Diapausing bumble bee queens avoid drowning by using underwater respiration, anaerobic metabolism and profound metabolic depression

Overwintering bumble bee queens enter a state of diapause, remaining buried underground until spring. Remarkably, queens of the common eastern bumble bee (Bombus impatiens) can survive complete submersion for at least one week. We investigated the physiological mechanisms enabling this tolerance, testing the hypothesis that submerged diapausing queens rely on both underwater respiration and anaerobic metabolism for survival. Using respirometry, we detected low but consistent CO2 production during submersion, persisting through 4 and 8 days under water. Underwater gas exchange, measured from CO2 levels in the headspace of a respirometry chamber, was supported by a decline in dissolved oxygen in the water.…

• NS
  Natural Sciences and Engineering Research Council of Canada

  Awards: RGPIN-2020, PDF-5783-2023
• FD
  Fonds de recherche du Québec – Nature et technologies