Corals that walk and migrate? Fascinating climate change survival strategy discovered

A species of free-living coral, Cycloseris cyclolites, defies traditional coral behavior by actively migrating toward light using a movement strategy reminiscent of jellyfish.

A new study from Queensland University of Technology (QUT) sheds light on the coral’s sophisticated navigation and mobility mechanisms, with implications for understanding its survival strategies amid changing environmental conditions.

Free-living corals that migrate

Unlike most corals that remain anchored to the reef substrate, Cycloseris cyclolites is a solitary, free-living mushroom coral capable of migrating in search of better habitats. 

Dr. Brett Lewis, the lead author from QUT’s School of Atmospheric and Earth Sciences and the Reef Restoration and Adaptation Program, emphasized the unique lifestyle of these mobile corals.

“Not all corals are attached to the substrate; some are solitary and free-living, allowing them to migrate into preferred habitats,” Lewis explained.

Despite their remarkable behavior, the mechanisms underlying their movement and navigation have largely remained a mystery – until now.

Migration strategy of corals

Using high-resolution time-lapse imaging, the research team discovered that Cycloseris cyclolites moves through a process called pulsed inflation.

This mechanism involves rhythmic inflating and deflating of the coral’s tissue, propelling it forward in a manner strikingly similar to jellyfish locomotion.

“Our findings suggest that pulsed inflation is not just a survival strategy but a critical mechanism for migration and navigation,” Lewis noted.

This movement enables the coral to perform several essential functions, including righting itself when flipped upside down, expelling sediment that might bury it during storms, and migrating toward optimal environmental conditions.

Corals move to optimal depths 

One of the study’s key findings was the coral’s strong preference for blue light. When exposed to various light sources, 86.7% of the corals migrated toward blue light, compared to only 20% for white light.

This behavior aligns with the coral’s preference for deeper water habitats, where blue wavelengths dominate.

“The ability of Cycloseris cyclolites to move towards specific light sources is a fascinating parallel to other marine species like jellyfish, which suggests they are more neurologically sophisticated than previously thought,” Lewis said.

This light sensitivity likely helps the corals navigate to optimal depths, where conditions are better suited for survival, reproduction, and dispersal.

Sgnificance of coral migration

The discovery of such advanced mobility and light sensitivity in Cycloseris cyclolites offers new insights into the evolution of nervous systems. 

The study draws parallels between the coral’s behavior and the movement strategies of jellyfish, a key evolutionary point in the development of centralized nervous systems, which humans also possess.

But the findings aren’t just an evolutionary curiosity – they carry important ecological implications.

By understanding how these migratory corals navigate their environment, scientists can better predict how they might adapt to the escalating challenges posed by climate change.

Coral reefs and climate change – the basics

As ocean temperatures rise, corals become stressed and expel the tiny algae that give them their vibrant colors and provide them with essential nutrients.

This process, known as coral bleaching, leaves the corals pale and weak, making it harder for them to survive and grow.

Without these algae, the entire reef ecosystem struggles, affecting countless marine species that rely on the reefs for shelter and food.

On top of the warming waters, ocean acidification is another major threat corals are facing.

Increased levels of carbon dioxide in the atmosphere are being absorbed by the oceans, lowering the pH levels and making it harder for corals to build their calcium carbonate skeletons.

This not only slows their growth but also makes them more vulnerable to erosion and breakage from storms.

Corals migrate to survive

As sea surface temperatures rise and other climate-driven changes impact coral habitats, the ability of Cycloseris cyclolites to migrate toward more favorable conditions could be crucial. 

By moving to deeper waters dominated by blue wavelengths, these corals may escape the warming and bleaching events that devastate many other reef species.

“Understanding their movement strategies could help scientists predict how migratory corals might resist, survive, or adapt to changes in environmental conditions,” Lewis explained. “With these climate-driven factors increasing, the faster the migration, the higher the chance of survival.”

Coral, climate change, and the future

This research highlights the remarkable adaptability of Cycloseris cyclolites, offering a new perspective on coral resilience and survival. 

As climate change continues to threaten coral reefs worldwide, these insights provide a foundation for further studies on coral behavior and potential conservation strategies. 

By unraveling the mechanisms that allow corals to thrive in dynamic and challenging environments, scientists hope to uncover new ways to protect these vital marine ecosystems.

The study is published in the journal PLOS One.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–