22 March 2019
Vol 363, Issue 6433

About The Cover

Cover image expansion

COVER Acropora tenuis, a reef-building coral, prepares to release pastel pink bundles of egg and sperm from its polyps. By harvesting the eggs and sperm, researchers have been able to cross-breed this species with others, in hopes of creating hybrids that can cope with warming seas. But the approach is controversial, and proposals to transplant such hybrids into the open ocean have met with resistance. See page 1264.
Image: BioQuest Studios