Incetology,the study of whales and othercetaceans,ablowholeis the hole (orspiracle) at the top of the head through which the animal breathes air. Inbaleen whales,these are in pairs. It ishomologouswith thenostrilof othermammals,and evolved via gradual movement of the nostrils to the top of the head.[1]The posterior placement of blowholes on cetacean heads is believed to minimize the energy used when breathing at the water's surface.[2]
Purpose and mechanism
editAir sacsjust below the blowhole allow whales to produce sounds for communication and, fortoothed whales,echolocation.These air sacs are filled with air, which is then released again to produce sound in a similar fashion to releasing air from a balloon. When whales dive under water their nasal plug covers the nasal passage to the blowhole. The muscles controlling the nasal plug are relaxed during this time, but when the whale comes up for air these muscles contract and allow for the blowhole to be opened and the process of exhalation and inhalation to occur.[3]
As whales reach the water surface to breathe, they forcefully expel air through the blowhole. The exhalation is released into the comparably lower-pressure, colder atmosphere, and anywater vaporcondenses. This spout, known as theblow,is often visible from far away as a white splash, which can also be caused by water resting on top of the blowhole. Spout shapes differ among species, which facilitates identification. This is followed by inhaling fresh air into the lungs. A humpback whale's lungs can hold about 5,000 litres (1,300 US gal) of air.[4][5]
Baleen whaleshave two blowholes positioned in a V-shape, whiletoothed whaleshave only one blowhole.[6]The blowhole of asperm whale,a toothed whale, is located left of centre in the frontal area of the snout, and is actually its left nostril, while the right nostril lacks an opening to the surface and its nasal passage is otherwise well developed.[citation needed]
Cultural significance
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The spouting of whales has been observed and used in whale hunting throughout the world since ancient times. This has been depicted inrock carvings at Alta(northern Norway), which mostly date to 5000–4000 BC and 2000–1000 BC.[7]Such carvings have also been found in South Korea (Bangudae Petroglyphs), British Columbia, and possibly New Zealand (Weka Passshelter).[8]
Whale spout features in Australianmyths of creation[9]and in European descriptions ofmonsters,such as theProcopius'Porphyriosand the Spouter inOlaus Magnus’Historia de Gentibus Septentrionalibus.[10]A spouting whale is a major attraction in the JapaneseNagasaki Kunchifestival, which has been taking place since the early 17th century.[11]It has been depicted in Western painting byWenceslaus Hollar(1620s–30s),[12]William James Linton(1830s),[13]andWilliam Morris Hunt(c. 1870).[14]Mocha Dick,a whale from the early 19th century which inspired the novelMoby-Dick,had an unusual way of spouting.[15]
A spouting whale has its properUnicode character(U+1F433;emoji:🐳) in theMiscellaneous Symbols and Pictographsblock.[16]
References
edit- ^"Whale evolution: The blowhole".18 March 2008.
- ^Reidenberg, Joy S.; Laitman, Jeffrey T. (2008)."Sisters of the Sinuses: Cetacean Air Sacs".The Anatomical Record.291(11): 1389–1396.doi:10.1002/ar.20792.ISSN1932-8494.PMID18951477.S2CID39634203.
- ^Rommel, S. A. (2023). "Elements of beaked whale anatomy and diving physiology and some hypothetical causes of sonar-related stranding".J. Cetacean Res. Manage.7(3): 189–209.CiteSeerX10.1.1.572.7820.doi:10.47536/jcrm.v7i3.730.
- ^Reidenberg, Joy S. (2007)."Anatomical adaptations of aquatic mammals".The Anatomical Record.290(6): 507–513.doi:10.1002/ar.20541.PMID17516440.S2CID42133705.
- ^Scholander, Per Fredrik (1940). "Experimental investigations on the respiratory function in diving mammals and birds".Hvalraadets Skrifter.22:1–131.
- ^Buono, Mónica (1 December 2014)."Anatomy of nasal complex in the southern right whale, Eubalaena australis (Cetacea, Mysticeti)".Journal of Anatomy.226(1): 81–92.doi:10.1111/joa.12250.PMC4313901.PMID25440939.
- ^Gjerde, Jan Magne (2019). "Marine Mammals in the Rock Art of Alta, Norway, Northernmost Europe".Whale on the Rock II.Ulsan Petroglyph Museum.
- ^Bahn, Paul G. (2013). "The Bangudae Whales in the Context of World Rock Art".Petroglyph Panels in Ulsan, Korea, in the Context of World Rock Art(PDF).pp. 37–66.
- ^"Shining a Light on the Cultural Significance of Whales".WWFAustralia. 14 March 2024.
- ^Ritchie, Steve (1 January 2008)."As it was".Hydro International.
- ^Jones, Matthew (8 October 2013)."Nagasaki Kunchi festival an unforgettable experience".Japan Today.
- ^"Three ships in a rough sea with a spouting whale".National Gallery of Victoria.Retrieved9 April2024.
- ^Hokanson, Alison (Spring 2016). "Turner's Whaling Pictures".The Metropolitan Museum of Art Bulletin.73(4). Metropolitan Museum of Art: 21.ISBN1588395944.
- ^"The Spouting Whale".Smithsonian Museum.Retrieved9 April2024.
- ^* J. N. Reynolds. "Mocha Dick: or the White Whale of the Pacific: A Leaf from a Manuscript Journal,"The Knickerbocker, or New-York Monthly Magazine.Vol. 13, No. 5, May 1839, pp. 377–392.
- ^"Spouting Whale".Emojipedia.Retrieved9 April2024.
External links
edit- "Whales don't spray water out of their blowholes",Gizmodo, Emily Upton, October 15, 2013.
- Whales of the World