Melanism

Melanism is a development of the dark-colored pigment melanin in the skin or its appendages and is the opposite of albinism. The word melanism is derived from the Greek: μελανός.

Overview

Pseudo-melanism, also called abundism, is another variant of pigmentation, characterized by dark spots or enlarged stripes, which cover a large part of the body of the animal, making it appear melanistic. A deficiency in or total absence of melanin pigments is called amelanism. The morbid deposition of black matter, often of a malignant character causing pigmented tumors, is called melanosis. For a description of melanin-related disorders, see melanin, melanosis coli and ocular melanosis.

In animals

Melanism related to the process of adaptation is called adaptive. Most commonly, dark individuals become fitter to survive and reproduce in their environment as they are better camouflaged. This makes some species less conspicuous to predators, while others such as leopards use it as a foraging advantage during night hunting. A theory that suggests that melanism may be linked to aggressive behavior in certain species is called the aggression hypothesis.

In humans

In humans, melanism is an undue development of dark-colored pigment in the skin or its appendages, and is the opposite of albinism. The medical term for this condition is hyperpigmentation.

Gallery

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  Melanistic squirrel
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  Licorice guinea pig
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  Melanistic snake
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  Melanistic jaguar
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  King cheetah
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  Melanistic eastern gray squirrel
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  Silkie chicken
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  Black silkie rooster

See also

• Industrial melanism
• Polymorphism (biology)
• Heterochromia iridum
• Piebaldism
• Vitiligo