Coral larvae survive being frozen and thawed for the first time
A technique called cryopreservation might help save some threatened coral reefs
By Susan Milius
For the first time, researchers have quick-frozen coral larvae and then — the tough part — safely thawed them.
Swathing larvae in specks of gold and then heating them with a laser warmed the frozen coral babies in milliseconds. Thawed this way, 43 percent of 2-day-old test larvae recovered well enough to start swimming again, physiologist and cryobiologist Mary Hagedorn and her colleagues report October 24 in Scientific Reports.
This success with Fungia scutaria larvae, a colorful mushroom coral species from Hawaii, opens up much-needed conservation possibilities, says Hagedorn, of the Smithsonian Conservation Biology Institute in Front Royal, Va. Biologists knew how to freeze coral sperm, but ice crystal damage from the process can kill bigger, fat-rich structures such as coral eggs and larvae. Being able to bank more than sperm may help preserve coral genetic diversity for attempts to aid reefs that falter as the climate warms.