The annual spawning event

Right now the corals spawn and release a lot of eggs and sperm in the aquaria at Tjärnö marine laboratory (see also news Coral factory running). Lophelia pertusa reproduce sexually in annual spawning events where gametes are released into the free water mass, and fertilization takes place externally. In the lab, eggs and sperm are siphoned over to large glass bowls, in which fertilization then takes place and larvae develop. February seems to be the month when Lophelia pertusa are spawning in our waters, also in the aquariums. The corals that are spawning now were retrieved from the Tisler reef in Ytre Hvaler in Norway in mid-November. They have been cared for and fed by the researchers on Tjärnö since then. Once the larvae have grown, the researchers will use them in various experiments including to test which materials the larvae prefer to attach to. These materials will then be used for the artificial reef structures with which we will restore the coral reefs in the Koster-Väderöfjord.

Upplyst glasburk fylld med vatten innehållande ägg och spermier från koraller som syns som vita små prickar.
Glass bowls with eggs and sperm. Photo Susanna Strömberg.
Vita koraller med många vita prickar som svävar mot svart bakgrund.
Lophelia pertusa with eggs in the water. Photo Susanna Strömberg.
Spawning corals, the white dots are eggs just released into the water. Photo Nina Luckas