Redbreast Sunfish - Ecology

Ecology

“late studies indicated that temperature and body size influence food consumption of fishes. The function f(T)=V^x e(X(1-V)) helps better understand fish diets. The function first increases nearly exponentially with increasing temperature, then slowly increases to the maximum value of 1.0 at a temperature of T, then declines steeply at higher temperatures.”( Cooke 471) Thus proving that sunfish are opportunistic feeders, but also that temperature plays a large role in how often they feed. As temperature increases feeding occurrences increase. Sunfish depending on location feed just enough to keep their metabolic rate constant. “Metabolic rate of fish is a measure of the rate of energy expenditure and is commonly estimated by measuring rate often expressed in units of oxygen consumed per unit weight of fish per unit time”(Cooke 474). Redbreast sunfish list main food consumption as immature aquatic insects. Mayflies, Small fish, and dragonfly larvae consist of the majority of the sunfish’s diet according to a study measuring percent volume of the sunfish's stomach content. Being an opportunistic feeder, the Redbreast Sunfish competes with other sunfish and larger predatory fish that prey on the same food that they do. Larger piscivorous fish are the main predators of smaller Redbreast Sunfish. Micropterus species are a major threat to sunfish because of the shared habitat and the large availability of the sunfish. As the sunfish increases in size its list of predators starts to decrease due to digestibility. The sunfish prefers structure around banks and overhanging branches that provide shade to provide food and protection. Lepomis Auritus survives best in water with current and a pH between 7.0-7.5. Lack of current or too acidic or basic water can dramatically affect the sunfish’s survival rate. Human influence on abiotic and biotic factors such as sunlight and predator numbers can have a major influence on sunfish. Factors such as clearing debris bank cover can increase amount of sunlight into the water and increase water temperature and decrease defense habitats, also decreasing the number of predators by eating larger predatory fish will increase the survival rate of the Redbreast Sunfish.