfish, with large mouths to have smaller pectoral fins. Higham explains that those with smaller pectoral fins not only have a stronger suction for feeding, but can swim faster.

Adaptations to Environment

Species in Lepomis are known as visual feeders; they are attracted to movement and will eat just about anything.  They can learn to eat what is available in their specific environment (Miller 1963).  As explained by Helen Miller, members of the Lepomis living in an aquaria even adapted to eating non-living food.