Editing Blue whale (section)

=== Size ===
[[File:Joey williams with a 19&nbsp;foot long blue whale skull.jpg|thumb|upright|right|alt=Photograph of a blue whale skull |A blue whale [[skull]] measuring {{convert|19|ft|m|order=flip|sp=us}}]]
The blue whale is the largest animal known ever to have existed.<ref name="Ruud_1956">{{cite journal|author1=Ruud, J. T.|date=1956|title=The blue whale|journal=[[Scientific American]]|volume=195|issue=6|pages=46–50|doi=10.1038/scientificamerican1256-46|bibcode=1956SciAm.195f..46R}}</ref><ref name="Lockyer_1981">{{cite journal|author1=Lockyer, C.|date=1981|title=Growth and energy budgets of large baleen whales from the southern hemisphere|journal=FAO Fisheries Series (5) Mammals in the Seas|volume=3|pages=379–487}}</ref><ref name="Mizroch_1984">{{cite journal|author1=Mizroch, S. A.|author2=Rice, D. W.|author3=Breiwick, J. M.|date=1984|title=The blue whale, ''Balaenoptera musculus''|journal=Marine Fisheries Review|volume=46|pages=15–19}}</ref> Some studies have estimated that certain [[Shastasauridae|shastasaurid]] [[ichthyosaur]]s and the ancient whale ''[[Perucetus]]'' could have rivalled the blue whale in size, with ''Perucetus'' actually being heavier with a mean weight of {{cvt|180|t}}.<ref name="AT23" /><ref name="PLOS One2018">{{cite journal |last1=De la Salle |first1=Paul |last2=R. Lomax |first2=Dean |last3=A. Massare |first3=Judy |last4=Gallois |first4=Ramues |name-list-style=vanc |year=2018 |title=A giant Late Triassic ichthyosaur from the UK and a reinterpretation of the Aust Cliff 'dinosaurian' bones |url=https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0194742 |journal=PLOS ONE |volume=13 |issue=4 |doi=10.6084/m9.figshare.5975440}}</ref> However, these estimates were based on fragmentary remains, and the proposed size for ''Perucetus'' was disputed by studies in 2024.<ref name=MP24>{{Cite journal|last1=Motani |first1=R. |last2=Pyenson |first2=N. D. |year=2024 |title=Downsizing a heavyweight: factors and methods that revise weight estimates of the giant fossil whale ''Perucetus colossus'' |journal=PeerJ |volume=12 |at=e16978 |doi=10.7717/peerj.16978 |doi-access=free |pmid=38436015 |pmc=10909350 }}</ref> Other studies estimate that, on land, large [[Sauropoda|sauropods]] like ''[[Bruhathkayosaurus]]'' (mean weight: 110–170 tons) and ''[[Maraapunisaurus]]'' (mean weight: 80–120 tons) might have rivalled the blue whale, with the former even exceeding the blue whale based on its most liberal estimates (240 tons). However, these estimates were  based on even more fragmentary specimens that had disintegrated by the time estimates could be made.<ref name="Bruhathkayosaurus2023">{{Cite journal |last1=Paul |first1=Gregory S. |last2=Larramendi |first2=Asier |date=11 April 2023 |title=Body mass estimate of ''Bruhathkayosaurus'' and other fragmentary sauropod remains suggest the largest land animals were about as big as the greatest whales |journal=Lethaia |language=en |volume=56 |issue=2 |pages=1–11 |doi=10.18261/let.56.2.5 |bibcode=2023Letha..56..2.5P |s2cid=259782734 |issn=0024-1164|doi-access=free }}</ref>

The [[International Whaling Commission]] (IWC) whaling database reports 88 individuals longer than {{convert|30|m|sp=us}}, including one of {{convert|33|m|sp=us}}.<ref name="McClain_2015">{{cite journal | author1=McClain, C. R. | author2=Balk, M. A. | author3=Benfield, M. C. | author4=Branch, T. A. | author5=Chen, C. | author6=Cosgrove, J. | author7=Dove, A. D. M. | author8=Helm, R. R. | author9=Hochberg, F. G. | author10=Gaskins, L. C. | author11=Lee, F. B. | author12=Marshall, A. | author13=McMurray, S. E. | author14=Schanche, C. | author15=Stone, S. N. | title=Sizing ocean giants: patterns of intraspecific size variation in marine megafauna | journal=[[PeerJ]] | volume=e715 | page=e715 | date=2015 | doi=10.7717/peerj.715| pmid=25649000 | pmc=4304853 | doi-access=free }}</ref> The [[Discovery Committee]] reported lengths up to {{convert|102|ft|order=flip|sp=us}}.<ref name=Mackintosh_1942>{{cite journal | author1=Mackintosh, N. A. | title=The southern stocks of whalebone whales | journal=[[Discovery Reports]] | volume=22 | issue=3889 | pages=569–570 | date=1942| url=https://archive.org/details/cbarchive_120108_thesouthernstocksofwhalebonewh1943/page/n9/mode/2up| bibcode=1944Natur.153..569F | doi=10.1038/153569a0 | s2cid=41590649 }}</ref> The longest scientifically measured individual blue whale was {{convert|98|ft|order=flip|sp=us}} from rostrum tip to tail notch.<ref name=Sears_Calamb_2002>{{cite book | last1=Sears | first1=R. | last2=Calambokidis | first2=J. | title=Update COSEWIC status report on the blue whale (''Balaenoptera musculus'') in Canada | location=Ottawa, ON | publisher=[[Committee on the Status of Endangered Wildlife in Canada]] | page=32 | date=2002}}</ref> Female blue whales are larger than males.<ref name=Sears_Perr_2009/><ref name=Ralls_1976>{{cite journal | author1=Ralls, K. | title=Mammals in which females are larger than males | journal=[[The Quarterly Review of Biology]] | volume=51 | issue=2 | pages=245–270 | date=1976| doi=10.1086/409310 | pmid=785524 | s2cid=25927323 }}</ref> Hydrodynamic models suggest a blue whale could not exceed {{convert|33|m|ft}} because of metabolic and energy constraints.<ref name=Potvin_2012>{{cite journal | author1=Potvin, J. | author2=Goldbogen, J. | author3=Chadwick, R. E. | title=Metabolic Expenditures of Lunge Feeding Rorquals Across Scale: Implications for the Evolution of Filter Feeding and the Limits to Maximum Body Size | journal=[[PLOS ONE]] | volume=7 | issue=9 | page=e44854 | doi=10.1371/journal.pone.0044854 | pmid=23024769 | pmc=3443106 | date=2012| bibcode=2012PLoSO...744854P | doi-access=free }}</ref>

The average length of sexually mature female blue whales is {{convert|72.1|ft|order=flip|sp=us}} for Eastern North Pacific blue whales, {{convert|79|ft|order=flip|sp=us}} for central and western North [[Pacific]] blue whales, {{convert|68–78|ft|order=flip|sp=us}} for North [[Atlantic]] blue whales, {{convert|83.4|–|86.3|ft|order=flip|sp=us}} for Antarctic blue whales, {{convert|77.1|ft|order=flip|sp=us}} for Chilean blue whales, and {{convert|69.9|ft|order=flip|sp=us}} for pygmy blue whales.<ref name="McClain_2015"/><ref name=Branch_2007a>{{cite journal | author1=Branch, T. A. | author2=Abubaker, E. M. N. | author3=Mkango, S. | author4=Butterworth, D. S. | title=Separating southern blue whale subspecies based on length frequencies of sexually mature females | journal=[[Marine Mammal Science]] | volume=23 | issue=4 | pages=803–833 | date=2007| doi=10.1111/j.1748-7692.2007.00137.x | bibcode=2007MMamS..23..803B }}</ref><ref name=Gilpatrick_Perryman_2008>{{cite journal | author1=Gilpatrick, J. W. | author2=Perryman, W. L. | title=Geographic variation in external morphology of North Pacific and Southern Hemisphere blue whales (''Balaenoptera musculus'') | journal=Journal of Cetacean Research and Management | volume=10 | issue=1 | pages=9–21 | date=2008| doi=10.47536/jcrm.v10i1.654 | s2cid=256926335 | doi-access=free }}</ref>

In the Northern Hemisphere, males weigh an average {{convert|100|t|lb|sp=us}} and females {{convert|112|t|lb|sp=us}}. Eastern North [[Pacific]] blue whale males average {{convert|88.5|t|lb|sp=}} and females {{convert|100|t|lb|sp=}}. Antarctic males average {{convert|112|t|lb|sp=}} and females {{convert|130|t|lb|sp=}}. Pygmy blue whale males average {{convert|83.5|t|lb|sp=}} to {{convert|99|t|lb|sp=}}.<ref name=Lockyer_1976>{{cite journal | author1=Lockyer, C. | title=Body weights of some species of large whales | journal=[[J. Cons. Int. Explor. Mer]] | volume=36 | issue=3 | pages=259–273 | date=1976| doi=10.1093/icesjms/36.3.259 }}</ref> The weight of the heart of a stranded North Atlantic blue whale was {{convert|180|kg|lb|abbr=on|sp=}}, the largest known in any animal.<ref>{{cite web |url=http://www.bbc.com/earth/story/20150820-see-the-worlds-biggest-heart-blue-whales-is-first-to-be-preserved?ns_mchannel=social&ns_campaign=BBC_iWonder&ns_source=twitter&ns_linkname=knowledge_and_learning |title=See the world's biggest heart |access-date=21 August 2015 |archive-date=16 September 2020 |archive-url=https://web.archive.org/web/20200916133445/http://www.bbc.com/earth/story/20150820-see-the-worlds-biggest-heart-blue-whales-is-first-to-be-preserved?ns_mchannel=social&ns_campaign=BBC_iWonder&ns_source=twitter&ns_linkname=knowledge_and_learning |url-status=dead }}</ref> The record-holder blue whale was recorded at {{convert|173|tonne|short ton|-1|lk=on|abbr=off}},<ref>{{cite web | title = Assessment and Update Status Report on the Blue Whale ''Balaenoptera musculus'' | publisher = Committee on the Status of Endangered Wildlife in Canada | year = 2002 | url = http://www.sararegistry.gc.ca/virtual_sara/files/cosewic/sr_blue_whale_e.pdf | access-date = 19 April 2007}}</ref> with estimates of up to {{convert|199|tonne|short ton|-1|lk=on|abbr=off}}.<ref>{{cite journal |last1=McClain |first1=Craig R. |last2=Balk |first2=Meghan A. |last3=Benfield |first3=Mark C. |last4=Branch |first4=Trevor A. |last5=Chen |first5=Catherine |last6=Cosgrove |first6=James |last7=Dove |first7=Alistair D.M. |last8=Gaskins |first8=Leo |last9=Helm |first9=Rebecca R. |last10=Hochberg |first10=Frederick G. |last11=Lee |first11=Frank B. |last12=Marshall |first12=Andrea |last13=McMurray |first13=Steven E. |last14=Schanche |first14=Caroline |last15=Stone |first15=Shane N. |last16=Thaler |first16=Andrew D. |title=Sizing ocean giants: patterns of intraspecific size variation in marine megafauna |journal=PeerJ |date=13 January 2015 |volume=3 |pages=e715 |doi=10.7717/peerj.715 |pmid=25649000 |pmc=4304853 |doi-access=free }}</ref>

In 2024, Motani and Pyenson calculated the body mass of blue whales at different lengths, compiling records of their sizes from previous academic literatures and using regression analyses and volumetric analyses. A {{convert|25|m|ft}} long individual was estimated to weigh approximately {{convert|101|-|119|tonne|ST}}, while a {{convert|30|m|ft}} long individual was estimated to weigh approximately {{convert|184|-|205|tonne|ST}}. Considering that the largest blue whale was indeed {{convert|33|m|ft}} long, they estimated that a blue whale of such length would have weighed approximately {{convert|252|-|273|tonne|ST}}.<ref name=MP24/>

During the harvest of a female blue whale, Messrs. Irvin and Johnson collected a fetus that is now 70% preserved and used for educational purposes. The fetus was collected in 1922, so some shrinkage may have occurred, making visualization of some features fairly difficult. However, due to this collection researchers now know that the external anatomy of a blue whale fetus is approximately 133&nbsp;mm. Along with during the developmental phases, the fetus is located where the embryonic and fetal phases converge. This fetus is the youngest gestational age of the specimen recorded.<ref>{{Cite journal |last=Roston |first=Rachel A. |date=2013 |title=Anatomy and Age Estimation of an Early Blue Whale (Balaenoptera musculus) Fetus |url=https://anatomypubs.onlinelibrary.wiley.com/doi/pdf/10.1002/ar.22678 |access-date=23 November 2024 |journal=The Anatomical Record|volume=296 |issue=4 |pages=709–722 |doi=10.1002/ar.22678 |pmid=23447333 |doi-access=free }}</ref>