Bowhead whale
The bowhead whale (Balaena mysticetus) is a species of baleen whale belonging to the family Balaenidae and is the only living representative of the genus Balaena. It is the only baleen whale endemic to the Arctic and subarctic waters, and is named after its characteristic massive triangular skull, which it uses to break through Arctic ice. Other common names of the species included the Greenland right whale, Arctic whale, steeple-top, and polar whale.[5]
Bowheads have the largest mouth of any animal[6] representing almost one-third of the length of the body, the longest baleen plates with a maximum length of 4 metres (13 feet),[7] and may be the longest-lived mammals, with the ability to reach an age of more than 200 years.[8]
The bowhead was an early whaling target. Their 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.[3][9]
Health[edit]
Lifespan[edit]
Bowhead whales are considered to be the longest-living mammals, living for over 200 years.[32] In May 2007, a 15 m (49 ft) specimen caught off the Alaskan coast was discovered with the 90 mm (3.5 in) head of an explosive bomb lance of a model manufactured between 1879 and 1885, so the whale was probably bomb lanced sometime between those years, and its age at the time of death was estimated at between 115 and 130 years.[33] Spurred by this discovery, scientists measured the ages of other bowhead whales; one specimen was estimated to be 211 years old.[34] Other bowhead whales were estimated to be between 135 and 172 years old. This discovery showed the longevity of the bowhead whale is much greater than originally thought.[35] Researchers at CSIRO, Australia's national science agency, estimated that bowhead whales' maximum natural lifespan is 268 years based on genetic analysis.[36]
Genetic benefits[edit]
A greater number of cells present in an organism was once believed to result in greater chances of mutations that cause age-related diseases and cancer.[37] Although the bowhead whale has thousands of times more cells than other mammals, it has a much higher resistance to cancer and aging. In 2015, scientists from the US and UK were able to successfully map the whale's genome.[38] Through comparative analysis, two alleles that could be responsible for the whale's longevity were identified. These two specific gene mutations linked to the bowhead whale's ability to live longer are the ERCC1 gene and the proliferating cell nuclear antigen (PCNA) gene. ERCC1 is linked to DNA repair and increased cancer resistance. PCNA is also important in DNA repair. These mutations enable bowhead whales to better repair DNA damage, allowing for greater resistance to cancer.[37] The whale's genome may also reveal physiological adaptations such as having low metabolic rates compared to other mammals.[39] Changes in the gene UCP1, a gene involved in thermoregulation, can explain differences in the metabolic rates in cells.
The bowhead is listed in Appendix I by CITES. While the global population is thought to be secure, thus assigned "least concern" status,[3] some populations are listed by the National Marine Fisheries Service as "endangered" under the auspices of the United States' Endangered Species Act. The IUCN Red List data are:[89]
The Alaska Department of Fish and Game and the USA government list the bowhead whale as federally endangered.[103]
The bowhead whale is listed in Appendix I[104] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), as this species has been categorized as being in danger of extinction throughout all or a significant proportion of its range. CMS Parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration, and controlling other factors that might endanger them.[89]
Whales swimming in the Lindholm Strait of the Shantar Islands, in the northwestern Sea of Okhotsk[105]
![Whales swimming in the Lindholm Strait of the Shantar Islands, in the northwestern Sea of Okhotsk[105]](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Bowhead_whales_swimming_in_Lingolm_strait_by_Vladislav_Raevskii.JPG/120px-Bowhead_whales_swimming_in_Lingolm_strait_by_Vladislav_Raevskii.JPG)
![Cavorting whale in northwestern part of Sea of Okhotsk[64]](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/A_bowhead_whale_is_tail-slapping_in_the_coastal_waters_of_western_Sea_of_Okhotsk_by_Olga_Shpak%2C_Marine_Mammal_Council%2C_IEE_RAS.jpg/120px-A_bowhead_whale_is_tail-slapping_in_the_coastal_waters_of_western_Sea_of_Okhotsk_by_Olga_Shpak%2C_Marine_Mammal_Council%2C_IEE_RAS.jpg)
Blowholes
Fluke up before diving
Whale showing one of pectoral fins
Tip of whitish chin visible
