Algae called dinoflagellates can help corals, which in turn form barriers that protect coasts from storms and debris.
Climate change especially affects corals and other animals that live on the seabed. Certain algae, known as dinoflagellates, were already known to be beneficial to coral health. Now, researchers from Rice University in Texas, the United States and the Spanish Institute of Oceanography, confirmed that these tiny marine plants not only multiply by dividing in half, but can also reproduce by sex.
This paves the way for the breeding of strains of dinoflagellate symbionts that accompany corals and not only help them show off their wonderful color palette to divers, but also turn sunlight into food for them.
According to Howe-Kerr, author of the article, “Most rocky corals cannot survive without their symbionts and these have the potential to help corals respond to climate change. These dinoflagellates have generation times of a few months, while corals only reproduce once a year. ‘
Ultimately, if symbiotic algae can adapt more quickly to new environmental conditions created by climate change, they could also help corals survive high temperatures.
The advantages of sexual reproduction for algae
Rice University’s discovery came after sampling on coral reefs in Mo’orea, French Polynesia, in July 2019. The algae were then examined using advanced microscopes that allow better visualization of three-dimensional structures. It was the first proof that these symbionts, encased in coral cells, reproduced sexually.
Dividing algae only inherit the DNA of their single parent cell, making them essentially clones, which increases a colony’s diversity. On the other hand, children, through sexual reproduction, obtain their parents’ DNA, which allows for faster genetic adaptation to new conditions.
In this way, symbionts become more tolerant of environmental stress throughout evolution, something that would be very positive for corals.
REFERENCE
Sex and the symbiote: Can algal connections help corals survive?
