Jellyfish bloom in spring when winter ‘timer’ dings
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2014/01/moonjelly_free.jpg?fit=860%2C460&ssl=1)
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