(CN) — Researchers worked hard to figure out how corals have sex.
University of Tokyo scientists knew some of the basics. Corals are animals with branching shapes or waving tendrils that reproduce with eggs and sperm once a year, according to a study published Thursday in Royal Society Open Science.
Study author Shinichiro Maruyama admitted that he and the team did not know much else.
“Coral mass spawning, where corals release their eggs and sperm in synchronized bundles over several days following a full moon, is one of the most spectacular reproduction events in the world,” said Maruyama, a professor of integrated biosciences at the University of Tokyo.
“However, despite decades of studies, environmental drivers of the synchronous spawning remain unclear,” he said. “Coral spawning data is very sparse; it’s usually only an annual event. Putting such sparse data into a model that can explain the overall pattern of spawning has been impossible, but we’ve finally found a way that works.”
The team quickly realized that studying corals on site was impractical. They would have to install various types of robust environmental sensors around coral beds and make daily dives to observe them — not to mention potential complications at night or during bad weather.
Luckily, an aquarium proved a surprisingly useful resource.
“The Okinawa Churaumi Aquarium had kept 15 years of coral spawning records for Acropora corals, a reef-building coral commonly found in Japan’s southernmost prefecture Okinawa, but this data had not been used for this kind of research before,” said Maruyama.
The data showed that multiple factors — including rainfall, wind speed and, most importantly, temperature — affected when how coral time their spawning.
“An increase in the number of individuals that respond in a similar way to these environmental factors may contribute to an increase in spawning synchrony and thus reproductive success,” said Maruyama via email. “There are still many unknowns as to why and how these effects will be affected, and this is a subject for future research.”
The researchers have more than curiosity fueling their desire for future research. Corals are vital to ocean ecosystems and support related animal life. By learning how corals reproduce, the researchers believe they can create strategies to reduce the harm of climate change and human activities, if not outright eliminate them.
For now, using aquariums is a useful first step.
“Aquariums are treasure troves of research resources with a wealth of untouched and valuable data,” Maruyama said. “On the other hand, some scientists tend to think that they don’t truly reflect nature, and also that they are not as well organized as a laboratory. We were fascinated by that gap in recognition and the possibilities that had been hidden, overlooked and sometimes neglected.”
He added: “Here, we analyzed past data to make a model that fits that data. Next, we plan to produce a mathematical model to predict future spawning events in nature.”