Fact of the Day .CA

Albinism is found in a wide variety of species from plants to animals to humans.  It is a recessive gene that causes the production of the pigment melanin to be below normal levels.  This can leave the skin, hair, and/or eyes with a different colour, usually a shade between white and pink, depending on its severity.  White tigers are an example of albinism; zoos use special breeding programs in order to retain this effect.  Due to lacking pigment in the skin albinism leaves skin vulnerable to the Sun’s UV rays,  resulting in faster and more frequent cases of sunburn and a higher risk of skin cancer.  The lack of pigment in the iris of the eye can damage the retina due to a larger amount of light entering the eye.  Albino animals that have small eyes, such as mice and rats, appear to have red eyes because the blood vessels of the retina are visible through the clear iris.  Red eyes are rare in larger animals such as humans; the iris is usually a pale blue but some cases have been reported as red or purple.  There appear to be no other physical disadvantages for albinos, other than the incapability of animals to camouflage which decreases their chances of survival.

Cetacea is the Latin order for whales, dolphins, and porpoises.  The WDSC North America states that there are 20 species recorded to have cases of albino individuals.  Some of these species include Sperm Whales, Pilot Whales, Humpback Whales, and Bottlenose Dolphins.  In 1982 there was a  paper published in the Journal of Mammalogy stating that there had been two albino Pilot Whale sightings in 1976 and 1980 at 215 km SE beyond the continental shelf edge of Halifax, Nova Scotia and 211 km SE beyond the continental shelf edge of Nantucket Island, Massachusetts respectively.  It is unknown whether these two sightings were of the same animal or two separate animals.  The paper suggests that the disadvantages of albinism in cetaceans would be their inability to blend in with the rest of the pod (for social species) or with their environment.  Sunburns are less of a problem for cetaceans because they spend the majority of their life under the water.  Being a different colour than the rest of the animals in the species causes the albino to be susceptible to predation and extra human attention.  Additionally it may decrease their reproductive success because in the animal kingdom differences in colour can be a health indicator and a difference in colour could deter mates.

Albino cetaceans are not to be confused with species that are naturally white or light in colour.  One such species is the Beluga Whale, also known as the White Whale.  These animals are born a pale brown-grey colour; their pigmentation darkens in approximately the first 6 to 7 years of their life.  They then begin to lighten up and at around 10 to 12 years of age they are almost white.  They continue to become more vibrantly white as they age.  These animals can be found in the Arctic and the St. Lawrence River of Quebec.

Another cetacean which has different pigments but is not albino is the Amazon River Dolphin or Boto (Inia geoffrensis) which has been called the pink dolphin.  It is thought that the pink markings in this species are scars that result from male aggressive interactions.  This is thought because the pink colour is mostly found on males  that have shown aggressive behaviours amongst each other.

Next time you find yourself in a dicussion about the book Moby Dick, which is about a white whale, be sure to mention that he is an albino cetacean (sperm whales are normally black).  Your friends will be wildly impressed, I guarantee.

Special Thanks:
Whitehead Lab at Dalhousie