How long do they live? Up to 110 years old that we know of [1]. From what I’ve read, it’s tough to estimate a Blue whale’s age. Blue whales are very important to maintaining ecosystem balance and biodiversity within the ocean, click this 5 minute Ted talk to find out why whale poo is more important than you’d think.

Where are they found? The ocean. I’m not being sarcastic, they are found in every ocean of this planet.

What do they eat? Blue whales are filter feeding giants and they take in enormous amounts of krill from the ocean.

What do they look like? The Blue whale is the largest animal on the planet! They can reach over 89 feet in length and weigh over 210 tons, which is just hard to even wrap my head around. The Blue whale is so large that a human could swim through their heart [2]. See figures 1, 2, and 3.

Figure 1. Over 200 tons, let that sink in a moment.
Figure 2. A female Blue whale with her calf.
Figure 3. A gentle giant.

How do they reproduce? Male and female Blue whales reach sexual maturity between 6 to 15 years of age [3]. The female gestation period is 11 to 12 months and they usually only have one calf at a time. There’s little information on how often they reproduce, but one source indicated every 2 -3 years [4]. There’s even less information on reproductive senescence in this species.

How do scientists know how old they are? By counting the waxy layers of the ear plugs [5], which sounds like the opposite of fun.

So what are we lacking? When do these whales stop reproducing? There’s no information regarding the nuclear genome of the Balaenoptera musculus on NCBI, but there is mitochondrial sequencing data available.

Conservation status: Endangered as indicated by the IUCN Red List. Thanks to protective laws the Blue whale’s population is slowly increasing.

Interesting facts: Not only can the Blue whale reproduce with the Fin whale, it looks like their hybrid offspring are capable of reproduction [6], which is pretty awesome.


  1. Carey, J., and D. Judge. “Longevity records: Life spans of mammals, birds, amphibians, reptiles, and fish.” On-line). Accessed 9/25/2016.
  2. National Geographic. Facts that will Blow your Mind. Accessed 9/25/2016.
  3. Whale Facts. Marine Mammal Facts and Information. Online. Accessed 9/25/2016.
  4.  Animal The Blue Whale. Online. Accessed 9/25/2016.
  5. NOAA Fisheries. Office of Protected Resources. Fin Whale. 9/21/2016.
  6. Spilliaert, R., et al. “Species hybridization between a female blue whale (Balaenoptera musculus) and a male fin whale (B. physalus): molecular and morphological documentation.” Journal of Heredity 82.4 (1991): 269-274.