Jellyfish bloom in spring when winter ‘timer’ dings

Colder water triggers moon jellyfish to secrete a protein that kicks off their metamorphosis from polyp to adult form.
Luc Viatour/Wikimedia Commons
Colder water triggers moon jellyfish to secrete a protein that kicks off their metamorphosis from polyp to adult form.
Luc Viatour/Wikimedia Commons