The bluegill (Lepomis macrochirus) is a species of freshwater fish sometimes referred to as bream, brim, or copper nose. It is a member of the sunfish family Centrarchidae of the order Perciformes. It is native to North America and lives in streams, rivers, lakes, and ponds. It is commonly found east of the Rockies. It usually hides around, and inside, old tree stumps and other underwater structures. It can live in either deep or very shallow water, and will often move back and forth, depending on the time of day or season. Bluegills also like to find shelter among water plants and in the shade of trees along banks.
Bluegills can grow up to 12 inches (30 cm) long and about 4 1⁄2 pounds. They have very distinctive coloring, with deep blue and purple on the face and gill cover, dark olive-colored bands down the side, and a fiery orange to yellow belly. The fish are omnivores and will eat anything they can fit in their mouth. They mostly feed on small aquatic insects and fish. The fish play a key role in the food chain, and are prey for muskies, walleye, trout, bass, herons, kingfishers, snapping turtles, and otters.
The bluegill is noted for the black spot that it has on the posterior edge of the gills and base of the dorsal fin. The sides of its head and chin are a dark shade of blue. It usually contains 5–9 vertical bars on the sides of its body, but these stripes are not always distinct. It has a yellowish breast and abdomen, with the breast of the breeding male being a bright orange. The bluegill has three anal spines, ten to 12 anal fin rays, six to 13 dorsal fin spines, 11 to 12 dorsal rays, and 12 to 13 pectoral rays. They are characterized by their deep, flattened bodies. They have a terminal mouth, ctenoid scales, and a lateral line that is arched upward anteriorly. The bluegill typically ranges in size from about four to 12 inches, and reaches a maximum size just over 16 inches. The largest bluegill ever caught was four pounds, 12 ounces in 1950.
The bluegill is most closely related to the orangespotted sunfish and the redear sunfish, but different in a distinct spot at or near the base of the soft dorsal fin.
Distribution and habitat
The bluegill occurs naturally in the United States east of the Rocky Mountains from coastal Virginia to Florida, west to Texas and northern Mexico, and north to western Minnesota and western New York. Today they have been introduced to almost everywhere else in North America, and have also been introduced into Europe, South Africa, Zimbabwe, Asia, South America, and Oceania. Bluegills have also been found in the Chesapeake Bay, indicating they can tolerate up to 1.8% salinity.
In some locations where they have been transplanted, they are considered pests: trade in the species is prohibited in Germany and Japan. In the case of Japan, bluegills were presented to the then-crown prince, Akihito in 1960 as a gift by Richard J. Daley, mayor of Chicago. The prince, in turn, donated the fish to fishery research agencies in Japan from which they escaped, becoming an invasive species which has wreaked havoc with native species, specifically in Lake Biwa in Shiga Prefecture. The emperor has since apologized.
Bluegill live in the shallow waters of many lakes and ponds, along with slow-moving areas of streams and small rivers. They prefer water with many aquatic plants, and hide within fallen logs or water weeds. They can often be found around weed beds, where they search for food or spawn. In the summer, adults move to deep, open water where they suspend just below the surface and feed on plankton and other aquatic creatures. Bluegill try to spend most of their time in water from 60 to 80 °F (16 to 27 °C), and tend to have a home range of about 320 square feet (30 m2) during nonreproductive months. They enjoy heat, but do not like direct sunlight – they typically live in deeper water, but will linger near the water surface in the morning to stay warm. Bluegill are usually found in schools of 10 to 20 fish, and these schools will often include other panfish, such as crappie, pumpkinseeds, and smallmouth bass.
Bluegills have the ability to travel and change directions at high speeds by means of synchronized fin movements. They use notched caudal fins, soft dorsal fins, body undulations, and pectoral fins to move forward. Having a notched caudal fin allows them to accelerate quickly. The speed of their forward motion depends on the strength of which they abduct or adduct fins. The flat, slender body of the bluegill lowers water resistance and allows the bluegills to cut effectively through water. The large, flexible pectoral fins allow the fish to decelerate quickly. This superior maneuverability allows the bluegill to forage and escape predators very successfully. Bluegills have a lateral line system, as well as inner ears, that act as receptors for vibration and pressure changes. However, bluegills rely heavily on sight to feed, especially in their foraging. Optimal vision occurs in the daylight hours. The mouth of the bluegill is very small and requires the use of the pharynx to suck in prey.
The rock bass (Ambloplites rupestris), also known as the rock perch, goggle-eye, red eye, is a fresh water fish native to east-central North America. This red eyed creature is a species of freshwater fish in the sunfish family (Centrarchidae) of order Perciformes and can be distinguished from other similar species by the six spines in the anal fin (other sunfish have only three anal fin spines).
Rock bass are native to the St Lawrence River and Great Lakes system, the upper and middle Mississippi River basin in North America from Québec to Saskatchewan in the north down to Missouri and Arkansas, south to the Savannah River, and throughout the eastern U.S. from New York through Kentucky and Tennessee to the northern portions of Alabama and Georgia and Florida in the south. The rock bass has also been found in the Nueces River system in Texas.
They are similar in appearance to smallmouth bass, but are usually quite a bit smaller. Identifying characteristics of rock bass are their two dorsal fins that have spinous and soft-rayed united portions, a large mouth, six anal spines, red eyes; rows of dark dots on their sides. The mouth of a Rock bass is located in the terminal position, below the snout, with small conical teeth to eat prey. The average rock bass is between 6 and 10 in, and they rarely weigh over a pound. Few rock bass live beyond 10 to 12 years. A. rupestris, the largest and most common of the Ambloplites species, has reached a maximum recorded length of 43 cm (17 in), and a maximum recorded weight of 1.4 kg (3.0 lb). It can live as long as 10 years. These fish have body coloring from golden brown to olive with a white to silver colored belly and have the ability to rapidly change their color to match their surroundings. This chameleon-like trait allows them to thrive throughout their wide range.
Rock bass prefer clear, rocky, and vegetated stream pools and lake margins. Rocky banks of northeastern lakes and reservoirs are a common habitat for rock bass. Their favorite habitat contains some vegetation with rocky bottoms and cool to warm waters. Rock bass species are usually found near rocky shorelines. They can be surprisingly unflustered by the presence of human activity, living under lakeside docks and near swimming areas. Rock bass are frequently seen in groups, particularly near other sunfish.