dcsimg
Reproduction
provided by Animal Diversity Web

Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Myers, P. 1999. "Balaenopteridae" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Balaenopteridae.html
photographer
Phil Myers, Museum of Zoology, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web
ID
Balaenopteridae/reproduction
Behavior
provided by Animal Diversity Web

Perception Channels: tactile ; chemical

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Myers, P. 1999. "Balaenopteridae" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Balaenopteridae.html
photographer
Phil Myers, Museum of Zoology, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web
ID
Balaenopteridae/communication
Morphology
provided by Animal Diversity Web

Other Physical Features: endothermic ; bilateral symmetry

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Myers, P. 1999. "Balaenopteridae" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Balaenopteridae.html
photographer
Phil Myers, Museum of Zoology, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web
ID
Balaenopteridae/physical_description
Rorqual
provided by wikipedia EN

Rorquals /ˈrɔːrkwəl/ (Balaenopteridae) are the largest group of baleen whales, a family with nine extant species in two genera. They include what is believed to be the largest animal that has ever lived, the blue whale, which can reach 180 tonnes (200 short tons), and the fin whale, which reaches 120 tonnes (130 short tons); even the smallest of the group, the northern minke whale, reaches 9 tonnes (9.9 short tons).

Rorquals take their name from French rorqual, which derives from the Norwegian word røyrkval, meaning "rorqual-whale" (the first element røyr originated from the Old Norse name for this type of whale, reyðr,[3][4] probably related to the Norse word for "red").[5] The family name Balaenopteridae is from the type genus, Balaenoptera.

Characteristics

All members of the family have a series of longitudinal folds of skin running from below the mouth back to the navel (except the sei whale and common minke whale, which have shorter grooves). These furrows allow the mouth to expand immensely when feeding, "permitting them to engorge great mouthfuls of food and water in a single gulp".[6] These "pleated throat grooves" distinguish balaenopterids from other whales.[6]

Rorquals are slender and streamlined in shape, compared with their relatives the right whales, and most have narrow, elongated flippers. They have a dorsal fin, situated about two-thirds the way back. Rorquals feed by gulping in water, and then pushing it out through the baleen plates with their tongue. They feed on crustaceans, such as krill, but also on various fish, such as herrings and sardines.[7]

Gestation in rorquals lasts 11–12 months, so that both mating and birthing occur at the same time of year. Cows give birth to a single calf, which is weaned after 6–12 months, depending on species.[7] Of some species, adults live in small groups, or "pods" of two to five individuals. For example, humpback whales have a fluid social structure, often engaging behavioral practices in a pod, other times being solitary.

Distribution and habitat

 src=
This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2016) (Learn how and when to remove this template message)

Distribution is worldwide: the blue, fin, humpback, and the sei whales are found in all major oceans; the common (northern) and Antarctic (southern) minke whale species are found in all the oceans of their respective hemispheres; and either of Bryde's whale and Eden's whale occur in the Atlantic, Pacific, and Indian oceans, being absent only from the cold waters of the Arctic and Antarctic.

Most rorquals are strictly oceanic: the exceptions are Bryde's whale and Eden's whale (which are usually found close to shore all year round) and the humpback whale (which is oceanic but passes close to shore when migrating). It is the largest and the smallest types — the blue whale and Antarctic minke whale — that occupy the coldest waters in the extreme south; the fin whale tends not to approach so close to the ice shelf; the sei whale tends to stay further north again. (In the northern hemisphere, where the continents distort weather patterns and ocean currents, these movements are less obvious, although still present.) Within each species, the largest individuals tend to approach the poles more closely, while the youngest and fittest ones tend to stay in warmer waters before leaving on their annual migration.

Most rorquals breed in tropical waters during the winter, then migrate back to the polar feeding grounds rich in plankton and krill for the short polar summer.

Feeding habits

 src=
Humpback feeding on young pollock off Alaska

As well as other methods, rorquals obtain prey by lunge-feeding on bait balls.[8] Lunge feeding is an extreme feeding method, where the whale accelerates to a high velocity and then opens its mouth to a large gape angle. This generates the water pressure required to expand its mouth and engulf and filter a huge amount of water and fish.[8]

Rorquals have a number of anatomical features that enable them to do this, including bilaterally separate mandibles, throat pleats that can expand to huge size, and a unique sensory organ consisting of a bundle of mechanoreceptors that helps their brains to coordinate the engulfment action.[9] Furthermore, their large nerves are flexible so that they can stretch and recoil.[10] In fact, they give rorquals the ability to open their mouths so wide that they would be capable of taking in water at volumes greater than their own sizes. These nerves are packed into a central core area that is surrounded by elastin fibers. Opening the mouth causes the nerves to unfold, and they snap back after the mouth is closed.[10] According to Potvin and Goldbogen, lunge feeding in rorquals represents the largest biomechanical event on Earth.[11]

Taxonomy

 src=
Cladogram of the family Balaenopteridae using complete mtDNA sequences and short interspersed repetitive element (SINE) insertion data.
 src=
Skeleton of the extinct "Megaptera" hubachi at the Museum für Naturkunde, Berlin

Formerly, the rorqual family Balaenopteridae was split into two subfamilies, the Balaenopterinae and the Megapterinae, with each subfamily containing one genus, Balaenoptera and Megaptera, respectively. However, the phylogeny of the various rorqual species shows the current division is paraphyletic, and in 2005, the division into subfamilies was dropped.[12] The discovery of a new species of balaenopterid, Omura's whale (Balaenoptera omurai), was announced in November 2003, which looks similar to, but smaller than, the fin whale; individuals of this species were found in Indo-Pacific waters.

Alternative generic taxonomy for living rorquals

In 2012, the following alternate taxonomy was presented:[14]

A 2018 genetic study suggests that gray whales (Eschrichtius robustus) be counted among the rorquals.[15]

References

Notes

  1. ^ Mead, J.G.; Brownell, R. L. Jr. (2005). "Order Cetacea". In Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 723–743. ISBN 978-0-8018-8221-0. OCLC 62265494..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
  2. ^ "Family Balaenopteridae Gray 1864 (rorqual)". Fossilworks. Retrieved 9 April 2018.
  3. ^ "Rorqual". Merriam-Webster Dictionary.: "from Norwegian rørhval, from Old Norse reytharhvalr, from reythr rorqual + hvalr whale".
  4. ^ "rorqual". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.): "ad. Norw. røyrkval, repr. ON. *røyðar-, OIcel. reyðar-hvalr, f. reyðurreyðr the specific name + hvalr whale."
  5. ^ The Century Dictionary. 1895. p. 5228.
  6. ^ a b Minasian, Stanley M.; Balcomb, Kenneth C.; Foster, Larry, eds. (1984). The World's Whales: The Complete Illustrated Guide. New York: The Smithsonian Institution. p. 18. ISBN 0-89599-014-8.
  7. ^ a b Gambell, Ray (1984). Macdonald, D, ed. The Encyclopedia of Mammals. New York: Facts on File. pp. 222–225. ISBN 0-87196-871-1.
  8. ^ a b Reeves, RR; Stewart, BS; Clapham, PJ; Powell, JA (2002). National Audubon Society Guide to Marine Mammals of the World. Chanticleer Press. ISBN 978-0-375-41141-0.[page needed]
  9. ^ Pyenson, N.D.; Goldbogen, J.A.; Vogl, A.W.; Szathmary, G; Drake, R.L.; Shadwick, R.E. (2012). "Discovery of a sensory organ that coordinates lunge feeding in rorqual whales". Nature. Nature Publishing Group. 485 (7399): 498–501. Bibcode:2012Natur.485..498P. doi:10.1038/nature11135. PMID 22622577. Retrieved 28 December 2012.
  10. ^ a b McSpadden, Kevin (5 May 2015). "Gigantic Whales Eat Thanks To 'Bungee-Cord' Nerves". TIME.com. Retrieved 6 May 2015.
  11. ^ Potvin, J; Goldbogen, J.A. (2009). "Passive versus active engulfment: verdict from trajectory simulations of lunge-feeding fin whales Balaenoptera physalus". J. R. Soc. Interface. 6 (40): 1005–1025. doi:10.1098/rsif.2008.0492. PMC 2827442. PMID 19158011.
  12. ^ Deméré, T.A.; Berta, A.; McGowen, M.R. (2005). "The taxonomic and evolutionary history of fossil and modern balaenopteroid mysticetes". Journal of Mammalian Evolution. 12 (1/2): 99–143. doi:10.1007/s10914-005-6944-3.
  13. ^ Thalassotherii in the Paleobiology Database. Retrieved October 2013.
  14. ^ Hassanin, A.; Delsuc, F.; Rpiquet, A.; Hammer, C.; Vuuren, B. J.; Matthee, C.; Ruiz-Garcia, M.; Gatzeflis, F.; Areskoug, V.; Nguyen, T. T.; Couloux, A. (2012). "Pattern and timing of diversification of Cetartiodactyla (Mammalia, Laurasiatheria), as revealed by a comprehensive analysis of mitochondrial genomes". Comptes Rendus Biologies. 335: 32–50. doi:10.1016/j.crvi.2011.11.002. PMID 22226162.
  15. ^ Árnason, Úlfur; Lammers, Fritjof; Kumar, Vikas; Nilsson, Maria A.; Janke, Axel (2018). "Whole-genome sequencing of the blue whale and other rorquals finds signatures for introgressive gene flow". Science Advances. 4 (4). doi:10.1126/sciadv.aap9873.

Sources

.mw-parser-output .refbegin{font-size:90%;margin-bottom:0.5em}.mw-parser-output .refbegin-hanging-indents>ul{list-style-type:none;margin-left:0}.mw-parser-output .refbegin-hanging-indents>ul>li,.mw-parser-output .refbegin-hanging-indents>dl>dd{margin-left:0;padding-left:3.2em;text-indent:-3.2em;list-style:none}.mw-parser-output .refbegin-100{font-size:100%}

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN
ID
700fe191d82089c4dad35235f552d3e8
Rorqual: Brief Summary
provided by wikipedia EN

Rorquals /ˈrɔːrkwəl/ (Balaenopteridae) are the largest group of baleen whales, a family with nine extant species in two genera. They include what is believed to be the largest animal that has ever lived, the blue whale, which can reach 180 tonnes (200 short tons), and the fin whale, which reaches 120 tonnes (130 short tons); even the smallest of the group, the northern minke whale, reaches 9 tonnes (9.9 short tons).

Rorquals take their name from French rorqual, which derives from the Norwegian word røyrkval, meaning "rorqual-whale" (the first element røyr originated from the Old Norse name for this type of whale, reyðr, probably related to the Norse word for "red"). The family name Balaenopteridae is from the type genus, Balaenoptera.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN
ID
256c3a1d22196e30ca6b8eff1976b792
Description
provided by World Register of Marine Species
This family contains the larges animals ever to live; all balaenopteroids have adult body lengths of over 7 m, but some are much larger. The rorquals are streamlined animals (the humpback whale somewhat less than the others), with a series of long pleats extending from the snout tip to as far back as the navel on the ventral surface. Balaenopterids are fast and active lunge feeders; their morphology allows them to open their jaws very widely and distend their throats to take in huge mouthfuls of water during feeding. The baleen plates are of moderate length and fringe fineness. Density and fringe diameter vary among species, and along with plate number and width to length ratio, are diagnostic characters. Rorquals have dorsal fins (varying in size and shape) set beyond the midpoint of the back. The upper jaw has a relatively flat profile, a feature reflecting the structure of the skull. Within a given feature, differences among balaenopterids are often subtle variations on a theme, rather than class distinctions. Therefore, information on many features may be needed to distringuiish among them and reliance on a single character for identification is discouraged. <123>
license
cc-by-4.0
copyright
WoRMS Editorial Board
bibliographic citation
MASDEA (1997).
i18n: Contributor
Edward Vanden Berghe [email]
original
visit source
partner site
World Register of Marine Species
ID
WoRMS:note:80305