* una testa più grande rispetto alle dimensioni corporee.
La coda più corta dà a questa sottospecie una forma a [[girino]] Thee shorterporta tailanche givesad thealcune Pygmydifferenze Bluenelle Whalemodalità moredi of a [[tadpole]]-like shape, and reflects in differences in diving behaviourimmersione: whereasmentre innelle the«vere» "true"balenottere Bluesazzurre theresi isriscontra aun delayritardo betweentra thel'immersione submergence of thedella [[dorsalpinna findorsale]] ande thedel [[caudalpeduncolo peduncle]]caudale, in Pygmyquella Bluepigmea Whalesla thedorsale dorsale andil peduncolo pedunclesi submergeimmergono simultaneouslycontemporaneamente. PygmyTende Blueinoltre Whalesad alsoavere tenduna tocolorazione bepiù darkerscura thandelle thealtre othersottospecie subspeciesed ofha Bluelo Whalesfiatatoio anddi theforma shapedifferente of their blowhole is different.<ref name="BBC" /><ref>{{cite web|url=http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=36|title=Balaenoptera musculus — Blue Whale|publisher=Australian Government: Department of the Environment and Water Resources|___location=Canberra|date=2007|accessdate=15 June 2007}}</ref> .
southernLa Indianbalenottera Oceanazzurra andpigmea southè westernl'unica Pacificdelle Ocean,tre breedingsottospecie riconosciute a vivere regolarmente in theacque Indiantropicali. andÈ Southdiffusa Atlanticdalla oceanszona andsubantartica travellingfino southall'Oceano toIndiano themeridionale Antarctice tonel Pacifico sud-occidentale; si riproduce nell'Oceano Indiano e nell'Atlantico meridionale e per nutrirsi si sposta verso sud fino all'Antartico feed.<ref name="BBC" /><ref name="Can">{{cite web|url=http://www.wildwhales.org/cetaceans/blue/sr_blue_whale_e.pdf.pdf|publisher=Committee on the Status of Endangered Wildlife in Canada|date=2002|title=Assessment and Update Status Report on the Blue Whale ''Balaenoptera musculus''|accessdate=15 June 2007}}</ref> .▼
The Pygmy Blue Whale is the only one of the three identifiable subspecies to be found regularly in tropical waters. It occurs from the sub-Antarctic zone up to the
▲southern Indian Ocean and south western Pacific Ocean, breeding in the Indian and South Atlantic oceans and travelling south to the Antarctic to feed.<ref name="BBC" /><ref name="Can">{{cite web|url=http://www.wildwhales.org/cetaceans/blue/sr_blue_whale_e.pdf.pdf|publisher=Committee on the Status of Endangered Wildlife in Canada|date=2002|title=Assessment and Update Status Report on the Blue Whale ''Balaenoptera musculus''|accessdate=15 June 2007}}</ref>
AUna fourthquarta subspeciessottospecie, ''B. m. indica'', wasvenne identifiedidentificata byda [[Edward Blyth|Blyth]] innel 1859 innell'Oceano theIndiano northernsettentrionale, Indianma Ocean,la butdifficoltà difficultiesnel indistinguerla identifyingdalle distinguishingaltre featuresha forspinto thisalcuni subspeciesstudiosi leada toconsiderare itquesta beingdicitura usedcome aun synonymsinonimo fordi ''B. m. musculusbrevicauda''., Itla isbalenottera nowazzurra thoughtpigmea. itI coulddati beregistrati thedai samebalenieri subspeciessovietici assembrano theindicare Pygmyche Bluele Whale.dimensioni Recordsdelle forfemmine Sovietadulte catchessiano seempiù tosimili indicatea thatquelle thedella femalebalenottera adultazzurra sizepigmea ische closer to that of the Pygmya Bluequelle thandi ''B. m. musculus'', althoughsebbene thele populationspopolazioni ofdi ''B. m. indica'' ande ''B. m. brevicauda'' appearsembrino todistinte begeograficamente discretee andla theloro breedingstagione seasonsdegli differamori bycada almostcon sixuna differenza di sei mesi months.<ref>{{cite web|title=Past and present distribution, densities and movements of blue whales in the Southern Hemisphere and adjacent waters|url=http://www.iwcoffice.org/_documents/sci_com/SC59docs/SC-59-ForInformation26.pdf|author=T. A. Branch, K. M. Stafford ''et al.''|publisher=International Whaling Commission|date=2007|accessdate=15 June 2007}}</ref> .
PygmySi Blueritiene Whalesche arele believedbalenottere toazzurre bepigmee moresiano numerouspiù thannumerose thedelle otheraltre subspeciessottospecie. EstimatesLe putstime theireffettuate numbersparlano atdi aroundcirca 10,.000 individualsesemplari, whereasmentre thetutte otherle subspeciesaltre combinedsottospecie aremesse estimatedinsieme toraggiungono totalsolo aroundi 5,0005000 esemplari. Although the designation is widely accepted, because of the relatively healthy stocks of Pygmy Blues compared to the other subspecies, The Committee on the Status of Endangered Wildlife in [[Canada]] has questioned whether the sub-classification of the Pygmy Blue Whale has been driven by the interests of the whaling industry.<ref name="Can" />
