Redbreast sunfish

Redbreast Sunfish
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Centrarchidae
Genus:	Lepomis
Species:	L. auritus
Binomial name
Lepomis auritus (Linnaeus, 1758)

The redbreast sunfish (Lepomis auritus) is a species of freshwater fish in the sunfish family (family Centrarchidae) of order Perciformes. The type species of its genus, it is native to the river systems of eastern Canada and the United States.

The redbreast sunfish reaches a maximum recorded length of about 30 cm (12 in), with a maximum recorded weight of 790 g (1.7 lb).

The species prefers vegetated and rocky pools and lake margins for its habitat. Its diet can include insects, snails, and other small invertebrates.

A panfish popular with anglers, the redbreast sunfish is also kept as an aquarium fish by hobbyists.

Redbreast sunfish are usually caught with live bait such as nightcrawlers, crickets, grasshoppers, waxworms, or mealworms. They can also be caught using small lures or flies. Most anglers use light spinning tackle to catch redbreast sunfish.

As is typical for the sunfishes, the female redbreast sunfish lays her eggs (approximately 1000) in a substrate depression built by the male. The male guards the eggs and fry.

L. auritus has been transplanted to and become established in Germany, Italy, Mexico, and Puerto Rico, sometimes with a harmful effect on native species.

The specific epithet, auritus, derives from the Latin auritus (big-eared).

Typical Redbreast Sunfish from the Tallapoosa River, Alabama (Released)

Abstract

This is a management plan for the Redbreast sunfish (Lepomis Auritus). The species native range is condensed to Eastern North America. Starting in Canada and drifting all the way south to the rivers emptying into the Atlantic Ocean. The species has been introduced as far west as Texas. This fish primarily feeds on small insect larva, small crayfish, and sometimes small fish. Lepomis auritus thrives in streams and rivers with shelter and structure usually around banks where the water pH doesn’t stray far from 7.0-7.5. The Redbreast Sunfish is a spring spawner in sand-gravel substrate depending on location, or when water temperatures reach 16-26 degrees Celsius. Average clutch size for the sunfish is around 2000 depending on the age of the female. The average length of the sunfish is around 11 cm with a record 30.5 cm. The record weight for the fish is 1.75 pounds. There are very few management plans set for Lepomis Auritus. There is rarely a limit on the number of fish that can be harvested due to their large numbers and high reproductive capabilities. However, if a particular occurrence arises where the sunfish needs to be more intensely managed a set fishing limit per day could be useful. Also, another factor that could greatly help this sunfish to survive would be habitat construction. Limits on fish are crucial to the survival success of sunfish. If a particular area is subject to over fishing or habitat destruction managements plans should be put into effect to preserve the abundance of this great sunfish.

Geographic Distribution

Lepomis Auritus tends to be more of a cool river species, but also inhabits fresh water lakes and streams in Eastern North America ranging from Canada down the Atlantic slope to the Southeastern United States around central Florida. The sunfish species has been introduced as far west as Louisiana and Western Texas. Native range of the sunfish is a relatively large area with the species new introduction points not straying far from its native habitats. Eastern North America provides the Redbreast Sunfish with habitat and forage necessary to survive and thrive in its diverse native habitat.

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.

Life History

The Redbreast Sunfish is a fall spawner in sand-gravel substrate depending on location, or when water temperature reaches 16-26 degrees Celsius. According to Stanley Sharp, “The mature male generally builds a nest in shallow water or may simply use the abandoned nest of another Centrarchid. The female eventually enters the nest, releases her adhesive eggs, and then leaves. The male remains to guard and fan the eggs and possibly even to guard the young for a brief period. The male and female will then move out of the shallow water after spawning and into deeper water. A male sunfish will breed with more than one female, just as female sunfish will breed with more than on male. Average clutch size for the sunfish is around 2000 depending on the age of the female. Mature ova are around 1.1 mm in diameter. Reproductive maturity is reached the second year of life. Lepomis Auritus have been known to have a max lifespan of around seven years for primarily males. Currently humans do not play a large role in influencing life history due to large populations and secluded areas.

Current Management

Currently the Redbreast Sunfish is not on the federally or state listed endangered or threatened species list. The species is alive and well and thriving in its naturally occurring environment. However, just because this species is not threatened now doesn’t mean the situation cannot occur. There are state management practices ready to be implemented in the case that the species could encounter becoming endangered. A few things that could be done to limit human impact in the case of an emergency would be increased habitat creation, fishing limits or complete halt of harvest, and decrease competitive invasive species that may be out competing the sunfish species. In the case that the Redbreast Sunfish encountered endangerment; management practices are ready and proven to be effective. If the fish were to become endangered it would most likely be due to over fishing or pollution. Both of these factors can be avoided with guidelines and regulations. State agencies such as TWRA conduct fish counting exercises where the use electro fishing to gather the best understanding of fish species populations. This exercise which is usually done in shallow water, where redbreast sunfish thrive, is the best way to keep up with management practices for this particular species. There are not currently any conservation easements set up for the redbreast sunfish because of its excellent success rate.

Management Recommendations

The Redbreast Sunfish is not an endangered species. Therefore, the species does not have to be managed as intensely as others. Nevertheless, this species still requires some attention to make sure the species receives the proper attention. One way to monitor and measure the species numbers is electro fishing. By shocking in shallow water where these fish naturally occur, this exercise could get an accurate estimate of the fish in a certain area. By conducting this experiment on every major reservoir and river in the native range of the redbreast sunfish numbers can be recorded and tallied to understand if there are any management practices needed. While numbers are still high with the sunfish and not endangered this experiment could be conducted just once to twice a year in randomly picked shallow water areas. When numbers are seen to be decreasing testing occurrences should increase to better understand what the species is experiencing to cause the decrease in population size. If the species ever becomes threatened or endangered areas should be set aside where they are intensely managed for sunfish species. Also if the population numbers are being drastically decreased due to invasive species, then the native species should be protected at all costs.

References

• FishBase: Lepomis auritus
• ITIS: Lepomis auritus
• Ellis, Jack (1993). The Sunfishes-A Fly Fishing Journey of Discovery. Bennington, VT: Abenaki Publishers, Inc.. ISBN 0-936644-17-6. 

• Rice, F. Philip (1964). America's Favorite Fishing-A Complete Guide to Angling for Panfish. New York: Harper Row. 

• Rice, F. Philip (1984). Panfishing. New York: Stackpole Books. ISBN 0-943822-25-4. 

• Malo, John (1981). Fly-Fishing for Panfish. Minneapolis, Minnesota: Dillon Press Inc.. ISBN 0875182089. 

• Cooke, Steven, and David P. Philipp. Centrarchid Fishes: Diversity, Biology, and Conservation. Chichester, U.K.: Wiley-Blackwell, 2009. Print.

• Dewoody, Andrew, Dean Fletcher, and David Wilkins. "Molecular Genetic Dissection of Spawning, Parentage, and Reproductive Tactics in a Population of Redbreast Sunfish, Lepomis Auritus." Evolution 52.6 (1998): 1802-810. Print.

• Nadig, Susan G. Evaluating Potential Alteration of Genetic Diversity in Populations of Redbreast Sunfish (Lepomis Auritus) Using RAPD ASSAY. Thesis. The University of Tennessee Knoxville, 1996. Print.

• Sharp, Stanley K. Serum Levels of 17B-Estradiol and Testosterone as Indicators of Environmental Stress in Redbreast Sunfish, Lepomis Auritus. Thesis. The University of Tennessee, Knoxville, 1994. Print.

• Shepard, Kenneth L. Use of Standard Metabolic Rate as an Indicator of Environmental Stress in Redbreast Sunfish, Lepomis Auritus. Thesis. The University of Tennessee Knoxville, 1988. Print.