Legends about unicorns have been circulating by word of mouth since ancient times, although they are probably inspired by the narwhal. This marine animal is characterized by having a very showy horn right on the front of its head, for this reason it has been linked to magic and the mystical. However, the origin of the narwhal horn goes beyond that, it is an evolutionary part of the species that has become one of the most admired by man and known as the marine unicorn.
The narwhal (Monodon monoceros) is a species of Odontocene cetacean that lives in the icy waters of the North Atlantic. It is extremely special, as it is the only member of the genus Monodon and one of the two species of the taxonomic family along with the beluga. The narwhal is characterized by its sexual dimorphism, which means that there is a physiognomic difference between females and males.
The main difference is that males have a horn, which is actually a tusk, very long and twisted right on the front of their head. It is a species of horn that can measure up to two meters and weigh approximately 10 kilograms. And although magical qualities have been attributed to it and myths have arisen around its horn, in reality it is an organ that helps males develop various functions.
What is the narwhal horn used for?
There are various investigations on this matter and from the conclusions, it seems that the narwhal horn does not have a single function, but rather that it is used for various purposes. A study from the University of Manitoba in found a correlation between testicular mass and horn length. The larger the testicular sac, the greater the length of the horns present only in males. In this sense, it is suggested that one of the functions of its large tusk is to attract females in order to reproduce and guarantee the survival of the species.
But it is not the only function that has been discovered about this intriguing tusk. Another research from Harvard University found that male narwhals use their protruding tusks as a kind of sensor that warns them about weather conditions. They reached this conclusion by observing the structure of the tusk, which, unlike other teeth, is not covered by enamel, so water penetrates directly into it. The water advances through a type of tubules to the base of the tusk where it finally excites millions of nerve endings in the dental pulp that send information to the narwhal’s brain. From this action, narwhals can determine parameters about water conditions such as temperature and salinity.
A functional tool
Although there seem to be more functions that narwhals give to their horn. Recent recordings have revealed that sea unicorns also use their giant tusk as a kind of tool to hunt fish. Footage filmed in Tremblay Sound in Canada demonstrated for the first time that narwhals hit their prey with their horn until they are stunned just before devouring them.
Therefore, although this evolutionary advantage seems to arise from sexual dimorphism, it is not the only function it plays. The narwhal’s horn is more complex than previously believed and makes this cetacean one of the most intriguing on the planet.