Balaenoptera bonaerensis

Ballena Minke (Balaenoptera bonaerensis)

Balaenoptera bonaerensis

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Classis: Mammalia
Subclassis: Theria
Infraclassis: Placentalia
Superordo: Cetartiodactyla
Ordo: Cetacea
Subordo: Mysticeti
Familia: Balaenopteridae
Genus: Balaenoptera
Species: B. bonaerensis

Name

Balaenoptera bonaerensis (Burmeister, 1867)

References

* Balaenoptera bonaerensis in Mammal Species of the World.
* Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Mammal Species of the World : A Taxonomic and Geographic Reference, 2-volume set(3rd ed).
* [1] Listed animal in CITES Appendix I

Vernacular names
English: Southern Minke Whale, Antarctic Minke Whale
Español: Rorcual austral
日本語: クロミンククジラ
Português: Baleia-minke-antártica
Türkçe: Antarktik minke balinası

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The Antarctic minke whale or southern minke whale (Balaenoptera bonaerensis), is a species of minke whale within the suborder of baleen whales.


Taxonomy

Until recently, all minke whales were considered a single species. However, the common minke whale was recognized as a separate species from the Antarctic minke whale based on mitochondrial DNA testing.[3] This testing also confirmed the Antarctic minke whale is the closest relative of the common minke whale, thus confirming the validity of the clade.[3]

Physical description

The Antarctic minke whale is one of the smallest of the rorquals, and one of the smallest baleen whales. Among rorquals, only the common minke whale is smaller, and among baleen whales, the pygmy right whale is also smaller. Length ranges from 7.2 to 10.7 meters and weight ranges from 5.8 to 9.1 tons.[4] On average, females are about 1 meter longer than males.[4] Newborns range from 2.4 to 2.8 meters.[4]

The back is dark grey and the belly white. There is a double blaze of lighter grey on each side rising up from the belly. Flippers are dark with a white leading edge.[4]

The Antarctic minke whale differs from the common minke whale in several respects. The Antarctic minke is slightly larger than the common, and the common has a white band in the middle of each flipper. There are also less distinctive differences in body coloration and shape.[4]

Distribution

The Antarctic minke whale inhabits all oceans in the Southern Hemisphere. Its summer range is close to Antarctica, but it moves further north in winter, overlapping in range with the dwarf form of the common minke whale.

Whaling
Main article: Whaling

The first recorded catch of what was probably an Antarctic minke whale (the record did not state whether it was a dwarf or Antarctic minke, but it was probably the latter) was made by the British in the 1950-51 Antarctic season. By 1957-58, the Antarctic catch had reached 493. The catch was significantly less and much more sporadic the following seasons, until 1967-68, when 605 were taken. A total of 3,021 were caught in 1971-72. Not wanting to repeat the same mistakes it had made with previous species, the IWC set a quota of 5,000 minke whales for the following season, 1972-73. Despite these precautions, the quota was exceeded by 745.

The quota was again set at 5,000 for 1973-74, but Japan and the Soviet Union, the two nations then responsible for filling all of the Antarctic quota of this species, protested, and the quota was raised to 7,713 (of which all were caught). The catch fluctuated between slightly less than 5,000 and 7,000 (with a peak of 7,900 in 1976-77) from then until 1986-87, when open commercial whaling of this species in the Southern Ocean ended.

From 1987 to the present, Japan has been sending a fleet consisting of a single factory ship and several catcher/spotting vessels to the Southern Ocean to catch Antarctic minkes under Article VIII of the IWC, which allows the culling of whales for scientific research. The first research program, Japanese Research Program in the Antarctic (JARPA), began in 1987-88, when 273 Antarctic minkee were caught. The quota and catch soon increased to 330 and 440. In 2005-06, the second research program, JARPA II, began. In its first two years, in what Japan called its "feasibility study", 850 Antarctic minkes, as well as 10 fin whales, were to be taken each season (2005–06 and 2006–07). The quota was reached in the first season, but due to a fire, only 508 Antarctic minkes were caught in the second. In 2007-08, because of constant harassment from environmental groups, they failed to reach the quota again, with a catch of only 551 whales.

Conservation Status

The Antarctic minke whale is considered Data Deficient by the IUCN red list.[2] and as of January, 2010, with respect to populations status the IWC states it is "unable to provide reliable estimates at the present time" and that a "major review is underway by the Scientific Committee." [5]

References

1. ^ Mead, James G.; Brownell, Robert L., Jr. (16 November 2005). "Order Cetacea (pp. 723-743)". In Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3/browse.asp?id=14300013.
2. ^ a b Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. (2008). Balaenoptera bonaerensis. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 7 October 2008.
3. ^ a b "Cetacean mitochondrial DNA control region: sequences of all extant baleen whales and two sperm whale species". http://mbe.oxfordjournals.org/cgi/content/abstract/10/5/960. Retrieved 2007-07-13.
4. ^ a b c d e Jarrett, Brett and Shirihai, Hadoram (2006). Whales Dolphins and other Marine Mammals of the World. pp. 62–68. ISBN 0-691-12757-3.
5. ^ ^ "Whale Population Estimates". http://www.iwcoffice.org/conservation/estimate.htm. Retrieved January, 2010.

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