Pygmy right whale
Pygmy right whale Ma Late Miocene – Recent[2]
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Size compared to an average human | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Artiodactyla |
Infraorder: | Cetacea |
Family: | Cetotheriidae |
Subfamily: | Neobalaeninae (Gray, 1873) |
Genus: | Caperea Gray, 1864 |
Species: | C. marginata
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Binomial name | |
Caperea marginata (Gray, 1846)
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Pygmy right whale range |
The pygmy right whale (Caperea marginata) is a species of
The pygmy right whale is found in temperate waters of the
Taxonomy
During the 1839-43 voyage of James Clark Ross, naturalists found bones and baleen plates resembling a smaller version of the right whale. In his Zoology of the Voyage of HMS Erebus and Terror (1846), John Edward Gray described the new species, naming it Balaena marginata. In 1864, Gray established a new genus (Caperea) after receiving a skull and some bones of another specimen. Six years later, in 1870, he added the name Neobalaena. He soon realized the three species were one and the same: Caperea marginata[7] (caperea means "wrinkle" in Latin, "referring to the wrinkled appearance of the ear bone"; while marginata translates to "enclosed with a border", which "refers to the dark border around the baleen plates of some individuals").[8] In research findings published on December 18, 2012, paleontologist Felix Marx compared the skull bones of pygmy right whales to those of extinct cetaceans, finding it to be a close relative to the Cetotheriidae, making the pygmy right whale a living fossil.[5][9] A 2023 study using genomic DNA confirmed that pygmy right whales are more closely related to rorquals than to balaenid right whales, consistent with a close relationship with the cetotheres.[10]
In 2012, Italian palaeontologist Michelangelo Bisconti described
Description
The pygmy right whale is rarely encountered and consequently little studied. However, it is known that it is by far the smallest of the baleen whales. Calves are estimated to be about 1.6 metres (5 ft 3 in) to 2.2 metres (7 ft 3 in) at birth[13] (an approximately 2 metres (6 ft 7 in) fetus was reported from a 6 metres (20 ft) female that had stranded in Perkins Bay, Tasmania, in 1982[14]). By the time they are weaned, they may be about 3 to 3.5 metres (9.8 to 11.5 ft) long. It is believed they become sexually mature at about 5 metres (16 ft) and physically mature at about 6 metres (20 ft).[6] The longest male registered, was a 6.1 metres (20 ft) individual which had stranded in Cloudy Bay, Tasmania,[15] while the longest female was a 6.45 metres (21.2 ft) individual which had stranded in Stanley, Tasmania in 1981.[14] Pygmy right whales can weigh as much as 3,430 kilograms (7,560 lb).[6] A 6.21 metres (20.4 ft) female weighed 3,200 kilograms (7,100 lb) and a 5.47 metres (17.9 ft) male weighed 2,850 kilograms (6,280 lb).[16] Gestation and lactation periods and longevity are all unknown. Part of the reason for the scarcity of data may be the relative inactivity of the whale, making location for study difficult. The blow is small and indistinct and the whale is usually a slow undulating swimmer, although capable of bursts of acceleration.[citation needed]
The coloring and shape of the pygmy right whale, dark gray dorsally and lighter gray ventrally, commonly with a pair of chevron-shaped lighter patches behind the eyes, is similar to that of the
The skull and skeleton of the pygmy right whale is unlike those of any other extant whale: the supraoccipital shield extends farther posteriorly; the ear bone has a lateral wrinkle and is roughly square in outline. All seven cervical vertebrae are fused, and the pygmy right has only 44 vertebrae. The 18 pairs of ribs are broad and flat, and make up 39–45% of the vertebral column (compared to 33% in other mysticetes).[6][17] Each thoracic vertebrae has a pair of huge wing-like transverse processes, many of which overlap. The dorsal end of the ribs are remarkably thin and almost fail to make contact with the transverse processes. The reduced tail (or sacrocaudal region) features a vestigial pelvis and small chevron bones.[18] The flippers have four digits. The lungs and heart are relatively small, which suggests that the pygmy right whale is not a deep diver. The larynx is reported to be different from any other cetacean.[6]
Like other mysticetes, the pygmy right whale has a large
Behavior and ecology
Analysis of the stomach contents of dead pygmy right whales indicates that it feeds on
The flukes,
Population and distribution
The pygmy right whale is among the least studied cetaceans; until 2008, fewer than 25 sightings of the species had been made at sea.[6] The species lives in the Southern Hemisphere and is believed to be circumpolar, living in a band from about 30°S to 55°S[3] in areas with surface water temperatures between 5 and 20 °C (41 and 68 °F).[19] Individuals have been found on the coasts of Chile,[23] Tierra del Fuego, Namibia, South Africa, Australia and New Zealand. One group may be a year-round resident off Tasmania.[19] The total population is unknown.
There is an extralimital stranding record in the Northern Hemisphere.[24]
Whaling and whale-watching
On account of its relatively small size and sparse distribution, the pygmy right whale has rarely been taken by whalers. A 3.39 metres (11.1 ft) male was taken off South Africa in 1917,
Most data about pygmy right whales come from individual specimens washed up on coastlines; they are rarely encountered at sea and so they are not the primary subject of any whale watching cruises.
Conservation
The pygmy right whale is listed on Appendix II [27] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II,[27] as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.
The pygmy right whale is also covered by Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MOU).[28]
See also
References
- OCLC 62265494.
- ^ PMID 29942692.
- ^ . Retrieved 19 November 2021.
- ^ "Appendices | CITES". cites.org. Retrieved 14 January 2022.
- ^ PMID 23256199.
- ^ a b c d e f g h Kemper, Catherine (2008). "Pygmy Right Whale". In Perrin, W.; Wursig, B.; Thewissen, J. (eds.). Encyclopedia of Marine Mammals. Academic Press. pp. 939–41.
- ^ Cousteau, Jacques, Whales (1986), p. 70.
- ^ Reeves, Randall, Guide to Marine Mammals of the World (2002), p. 202.
- ^ "'Extinct' whale found: Odd-looking pygmy whale traced back 2 million years". CSMonitor.com. 23 April 2012. Retrieved 19 December 2012.
- .
- .
- S2CID 83784488.
- ^ a b Klinowska, M. (1991). Dolphins, Porpoises and Whales of the World: The IUCN Red Data Book. Cambridge, U.K.: IUCN.
- ^ .
- ^ Mead, James G. and Joy P. Gold (2002). Whales and Dolphins In Question: the Smithsonian Answer Book. Washington D.C.: Smithsonian Institution Press.
- ^ Nowak, Ronald M. (1999). Walker's Mammals of the World. Baltimore: Johns Hopkins University Press.
- ^ a b Naish, Dairen (October 2010). "Pouches, pockets and sacs in the heads, necks and chests of mammals, part III: baleen whales". Retrieved 31 December 2013.
- . Retrieved 31 December 2013.
- ^ ISBN 978-0-69112757-6.
- . Retrieved 30 September 2013.
- .
- ^ Best, P.B., A. Meyer, and C. Lockyer. 2010. "Killer whales in South African waters – a review of their biology". African Journal of Marine Science 32:171-186.
- ^ Cabrera, E.; Carlson, C.; Galletti, V.M.B.; Cardenas, J.C.; Brownell Jr., R.L. (2005). A pygmy right whale (Caperea marginata) from Chiloe Island, Chile. SC/57/O20.
- PMID 30574356.
- ^ Best, P. B.; Ross, G. J. (1986). "Catches of right whales from shore-based establishments in southern Africa, 1792-1975". Reports of the International Whaling Commission. 10: 275–289.
- ^ Cousteau, J. T. and Y. Paccalet. 1988. Whales. Harry N. Abrams, Inc., New York, p. 169.
- ^ a b "Appendix II Archived 11 June 2011 at the Wayback Machine" of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5 March 2009.
- ^ "CMS Pacific Cetaceans MOU for Cetaceans and their Habitats in the Pacific Islands Region".
Further reading
- Encyclopedia of Marine Mammals, Perrin Wursig and Thewissen (eds). ISBN 0-12-551340-2
- Whales, Dolphins and Porpoises, Mark Carwardine. ISBN 0-7513-2781-6
- National Audubon Society Guide to Marine Mammals of the World. ISBN 0-375-41141-0
External links
- Reidenberg, Bruce (May 2008). "What are we looking for in the throat? Dissection of a stranded pygmy right whale". Retrieved 30 November 2013.