Thursday, February 12, 2015

ALBINO Animals

Albinism (from Latin albus, "white" also called achromia, achromasia, or achromatosis) is a form of hypopigmentary congenital disorder, characterized by a partial or total lack of melanin pigment in the eyes, skin and hair, or more rarely in the eyes alone. Albinism results from inheritance of recessive alleles. The condition is known to affect mammals (including humans), fish, birds, reptiles and amphibians. While the most common term for an organism affected by albinism is "albino" (noun and adjective), the word is sometimes used in derogatory ways towards people; more neutral terms are "albinistic" (adjective) and "person with albinism" (noun). Additional clinical adjectives sometimes used to refer to animals are "albinoid" and "albinic".
"Pinky" the bottlenose dolphin

It is not the same as leucism, where all integumental pigment is absent at least in patches but the eyes have their usual color.Leucistic animals are often mistaken as being albino creatures, such as white lions. Leucism is a condition similar to albinism, characterized by reduced pigmentation in general and can also affect distribution of pigment on the hair shaft, but unlike albinism, it’s caused by a reduction in all types of skin pigment, not just melanin. Chinchilla and other mutations can also cause white animals, such as some of the animals depicted here, including white peacocks, and white tigers, which are typically white rather than albino.

Albinism is hereditary; it is not an infectious disease and cannot be transmitted through contact, blood transfusions, or other vectors. The principal gene which results in albinism prevents the body from making the usual amounts of the pigment melanin. Most forms of albinism are the result of the biological inheritance of genetically recessive alleles (genes) passed from both parents of an individual, though some rare forms are inherited from only one parent. There are other genetic mutations which are proven to be associated with albinism. All alterations, however, lead to changes in melanin production in the body

"Snowflake" the white gorilla
The chance of offspring with albinism resulting from the pairing of an organism with albinism and one without albinism is low . However, because organisms can be carriers of genes for albinism without exhibiting any traits, albinistic offspring can be produced by two non-albinistic parents. Albinism usually occurs with equal frequency in both genders. An exception to this is ocular albinism, because it is passed on to offspring through X-linked inheritance. Thus, males more frequently have ocular albinism as they do not have a second X chromosome.

Most humans and many animals with albinism appear white or very pale; the multiple types of melanin pigment are responsible for brown, black, gray, and some yellow colorations. In some animals, especially 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), due to the presence of other pigments unaffected by albinism such as porphyrins, pteridines and psittacins, as well as carotenoid pigments derived from the diet.

Some animals are white or pale due to chromatophore (pigment cell) defects, do not lack melanin production, and have normal eyes; they are referred to as leucistic. 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), is known as melanism, and results in an appearance darker than non-melanistic specimens from the same genepool.

Albinism-like conditions may affect other pigments or pigment-production mechanisms in some animals (e.g. "whiteface", a lack of psittacins that can affect some parrot species.).Another is common in reptiles and amphibians: axanthism, in which xanthophore metabolism, instead of synthesis of melanin, is affected, resuling in reduction or absence of red and yellow pteridine pigments. Of all these conditions, only albinism and melanism affect humans.

Best known Albino animals:

Toug-Toulog the sacred white elephant was imported to the Barnum & London Show in 1884. 

Mocha Dick was a notorious male sperm whale that lived in the Pacific Ocean in the early 19th century, usually encountered in the waters near the island of Mocha, off southern Chile. Unlike most sperm whales, Mocha Dick was white, and was the inspiration for Herman Melville's 1851 novel Moby-Dick.

Pinky is an albino bottlednose dolphin found in Calcasieu Lake, Louisiana. Pinky was first spotted in 2007 by a boat captain, Erik Rue. The dolphin has become a tourist attraction, and conservationists have asked visitors to leave the dolphin alone.  Not to be confused with the Amazon River Botos, called pink dolphins, which live in South America in the Amazon.

Snowflake (c. 1964 – November 24, 2003) was an albino gorilla. He was the most popular resident of the Barcelona Zoo in Catalonia, Spain. 

The official story is that an ape specialist, Jordi Sabater Pi, found the animal in 1966 in Ikunde, in the then Spanish colony of Spanish Guinea, modern-day Equatorial Guinea. The only albino gorilla known to man, he was captured outside Nko, in the Equatorial forest of Nko, near Rio Campo, in the Rio Muni region, on October 1, 1966, by Benito Mañé, an ethnic Fang farmer, who had killed the rest of his group (all charcoal black in color) in order to obtain this unusual albino specimen. During the massacre, his mother was shot by Mañé whilst she tore a banana stem apart in his banana plantation. The small creature was found clinging to his mother's neck, his head buried deep in her black fur.

Benito kept him at his own home for four days and then transported him to Bata, where he was purchased by Sabater Pi, who worked for the Barcelona Zoo's Ikunde Center, in Spanish Guinea, and paid 10,500 pesetas for the gorilla. A National Geographic-funded study of gorillas in the region was underway at the time of Snowflake's discovery.

Snowflake was a Western Lowland Gorilla. He spent most of his life at the Barcelona Zoo in the Parc de la Ciutadella. He was known worldwide, mentioned in tourist guides and put on postcards, becoming the unofficial mascot for the city. Barcelona Zoo director Antonio Jonch in wrote in 1967:

Snowflake resting in his enclosure. "CopitoDeNieveGorilaAlbinoZooBarcelona" by aTarom - Cámara: FinePix 6900ZISO: 100Tv: 1/500Av: 5.6. Licensed under Public Domain via Wikimedia Commons 
"The gorilla was a male about two years of age. Morphologically it was normal except that it was white, skin and hair being completely devoid of pigmentation. The eye had a blueish sclera, a normal cornea, and a light blue iris which was very transparent to transillumination. Accommodation and refraction were normal. The media were transparent and the fundus of the eye normal and totally depigmented. The choroidal vessels were perfectly visible and the pupil was normal. The animal displayed marked photophobia which caused it to close its eyes repeatedly when exposed to bright light. In diffuse light similar to that in its biotope, we calculated that it blinked on an average of 20 times a minute."

Snowflake fathering twenty-two offspring by three different mates, or "dams". Six of his offspring survived to adulthood. None of Snowflake's offspring were albino, but all should be heterozygous, recessive carriers, for the albino gene. His grandchildren have 50% mathematical probability for carrying the albino gene. If both parents were albino gene carriers they have 25% chance of producing an albino offspring. As of May 2014, Snowflake has a total of 21 grandchildren (11 survive) and four great-grandchildren (all living). 

Snowflake's great-grandson N'Kou has pink fingers, which is perhaps suggestive of partial albinism. In 2001, Snowflake was diagnosed with an unusual form of skin cancer, almost certainly related to his albinism condition. By 2003, Snowflake's health began to deteriorate. After he began losing interest in his usual activities, began isolating himself from other gorillas and began exhibiting signs of physical pain, Snowflake's keepers decided to euthanize him. The decision was publicly announced in September 2003. Thousands of people visited Snowflake at the Barcolena Zoo before he was euthanized on November 24, 2003. At the time of his death, Snowflake was thought to be between 38 and 40 years old.

Source: wikipedia


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