Longear sunfish

Distribution

Longear sunfish are found in North America, primarily in the Mississippi and Great Lakes regions. Longear sunfish are mostly found in freshwater areas west of the Appalachian Mountains. Some Lepomis populations are located as far north and west as southern Quebec and Minnesota. The species has also been spotted in places as far south and west as central Mexico and New Mexico. The native territory of the longear sunfish is exclusive to the North American Continent. It is found primarily in the Mississippi and Great Lakes watersheds. The longear sunfish is restricted in range to certain large streams. This species can be located in the St. Lawrence and Great Lakes, Hudson Bay, and Mississippi River. The species has been introduced to stream ecosystems along the eastern coast of the United States. The distribution of the longear sunfish throughout North America has not been affected since the species has been followed. This may be due to the species' ability to travel throughout large bodies of water, thus avoiding dams and man-made interferences along smaller streams. They are also able to occupy different body of water types, thus making them more resilient to a decrease in their range distribution.

Habitat

Longear sunfish feed more extensively near the surface of the water than other sunfish species. ''Lepomis megalotis'' is mostly a carnivorous fish that eats aquatic insects, small crustaceans, fish eggs, young bass, and even young sunfish. They have also been observed eating dragonflies and other insects which travel over the surface of the water. Other observed prey have been detritus, gnat larvae, snails, day flies and leeches. The diets of adult longear are composed of terrestrial insects , fish , aquatic insects , and fish eggs . Largemouth bass, smallmouth bass and wading birds are all natural predators to the longear sunfish. Smaller species of longear can be preyed on by larger sunfish populations. Sunfish are an important link in the food chain. They act as both predator and prey within their ecosystems. Other sunfish species and larger predatory fishes compete with the longear for food and resources.

Longear sunfish, like additional members of the family Centrarchidae, are freshwater fish. They prefer streams with a firm clay bottom or gravel with clear waters and they typically stay nearby aquatic vegetation. Although more abundant near the sources of streams, sunfish can be found in water sources of all sizes and are also found in lakes. Longear sunfish usually reside in shallower, warmer headwaters of streams with a steady flow. They spend most of their time near aquatic vegetation, or other forms of cover such as roots, brush piles, and undercut banks. This allows for them to hide from potential predators. Sunfish species are especially intolerant to turbid waters. Human-induced changes to stream ecosystems could potentially disrupt the sunfish distribution. Destruction of aquatic vegetation from human runoff could destroy aquatic plants that are essential for the protection and cover of this species against predators. Chemical runoff into large rivers could also disturb the pH of the longear's natural ecosystem.

Evolution

Longear sunfish tend to breed during the late spring and early summer . During breeding seasons they are generally found in shallower, warmer waters near the sources of streams which have pools. Like most other members of ''Lepomis'', longear sunfish are colonial nesters. Male longear sunfish build the nests without assistance from the females. Preferred substrate for nesting is gravel, if available, but they will build in sand or hard mud if necessary. A male longear will guard the nest territory during all phases of reproduction. The clutch size can be anywhere from 140 to 2800 eggs per reproductive cycle. After hatching, it only takes the longear sunfish 2–3 years to reach sexual maturity. The average life-span of the ''Lepomis megalotis'' in the wild is usually 4–6 years, but there have been cases where individuals have lived up to 9 years. Longear sunfish cannot tolerate cloudy or mucky water. Throughout the 20th century their populations have been reduced in areas where their native streams have suffered increased cloudiness. This cloudiness could potentially be a result of human induced erosion for agriculture or industry purposes. Increased human disturbance along streams and rivers could continue to increase the reduction of longear populations due to the murkiness of rivers and streams.