Little is known about the lifespan of north Pacific right whales, but it is likely quite long. An individual of a closely related species, Eubalaena glacialis (north Atlantic right whale) lived to be at least 67 years of age. Other close relatives, Balaena mysticetus (bowhead whales), have been confirmed living to 200 years of age.
- NOAA NMFS SWFSC PRD, 2010. "Eubalaena japonica" (On-line). Encyclopedia of Life. Accessed November 07, 2010 at http://www.eol.org/pages/327946.