The olm or proteus is an aquatic salamander in the family Proteidae. It is endemic to the waters that flow underground through the limestone bedrock of the karst of Central and Southeastern Europe. The olm’s eyes are undeveloped, leaving it blind, while its other senses, particularly those of smell and hearing, are acutely developed.
About Olm in brief
The olm or proteus is an aquatic salamander in the family Proteidae. It is endemic to the waters that flow underground through the limestone bedrock of the karst of Central and Southeastern Europe. The olm’s eyes are undeveloped, leaving it blind, while its other senses, particularly those of smell and hearing, are acutely developed. Its body is covered by a thin layer of skin, which contains very little of the pigment riboflavin, making it yellowish-white or pink in color. It also exhibits neoteny, retaining larval characteristics like external gills into adulthood, like some American amphibians, the axolotl and the mudpuppies. The word olm is a German loanword that was incorporated into English in the late 19th century. The origin of the German original, Olm or Grottenolm ‘cave olm’, is unclear. It may be a variant of the word Molch’salamander’ Some specimens of the olm can reach up to 40 centimetres long. The limbs are small and thin, with a reduced number of digits compared to other amphibians: the front legs have three digits instead of the normal four, and the rear have two digits. The internal organs can be seen shining through on the abdominal part of the body. It retains the ability to produce melanin, and will gradually turn dark when exposed to light. The mouth opening is small, with tiny teeth forming a sieve to keep larger particles inside the mouth.
The nostrils are so small as to be imperceptible, but are placed somewhat laterally near the end of the snout. The nose is so small that the nostrils must be placed somewhat further away from the head. The eyes are blind, but can use the eyes for orientation, which are better developed than in amphibians living on the surface. It has three toes on its forelimbs, but only two toes onIts hind feet. The body is snakelike, 20–30 cm long, with some specimens reaching up to40 centimetre. Females grow larger than males, but otherwise the primary external difference between the sexes is in the cloaca region when breeding. The trunk is cylindrical, uniformly thick, and segmented with regularly spaced furrows at the myomere borders. The tail is relatively short, laterally flattened, and surrounded by athin fin. The head ends with a short, dorsoventrally flattened snout; in some cases the larvae are also colored. The lungs are red in color because of the oxygen-rich, non-visual, blood shows through the non-pigmented skin. The Olm also has lungs in respiration except during hypoxic conditions, but is only accessory, but shows their role in the life of the cave. Although blind, it is able to carry a larger number of sensory receptors and is thus able to swim away from light.
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This page is based on the article Olm published in Wikipedia (as of Nov. 08, 2020) and was automatically summarized using artificial intelligence.
