Science Facts

Why Do Fish Have Different Colors? – Coloration

Fish Coloration

The different factors affect a fish’s color. Six factors affect the fish’s color: lighting, environment, food, age of fish, moods of fish, and then the genes. Rainbow fishes are known to be very colorful. Castle can be adjusted depending on the temperature. Environment plays a lot of role in keeping the fish coloration The more natural color the environment is, the more secure the fish would feel. It is because they need to hide from predators.

Why do fish have different colors? (Coloration)

The color of a fish’s flesh isn’t just random. It’s based on a combination of factors, including genetics file pigments and even its swimming routine. Tuna, for example, is typically a reddish-pink color. It is because of their extreme endurance. Their bodies need extra oxygen to feed their muscles. That comes from a protein called myoglobin which stores oxygen in the muscles and acts as a pigment giving them that reddish hue. Many seafood hawkers artificially enhance the color of tuna by exposing it to carbon monoxide gas. It changes it from a gross brown color back into a bright red.

Fish with light-colored flesh like the Pacific halibut lead far less active lives than their red-blooded counterparts. Most of their time is spent resting on the seafloor. So all of their activity comes in very short bursts. The cooking process causes the proteins in the meat to coagulate, transforming it into a milky white color. That same process occurs in every kind of animal, so raw meat always looks different from cooking.

Salmon are fond of eating krill, and krill are fond of eating algae. The algae eat carotenoids which are pigments that give food and plants their bright colors. So when krill eat algae and eat krill, the salmon indirectly consumes those carotenoids, which gives their flesh a bright orange color. But salmon aren’t the only fish who eat krill. So why are they orange and the others aren’t? That is where the genetics part comes in.

Most salmon have a color gene that allows carotenoids to penetrate their muscle tissue. Some salmon, however, lack that gene. So even though they’re identical to the orange. Salmon flesh is a grayish-white color. They’re called ivory kings, and typically they sell for a bit more than regular salmon. However, they can be hard to get off the shelves because people are so used to seeing that orange color.

Fish coloration
Fish coloration

Whitefish has the blue link. Sometimes their flesh will take on a blue color. That’s caused by a bio pigment called Villa Vernon, which gets into the blood serum and turns their flesh into a highly bright shade of blue.

  • Majority of fishes are vividly and brightly colored.
  • Enormous range of colors and patterns produced in fishes are generally related to their environment.
  • Normally, darker on the dorsal and lighter on the sides or ventral sides. It gives them protection from above and below.
  • Irridocytes can combine with the chromatophores to produce reflective colors.

Coloration is one of the most common phenomena found among the fish’s enormous range of colors, and patterns produced in fishes are generally related to their environment.

  • When a predator sees from the below side, the body color of the fish resemble the color of the sky and camouflaged.
  • When a predator sees on the above side, the body color of the above side of fish camouflage with the stones of the Seas present inside.

Fishes have a uniform correlation as found in the golden fish. There are irridocytes on the surface of the scales. It will have a silvery appearance such as that found on the hatchet fish. It is the lower side having irridocytes of the skin. The fish has a white color. In cases, the irridocytes can combine with the chromatophores, and then it produced reflective colors. So the important feature is the presence of irridocytes.

The coloration in fish is due to the different pigmentations present in the fish and color according to the pigment. Fish comes in lots of different colors and patterns.

  • Free swimming: Simple coloration, whitish belly, silvery lower sides, back are blue or green.
  • Bottom dwellers: Strongly marked above while pale beneath.
  • Coral reefs: Most brilliantly and elegantly colored, includes Camfinalfishes, butterflyfishes, triggerfishes, parrotfishes.
  • Oceanic: Silver in the upper, red in the middle image, and violet or black in the greater depths.

Their living behavior their environment decide the coloration of the fishes. The pigment present in the body may not be active in the other environment. Mostly the free-swimming fishes have simple coloration. The whitish belly silver lower sires back are blue. The bottom dweller fishes have strongly marked above white pale beneath. Their upper portion of the body is marked with lines mostly, and their belly is pale in color. The fishes present in the coral reefs mostly they are brilliantly and elegantly colored.

Oceanic fishes are silver on the upper side. Their middle portion is mainly in the red range, and their depth is violet or black. In-depth, the bottom dweller fishes have strongly marked lines. They have different colors, and their pattern is very rare. It shows mostly the beautiful different color patterns and likes rainbow colors present in these fishes.

Sources of color scales

There are some kinds of sources responsible for color scales.

  • Due to schemachromes ( physical configuration) & biochromes true pigments).
  • Schemachromes:

White: Skeleton, gas bladder, scales & testes.
Blue & violets: iris.
Iridescent: scales, eyes & intestinal membranes.

  • Biochromes includes:

Carotenoids: Yellow, red.
Chromolipoids: Yellow to brown.
Indigoids: Red, blue & green.

Mostly the color scales are only due to the presence of the pigments. Due to the presence of schema Chromes, the physical configuration and Biomes are the true pigments. These are the reasons that the body of the fishes have different color patterns. They are mostly present in white, blue, violet, and indecent colors. The oceanic fishes mostly have silvery colors because the purines are present in them. The Pterins make primarily white, yellow, red, and orange.

Presence of biochromes

  • Carotenoids and purines appear in fish skin Liver, eggs, and eyes have carotenoids.
  • Melanin occurs in the endoderm & skin.
  • Porphyrins are found in muscle and blood.
  • Bile pigments are found in skeleton and bile.
  • Flavins are found in blood, muscle, spleen, gills, heart, kidneys, eggs, liver & eyes.
  • Purines are in the scales and eyes also.
  • Pterins are in the eyes, blood, liver, kidneys, and stomach.

These are the pigments that are present in the different organs. And here’s why that organ shows a different color.

Special cell for color

The special cells are specified for the coloration or the pigmentations. Two kinds of cells present the chromatophores and the iridocytes.

Chromatophores: The chromatophores impact true colors. And these are located in the dermis of the skin, either outside or beneath the scale. These are also found in the peritoneum and deeply around the brain and spinal cord.

The primary type of chromatophores are:

Erythrophores: Red and orange.
Xynthophores: Yellow.
Melanophores: Black.
Leucophores: White.

Iridocytes: It is also known as mirror cells because they contain reflecting materials that mirror colors outside the fishes. It reflects the body of the fish.

Significance of coloration of scales

Different fishes show different colors.

  • For communication with either the same species (intraspecific) or with different species (interspecific).
  • Intraspecific signals for recognition threat or warning. For sexual purposes and recognition of their parents.
  • Interspecific signals for warning or intimidating potential predators.

Functions of coloration of scales

Principal functions of coloration are:

  • Concealment.
    General color resemblance.
    Variable color resemblance.
    Obliterative shading.
    Disruptive coloration.
  • Disguise.
  • Advertisement.

General color resemblance: It is vital in resemblance b/w fish and its background. E.g., many coral reefs are very bright in colors according to colors in that coral reefs. Some Fishes living over light-shaded bottoms are light-colored, but the same species are dark over dark bottoms.

Variable color resemblance: Fish can change color gradually or rapidly to match their background. Rainbow trout (stream resident phase) is multicolored, including dark spots (young) and rosy sides in adults. The same individuals in the sea are blue above and white below. Variations also occur according to seasons, day or night.

Obliterative shading: It is countershading or Thayer’s law. That is for the darkening and counterweighted.

Disruptive coloration: It is disruptive camouflage or disruptive patterning that irregular patches. It prevents or delays as long a,s possible recognition on sight.

Many coral reefs are very bright in color. According to the coral colors present in the environment, some fishes living over light-shaded bottoms are light-colored, and the same species are dark over dark bottoms. This is the type of concealment. They can change their body color according to their environment, and it is also the type of camouflage in the fish. So the variable color is the ability of fish to change their color to match their environment gradually.

More Articles:


“Morphological color changes in fish: Regulation of pigment cell density and morphology.” Microscopy Research and Technique.
The diversity of fishes: biology, evolution, and ecology. Helfman, Gene S., Helfman, Gene S. (2nd ed.).
Endler, John, William C.; Wallace, Bruce (eds.), A Predator’s View of Animal Color Patterns, Evolutionary Biology, Springer US
“Significance of colors and patterns of coral reef fishes: an overview.” ReefCI.
Price, Anna; Weadick, Cameron; Shim, Janet; Rodd, Frieda. “Pigments, Patterns, and Fish Behavior.”
“How fish color their skin: A paradigm for development and evolution of adult patterns.” BioEssays.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button
error: Content is protected !!