Sexual reproduction of corals is a very challenging undertaking, which could greatly benefit coral reefs in the future. A collaboration between several scientists, called SECORE (short for Sexual Coral Reproduction), is now dedicated to this mission. The project started in 2001, led by marine biologists Dirk Petersen and Michaël Laterveer.

Recently, we published about this year's SECORE workshop which was held in August, in Puerto Rico. Fortunately, the scientists were again successful, and shipped 2.2 million Acropora palmata larvae to America and Europe! First, they had to collect the egg-sperm bundles from the corals for ex situ (outside the water, in the lab) fertilization. Just after the August full moon, all the Acropora corals spawned in synchrony. 

Scientists from project SECORE have successfully collected and fertilized gametes from Acropora palmata. The larvae have been shipped to various countries, for rearing them and for future research!

Transporting coral larvae over such distances is a challenge, as they will begin settling after several days (although this depends greatly on species). When the larvae have reached their destination, they will be put into settling tanks, allowing them to find a suitable substrate. They will next metamorphose into a primary polyp and start a whole new coral colony. To see actual swimming Acropora larvae, see the video below (credit: Dr. Iliana Baums).

These larvae will grow out to new A. palmata, which are used for stocking aquarium exhibits, conducting research and even reef restoration! The larvae will also be frozen in nitrogen, for setting up a genetically diverse coral databank. These larvae can later be thawed, which they seem to survive! Experiments are now carried out each year to determine how long coral larvae can be frozen without affecting their viability.

Movies copyright SECORE

References:

www.secore.org