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75-463: Herrington Lake contains many species of fish, including bluegill , catfish , crappie , hybrid striped bass , largemouth bass , spotted bass , and white bass . Dix Dam , the dam that made the lake, was the largest earth-filled dam in the world at the time, and considered to be a major engineering feat. Kentucky Utilities' main dispatch and communication center is located on the site. This Boyle County, Kentucky state location article

150-670: A mutation , as in albinism ), not all pigment-containing cells are chromatophores. Haem , for example, is a biochrome responsible for the red appearance of blood. It is found primarily in red blood cells (erythrocytes), which are generated in bone marrow throughout the life of an organism, rather than being formed during embryological development. Therefore, erythrocytes are not classified as chromatophores. Chromatophores that contain large amounts of yellow pteridine pigments are named xanthophores; those with mainly red / orange carotenoids are termed erythrophores. However, vesicles containing pteridine and carotenoids are sometimes found in

225-499: A biological assay for rapidly identifying potential bioactive compounds using melanophores from the African clawed frog . Other scientists have developed techniques for using melanophores as biosensors , and for rapid disease detection (based on the discovery that pertussis toxin blocks pigment aggregation in fish melanophores). Potential military applications of chromatophore-mediated colour changes have been proposed, mainly as

300-594: A cyan biochrome of unknown chemical structure in cells named cyanophores. Although they appear unusual in their limited taxonomic range, there may be cyanophores (as well as further unusual chromatophore types) in other fish and amphibians. For example, brightly coloured chromatophores with undefined pigments are found in both poison dart frogs and glass frogs , and atypical dichromatic chromatophores, named erythro-iridophores have been described in Pseudochromis diadema . Many species are able to translocate

375-501: A leucistic disorder. Chromatophores are sometimes used in applied research. For example, zebrafish larvae are used to study how chromatophores organise and communicate to accurately generate the regular horizontal striped pattern as seen in adult fish. This is seen as a useful model system for understanding patterning in the evolutionary developmental biology field. Chromatophore biology has also been used to model human condition or disease, including melanoma and albinism. Recently,

450-401: A terminal mouth , ctenoid scales, and a lateral line that is arched upward anteriorly. The bluegill typically ranges in size from about 4 to 12 inches (100–300 mm), and reaches a maximum size just over 16 inches (410 mm). The largest bluegill ever caught was 4 lb 12 oz (2.2 kg) in 1950. The bluegill is most closely related to the orangespotted sunfish and

525-411: 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

600-408: A basket-like melanophore layer with processes covering the iridophores. Both types of melanophore are important in physiological colour change. Flat dermal melanophores often overlay other chromatophores, so when the pigment is dispersed throughout the cell the skin appears dark. When the pigment is aggregated toward the centre of the cell, the pigments in other chromatophores are exposed to light and

675-429: A change in environment. This type of camouflage, known as background adaptation , most commonly appears as a slight darkening or lightening of skin tone to approximately mimic the hue of the immediate environment. It has been demonstrated that the background adaptation process is vision-dependent (it appears the animal needs to be able to see the environment to adapt to it), and that melanin translocation in melanophores

750-410: 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

825-431: 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 swamps 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 plants and in the shade of trees along banks , and will often move from one cover to another depending on

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900-404: 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

975-489: A manner that clouds, varying in tint between a hyacinth red and a chestnut-brown, were continually passing over the body. Any part, being subjected to a slight shock of galvanism, became almost black: a similar effect, but in a less degree, was produced by scratching the skin with a needle. These clouds, or blushes as they may be called, are said to be produced by the alternate expansion and contraction of minute vesicles containing variously coloured fluids. The term chromatophore

1050-480: A novel deep (wine) red-colour pigment was identified in the melanophores of phyllomedusine frogs . Some species of anole lizards, such as the Anolis grahami , use melanocytes in response to certain signals and hormonal changes, and is capable of becoming colors ranging from bright blue, brown, and black. This was subsequently identified as pterorhodin , a pteridine dimer that accumulates around eumelanin core, and it

1125-419: A number of cell types generated in the neural crest , a paired strip of cells arising at the margins of the neural tube . These cells have the ability to migrate long distances, allowing chromatophores to populate many organs of the body, including the skin, eye, ear, and brain. Fish melanophores and iridophores have been found to contain the smooth muscle regulatory proteins [calponin] and caldesmon . Leaving

1200-419: A series of catalysed chemical reactions. It is a complex chemical containing units of dihydroxyindole and dihydroxyindole-2- carboxylic acid with some pyrrole rings. The key enzyme in melanin synthesis is tyrosinase . When this protein is defective, no melanin can be generated resulting in certain types of albinism. In some amphibian species there are other pigments packaged alongside eumelanin. For example,

1275-543: A similar effect by cell signalling . Such signals can be hormones or neurotransmitters and may be initiated by changes in mood, temperature, stress or visible changes in the local environment. Chromatophores are studied by scientists to understand human disease and as a tool in drug discovery . Aristotle mentioned the ability of the octopus to change colour for both camouflage and signalling in his Historia animalium (ca 4th century BC): The octopus ... seeks its prey by so changing its colour as to render it like

1350-483: A single bluegill population may eat up to six times its own weight in just one summer. However, certain species of bluegill can become overpopulated and overrun a pond's ecosystem if not managed properly. Pond owners typically control the bluegill population by handfishing and trapping of the fish to control population size. Chromatophore Chromatophores are cells that produce color, of which many types are pigment -containing cells, or groups of cells, found in

1425-629: A spectacular array of skin colours by making good use of the divisional effect. The control and mechanics of rapid pigment translocation has been well studied in a number of different species, in particular amphibians and teleost fish. It has been demonstrated that the process can be under hormonal or neuronal control or both and for many species of bony fishes it is known that chromatophores can respond directly to environmental stimuli like visible light, UV-radiation, temperature, pH, chemicals, etc. Neurochemicals that are known to translocate pigment include noradrenaline , through its receptor on

1500-428: A type of active camouflage , which could as in cuttlefish make objects nearly invisible. Coleoid cephalopods (including octopuses, squids and cuttlefish ) have complex multicellular organs that they use to change colour rapidly, producing a wide variety of bright colours and patterns. Each chromatophore unit is composed of a single chromatophore cell and numerous muscle, nerve, glial , and sheath cells. Inside

1575-483: 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 insects and baitfishes . The fish are important prey for bass , other larger sunfish , northern pike and muskellunge , walleye , trout , herons , kingfishers , snapping turtles and otters , and play

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1650-721: A wide range of animals including amphibians , fish , reptiles , crustaceans and cephalopods . Mammals and birds , in contrast, have a class of cells called melanocytes for coloration . Chromatophores are largely responsible for generating skin and eye colour in ectothermic animals and are generated in the neural crest during embryonic development . Mature chromatophores are grouped into subclasses based on their colour under white light: xanthophores (yellow), erythrophores (red), iridophores ( reflective / iridescent ), leucophores (white), melanophores (black/brown), and cyanophores (blue). While most chromatophores contain pigments that absorb specific wavelengths of light,

1725-444: Is a stub . You can help Misplaced Pages by expanding it . This Mercer County, Kentucky state location article is a stub . You can help Misplaced Pages by expanding it . This Garrard County, Kentucky state location article is a stub . You can help Misplaced Pages by expanding it . Bluegill Lepomis purpurescens Cope , 1870 The bluegill ( Lepomis macrochirus ), sometimes referred to as "bream", "brim", "sunny", or, as

1800-543: Is also occasionally used as bait for larger game fish species, such as blue catfish , flathead catfish and largemouth bass . 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 will even allow themselves to be stroked by human observers. Because of their size and

1875-446: Is also present in a variety of tree frog species from Australia and Papua New Guinea . While it is likely that other lesser-studied species have complex melanophore pigments, it is nevertheless true that the majority of melanophores studied to date do contain eumelanin exclusively. Humans have only one class of pigment cell, the mammalian equivalent of melanophores, to generate skin, hair, and eye colour. For this reason, and because

1950-698: Is common in Texas , "copper nose", is a species of North American 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, crappies and black basses ) in the order Perciformes ( perch -like fish). Bluegills can grow up to 16 in (41 cm) long and about 4 + 1 ⁄ 2  lb (2.0 kg). While their color can vary from population to population, they typically have

2025-425: Is not always obvious, but, in general, iridophores are considered to generate iridescent or metallic colours , whereas leucophores produce reflective white hues. Melanophores contain eumelanin , a type of melanin , that appears black or dark- brown because of its light absorbing qualities. It is packaged in vesicles called melanosomes and distributed throughout the cell. Eumelanin is generated from tyrosine in

2100-532: 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. The bluegill, amongst a wide array of other fishes, exhibits the C-start escape response , which is generated by large neurons called Mauthner cells . Mauthner cells operate as

2175-424: Is scarce, bluegill will also feed on aquatic vegetation and algae , 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

2250-721: Is the state fish of Illinois . At Lake St. Helen , Michigan, an annual "Blue Gill Festival" is held in July. 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 , and very small fish. The bluegill itself

2325-441: Is the major factor in colour change. Some animals, such as chameleons and anoles , have a highly developed background adaptation response capable of generating a number of different colours very rapidly. They have adapted the capability to change colour in response to temperature, mood, stress levels, and social cues, rather than to simply mimic their environment. During vertebrate embryonic development , chromatophores are one of

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2400-534: 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. 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

2475-836: 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 and became an invasive species that wreaked havoc with native species, especially in Lake Biwa . Akihito has since apologized. Bluegill live in

2550-400: The larvae 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

2625-603: The melanocyte , has been identified in these animals. It was only in the 1960s that chromatophores were well enough understood to enable them to be classified based on their appearance. This classification system persists to this day, even though the biochemistry of the pigments may be more useful to a scientific understanding of how the cells function. Colour-producing molecules fall into two distinct classes: biochromes and structural colours or "schemochromes". The biochromes include true pigments, such as carotenoids and pteridines . These pigments selectively absorb parts of

2700-676: The optic cup , which, in turn, forms the retina . When and how multipotent chromatophore precursor cells (called chromatoblasts ) develop into their daughter subtypes is an area of ongoing research. It is known in zebrafish embryos, for example, that by 3 days after fertilization each of the cell classes found in the adult fish—melanophores, xanthophores and iridophores—are already present. Studies using mutant fish have demonstrated that transcription factors such as kit , sox10 , and mitf are important in controlling chromatophore differentiation. If these proteins are defective, chromatophores may be regionally or entirely absent, resulting in

2775-628: The redear sunfish , but different in a distinct spot at or near the base of the soft dorsal fin. 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 , New York and southeastern Ontario . They have been introduced widely in North America and Europe , South Africa , Zimbabwe , Asia , South America , and Oceania . Bluegills have also been found in

2850-633: The visible light spectrum that makes up white light while permitting other wavelengths to reach the eye of the observer. Structural colours are produced by various combinations of diffraction, reflection or scattering of light from structures with a scale around a quarter of the wavelength of light. Many such structures interfere with some wavelengths (colours) of light and transmit others, simply because of their scale, so they often produce iridescence by creating different colours when seen from different directions. Whereas all chromatophores contain pigments or reflecting structures (except when there has been

2925-528: 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. Spawning season for bluegills starts late in May and extends into August. The peak of

3000-490: 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

3075-411: The brain in a pattern isomorphic to that of the chromatophores they each control. This means the pattern of colour change functionally matches the pattern of neuronal activation . This may explain why, as the neurons are activated in iterative signal cascade, one may observe waves of colour changing. Like chameleons, cephalopods use physiological colour change for social interaction . They are also among

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3150-446: The cell, cyclic adenosine monophosphate (cAMP) has been shown to be an important second messenger of pigment translocation. Through a mechanism not yet fully understood, cAMP influences other proteins such as protein kinase A to drive molecular motors carrying pigment containing vesicles along both microtubules and microfilaments . Most fish, reptiles and amphibians undergo a limited physiological colour change in response to

3225-447: The cell. However, a similar effect is achieved.The energy cost of the complete activation of the chromatophore system is very high equally being nearly as much as all the energy used by an octopus at rest. Octopuses and most cuttlefish can operate chromatophores in complex, undulating chromatic displays, resulting in a variety of rapidly changing colour schemata. The nerves that operate the chromatophores are thought to be positioned in

3300-436: 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

3375-417: The chromatophore cell, pigment granules are enclosed in an elastic sac, called the cytoelastic sacculus. To change colour the animal distorts the sacculus form or size by muscular contraction, changing its translucency , reflectivity, or opacity . This differs from the mechanism used in fish, amphibians, and reptiles in that the shape of the sacculus is changed, rather than translocating pigment vesicles within

3450-530: The color of leucophores and iridophores is produced by their respective scattering and optical interference properties. Some species can rapidly change colour through mechanisms that translocate pigment and reorient reflective plates within chromatophores. This process, often used as a type of camouflage , is called physiological colour change or metachrosis . Cephalopods, such as the octopus , have complex chromatophore organs controlled by muscles to achieve this, whereas vertebrates such as chameleons generate

3525-601: The colour of the stones adjacent to it; it does so also when alarmed. Giosuè Sangiovanni was the first to describe invertebrate pigment-bearing cells as cromoforo in an Italian science journal in 1819. Charles Darwin described the colour-changing abilities of the cuttlefish in The Voyage of the Beagle (1860): These animals also escape detection by a very extraordinary, chameleon-like power of changing their colour. They appear to vary their tints according to

3600-499: The constructive interference of light. Fish iridophores are typically stacked guanine plates separated by layers of cytoplasm to form microscopic, one-dimensional, Bragg mirrors . Both the orientation and the optical thickness of the chemochrome determines the nature of the colour observed. By using biochromes as coloured filters, iridophores create an optical effect known as Tyndall or Rayleigh scattering , producing bright- blue or - green colours. A related type of chromatophore,

3675-475: The daylight hours. The mouth of the bluegill is very small and requires the use of the pharynx to suck in prey. 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

3750-441: 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

3825-403: 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

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3900-430: 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

3975-552: 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 year. [1] The bluegill

4050-401: 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 , 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,

4125-422: 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

4200-609: The gene responsible for the melanophore-specific golden zebrafish strain, Slc24a5 , was shown to have a human equivalent that strongly correlates with skin colour . Chromatophores are also used as a biomarker of blindness in cold-blooded species, as animals with certain visual defects fail to background adapt to light environments. Human homologues of receptors that mediate pigment translocation in melanophores are thought to be involved in processes such as appetite suppression and tanning , making them attractive targets for drugs . Therefore, pharmaceutical companies have developed

4275-537: The large number and contrasting colour of the cells usually make them very easy to visualise, melanophores are by far the most widely studied chromatophore. However, there are differences between the biology of melanophores and that of melanocytes . In addition to eumelanin, melanocytes can generate a yellow/red pigment called phaeomelanin . Nearly all the vibrant blues in animals and plants are created by structural coloration rather than by pigments. However, some types of Synchiropus splendidus do possess vesicles of

4350-416: The leucophore, is found in some fish, in particular in the tapetum lucidum . Like iridophores, they utilize crystalline purines (often guanine) to reflect light. Unlike iridophores, leucophores have more organized crystals that reduce diffraction. Given a source of white light, they produce a white shine. As with xanthophores and erythrophores, in fish the distinction between iridophores and leucophores

4425-493: The method of cooking them, bluegills are often called panfish . The IGFA all tackle world record for the species stands at 2.15 kg (4 lb 12 oz) caught from Ketona lake in Alabama in 1950. 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

4500-450: The nature of the ground over which they pass: when in deep water, their general shade was brownish purple, but when placed on the land, or in shallow water, this dark tint changed into one of a yellowish green. The colour, examined more carefully, was a French grey, with numerous minute spots of bright yellow: the former of these varied in intensity; the latter entirely disappeared and appeared again by turns. These changes were effected in such

4575-417: The neural crest in waves, chromatophores take either a dorsolateral route through the dermis, entering the ectoderm through small holes in the basal lamina , or a ventromedial route between the somites and the neural tube. The exception to this is the melanophores of the retinal pigmented epithelium of the eye. These are not derived from the neural crest. Instead, an outpouching of the neural tube generates

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4650-648: The pigment inside their chromatophores, resulting in an apparent change in body colour. This process, known as physiological colour change , is most widely studied in melanophores, since melanin is the darkest and most visible pigment. In most species with a relatively thin dermis , the dermal melanophores tend to be flat and cover a large surface area. However, in animals with thick dermal layers, such as adult reptiles, dermal melanophores often form three-dimensional units with other chromatophores. These dermal chromatophore units (DCU) consist of an uppermost xanthophore or erythrophore layer, then an iridophore layer, and finally

4725-448: The same cell, in which case the overall colour depends on the ratio of red and yellow pigments. Therefore, the distinction between these chromatophore types is not always clear. Most chromatophores can generate pteridines from guanosine triphosphate , but xanthophores appear to have supplemental biochemical pathways enabling them to accumulate yellow pigment. In contrast, carotenoids are metabolised and transported to erythrophores. This

4800-414: 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 . In the summer, adults move to deep, open water where they suspend just below

4875-439: The shape of the fish makes them hard to swallow. Raccoons are also believed to be among their predators. 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

4950-404: 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 fin 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

5025-434: The signal into the cell. Melanocortins result in the dispersion of pigment, while melatonin and MCH results in aggregation. Numerous melanocortin, MCH and melatonin receptors have been identified in fish and frogs, including a homologue of MC1R , a melanocortin receptor known to regulate skin and hair colour in humans. It has been demonstrated that MC1R is required in zebrafish for dispersion of melanin. Inside

5100-461: The skin takes on their hue. Likewise, after melanin aggregation in DCUs, the skin appears green through xanthophore (yellow) filtering of scattered light from the iridophore layer. On the dispersion of melanin, the light is no longer scattered and the skin appears dark. As the other biochromatic chromatophores are also capable of pigment translocation, animals with multiple chromatophore types can generate

5175-568: The spawning season usually occurs in June in waters of 67 to 80 °F (19 to 27 °C). 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

5250-569: 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

5325-955: 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 m ) 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 . Young bluegills' diet consists of rotifers , copepods , water fleas , and insects (mainly chironomids ). The adult diet consists of aquatic insect larvae ( mayflies , caddisflies , dragonflies ), but can also include terrestrial insects, zooplankton , shrimp , crayfish , leeches , other worms , snails , and other small fish (such as minnows ). If food

5400-490: The surface on melanophores. The primary hormones involved in regulating translocation appear to be the melanocortins , melatonin , and melanin-concentrating hormone (MCH), that are produced mainly in the pituitary, pineal gland, and hypothalamus, respectively. These hormones may also be generated in a paracrine fashion by cells in the skin. At the surface of the melanophore, the hormones have been shown to activate specific G-protein-coupled receptors that, in turn, transduce

5475-439: The time of day or season. The bluegill is noted for the large black appendage (the "ear") on each side of the posterior edge of the gill covers as well as the base of the dorsal fin. The sides of its head and chin are commonly a dark shade of blue, hence the name "bluegill". 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

5550-532: Was adopted (following Sangiovanni's chromoforo ) as the name for pigment-bearing cells derived from the neural crest of cold-blooded vertebrates and cephalopods. The word itself comes from the Greek words chrōma ( χρῶμα ) meaning "colour," and phoros ( φόρος ) meaning "bearing". In contrast, the word chromatocyte ( kytos ( κύτος ) meaning "cell") was adopted for the cells responsible for colour found in birds and mammals. Only one such cell type,

5625-500: Was first demonstrated by rearing normally green frogs on a diet of carotene -restricted crickets . The absence of carotene in the frogs' diet meant that the red/orange carotenoid colour 'filter' was not present in their erythrophores. This made the frogs appear blue instead of green. Iridophores, sometimes also called guanophores, are chromatophores that reflect light using plates of crystalline chemochromes made from guanine . When illuminated they generate iridescent colours because of

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