The bluegill (''Lepomis macrochirus''), sometimes referred to as "bream", "brim", "sunny", or "copper nose" as is common in
Texas, is a
species of
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
n
freshwater fish, native to and commonly found in streams, rivers, lakes, ponds and
wetlands east of the
Rocky Mountains. It is the
type species of the
genus ''
Lepomis'' (true sunfish), from the
family Centrarchidae (sunfishes,
crappie
Crappies () are two species of North American freshwater fish of the genus ''Pomoxis'' in the family Centrarchidae (sunfishes). Both species of crappies are popular game fish among recreational anglers.
Etymology
The genus name ''Pomoxis'' ...
s and
black basses) in the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
Perciformes (
perch-like fish).
Bluegills can grow up to long and about . While their color can vary from population to population, they typically have a 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. They are
omnivorous and will consume anything they can fit in their mouth, but mostly feed on small
aquatic insect
Aquatic insects or water insects live some portion of their life cycle in the water. They feed in the same ways as other insects. Some ''diving'' insects, such as predatory diving beetles, can hunt for food underwater where land-living insects c ...
s and
baitfishes. The fish are important prey for
bass
Bass or Basses may refer to:
Fish
* Bass (fish), various saltwater and freshwater species
Music
* Bass (sound), describing low-frequency sound or one of several instruments in the bass range:
** Bass (instrument), including:
** Acoustic bass gui ...
, other larger
sunfish,
northern pike and
muskellunge,
walleye,
trout,
herons,
kingfishers,
snapping turtles and
otters, and
play a key role within the
food chain of its
freshwater ecosystem.
A popular
panfish among
anglers, bluegill usually hide around and inside old tree stumps in
swamp
A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...
s and other underwater structures (e.g.
snags), and can live in either deep or very shallow water. Bluegills also like to find shelter among
aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that ...
s and in the shade of trees along
banks, and will often move from one cover to another depending on the time of day or season.
Description
The bluegill is noted for the black spot (the "ear") that it has on each side of the posterior edge of the gills and base of the
dorsal fin. The sides of its head and chin are commonly a dark shade of blue. The precise coloration will vary due to the presence of neurally controlled
chromatophores under the skin. The fish usually displays 5–9 vertical bars on the sides of its body immediately after being caught as part of its threat display. It typically 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
The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...
that is arched upward anteriorly.
[Sublette, J. E., M. D. Hatch, and M. Sublette. 1990. University of New Mexico Press, Albuquerque. 393 pp] 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 4 lbs. 12 oz. in 1950.
[Ross, S. T. 2001. ''The Inland Fishes of Mississippi''. University Press of Mississippi, Jackson. 624 pp]
The bluegill is most closely related to the
orangespotted sunfish and the
redear sunfish
The redear sunfish (''Lepomis microlophus''), also known as the shellcracker, Georgia bream, cherry gill, chinquapin, improved bream, rouge ear sunfish and sun perch) is a freshwater fish in the family Centrarchidae and is native to the southeast ...
, 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
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
. Today they have been introduced to almost everywhere else in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, 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.
[Schultz, Ken. ''Ken Schultz's Field Guide to Freshwater Fish''. Hoboken, NJ: J. Wiley & Sons, 2004]
In some locations where they have been transplanted, they are considered pests: trade in the species is prohibited in
Germany and
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
. 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 and became an
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
that has wreaked havoc with native species, especially in
Lake Biwa in
Shiga Prefecture. Akihito has since apologized.
[McCurry, Justin (November 26, 2007)]
"Japan in culinary offensive to stop spread of US fish"
'' The Guardian''.
Bluegill live in the shallow waters of many lakes and ponds, along with streams, creeks, and rivers. They prefer water with many aquatic plants, and seclude themselves within or near fallen logs, water weeds or any other structure (natural or manmade) that is under water. They can often be found around weed beds, where they search for food or
spawn.
[Lee, D. S. 1980. Lepomis macrochirus (Rafinesque 1819), Bluegill. pp. 597 in D. S. Lee, et al. Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, 854 pp] 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 , and tend to have a home range of about 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
Crappies () are two species of North American freshwater fish of the genus ''Pomoxis'' in the family Centrarchidae (sunfishes). Both species of crappies are popular game fish among recreational anglers.
Etymology
The genus name ''Pomoxis'' ...
,
pumpkinseeds, and
smallmouth bass.
[Paulson, Nicole, and Jay T. Hatch]
"Fishes of Minnesota – Bluegill."
GC 1112 Welcome. Minnesota Department of Natural Resources, 18 June 2004. Web. 04 May 2011.
Ecology
Young bluegills' diet consists of
rotifers,
copepods
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have p ...
,
water fleas
The Diplostraca or Cladocera, commonly known as water fleas, are a superorder of small crustaceans that feed on microscopic chunks of organic matter (excluding some predatory forms).
Over 1000 species have been recognised so far, with many more ...
, and
insects (mainly
chironomids).
The adult diet consists of aquatic insect larvae (
mayflies,
caddisflies,
dragonflies), but can also include terrestrial insects,
zooplankton,
shrimp
Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...
,
crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...
,
leeches, other
worms,
snails, and other small fish (such as
minnows).
[Carlander, K.D. 1997. Handbook of freshwater fishery biology. Volume 2. Life history Data on centrarchid fishes of the United States and Canada. Iowa State Univ.Press, Iowa.] If food is scarce, bluegill will also feed on aquatic vegetation and
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
,
and if scarce enough, will even feed on their own eggs or offspring. As bluegill spend a great deal of time near the surface of water, they can also feed on surface bugs. Most bluegills feed during daylight hours, with a feeding peak being observed in the morning and evening (with the major peak occurring in the evening).
Feeding location tends to be a balance between food abundance and predator abundance. Bluegill use
gill rakers and bands of small teeth to ingest their food. During summer months, bluegills generally consume 3.2 percent of their body weight each day. To capture prey, bluegills use a suction system in which they accelerate water into their mouth. Prey comes in with this water. Only a limited amount of water is able to be suctioned, so the fish must get within 1.75 centimeters of the prey.
In turn, bluegill are
prey to many larger species, including
largemouth bass,
smallmouth bass,
striped bass
The striped bass (''Morone saxatilis''), also called the Atlantic striped bass, striper, linesider, rock, or rockfish, is an anadromous perciform fish of the family Moronidae found primarily along the Atlantic coast of North America. It has al ...
,
trout,
muskellunge,
turtles,
northern pike,
yellow perch,
walleye,
catfish, and even larger bluegill.
Herons,
kingfishers,
and
otters have also been witnessed catching bluegill in shallow water. However, the shape of the fish makes them hard to swallow.
Raccoons are also believed to be among their predators.
Adaptations
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
The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...
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.
[Swingle, H. S. and E. V. Smith. 1943]
Factors affecting the reproduction of bluegill bream and large black bass in ponds
Ala. Poly-Tech. Inst. Agr. Exp. Stn. Circ. 87:8
Standard and backward swimming
The bluegill sunfish relies heavily on the flexibility of its fins to maintain maneuverability in response to fluid forces. The bluegill's segmentation in its pectoral fin rays mitigates the effects of fluid forces on the fish's movement. The bluegill has a variety of unusual adaptations that allow it to navigate different environments. In conditions where the bluegill is deprived of its various sensory abilities, it utilizes its pectoral fins in navigation.
If the bluegill's visual input or lateral line input were to be compromised, its pectoral fins are then able to be utilized as mechanosensors through the bending of the fin(s) when the fish comes into contact with its environment.
In standard swimming the bluegill sunfish relies on its caudal (tail) fin, dorsal fin, and anal fin.
The bluegill's caudal fin muscles are important in the fish's slow swimming and also important in the beginning stages of the fish increasing its swimming speed.
The dorsal and anal fins are two types of median fins that work in parallel to balance torque during steady swimming.
When swimming backwards, the bluegill utilizes a plethora of fin muscles located in various parts of its body.
Backward swimming in the bluegill is more complex than steady swimming, as it is not just the reversal of forward swimming. The fish utilizes its pectoral fins to provide a rhythmic beat while the dorsal and anal fins produce momentum to drive the fish backwards.
The pectoral fins' rhythmic beat is asymmetric and aids the fish's balance in its slow, backward movement.
C-start escape response
The bluegill, amongst a wide array of other fishes, exhibits the
C-start escape response, which is generated by large neurons called
Mauthner cells The Mauthner cells are a pair of big and easily identifiable neurons (one for each half of the body) located in the rhombomere 4 of the hindbrain in fish and amphibians that are responsible for a very fast escape reflex (in the majority of animals ...
.
Mauthner cells operate as a command center for the escape response and respond quickly once the neural pathway has been activated by an initial stimulus.
The cells trigger a contraction of muscle that bends the fish body into a 'C' to then aid in the propulsion away from a predator.
The C-start trajectory is highly variable, allowing the fish to alter its escape response each time. Because of this high variability, predators have a lower chance of learning a successful predation technique to capture the fish. The C-start escape response produces other advantages, including the ability to move quickly and unpredictably to capture prey.
Hydrodynamically, the bluegill exhibits specific flow patterns that accompany its C-start escape response.
The caudal (tail) fin is a main source of momentum in typical
kinematic models of the C-start escape response but the bluegill draws a majority of its momentum from the body bending associated with the response, as well as its dorsal and anal fins.
The dorsal and anal fins' roles as propulsors during escape response suggest that the size of the fins could lead to an evolutionary advantage when escaping predators.
Reproduction and lifestyle
Spawning season for bluegills starts late in May and extends into August. The peak of the spawning season usually occurs in June in waters of . The male bluegills arrive first at the mating site. They will make a spawning bed of six to 12 inches in diameter in shallow water, clustering as many as 50 beds together. The males scoop out these beds in gravel or sand. Males tend to be very protective and chase everything away from their nests, especially other male bluegills. Some bluegills, regardless of their small size, will even attack snorkelers if they approach the edge of the nest. As a female approaches, the male will begin circling and making grunting noises. The motion and sound of the males seem to attract the females. Females are very choosy and will usually pick males with larger bodies and "ears", making larger size a desirable trait for males to have. If the female enters the nest, both the male and female will circle each other, with the male expressing very aggressive behavior toward the female. If the female stays, the pair will enter the nest and come to rest in the middle. With the male in an upright posture, the pair will touch bellies, quiver, and
spawn. These actions are repeated at irregular intervals several times in a row. Once the spawning is done, the male will chase the female out of the nest and guard the eggs.
The
fertilization process is entirely external. The male's sperm combines with the female's eggs in the water. Smaller males will often hide in nearby weeds and dart into the nest as they attempt to fertilize the eggs. They then quickly dart away.
The size of the female plays a large role in how many eggs will be produced. A small female can produce as few as 1,000 eggs, and a large, healthy female can produce up to 100,000 eggs. The male continues to watch over the nest until the
larvae
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
are able to hatch and swim away on their own. The bluegill generally begins its spawning career at one year of age, but has been found to spawn as early as four months of age under favorable conditions. Anglers find spawning season to be a very successful time to fish for bluegills, as they aggressively attack anything, including a hook, that comes near.
The growth of the bluegill is very rapid in the first three years, but slows considerably once the fish reaches maturity. Many fish reach five to eight years old, and in extreme cases, can live 11 years.
Hybridization with other species
Occasionally a bluegill may spawn with another member of its genus, though this is rare. This tends to happen in bodies of water that are fairly isolated and have a decent population of bluegill in close proximity to another, smaller, population of lepomid species such as
green sunfish. Limited nesting grounds can also factor in hybridization causing the females of one species to prefer the nest of another. Bluegill can theoretically hybridize with all other species in the genus lepomis, though the most common hybrid is the
Greengill. The hybrid fish are aggressive and have larger mouths than their Bluegill parent. These fish also grow faster than other small mouth fish due to its bigger mouth. Greengills or hybrid Bluegills are the most efficient in growth and can reach approximately 2 lbs or 0.91 kg in one yea
Relationship with humans
The bluegill is the
state fish
This is a list of official and unofficial U.S. state fishes:
__TOC__
Table
See also
* Lists of U.S. state insignia
* Lists of U.S. state animals
Notes
References
Netstate.com state fish tables
External links
{{state insignia
.State ...
of
Illinois.
At
Lake St. Helen
Lake St. Helen is a public lake located in Roscommon County in the U.S. state of Michigan, and borders on the community of St. Helen, Michigan. It is the headwaters for the south branch of the Au Sable River.
From 1998 to 2003, the Lake was sub ...
, Michigan, an annual "Blue Gill Festival" is held in July.
Fishing
Bluegills are popular
panfish, caught with live bait such as worms, crickets, grasshoppers,
flies, minnows, maggots or small frogs, as well as small shrimp bits, processed bait, bread, corn, other table scraps, small crankbaits, spinners, fake worms, or even a bare hook. They mostly bite on vibrant colors like orange, yellow, green, or red, chiefly at dawn and dusk. They are noted for seeking out underwater vegetation for cover; their natural diet consists largely of crickets, water bugs,
larvae
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
, and very small fish. The bluegill itself is also occasionally used as bait for larger game fish species, such as
blue catfish, flathead catfish and
largemouth bass.
[Coble, Daniel W. "Effects of Angling on Bluegill Populations: Management Implications." North American Journal of Fisheries Management 8.3 (1988): 277]
Fishermen are sometimes able to use
polarized sunglasses to see through water and find bluegills' spawning beds. Bluegill have a rather bold character; many have no fear of humans, eating food directly dropped into the water, and a population in
Canada's
Lake Scugog
Lake Scugog is an artificially flooded lake in Scugog, Regional Municipality of Durham and the unitary city of Kawartha Lakes in central Ontario, Canada. It lies between the communities of Port Perry and Lindsay. The lake has been raised a ...
will even allow themselves to be stroked by human observers. Because of their size and the method of cooking them, bluegills are often called
panfish.
["Fishes of Minnesota: Bluegill](_blank)
Minnesota DNR." Minnesota Department of Natural Resources: Minnesota DNR. Web. 04 May 2011.
The
IGFA all tackle world record for the species stands at 2.15 kg (4 lb 12oz) caught from Ketona lake in
Alabama in 1950.
Management
Bluegill populations are notably vulnerable to effects of angling and harvest, particularly in size-structure. Large males appear to be especially vulnerable to effects of fishing because of their tendency to guard nests in the center of colonies. Populations with large males are increasingly difficult to find, and are usually only found in remote locations without angling pressure
or in more southern regions where growth rates are high. Reduced bag limits appear to show potential for improving size-structure in over-fished populations.
Bluegills play an important role in pond and lake management to keep
crustacean and insect populations low, as a single bluegill population may eat up to six times its own weight in just one summer.
References
{{Taxonbar, from=Q1148148
Fish described in 1810
Fauna of the Eastern United States
Fish of the Great Lakes
Fish of the United States
Freshwater fish of the Southeastern United States
Freshwater fish of South Africa
Lepomis
Taxa named by Constantine Samuel Rafinesque
Symbols of Illinois