Image of the Day: Cryo Corals
Image of the Day: Cryo Corals

Image of the Day: Cryo Corals

With the help of gold nanorods and a cryoprotectant, coral larvae are brought back to life after cryopreservation.

Oct 26, 2018
Ashley Yeager

ABOVE: Adult mushroom coral, Fungia scutaria 
COURTESY OF SMITHSONIAN NATIONAL ZOO AND SMITHSONIAN CONSERVATION BIOLOGY INSTITUTE

Mushroom coral larvae have come back to life after being frozen and then thawed, researchers reported October 24 in Scientific Reports. The successful larvae revival is a small step toward helping conservationists save at-risk coral species and boost the biodiversity of coral reefs worldwide.

When thawing frozen cells, researchers have to work quickly to prevent ice crystals from forming and rupturing the cell membrane. In the study, researchers encapsulated coral larvae in cryoprotectant and gold nanorods, then fired an infrared laser pulse at them. The gold nanorods absorbed the laser pulse and converted it into heat, which then spread uniformly through the larvae, while the cryoprotectant warded off any ice crystal formation.

While the numbers of larvae revived in this study were small, the researchers hope to scale-up the thawing process so they can reanimate hundreds of thousands of larvae at a time in the future for repopulating reefs.

J. Daly et al. “Successful cryopreservation of coral larvae using vitrification and laser warming,” Scientific Reports, doi:10.1038/s41598-018-34035-0, 2018.

Developing F. scutaria larvae stained for actin, showing the growth of the gastrovascular cavity, essential for digestion and circulation
COURTESY OF SMITHSONIAN National Zoo and Smithsonian Conservation Biology Institute