Two Iconic sea Animals are squaring off against each other, which would win in a fight? Let's figure it out! Concerning the Orca, here are multiple length weight regression formulas we can use :
Combining them into a composite formula would yield : W(ton)=0.0175680137872*TL(m)^2.921269337979-n=287
This formula will be useful to determine the body weight of the average Killer Whale Ecotypes. According to this study,Type A Orca Males of the Antarctic Peninsula average 7.8 meters and the females 6.76 Meters :
https://www.int-res.com/journals/meps/articles/meps13866 This results in body weight estimates of 7.092 and 4.75 tons respectively. The Type A Orcas of South Africa average 7.745 and 6.745 meters for males and females respectively :
Making them reach body masses of 6.945 and 4.639 tons. The Ones in Southern Antarctica have asymptotic lengths of 7.8 and 6.8 meters for males and females respectively :
https://www.int-res.com/journals/meps/articles/meps13866 They should reach weights of 7.092 and 4.75 tons respectively. The same source states that the mean length of Females is 6.2 meters, meaning their weight is 3.627 tons. But overall, Type A Orcas are very massive Animals. What about the other Ecotypes? Male Bigg's transient Whales average 7.2 meters in length and 5.6 tons in weight and the females 6.4 meters and 3.979 tons :
The Same source states that Males have an asymptotic length of 7.3 meters which yields a figure of 5.844 tons. Type B1 Killer Whales have mean body lengths of 7.58 and 6.93 meters for males and females respectively, making them reach weights of around 6.523 tons for males and 5.02 tons for females :
https://www.int-res.com/journals/meps/articles/meps13866 Southern Resident Orcas are even smaller than all the aforementioned Ecotypes as the Males reach 6.76 meters and 4.669 tons and the females 6.01 meters and 3.311 tons :
Another source states that the Males and Females belonging to the Ecotype reach Asymptotic Lengths of 6.9 (4.957 tons) and 6 meters (3.295 tons) respectively :
https://www.int-res.com/journals/esr/articles/esr00330 Even smaller still are the Type B2 Whales of the Antarctic Peninsula as the males and females average 6.44 and 5.82 meters respectively :
https://www.int-res.com/journals/meps/articles/meps13866 They hardly weigh 4 tons and 3 tons respectively. We also have Norwegian Type 1 Orcas that reach asymptotic lengths of 6.7 and 5.8 meters for males and females respectively :
https://www.biorxiv.org/content/10.1101/2024.09.05.610699v3
Meaning the Males weigh 4.55 tons and the Females 2.985 tons. Interestingly enough, the Mean Length of Females in the same source is 5.5 meters, yielding a body mass of 2.54 tons. However the absolute smallest Ecotype is the Ross sea Type C Orca. Males average 5.6 meters in length and 2.683 tons in weight whereas the females are 5.2 meters in length and around 2.2 tons in weight :
https://www.researchgate.net/publication/237233817_A_Dwarf_Form_of_Killer_Whale_in_Antarctica
As you can see, The Iconic Animals vary dramatically in size, from females weighing 2.2 tons to Males of 7 tons. What about Pseudorca ? The Largest Individual measured has a total length of 5.66 meters :
The above link also provide length weight regression formulas :
Just like we did for Orcas,
We can combine them into a single formula :
W(kg)=4.8*10^-6*TL(cm)^3.111-n=22
With this in mind, the absolute Largest False Killer Whale would barely weigh 1.759 tons. This means that even a normal sized female type C Orca is significantly heavier than the Absolute Biggest False Killer Whale. This comparison even shows how said Female has a bulkier and stronger Physique than The biggest Male Pseudorca :
We can go a step further because the following data shows that Killer Whales have a fineness ratio of 4.81-n=6 whereas False Killer Whales have a ratio of 6.5-n=5 :
The Killer Whale has a lower score and it is interesting to note because a higher score indicates that the body is built relatively more slender i.e less physically strong :
Another metric that we can use is the volumetric coefficient :
Cv=(body mass/seawater density)/(0.1*TL)^3
a higher score indicates a stockier body as suggested by this article :
https://www.wcupa.edu/sciences-mathematics/biology/fFish/documents/2006JMorph.pdf
The Largest Pseudorca would score 9.46 Whereas the Average Female Type C Killer Whale would score 15.26. So the Orca consistently owns a proportionally more robust body. People might say that Because Pseudorca here is more elongated and more slender, it should at least be faster and more agile, right ? Well surprisingly, this might actually be not the case. According to this study, Having a higher score in reduced frequency and lower score in aspect flipper ratio increases the agility and maneuverability of the Animal :
This is important Because the supplementary material actually shows that the Orca has both a higher reduced frequency (0.32 vs 0.22) and lower aspect ratio (4.17 vs 4.8). Both Factors make the Killer Whale relatively more agile despite its more robust build. This is further corroborated by the fact that Orcas generally display an arguably lower turn radius and higher turn degree/second value than Pseudorca, making the former more agile :
https://www.wcupa.edu/sciences-mathematics/biology/fFish/documents/2004IEEEJOE.pdf
As for speed, the following study shows that While Both Species are relative to each other in mass specific thrust power and Froude Efficiency, the Orca has a much lower drag coefficient :
These were the three factors taken into account in the abstract and because the Orca experiences significantly less drag than Pseudorca whilst being comparable in efficiency and mass specific thrust power, it should achieve greater Speeds. It isn't far-fetched to say Orcas can swim faster than smaller species despite their bulk because we have blatant observations showing how Pilot Whales for example never actually manage to catch up to Fish eating Resident Orcas whenever they engage in a chase sequence :
Overall, this matchup isn't close because as we've seen, even Normal sized Females of the Smallest Orcas Ecotype are not only bigger and stronger than the Biggest False Killer Whales captured but are faster and more Agile as well !
