The Role of the Moon in Synchronizing Coral Reproduction: Study from Ruhr University Bochum

In order for the eggs and sperm cells of corals from different colonies to mix with each other, animals of the same species must reproduce at the same time. The moon plays an important role in their relationship. Press release from Ruhr University Bochum (RUB).

Sumber: Ruhr-University Bochum (RUB) 1 Juni 2023.

June 1, 2023 – Corals are groupers with colonies sometimes several hundred meters apart. It is important for the genetic health of corals that during sexual reproduction, egg and sperm cells from different colonies mix with each other. But for this it is necessary to spawn at the same time at a certain time.

Cooperation project in Indonesia
Marine biologist Dr. Mareike Huhn of the General Department of Zoology and Neurobiology at Ruhr-University Bochum is researching how animals synchronize with students and lecturers from local universities in the Banda Islands in Indonesia’s Indo-Pacific region.

To do this, the researchers compared spawning times with various environmental factors. What is the high tide on that day? What is the average water temperature and day length? When does the moon rise and set today? Is it a full moon or a new moon?

Several factors come into play
Marieke Hone concluded her observations: “There must be several main factors.” “Coral eggs must mature for several weeks before they can reproduce. That maturation process also has to be started by something – and for all coral species at the same time. And then the actual spawning time has to run synchronously.”

His notes provide an answer to this mystery: according to him, the first environmental factor that causes eggs to ripen is the temperature of the water. It always rises exactly one month before mating. Both the relative heating of the water’s surface temperature plays a role – it should rise 0.5 to 1 degree Celsius within four weeks – and the overall temperature, which should be between 28 and 30 degrees.

The full moon sets the pace
But how exactly do corals, sometimes several hundred meters apart, synchronize when it comes to mating night? “The moon plays a major role in this, because animals perceive their light through photoreceptors on the surface of their bodies,” explains Mareike Huhn. “Corals always lay their eggs five, six or seven days after the full moon. The exact number of days depends on the type of coral.”

The results so far are helping researchers better understand coral life. This is important because coral reefs make a very large contribution to environmental functions. They provide a home for countless sea creatures and the algae that live in them produce some of the oxygen we need to live on Earth.

original version
The full article appears in the science journal Rubin with a focus on “what holds the world together”. For editing purposes, the text on this site can be used free of charge, provided the source “Rubin – Ruhr-Universität Bochum” is cited, as well as images from the download area, provided copyright and terms of use are noted. Rubin’ is free to subscribe to as a newsletter or print edition.
https://news.rub.de/wissenschaft/2023-06-01-biologie-auf-los-gehts-los
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