Bowhead whale

The bowhead whale (Balaena mysticetus) is a species of the family Balaenidae, in parvorder Mysticeti, and genus Balaena, which once included the right whale. A stocky dark-coloured whale without a dorsal fin, it can grow 14 to 18 m (46 to 59 ft) in length. This thick-bodied species can weigh from 75 to 100 tonnes (74 to 98 long tons; 83 to 110 short tons). They live entirely in fertile Arctic and sub-Arctic waters, unlike other whales that migrate to low latitude waters to feed or reproduce. The bowhead was also known as the Greenland right whale or Arctic whale. American whalemen called them the steeple-top, polar whale, or Russia or Russian whale. The bowhead has the largest mouth of any animal. The bowhead was an early whaling target. The population was severely reduced before a 1966 moratorium was passed to protect the species. Of the five stocks of bowhead populations, three are listed as 'endangered', one as 'vulnerable', and one as 'lower risk, conservation dependent' according to the IUCN Red List. The global population is assessed as of least concern. Carl Linnaeus first described this whale in the 10th edition of his Systema Naturae (1758). Seemingly identical to its cousins in the North Atlantic, North Pacific and Southern Oceans, they were all thought to be a single species, collectively known as the 'right whale', and given the binomial name Balaena mysticetus. Today, the bowhead whale occupies a monotypic genus, separate from the right whales, as proposed by the work of John Edward Gray in 1821. For the next 180 years, the family Balaenidae was the subject of great taxonometric debate. Authorities have repeatedly recategorized the three populations of right whale plus the bowhead whale, as one, two, three or four species, either in a single genus or in two separate genera. Eventually, it was recognized that bowheads and right whales were different, but there was still no strong consensus as to whether they shared a single genus or two. As recently as 1998, Dale Rice, in his comprehensive and otherwise authoritative classification, Marine Mammals of the World: Systematics and Distribution, listed just two species: B. glacialis (the right whales) and B. mysticetus (the bowheads). Studies in the 2000s finally provided clear evidence that the three living right whale species comprise a phylogenetic lineage, distinct from the bowhead, and that the bowhead and the right whales are rightly classified into two separate genera. The right whales were thus confirmed to be in a separate genus, Eubalaena. The relationship is shown in the cladogram below: Balaena prisca, one of the five Balaena fossils from the late Miocene (~10 Mya) to early Pleistocene (~1.5 Mya), may be the same as the modern bowhead whale. The earlier fossil record shows no related cetacean after Morenocetus, found in a South American deposit dating back 23 million years. An unknown species of right whale, the so-called 'Swedenborg whale' which was proposed by Emanuel Swedenborg in the 18th century, was once thought to be a North Atlantic right whale by scientific consensus. Based on later DNA analysis those fossil bones claimed to be from 'Swedenborg whales' were confirmed to be from bowhead whales.