The mystery of why the narwhal has a long tusk may have been solved after one was filmed using it to catch cod.
The elusive Arctic whale has been described as the unicorn of the sea because of its spiral tusk, which can be up to 9ft long in adult males.
Charles Darwin thought that it was used to attract mates. A study in 2014 claimed that it was a sensory organ, and that its thousands of nerve endings were used to measure the water’s salinity to help it to navigate and find food. Other theories include it being an ice pick, a weapon used to compete for a mate and a tool for sonar.
Although the tusk is likely to have multiple purposes, footage