What is a large sea animal related to the dolphin? with the letters h.a.r.n.a.l.w?

Question

What is a large sea animal related to the dolphin? with the letters h.a.r.n.a.l.w?

Answer 1

narwhal - noun

· small Arctic whale the male having a long spiral ivory tusk  

Answer 2

the narwhal

The narwhal was one of the many species originally described by Linnaeus in his Systema Naturae.[1] This is based on the Old Norse word nár, meaning "corpse", in reference to the animal's pigmentation. In some parts of the world, the Narwhal is colloquially referred to as the Moon Whale or the Polar Whale. In Inuit language the narwhal is named qilalugaq

The most conspicuous characteristic of male narwhal is their single, extraordinarily long tusk. It is an incisor tooth that projects from the left side of the upper jaw and forms a left-handed helix. The tusk can be up to three metres (nearly 10 ft) long (compared with a body length of 4-6 m [13-16 ft]) and weigh up to 10 kg (22 lbs). About one in 500 males has two tusks, which occurs when the right incisor, normally small, also grows out. A female narwhal may also produce a tusk, and there is a single recorded case of a female with dual tusks.[3]

The purpose of the tusk has been the subject of much debate. Early scientific hypotheses suggested that the tusk was used to pierce the ice covering the narwhal's Arctic Sea habitat. Others suggested the tusk was used in echolocation. Scientists recently discovered that the elongated tooth is packed with nerve endings, making it extraordinarily sensitive. The whales may use it to determine the salinity of water and search for food. Male narwhals are also known to rub their tusks together, presumably because it gives off a unique sensation[1]. In yet another theory, some scientists believe the tusk is primarily used for showmanship and for dominance: males with larger tusks are more likely to successfully attract a mate. This hypothesis was suggested by the activity of "tusking", in which two males rub tusks .

However, recent work by a research team suggests that the tusk may in fact be a sensory organ.[4] Electron micrographs of tusks revealed millions of tiny, deep tubules extending from the tusk's surface, apparently connecting to the narwhal's nervous system. While such tubules are present in the teeth of many species, they do not typically extend to the surface of healthy teeth. The exact sensory purpose of the tusk remains unknown, but scientists now hypothesize that it may detect temperature, salinity, pressure, or particulate makeup of the water environment.[4] Unlike the tusks of elephants, narwhal tusks do not regenerate if they break off. If damaged, however, the tusks can repair themselves to a certain extent.