Albinism - in Other Animals

In Other Animals

Many animals with albinism lack their protective camouflage and are unable to conceal themselves from their predators or prey; the survival rate of animals with albinism in the wild is usually quite low. However the novelty of albino animals has occasionally led to their protection by groups such as the Albino Squirrel Preservation Society.

In what used to be called "partial albinism" but more often termed leucism there can be a single patch or patches of skin that lack melanin. Especially in albinistic birds and reptiles, ruddy and yellow hues or other colors may be present on the entire body or in patches (as is common among pigeons), because of the presence of other pigments unaffected by albinism such as porphyrins, pteridines and psittacins, as well as carotenoid pigments derived from the diet.

In some animals albinism-like conditions may affect other pigments or pigment-production mechanisms:

• "Whiteface," a condition that affects some parrot species, is caused by a lack of psittacins.
• Axanthism is a condition common in reptiles and amphibians, in which xanthophore metabolism is affected rather than synthesis of melanin, resulting in reduction or absence of red and yellow pteridine pigments.
• Leucism differs from albinism in that the melanin is, at least, partially absent but the eyes retain their usual color. Some leucistic animals are white or pale because of chromatophore (pigment cell) defects, and do not lack melanin.
• Melanism is the direct opposite of albinism. An unusually high level of melanin pigmentation (and sometimes absence of other types of pigment in species that have more than one) results in an appearance darker than non-melanistic specimens from the same genepool.

Intentionally bred albinistic strains of some animal species are commonly used as model organisms in biomedical study and experimentation, although some researchers have argued that they are not always the best choice. Examples include the BALB/c mouse and Wistar and Sprague Dawley rat strains, while albino rabbits were historically used for Draize toxicity testing. The yellow mutation in fruit flies is their version of albinism.

The incidence of albinism can be artificially increased in fish by exposing the eggs to heavy metals (arsenic, cadmium, copper, mercury, selenium, zinc).

The eyes of an albino animal appear red because the colour of the red blood cells in the underlying retinal blood vessels shows through where there is no pigment to obscure it.

Famous albino animals include Migaloo, a humpback whale off the coast of Australia; Pinky, a bottlenose dolphin living in and around in Calcasieu Lake, Louisiana; Snowflake, a Barcelona Zoo gorilla; Snowflake, a Bristol Zoo penguin; and Mahpiya Ska (Sioux for "White Cloud"), a buffalo in Jamestown, North Dakota. The inspiration for Herman Melville's novel Moby-Dick was a sperm whale known as Mocha Dick.